Bio-deterioration is process that involves undesirable change in the natural or other economically important material due to the activities of living beings, plants, animals or microorganisms. The process of bio-deterioration is associated with the negative role of microorganisms in the economically useful products. To inhibit the growth of the microorganisms in the useful products, preservatives in different forms are added to the product. A substance, which may be naturally occurring or synthetically produced, added to different products such as food, medicines, pharmaceutical products, paints, wood, different biological samples, etc to prevent them from biodegradation or deterioration or any other undesirable change by the microorganisms, is known as a preservative. They generally inhibit the growth of the microorganisms or kill them in rare cases.

Antimicrobial preservatives are chemical agents that are normally static in nature i.e. they inhibit the growth of the microorganisms in food, pharmaceuticals or cosmetic products that may be ingested. In most of the countries, based on the approval issued by FDA (Food and Drug Association), there are three categories of preservatives. In Group 1, the natural organic acids like lactic acid, citric acid, etc are included, while in Group 2, the substances, which have been classified as generally regarded as safe (GRAS), such as a) other organic acids such as benzoic acid, sorbic acid, etc., b) the parabens such as esters of para-hydroxybenzoic acid, and c) SO2 are included. The compounds, which do not belong to either Group 1 or Group 2 are included in Group 3. There are some compounds such as common salt, spices, vinegar, oil, etc, which act like preservative, but cannot be classified as ‘added preservatives’, due to the difference in their properties in comparison to the added preservatives. The main properties of the added preservatives in food are that they should be safe, and should be free from any sort of flavour or aroma. They should be added in very low concentration and must not be used to disguise the food from its poor manufacturing practice.

The action of the preservatives depends on the pH of the product, to which they are added. The undissociated form of the preservatives possesses anti-microbial activity. As the pH increases, it is seen that the anti-microbial activity of the compounds reduces, except sorbic acid and parabens, which possess anti-microbial activity until pH 6.5 and pH7.0-8.0 respectively. Hence, parabens have found wide application as preservative in food, pharmaceuticals, and cosmetics due to their favourable properties such as being colourless, tasteless, and stable, apart from their wide pH range. They also have high lethal dose as studied on rats. Lethal dose or LD50 can be defined as the dose of the substance in grams per kilograms of body weight of test animals at which 50% of the population are killed. The apparent drawbacks of using parabens are the low-grade sensitization as exhibited by some individuals ingesting it, their increased tendency to exhibit partition into oil, particularly vegetable oils and also their inability to show complete efficacy in presence of ethylene glycol, glycerol, etc. Although, the parabens inhibit the growth of many types of bacteria, yeasts, fungi, etc., they have been found to be almost ineffective against Gram-negative bacteria. The main action of the parabens is assumed to be on the microbial membranes, however they also affect the nucleic acid metabolism. They are used in mixtures for their synergistic action.

Apart from the organic acids, very few microbial products have found application as preservatives. The antibiotics are generally not used as preservatives due to the development of possible resistance and also the probable disturbance of the microbial ecology in the gut, toxicity, or different allergic reactions. The development of the antibiotics for use as preservatives is a lengthy, expensive and complex procedure. The long-term safety and toxicological study are also major concerns in their development. Natamycin, an antifungal agent that acts as surface antimycotic agent for cut and sliced foods, e.g. cheese and Nisin, a bacteriocin that is effective in heat processed foods and low pH foods, are the only antibiotic agents to be approved for use as food preservatives. Nisin is effective on the gram-positive bacteria but is very less effective against the gram-negative bacteria and yeast. Other biological preservatives used widely are lactoferrin; avidin, a biotin-chelator; ovoinhibitor, an inhibitor of protease; and lactoperoxidase, an SH group oxidiser. Lysozyme has also been used as a preservative, though it has limited bacteriolytic activity spectrum, for bacterial cell lysis. Chitin, a cell wall component of fungi has also found application as a food preservative.

Apart from food, pharmaceuticals and cosmetics, and other economically useful products such as wood, etc have also been found prone to biodeterioration. Due to biodeterioration, the active ingredient in the pharmaceuticals and cosmetics is lost making it useless and in some cases even toxic for use. Hence, the use of non-toxic preservatives in minute concentration have been recommended such that the products remain sterile for a longer period of time and are also safe for use. However, in-depth study about the conditions necessary, the nature of preservatives and its effect on the formulation of the products is very essential.

i am new to this site. so dont know if it is the relevant thread to post my question. Can cells be grown in exogenous supply of Malonyl-CoA and Malate. These are the first product/precursor of the first product of two major pathways and i want to check the effect of inhibition of these two pathways. please someone throw some light here. help would be highly appreciated.

Mosquito, now you may bite me. Thank you genetic engineering!

It has been estimated that 3 million people die of malaria disease. Majority of them are children’s under five year age. Accordingly malaria kills 3,000 children’s per day. This number is significantly more than AIDS. As we all known that malaria is caused by four species of Plasmodium protozoa parasites namely Plasmodium vivax, P. falciparum, P. ovale and P.malaria. The most dangerous is P. falciparum. The mosquito does not cause the malaria but is a vehicle for transfer of these parasites which actually cause disease. The Anopheline mosquitoes are responsible for transfer of these parasites.

In spite of combination therapies, including artesunate and mefloquine drugs etc, the complete eradication of malaria is yet not possible. But the new developments in biotechnology field have shown a promising technology which cans completely eradicate malaria. Biotechnology is employing the concept & knowledge of life cycle of parasite with respect to Anopheline mosquitoes. It has been known by research that the parasite need more than 2 weeks to be able to reproduce and completely establish in mosquito while the age of mosquito is only 3 weeks. Therefore, this is a clue, biotechnology has been successful in genetically modifying few of these Anopheline mosquitoes which reduced their life span by few days, such that the parasites cannot reproduce and establish themselves in mosquitoes as they need complete two weeks for the same and mosquitoes die before it happens. Thus even though mosquito’s bites, they will not transfer viable parasites as required for infection and establishment purpose. Neither the mosquitoes will be infected nor the humans. Once again thank you GE and biotechnology, for tomorrow you may save more than 3000 children’s a day from malaria!

The cellular membrane structure is a stable protein-lipid bilayer; however, it is not static in nature. The transport and the movement of the secretory proteins as well as different factors occur continuously across the membrane. The unique feature of the membranes to fuse with other membranes without losing continuity and the continuous reorganization of the membranes within the eukaryotic endo-membrane system is responsible for many of the biological functions of the membranes like transport, secretion, etc.

The specific membrane fusion between two membranes requires:

i) The recognition between the two membranes

ii) Apposition of the membranes with the removal of water molecules associated with the lipid polar head group

iii) The disruption in the bilayer structures resulting in hemifusion, i.e. fusion of the outer leaflet of each membrane

iv) The formation of continuous bilayer with the fusion of the two bilayers.

The triggering of the fusion between the bilayers at the appropriate time or in response to a particular and specific signal is required for the process of receptor-mediated endocytosis or for regulated secretion of various factors or proteins. These events are mediated by integral proteins in the membranes or within the cells called fusion proteins, which bring about specific recognition and the formation of a local distortion transiently for favouring membrane fusion. The secretion of neurotransmitters into the synapse and the process of neurotransmission is one of the most widely studied cases of membrane fusion.

The lipids play a very essential role in the process of exocytosis, being the building blocks of the membrane structure, as the distortion in the bilayer arrangement of the lipid in the membranes helps in the merging of the membranes during the process of fusion. It is facilitated by the presence of non-cylindrical lipids like lysolipids, phosphatidic acid, fatty acids, etc. The cellular concentration of these lipids is low in resting stage and increases with the stimulation and secretion of different lipases. The fact that lysolipids play an important role in exocytosis is supported by their presence in high concentration in the vesicles of the neuroendocrine cells and in the stimulated exocytosis of the neurotransmitters with the Phospholipase A2 secretion. The machinery involving the zippering of the N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) proteins has proved to be capable of mediating the membrane fusion in-vitro. Hence, the role of proteins is also very essential in the membrane fusion process.

The electric impulses travel across the axon of the neurons and the signals are transmitted to the next neuron or the target effectors or cells in the form of the neurotransmitters. These neurotransmitters are contained in the vesicles, which are present within the neurons. A Synapse is the junction between two neurons or between a neuron and its target cell and helps in the transmission of the signals through the synaptic cleft. In the resting stage, it is believed that the synaptic vesicles are loaded with neurotransmitters and they either remain free in the cytoplasm linked to the actin filaments with the help of synapsin bridges or remain docked in the pre-synaptic membrane. The main mechanism of the transmission occurs due to the depolarization of the pre-synaptic membrane leading to the opening of the voltage-gated Ca2+ channels, which triggers the entry of Ca2+ into the pre-synaptic membrane. This results in the fusion of the synaptic vesicles with the pre-synaptic membrane, thereby resulting in the release of the neurotransmitters into the synaptic cleft. These neurotransmitters then bind to the receptors on the post-synaptic membrane resulting in the opening of the ion-gated channels, which leads to the entry of Na+, K+, Ca2+, Cl- into the post-synaptic membrane, depending upon the selectivity of the ion channel. After the fusion and release of the neurotransmitters, the vesicle membranes are retrieved rapidly and are reutilized for the generation of further neurotransmitter-loaded vesicles. The ions, which enter through the opening of the voltage-gated channels or ion-gated channels are used for further cell signalling mechanism. This machinery of the exo-endocytic recycling coordination requires complex mechanisms integrating cell signal transduction, other dynamic changes within the membrane structure and rearrangements of the cytoskeletal elements within the cell.

Although, much research has been conducted regarding the study of the synaptic transmission through the vesicular traffic process, all the proteins involved in the exocytosis and endocytosis of the synaptic vesicles are not known yet. Recent evidence has suggested the role of Synaptotagmin, a phopholipid dependent Ca2+ binding protein involved in the exocytosis of the vesicles. However, the possible involvement of other proteins in the process is yet to be discovered. Proper understanding of the molecular mechanism of the fusion of the membranes of synaptic vesicles and pre-synaptic membrane can be achieved only through the identification and characterization of the different components of the fusion complex formed during the interaction of the synaptic vesicle with the pre-synaptic membrane.

The progress in the field of Recombinant DNA technology (RDT) has initiated the discovery of new medicines and therapeutics for various diseases. It has also helped in the diagnosis and detection of different infections, genetic diseases and Cancer. The nucleic acid-based biopharmaceuticals, which includes gene therapy and antisense therapy, have great potential to create a revolution in the field of medical science. However, their role in the medical field can materialise completely only after solving the different difficulties encountered in their successful implication.

Gene therapy can be utilized for the correction of different genetic diseases resulting due to the presence of a defective gene, which arises due to mutation or is inborn. The therapy works on the principle of the introduction of the stable gene, to correct the faulty gene expression or provide protective function, into the genetic complement of the cell with the use of different vectors useful for the purpose. The detailed understanding about the different molecular mechanisms related to the diseases within the body helps in the successful application of the gene therapy in combating the diseases. Due to the adaptation of the human body through evolution to resist the entry of foreign genetic material within its genome has posed a problem for the use of gene therapy. However, the use of viruses as vectors for the introduction of genes into the body has helped in overcoming the problem largely due to the ability of the viruses to overcome the barriers and incorporate their genetic material into the genome of the human cells.

There are three categories of somatic gene therapy:
i) ex-vivo, in which the cells removed from the body are incubated with vectors and then the modified, genetically engineered cells are re-introduced into the body. However, this procedure is restricted with blood cells, which can be removed from and re-introduced into the body.

ii) In-situ, in which the introduction of the vector carrying the gene is done into the affected tissues. This procedure is useful in the treatment of muscular dystrophy, which involves the introduction of the vector carrying the gene of dystrophin into the muscle and the treatment of cystic fibrosis, involving the introduction of the vector expressing the gene of cytokine or toxin into the tumor-infected muscle.

iii) In-vivo, in which the vectors carrying genes are introduced directly into the blood stream of the infected individual. This process has not been applied clinically yet, however to apply gene therapy for therapeutics, the development of in-vivo introduction of injectable vectors is essential.


For gene therapy, two types of vectors have been studied: RNA virus vectors and DNA virus vectors. The Retroviruses were initially chosen as the best vehicle for gene transfer due to a number of advantages they provided such as efficient gene transfer with stable integration into the host cell genome, providing the possibility of long-term expression. As they have evolved into non-pathogenic parasites, hence have minimal risk in their usage. These vectors are replication-defective due to the removal of all their viral genes. However, there are some problems faced by these vectors such as for obtaining proper efficient delivery into the target cells, transduction of the non-dividing cells, sustainment of long-term gene expression, and the development of a cost-effective method of manufacturing the viral vector. DNA viruses, which have been most often used for gene transfer are Adeno virus, Adeno associated virus (AAV), herpes simplex virus, etc. The immune response of the cells against the viruses, which affect the integration into the host genome as also the non-specific integration of the gene are some of the problems faced by the DNA virus vectors. Hence, to solve the problem of generation of immune response, non-viral vectors like liposomes and polypeptides are being developed, although their low transduction efficiency poses the biggest disadvantage of their use.

Thus, it can be said that although gene therapy has potential to be developed as therapeutics for a number of genetic diseases, however the application has some major limitations, due to which it has not found practical application, like:

i)the complexity of the genetic diseases affecting a number of cells and tissues at the same time and the molecular mechanisms involved with the development of the disease,

ii)the insufficiency in the level of gene expression and its regulation,

iii)improper identification of the actual genes responsible for a particular disease, and

iv)the insufficiency of the patient population to be studied for various diseases and for conducting clinical trials.

Hence, although gene therapy is making a very slow progress in being used as a form of treatment, it shows great promise and in future, the modification in the vectors used and the development of better strategies for the purpose will help in the practical application of gene therapy in therapeutics.

Ever since the beginning of the plant breeding, man was altering plants to ensure high production and best quality of the harvest. At the beginning, selective and cross-breeding were methods used, but for the last couple of decades man is using more sophisticated methods while designing the plants with all characteristics needed. Genetic engineering became popular in no time and genetically modified plants start sprouting all over that planet.

First experiments were focused on development of the plants resistant to pesticides, to prolong ripening time (tomato), to improve oil composition (canola) and by the 1996 - 8 transgenic plants were approved for cultivation. At the beginning of the 2000, one plant was modified for the first time to increase its nutritional value (golden rise).

Methods used for modification of the plant genome are relatively simple: either Agrobacterium tumefaciens or biolistic gun could be used. In the first case, A. tumefaciens will act as a vector, carrying and incorporating genes of interest in the plant’s genome. This method is useful for dicotyledonous plants like tomato and tobacco. Biolistic method uses DNA sequence attached to the gold or tungsten particles that are shoot into plant cell or tissue using high pressure. After penetrate the cell, DNA is released from the metal particle and start incorporates into the genome. Main disadvantage of this method is mechanical damage inflicted to the cells. However, this method is useful for plants that can’t be easily transfected with A. tumefaciens, like wheat or maize.

Plants could carry genes that will enable them to produce antigens for vaccinations, bacterial toxins or enzyme that will be used for therapeutic purposes. Carrot producing Taliglucerase alfa is used for Gaucher’s Disease treatment; banana producing vaccine against Hepatitis B virus is developed but not marketed; tobacco deriving therapeutic antibodies are under investigation…

Droughts, low temperatures, lack of nutrients are stressful environmental conditions that could negatively affect plant development. Plant could be modified to increase tolerance and survive drastic weather changes.
Herbicides are strong chemicals used to eliminate weed, allowing plant of interest to grow smoothly. Weed could become resistant to an herbicide over time, and genetic engineering is used to create a plant carrying more than one herbicide resistance gene that will allow regular spraying of the crop with multiple herbicides.

Insects and viruses could produce serious damage on the plants. Bacillus thuringiensis derived genes are incorporated into plant’s genome to ensure resistance against insects. Papaya production was dramatically reduced when ringspot virus starts spreading. Genetic modification solved the problem, and it’s still only solution against ringspot virus.
Golden rice is first genetically modified plant with increased nutritional value. Over 650 000 children under the age of 5 are dying each year due to vitamin A deficiency. Designing the rise enriched in beta-carotene gene with resulting high provitamin A level offered solution to the most affected areas. It’s not marketed yet.

Genetic engineering of the plants is useful way of producing biofuels. Algae are well known source of biomass that could be used for the biofuel production. Genetically modified maize that is accelerating ethanol production by converting its own starch into sugar is next promising candidate for biofuel production.

Pollution of the planet is one of the most important issues that mankind is facing today. Every solution that could help preserve environment or help reduce amount of existing waste is more than welcome. Genetically modified crop could be used in bioplastic development. Transgenic plants carrying bacterial genes are cleaning up environment from pollutants like mercury, selenium, PCBs…using bacterial enzymes that are digesting contaminants from the soil.

Genetically modified crops are hundred billion dollars worth business. A lot of people and steps are involved in crop development: from scientist that are experimenting with the plants, companies that are producing the seed, chemical industries developing herbicide and pesticide all the way to the farmers that are cultivating the plant…In 2010, 15 million farmers in 29 countries worldwide were growing genetically modified crops. Over 80% of cultivated corn, cotton and soya in the USA are genetically modified. Beside USA, Brasil, Argentina and India are the largest manufacturers of the genetically modified crops.

What plant will be modified, cultivated, used as a food source…depend on the country and the laws associated with genetically modified organisms. Europe has more strict legislation than USA for example, but still it produces GM crop as well. A lot of people are concerned how this food will affect their health and “health” of surrounding ecosystem. I’m concerned as well, but unfortunately most of us can’t cultivate organic plants and stay healthy for a longer period of time. I know that this is not way too comforting, but what doesn't kill you makes you stronger. To make things worse - I'm vegetarian

Transgenic or genetically modified animals are created when foreign DNA sequence is incorporated in their genome. Main purpose is to provide more information on human and/or animal related diseases, to enhance novel therapeutics development, to assess environmental pollution….

Whatever the purpose, first part of the experiment is always the same: DNA piece need to be inserted into animal’s genome. Mouse is often used for all kind of genetic experiments. Transgenic mouse can be created using two methods: transforming embryonic stem cell or by injecting DNA sequence into pronucleus of fertilized egg.

Mouse blastocyst derived stem cells are transfected with DNA sequence of interest. Sequence is attached to a vector, promoter and enhancer, to ensure proper functioning of the gene in the host’s genome. Successfully transfected embryonic stem cells are injected back into mouse blastocyst. Before implanting embryo in mouse, female is mating with sterile male to ensure hormonal changes necessary for uterus to accept embryo (mating is a trigger). 1 out of 3 implanted embryos survive until birth. After they are born, tissue sample will show if animal is carrying a gene of interest. Less than 20% of offspring will be positive for the gene tested and they will be heterozygous for that gene (present in only one copy of the gene). Mating two heterozygous animals will result in 25% percent of homozygous offspring. They have two copies of desired gene (both from mother and father) and that is the moment when new, transgenic, animal is created. Gene of interest starts to express on a regular basis.

Second method uses sperm head for incorporating sequence of interest. Prepared DNA piece (with vector, promoter…) is injected into male pronucleus before he fuses with egg’s pronucleus. At the stage of 2 cells, embryo will be implanted into female’s uterus (prepared the same way like in stem cell method) for further development.

These methods are applicable to a lot of animals and can be beneficial in medicine (to heal different protein deficiencies). For example, Alpha1-Antitrypsin Deficiency is genetic disorder resulting in lung damage. Transgenic goats carrying alpha1-antitrypsin gene were successfully created but high expenses of protein extraction and purification from goat’s milk prevented company to produce it on a large scale. One other company managed to overcome these difficulties and as from 2006 human antithrombin expressed in goat’s milk is widely used to prevent blood clotting during surgery.

Severe combined immunodeficiency disorder (SCID), known as bubble boy disease, is genetic disorder resulting in inability of organism to fight even slight infections. A lot of babies die in the first year of life due to severe and recurring infections. So far, bone marrow transplantation is only solution and it needs to be provided in the first few month of baby’s life of even in utero (before baby is born). Other solution that proved to be effective (at least at the beginning) was gene therapy using viral vectors “equipped” with gene of interest. Hematopoietic stem cells “enriched” with missing gene helped 4-year old girl to cope with SCID. Later studies showed that this kind of therapy could induce leukemia as retrovirus carrying a sequence of interest could trigger expression of the nearby oncogene as well. Today, efforts are made to produce viral vector that will not affect oncogenesis. A list of disorders that could be treated with gene therapy is long (muscular dystrophy, Parkinson disease, cystic fibrosis…) and even thought solutions are not perfect yet - this medical field is constantly improving.

Besides using transgenic animals or cells for therapeutic purposes, they could serve as model organisms for studying various disorders: triggering genes responsible for disease, mechanism of illness could be observed. Knock out animals are carrying dysfunctional genes that are not expressing proteins. They are designed to detect role and value of different proteins, enzymes, hormones… in the body. When protein expression is lacking, affected biochemical process and/or subsequent disorder will be easily recognized.

Some pets are hypo-allergic - genetically modified to prevent allergic reaction. Farm animals could be “improved” to grow faster or to digest some food that normally wouldn’t be able to do. Green fluorescent protein (GFP) can be perfect marker of environmental pollution once incorporated in zebrafish genome. It is also massively used as a marker of genetic expression, for analysis of neuronal activity, as a viability assay (in cryobiology)... Insects can be genetically altered as well: development of mosquitoes resistant to malaria and incorporation of lethal genes in male mosquitoes responsible for Dengue fever help combat these issues in affected areas.

When it comes to transgenic animals, my emotions are mixed: I encourage getting new knowledge and providing solutions that could help planet as a whole to become a better place, but idea that so many animals are sacrificed for that purpose is making me so sad. I hope that we'll find out that more benefits than damage is made, when we summarize everything we've done.

Technology is developing rapidly in the last decade and so are genetic tools and methods used for genome sequencing, creating transgenic organisms, cloning...Reproductive cloning is one of the most criticized and controversial technique used for creating genetically identical animals. Clone is exact genetic replica of organism that donated the cell (nucleus) used for cloning. A lot of animals are cloned so far. Dolly was first mammal that was made in laboratory, but cat, dog, goat, mule…followed soon after. Success in creating living animal clones made scientist think about cloning extinct animals. Although not one extinct animal is resurrected by now, we are closer that we think to see them in the near future.

In 1972, Oliver Ryder, geneticist at San Diego Zoo decided to collect as much animal skin samples as possible, hoping that tissue bank might be useful in future attempts to save endangered animals. He didn’t know that animals will be created using somatic cells in the future. Stored tissues were named “Frozen Zoo” thanks to preservation method used (liquid nitrogen). Until now, this collection grew to impressive number of ~9 000 samples belonging to ~1 000 different vertebrate species. Although initial idea wasn’t to create a gene pool that will be used for animal cloning, latest techniques and high rate of extinction made “Frozen Zoo” serving that purpose exactly.

First attempts to clone threatened animal species started at the beginning of the 2001 using South Asian ox – guar. SCNT (stem cell nuclear transfer) using guar’s somatic cells and cow’s egg resulted in successful embryo development, that was seeded into cow’s uterus. Noah was born seemingly healthy, but 2 days later – he died due to infection.

In 2000, Spanish ibex, known as bucardo, went extinct. That was the first time that scientist tried to clone extinct animal. Nucleus derived from ibex’s skin cell was implanted into de-nucleated egg of domestic goat - its closest relative. New ibex was born, but died soon after the birth due to severe lung defect. As with Dolly the sheep, a lot of attempts were made before viable embryo that could survive until the birth was created. In the case of bucardo, 439 SCNT were made, 57 embryos were implanted, 7 embryos resulted in pregnancy and just one managed to survive until the birth. He lived for 7 minutes: inability to breath normally prevent him to live longer.

Success rate of cloning is 1%. Beside the low success rate, born animals are unhealthy and prone to various infections that doesn’t keep them alive for a long period.

In 2007, Japanese scientist concluded experiments on mice, revealing that adult somatic cells could be reverted to embryo like stem cells. Those cells were named “induced pluripotent stem cells” (iPS cells) and they could be used for creating any cell lineage you want. Oliver Ryder and his co-workers from San Diego Zoo are using iPS cells to create Northern white rhino, snow leopard and small West African monkey replicas as the number of those species is incredibly low (7 remaining individuals of white rhino are kept in captivity).
Besides “saving” animals that are still alive, or that are extinct few years ago, scientific appetites are growing bigger. How about creating Woolly Mammoth using DNA from his leftovers found under Siberian permafrost recently? Japanese and Russian scientist promise to create a mammoth in couple of years, using mammoth’s nucleus and elephant’s egg. Only problem with resurrecting mammoth is age of the DNA and damage found in his genetic material. However, using modern methods, 80% of mammoth genome is decoded. Creating chimera animal could solve the problem: stem cell derived from mammoth (using iPS method) placed near elephant embryo would affect early embryo development, resulting in animal having tissues created out of both mammoth and elephant cells. We are closer that we think to see mammoth (probably weak and unhealthy, but still successfully created) walking the Earth again.

What is making me really angry and sad is that mankind is responsible for all recently (couple of hundred years) noted extinctions. Why don't we use money and effort made in cloning animals to prevent extinction instead? Don’t you think that those kinds of experiments are cruel to the animals? Who ask female elephant if she is willing to be a surrogate mother to a mammoth? Would you like to be a surrogate mother to a chimpanzee, as its closest relative? I don’t think so. We managed to destroy so many beautiful things on the planet Earth, but driving animals extinct instead preserving them and then resurrecting them just to show future generation how mammoth looked like before he went extinct - I just don’t get it! If human ever become critically endangered – please don't clone me!

Plants as bioreactors


There are different plant bioreactors classified based on where the protein is produced:

Plant suspension cultures

Chloroplast bioreactor

Image source:openi.nlm.nih.gov

Hairy root system bioreactor

Seed based plant bioreactors

• Seed protein storage vacuole bioreactors
  

• Seed oil body bioreactors
  

Advantages
They are cost effective, faster than transgenic animals, can produce large biomass and the pathogens do not effect animals and humans.


Disadvantages
The difference in codons of prokaryotes and plants  can lead to inefficient expression, different polysaccharides may be attached to proteins and some plants may contain allergic compounds.

When you think of cloning, Dolly the sheep is probably the first thing that comes to your mind. Artificial cloning came later; we stole that idea from nature. Asexual reproduction, typical for so many animals, is natural way to reproduce. New individual is created by division of the mother cell giving daughter cell with the same genetic material. Biotechnology found a way to utilize this natural process for production of novel molecules, cells or even organisms. Main purpose is to help solve certain medical issues or reveal genetic mysteries in various experiments that are taking place all over the world.

Molecular cloning is used to amplify DNA sequence (gene, promoter, non-coding sequence…) of interest. To ensure replication, DNA sequence must be linked with origin of replication – part of DNA that will initiate replication. Ligation is process of inserting DNA sequence into cloning vector (peace of DNA, carrier of the sequence). DNA ligaze will connect sequence and vector by “gluing” sticky ends at each DNA piece. Transfection of cell with vector carrying sequence of interest is next step. Electroporation, optical injection or biolistics are mostly used transfection techniques, but they are not successful always. Additional genes in cloning vector are necessary to ensure easy recognition of cells containing DNA piece of interest. Some of the most famous “markers” used are genes providing antibiotic resistance (when substrate with antibiotic is used for cell growing) or color markers (for blue/white cell screening). After cell colonies are formed, DNA sequence will be multiplied and analyzed using PCR, DNA sequencing or restriction fragment analysis.

Cellular cloning is production of cells containing same genetic info as mother cell. Cells derived from multi-cellular organism are much more complicated to clone than cells that are unicellular by nature. Technique “clone rings” is used for cloning multi-cellular organism derived cells. Cell suspension is exposed to mutagenic agent or drug and planted at high dilution, which result in new colonies formation. On a stage of few cells created, trypsin and polystyrene rings (covered in grease) are placed over each formed colony. Cells from the inner part of the ring are collected and moved to another substrate to develop further. Cellular cloning could solve serious medical issues that are non-treatable by conventional medication (such as Alzheimer disease). Cells used for this purpose are stem cells - as they could give raise to any cell lineage we want. SCNT (Stem Cell Nuclear Transport) is used for developing embryonic stem cells (ESC) that will have both research and therapeutic application. ESC are created by removing nucleus from the egg and implanting nucleus from adult somatic cell (containing both mother and father genetic material). Egg will act like it’s been fertilized and start dividing first to reach blastocyst stage and then toward any cell lineage we want. Procedure is the same with animal species and could be used to produce additional food source (by cloning farm animals) or to prevent extinction of endangered animals. It may sound like simple process, but success rate with this kind of genetic manipulation is pretty low. Dolly the sheep was first mammal created in laboratory. Out of 277 eggs used for SCNT, just 29 embryos were created. 3 survived until birth and only one - more famous by its given name – Dolly, survived until adulthood. Although, genetic material in the newly formed cell (organism) is the same as in donor’s cell, certain part of DNA is unique. Each cell contains mitochondria with its own genetic material. It’s inherited solely from the mother due to couple of reasons: egg contains more mtDNA than sperm; sperm derived mtDNA is easily degraded once inside or it can even fail to enter the egg. Thanks to this phenomenon, cloned cells can be considered genetic hybrids, as they contain both somatic DNA and mother mitochondrial genes.

Some large animals can create clones on their own. Lizards, snakes, ants, crustaceous species and even certain sharks are able to produce new individual by parthenogenesis – out of unfertilized egg. For most species, this is not obligatory way to reproduce but a method to overcome crisis in their environment. Komodo dragon, for example, can reproduce by parthenogenesis to increase the population in the habitat and then switch back to sexual reproduction to increase genetic diversity of the next generation.

To conclude, cloning is not something we invented, it’s natural phenomenon that we start exploiting recently. Wise and careful approach could be beneficial for the planet; we just need to pay attention not to cross the line, as genetic diversity is what allowed us to survive so far.

If you search for best biotechnology colleges in USA on the internet, you'll get couple of lists with completely different names mentioned. I prefer list created by user rating. Hope you'll find given info useful.

Purdue University

University is located in West Lafayette, Indiana. It’s established in 1868, thanks to generous donation of land and money by local businessman, John Purdue. It all started with 6 professors and 39 students, and today – Purdue is second largest college in Indiana. In 2010, 6,614 academic staff and 39,726 students were enrolled in various study programs. With 210 major areas of study, students can earn degree in different scientific, technological and agricultural disciplines.

Stanford University

Leland Stanford Junior University (full name) is located in Stanford, California. It’s founded in 1831 by Governor of California, in honor of his son who died of typhoid. Until 1930 tuition was free of charge. It survived San Francisco earthquake and several money crises. Today, that is prestigious college with over 40 Nobel Prizes won. Google, Yahoo, Hewlett Packard … are just few examples of the companies founded by the faculty members. University is divided in 7 schools: humanities and sciences, earth sciences, schools of business, education, engineering, law and medicine.

University of California San Diego

UCSD is located in La Jolla, California, near the Pacific Ocean. More than 23000 undergraduates and 5500 graduates are enrolled in ~200 study programs. It’s one of the best public undergraduate colleges (Public Ivy) in America. University operates 4 research institutes. For the past three years, it’s ranked No 1 University in nation by Washington Monthly. Successful research in oceanography, molecular biology and genetics, neuroscience and behavior, global warming phenomena, as well as Keeling Curve and green fluorescent protein discoveries are just few things that UCSD is famous for.

Boston University

BU is located in Boston, Massachusetts. That is private university with over 4000 teachers and 31000 students enrolled in study programs in 18 schools divided in two campuses. Martin Luther King earned PhD at BU and one out of the 7 Nobel Prizes that BU won. University is truly “green”, focused on proper waste management and recycling, energy efficiency and sustainable building development. BU is famous for its high research activity, just in 2009-2010 research expenditures were > 407.8 million dollars.

University of California Davis

UCD is located in Davis, California. It’s public research university, established in 1905. Nobel and Pulitzer Prizes, National Medal of Science, Presidential Early Career Award in Science and Engineering…are just some of the honors won by university members over the years. UCD undergraduate programs can be divided in 4 major categories (colleges): Agricultural and Environmental Sciences, Biological Science, Engineering and Letters & Science. UCD is listed as Public Ivy. Thanks to sustainability and climate change efforts, Sierra Magazine ranked UCD No 1 “coolest” in 2012 and “Newsweek” ranked it 10th “happiest” and 11th “greenest” school in USA in 2011.

Oregon State University

OSU is located in Corvallis, Oregon. Students (> 23000) can choose between 200 undergraduate programs. Microbiology, ecology, forestry, biochemistry, zoology, oceanography, food science and pharmacy…are some of the most popular. Jurassic Park story (and movie) is inspired by the OSU’s entomology professor George Poinar, Jr. and his work on DNA extraction from insects fossilized in amber.

Rensselaer Polytechnic Institute

RPI is located in Troy, New York. It’s private research university founded in 1824. University is divided in 5 schools that are offering 140 degree programs in 60 different fields. RPI is ranked No 7 by salary potential after graduation and it’s among top 50 national universities. Research centers operated by RPI are focused on biotechnology, energy & environment and nanotechnology, among other technical fields. James Fallon, adult stem cell pioneer, earned his diploma at RPI.

Columbia University

Columbia University is located in New York, New York. It’s founded as King’s college in 1754 and it’s considered to be one of the private Ivy colleges. Columbia University encompasses 20 schools and is lying on more than 6 city blocks. Some students became very rich and successful (20 living billionaires), powerful (29 heads of state, including 3 presidents) or famous (25 Academy Award winners) after graduating from Columbia. ~30 currently marketed medical products, green fluorescent protein labeling, 600 patents and 250 active license agreements…are showing how creative and fruitful work on Columbia can be.

Each of this school will provide necessary amount of knowledge, you just need to pick one that is oriented the most toward your favorite field of science and biotechnology.

The three very effective modes of gene transfer Transformation, Transduction and Transfection observed in bacteria fascinated the scientist leading to the development of molecular cloning. The basic principle applied in molecular cloning is transfer of desired gene from donor to a selected recipient for various applications in the field of medicine, research, gene therapy with an ultimate aim of beneficial to the mankind.

Transformation: Transformation is the naturally occurring process of gene transfer which involves absorption of the genetic material by a cell through cell membrane causing the fusion of the foreign DNA with the native DNA resulting in the genetic expression of the received DNA. Transformation is usually a natural method of gene transfer but as a result of technological advancement originated the artificial or induced transformation. Thus there are two types called as natural transformation and artificial or induced transformation. In natural transformation, the foreign DNA attaches itself to the host cell DNA receptor and with the help of the protein DNA translocase it enters the host cell. The presence of nucleases restricts the entry of two strands of the DNA, destroys a single strand thus allowing only one strand to enter the host cell. This single stranded DNA mingles with the host genetic material successfully.

The artificial or induced method of transformation is done under laboratory condition which is either a chemical mediated gene transfer or done by electroporation. In the chemical mediated gene transfer, the cold conditioned cells in calcium chloride solution are exposed to sudden heat which increases the permeability of the cell membrane allowing the foreign DNA. The electroporation method as the name indicates, pores are made in the cell by exposing it to suitable electric field, allowing the entry of the DNA. The opened up portions of the cell are sealed by the ability of the cell to repair.

Transduction: In transduction, a media like virus is required between two bacterial cells in transferring genes from one cell to the other. Researchers used virus as a tool to introduce foreign DNA from the selected species to the target organism. Transduction mode of gene transfer follows either a lysogenic phase or lytic phase. In the lysogenic phase, the viral (phage) DNA once joining the bacterial DNA through transduction stays dormant in the following generations. The induction of lysogenic cycle by an external factor like UV light results in lytic phase. In lytic phase, the viral or phage DNA exists a s a separate entity in the host cell and the host cell replicates viral DNA mistaking it for its own DNA.As a result many phages are produced within the host cell and when the number exceeds it causes the lysis of the host cell and the phages exits and infects other cells. As this process involves existence of both the genome of the phage and the genome of the bacteria in the same cell, it may result in exchange of some genes between the two DNA. As a result, the newly developed phage leaving the cell may carry a bacterial gene and transfer it to the other cell it infects. Also some of the phage genes may be present in the host cell. There are two types of transduction called as generalized transduction in which any of the bacterial gene is transferred via the bacteriophage to the other bacteria and specialized transduction involves transfer of limited or selected set of genes.

Transfection: One of the methods of gene transfer where the genetic material is deliberately introduced into the animal cell in view of studying various functions of proteins and the gene. This mode of gene transfer involves creation of pores on the cell membrane enabling the cell to receive the foreign genetic material. The significance of creating pores and introducing the DNA into the host mammalian cell contributed to different methods in transfection. Chemical mediated transfection involves use of either calcium phosphate or cationic polymers or liposomes. Electroporation, sonoporation, impalefection, optical transfection, hydro dynamic delivery are some of the non chemical based gene transfer. Particle based transfection uses gene gun technique where a nanoparticle is used to transfer the DNA to host cell or by another method called as magnetofection. Nucleofection and use of heat shock are the other evolved methods for successful transfection.

In the drug research process, a number of candidates fail to become therapeutic agents due to a number of reasons. In the drug discovery and development process, the aspect of the effect of genes has become a major issue in the present times. The discovery of a number of genetic diseases, the role of genes in regulating the pharmacokinetics of the drugs within the body and also the role of gene expression in determining the drug efficacy has resulted in the study of pharmacogenetics and pharmacogenomics largely.

Although the terms Pharmacogenetics and Pharmcogenomics are used interchangeably, there is considerable difference between the two. Pharmacogenetics identifies with the study of single gene mutations and its effect on the response of the drug within the body, while Pharmacogenomics has wider aspect covering the whole genome and the effect of different genes and their expression on the different aspects of drug response and efficacy within the body. The study of the pharmacogenomic profile of the patients helps in the determination of the target, its specificity and the whole drug development process, in general. It has been suggested that Pharmacogenetics may help in the differentiation between the patients while studying about a drug, while Pharmacogenomics may help in the differentiation and screening of the compounds.

It is seen that the medicines are being administered on the patients based on the symptoms and evidence after collecting the data of the clinical trials on the population as a whole. This general administration of the drug based on statistical data may give rise to differential response in the patient and may also result in possible toxicity. Hence, the study of the pharmacogenomic profile of the patient has become very important, in order to carry out proper treatment of the patient without any toxicity. The study of the SNPs (Single Nucleotide Polymorphisms) has become very essential as the occurrence of the SNP in the genome of an individual is high, which are also inherited resulting in the haplotype of an individual. Hence, in future the scanning of the genome for SNPs and the haplotype may help in the determination of the nature of drug response in a better way. Other Pharmacologic technologies such as DNA chips and Proteomics have also helped in the drug development process to a large extent.

Pharmacogenetics and Pharmacogenomics play important role in the target specification and pharmacokinetics of the drugs. The targets are polymorphic in nature as the targets are mainly protein in nature. The appropriate target selection is very essential for the pre-clinical trials of the prospective drugs as it gives a clear idea about drug efficacy. The polymorphic nature of the drug metabolizing enzymes, receptors, and transporters affects the pharmacokinetics of the drugs drastically. Hence, the knowledge about the pharmacogenomics of an individual is very essential. The study of the SNPs helps in knowing the safety profile of the drugs, which is helpful in avoiding toxic reactions in patients during the pre-clinical trials. The Pharmacogenomic profile gives a very clear idea about the variation in the genes responsible for the formation of the disease, thus giving an idea about the predisposition of people to develop particular diseases. This can help in further research related to the discovery of drugs and therapeutics like gene therapy for the treatment of the disease. The non-responsiveness to some drugs or development of adverse reactions for some drugs can also be known with the help of the pharmacogenomic profile of the patients.

Thus, it can be said that Pharmacogenomics has a very important role in the pharmaceutical industry. Genotype-guided therapies are becoming very crucial as patients respond to a drug based on their genetic factors. Pharmacogenomics helps in treating the right patient with the right drug and at right dose. This is the major implication of the study. However, it has to be kept in mind that Pharmacogenomics is important in healthcare and its study will be included as a part of the pre-clinical trial of the prospective drugs in near future. However, it is not important for all drugs, in general as its study is important for the drugs, which have narrow therapeutic index. The successful application of the knowledge of Pharmacogenomics in the drug discovery and development process will thus help in the reduction in the overall cost in the process by the reduction of the number of failures in the process.

The great advancement in the field of molecular biology has been the Human Genome Project, whereby the whole human genome was sequenced using DNA sequencing method. This project has marked a turning point and has opened the gate for various medical discoveries and technology. The advent of DNA chip technology or DNA microarray technology has ushered in a new era in the field of Systems biology, which has helped in studying the transcriptional behaviour of different genes. The DNA chip actually helps in knowing the expression of mRNA in its steady state. The DNA chips have proved to be very useful in the study of different diseases and the modification of the gene expression in the development of the disease.

Various breakthroughs in the field of technology have helped in the development of DNA or gene chips. The technology of DNA chip is the result of the combination of molecular biology and microfabrication technology. Although gene expression could be known by sequencing method, but the complete idea about the levels of gene expression or the activity of the genes could be known only after the study of mRNA transcribed from the genes as all the genes present are not transcribed into mRNA. The differences in the amount and nature of mRNA transcribed by the DNA of a particular organ or cell gives clear idea about the specific proteins transcribed from the specific organ or tissue or cell within the body and their effect on various diseases.

DNA chip technology works on the hybridization principle. There are mainly two types of chips: cDNA array and oligonucleotide array. The cDNA array consists of long DNA fragments purified by PCR, which are immobilised on glass or plastic wafer with the use of robots. They are generally used for the study of expression and screening. The oligonucleotide array consists of short fragments of DNA that are synthesised chemically or conventionally and are then immobilised on the glass substrate. They are generally used for the study of mutations, monitoring of gene expression, discovery and mapping. For the genomic analysis, both the types of arrays are used simultaneously. The probes used for the development of DNA chips are manufactured using a number of techniques such as light induced chemical synthesis, or the use of spraying solution, which deposits chemical probes on the chip substrate, or the use of robots, which deposit the probes on the substrate. The main idea is to miniaturize the whole technology of genomic analysis with the use of DNA chips. The level of the mRNA transcription can be studied with the use of DNA chips. The total mRNA is first isolated, purified and reverse transcribed to cDNA and then with the use of probes, it is hybridised on the immobilised DNA on the chip substrate and finally the level of its expression can be known.

The use of DNA chips have many advantages such as they can be used to monitor many genes at the same time, producing fast results, comparing diseased and normal cells according to the expression of various genes and also help in categorizing the subgroups of a particular disease with slight variations in the different genes. However, there are some disadvantages also of the technique. The technology is quite expensive and the production of too many results at a time requires long time for analysis, which is quite complex in nature. The reproducibility of the results is also a question as the results are not always quantitative. The DNA chips do not have very long shelf life, which proves to be another major disadvantage of the technology.

The applications of the DNA chip technology has gained much importance in the present time and will pave way for further innovative developments in molecular biology in future. The technology has found application in not only the study of mRNA expression but also the DNA replication in bacteria, yeasts, etc., the study of histone proteins, their modification, and the different mRNA binding proteins and even in the study of different mechanisms in cell biology. The development of DNA chip technology or nanoarray technology can be used to detect different diseases like Alzheimer’s disease, cystic fibrosis, different forms of cancer, etc. The DNA chip has also found application in the detection of Single Nucleotide Polymorphisms (SNPs) in the genome and also in the research related to effect of different drugs on the different cells of the body and drug efficacy.

Insulin is a protein hormone secreted from the specialized cells of the islet of Langerhans in pancreas. Only 2% of the pancreas has endocrine function secreting various types of hormones regulating the metabolism of glucose. Of them, the β cells constitute about 65-80% and they are responsible for the secretion of insulin. It is polypeptide in nature and affects almost all the cells and organs within the body. It affects the metabolism of carbohydrates, fats and proteins and is responsible for various anabolic reactions, which help in lowering the blood sugar level in the blood. Diabetes mellitus has become a very common disease in the present times after cancer and cardiovascular diseases. Hence, the role of insulin and its various aspects have become a topic for serious study and research.

Insulin is a simple polypeptide hormone consisting of 51 amino acids. It is made of two polypeptide chains A and B. A chain consists of 30 amino acids while the B chain consists of 21 amino acids and the two chains are linked by a disulfide bond. The insulin structure and composition varies in different species as the sequence of the amino acids in human insulin is highly conserved. Diabetes mellitus if of two types: Type I, which is an autoimmune disorder characterized by lower insulin levels in the body and Type II in which insulin levels are normal but the body develops peripheral resistance to it resulting in high blood sugar levels. Type I form is a very common disease; hence, different types of treatment to maintain insulin level in the body are being developed. It was seen that the administration of purified animal insulin could not be done as it resulted in immune response. Hence, two forms of treatment was followed, which are: artificial synthesis of insulin using amino acids, which is an expensive and long drawn process and the replacement of amino acids in the purified animal insulin to represent human insulin, known as semi-synthetic insulin. The synthesis of semi-synthetic insulin also faced problems in the form of limited availability of porcine insulin, which was most suitable for the purpose. In this situation, the research on the synthesis of recombinant insulin was carried out to meet the increasing demands for insulin.

Recombinant insulin is the first commercial biotech product. The advances in RDT (Recombinant DNA Technology) with the discovery of various restriction enzymes, cloning strategies, etc has helped in the successful formation of recombinant insulin. The use of recombinant insulin offers two main advantages: unlimited availability of insulin to meet increasing demands of diabetic patients and the identical similarity of human and recombinant insulin. The RDT has used both bacteria and yeast for the recombinant insulin production. The production uses two types of strategies:

i) The synthesis of the two chains of insulin and joining them with disulfide linkage using ideal conditions, and
ii) The synthesis of proinsulin, which then forms mature Insulin after the cleavage of C-peptide and formation of disulfide bond between the two chains.

In the first method, two DNA fragments based on the sequence of the amino acids in the A and B chains were synthesised. These fragments were inserted into plasmids, which were transformed into the bacteria. The two chains were then isolated and mixed under ideal conditions for the formation of disulfide links between them, producing functional Insulin. The other method involved the formation of proinsulin in bacteria, which then formed mature Insulin by a single enzymatic reaction. This was found to be a better procedure due to the lesser number of steps involved in the production and purification of mature insulin. After the formation of recombinant insulin from bacteria, purification is a very essential step as contamination with the C-peptide, proinsulin, etc may cause ineffective result in the use of recombinant insulin. In order to minimise the purification procedure, which may result in the loss of recombinant insulin, the latest technology involves the use of yeast for the production of proinsulin. The enzymes required for the formation of mature insulin like the ones present within the human body are present within the yeast yielding a better formation and isolation of the formed mature insulin from the media, where recombinant yeast is cultured.

Insulin is the first genetically engineered hormone opening the field of research for the generation of other important hormones and proteins for the treatment of different fatal diseases. The advance in genetic engineering technology is becoming the main gateway for the progress of medical science and discovery of helpful drugs for the welfare of living beings.

At the DNA or RNA level, please. For example, the method of RNAi.

Thank you!

Fermentation is the process of controlling microbes (bacteria, yeast, and moulds) to modify food, producing a desired product.

Often we talk about the negative issues caused by microorganisms in food such as food spoilage. But they can be used as efficient live factories to produce health beneficial food. Without some microorganisms, production of certain food items may not be possible or may be costly. Microbes are cheap resources that consist of numerous enzymes which can convert complex chemical structures into simple digestible molecules with a high efficiency. These microorganisms use the nutrients in the food as the substrate to produce energy and other required precursors for their growth in which a fermented food results. There are numerous examples for fermented food.

Fish sauce
In production of fish sauce, uneviscerated fish is mixed with salt and placed in fermented tanks to allow liquefaction for about six months. The collected liquid is further ripened for few more months. Halophillic microbes are involved in this fermentation process. Streptococcus, Micrococcus and Bacillus species predominate. This product is dark coloured with a distinct aroma.

Sauerkraut
This refers to fermented cabbage. Normal microflora in cabbage is involved in the fermentation process under anaerobic conditions. Leuconostoc mesenteroides and Lactobacillus plantarum is involved. Temperature is a crucial factor in the control of fermentation. If the temperature is below 21 degrees Celcius, Lactobacilli outgrow. L. mesenteroides require a lower temperature below 21 0C. Acidity created by Lactobacilli prevent the growth of L. mesenteroides.
Pickels
Pickels consist of vegetables like cucumber, onions, chilies etc. Lactic acid bacteria such as Leuconostoc mesenteroides, P. cerevisiae, L. brevis, L. plantarum are involved in the fermentation process These bacteria also take part in fermentation of olives.

Soy sauce
In production of soy sauce, a mixture of soybean and wheat flour is inoculated with Aspergillus oryzae and Aspergillus soyae. These fungi digest complex starch and produce sugars which facilitate the growth of bacteria. Anaerobic bacteria carry out fermentation to produce soy sauce.

Beer and Ale
Malted beverages are produced by brewing. Mainly the yeasts are involved in the process. Yeasts convert fermentable sugars to ethanol and carbon dioxide. As yeasts do not produce enough amylases to hydrolyze starch in barley grains, they are germinated prior to brewing. Hops which are added for bitterness have an inhibitory effect on gram positive bacteria. Saccharomyces carlsbergensis is the principle organism used. This species is subjected to various genetic modifications to increase the efficiency of the fermentation. In addition to ethanol and carbon dioxide, yeasts produce a small amount of glycerol, acetic acid and aromatic esters. Ale is a top fermented beverage with Saccharomyces cerevisiae.

Wine
Wine is made from grape juice in large scale. Yests; Saccharomyces cerevisiae var. ellipsoideus is the culture used in wine fermentation. High temperature is not suitable for this fermentation as yeasts die while low temperature allows the growth of lactic acid bacteria.

Environmental factors such as acidity, pH, oxygen level, moisture level, temperature, sugar content are important for this fermentation processes. In most food commodities, acidity is developed by microorganisms. This developed acidity is important for preserving the food. Proteolytic action may bring down the pH to a higher value. Some yeasts produce alkaline by products such as ammonia in their regular metabolism which is encouraged in the production of limburger cheese.

Alcohol, which is a byproduct of many fermentation pathways also have a preservative action. Alcohol content produced will depend on the sugar content, type of yeast involved in fermentation, temperature and the oxygen level. Most yeast can’t tolerate high alcohol levels.
Temperature has a direct effect on microbial fermentation which in turn affects the final quality of the product. Sauerkraut production is an ideal example to show the importance of temperature in fermentation process.
Microorganisms have different oxygen requirements for their growth and fermentation. In wine production, yeasts grow best under aerobic conditions. In baking, anaerobic conditions favour the quality of the final product. Vinegar production involves anaerobic as well as aerobic fermentation.

Lactic acid bacteria (LAB) are gram positive, non sporing, cocci or rods that produce lactic acid as the end product of sugar fermentation. The taxonomic boundaries of Lactic acid bacteria have been controversial. In fermented foods like yoghurt and lassi, lactic acid bacteria play a vital role in flavour development and preservation as well.

The classification of lactic acid bacteria into different genera is based on morphology, ability grow at harsh conditions, mode of glucose fermentation, chemotaxonomic markers, DNA sequence data etc. These include eight genera; Lactobacillus, Leuconostoc, Pediococcus, Streptococcus, Carnobacterium, Enterococcus, Lactococcus, Vagococcus of which the latter four genera were originally classified under Streptococci. These organisms are broadly divided into two groups as homofermenters who produce lactic acid as the major end product of glucose fermentation and heterofermenters who produce Carbon dioxide, Ethanol apart from lactic acid. Pediococcus, Lactococcus, Vagococcus belong to homofermenters and Leuconostoc, Carnobacterium and some Lactobacilli belong to heterofermenters.

Lactic acid bacteria cause some negative effects such as development of acidity in milk and spoilage of some other food such as meat etc. There is strong evidence that when consumed in sufficient quantities Lactic acid bacteria exhibit prophylactic and therapeutic effects. About one million viable cells are required to obtain these health beneficial effects.
Probiotics concept was introduced in clinical nutrition in 1980’s. This emphasized the positive physiological role of certain Lactic acid bacteria and Bifidobacteria. Probiotic lactic acid bacteria and Bifidobacteria are capable of passing through upper gastrointestinal tract and colonizing in the large intestine. Health benefits of LAB as probiotics include:

• Reduce the risk of diarrheal infections
• Enhance immune function
• Reduce the severity of lactose intolerance
• Reduce the population of harmful microorganisms in the colon
• Reduce the incidence of colon cancer
• Lower serum cholesterol level
• Lower blood pressure
• Improve mineral absorption
• Restore gut flora during or after antibiotic therapy
• Improve balance of microorganisms in the colon
• Improve bowel function by increasing stool frequency, increasing stool weight and increased production of short chain fatty acids (SCFA)

Dysbiosis is the condition where the harmful microorganisms in the gut overpopulate the beneficial bacteria. This is the major reason for many dietary diseases. The reasons for dysbiosis can be harmful pesticide residues remaining in food accumulated during a long period of time, food allergies and other disease conditions which can be overcome with the use of probiotics. Probiotic bacteria bring about these beneficial effects by competitive exclusion, production of bacteriocins and organic acids and altered absorption of the intestinal mucosa.

It was shown that incorporation of indigestible polysaccharides that escape digestion in the upper gastrointestinal tract are very effective in boosting the probiotic effects. These are known as prebiotics and increase the proportion of beneficial bacteria in the colon. Food entering the colon serves as substrate for endogenous colon bacteria, thus indirectly providing the host with energy, metabolic substrate and essential micronutrients. Prebiotic concept was introduced by Gibson et al. Cereal dietary fibre render prebiotic effects. Cereal based fermented foods carry both live bacteria and prebiotic dietary fibre. These dietary fibres should be soluble, hydrolysable and fermentable by the gut microflora. A prebiotic should,

• Be neither hydrolyzed nor absorbed in the upper Gastrointestinal tract
• Selectively stimulate the growth of potentially beneficial bacteria in the colon

End products of these fibres include short chain fatty acids ( acetic acid, propionic acid, butyrate acid etc.) , Carbon dioxide, Hydrogen Sulphide, Methane and Hydrogen. Gases are either excreted or metabolized. Short chain fatty acids are quickly absorbed in to the blood. Especially propionates and acetates have been reported to lower hepatic cholesterol synthesis. Resistant starch, unabsorbable sugars, oligo and polysaccharides (soybean oligosaccharides-stachyose and raffinose), β glucan. Arabinoxylans are few examples for prebiotics. These are also called as ‘colonic food’.

Synbiotics are the metabolites produced by the synergistic action of prebiotics and probiotics such as short chain fatty acids, amino acids, peptides, growth factors, signal molecules etc.

In the drug development process, the prospective drugs undergo a number of trials and are screened at various stages to generate the final potent drug for the treatment of various diseases. During the screening process, various properties are tested to see if the drug is suitable for the therapeutics and is non-toxic to the living system. After going through the different stages, the candidate found most suitable for the purpose is selected. Formulation of the drug plays a very important role in drug delivery to the target area within the body.

The testing of the viability of the drug within the living system is a very crucial issue in the drug discovery process. The drug must remain viable within the living system until it produces the required effect within the body after reaching the target organ or system. If the drug is very potent for the treatment but is immediately degraded after its entry into the living system due to various enzymes and the physical or biochemical environment within the living system, the administration of such a drug serves no use. Hence, the degradation and thereby clearance of the drug from the system must be avoided for proper drug action to take place. In such cases, drug formulation becomes important. Formulation of a drug has become a very important step in the drug discovery and development process. The potent drugs or biopharmaceuticals have different modes of delivery into the biological system like oral, pulmonary, nasal, transmucosal or transdermal routes depending on the characteristics of the drug, the drug target as well as the advantages of using the specific delivery route.

Formulation plays an essential role in the proper absorption of drugs within the living system. Proper formulation is necessary in solubilizing the drug in the formulation medium such that it helps in the delivery and release of the drugs to the target. Thus, formulation helps in increasing the bioavailability of the drug within the system by increasing its solubility, thus helping in improving its pharmacokinetics. The increase in the bioavailability helps in increasing the therapeutic effect of the drug shortening the time of the production of favourable effect and also in reducing the frequency of dose of the drug. It can also reduce the side effects of the drugs and the tissue specific formulations can help in the reduction of toxicity due to a particular formulation.

Different types of formulations are devised depending on the drug delivery route like for e.g. emulsion or solution for intravenous; solid, suspension or solution for oral; emulsion, suspension or solution for subcutaneous, etc. In case of insoluble compounds, various strategies have been adopted for proper formulation like:

1. the adjustment of the pH of the solution in case of ionizing compounds
as ionization increases the solubility of the compounds;

2. use of co-solvents like glycerine, ethanol, PEG, DMSO, etc to increase
its solubility, though proper care must be taken in the choice of co-
solvent in case of animal PK studies due to possible toxicity from the
co-solvent;

3. Surfactants like Tween 80, SDS, polysorbate, etc in proper dilutions
are used to help in the micellization of the drugs within the body,
which enhances the drug solubility, prevents precipitation due to
surface properties of the drugs, prevents aggregation of protein-based
drugs, thereby enhancing the stability of the drugs within the system.

Lipid based formulations are devised for the lipophilic compounds that are delivered as emulsion. The technology of the liposome delivery system has progressed in the application of oncology as well as for the treatment of viral, bacterial, and fungal infections. Its versatility is the reason, which has helped in the formulation of many classes of drugs.

The choice of proper formulation is very crucial in the PK studies, toxicity studies and in animal pharmacology studies. In the pharmacokinetic (PK) screening of the drug candidates, solubility is an important parameter and the choice of proper formulation is essential as the PK profile must remain unaffected while increasing the solubility of the drugs. The choice of proper surfactant and co-solvent is necessary such that it does not cause any form of toxicity while using the formulated drug. Optimal formulation is very important in the development of animal PK studies to demonstrate drug efficacy and activity. Recent studies have shown that formulation is being studied seriously in gene-delivery systems and in the delivery of drugs using nanoparticles.

I was thinking about getting a 2 year degree in Biotechnology.

Is this a good idea? Will there be job opportunities?