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Plastic From Nature-Bioplastic
Bioplastics are a kind of plastic, produced from natural compounds, and can be degraded into their base compounds. It is also known as Biodegradable plastics.

Genetic variations in plants have been made possible through many conventional methods since many years. The biotechnological approach for the desired plant was achieved by genetic engineering. Transgenes refers to gene or genes which are not native of an organism and are introduced by many methods. Transgenic plants refer to plants having one or more transgenes. This technique of involving plants to produce various chemical commodities and pharmaceuticals is known as phytofermentation.

A variety of biochemicals such as proteins, lipids and carbohydrates are obtained from plants. Production of transgenic plants has resulted in generating modified biochemical production in plants.

A reasonable amount of interest has been developed in the field of bioplastic as a result of increased concern about non degradability of plastics and environmental hazards. Bioplastic have been known to be produced by various means including vegetable fats, cornstarch etc

Biotechnological role:
The role of biotechnology in the field of bioplastic has been accounted mainly to the presence of the property of biodegradation by naturally occurring polyhydroxy- alkanoates(PHAs). These are naturally occurring polyesters produced by bacterial fermentation. Polyhydroxybutyrate(PHB) is a form of PHA. It is produced in the bacterial cell as a result of physiological stress in the form of energy storing molecules. These PHAs are metabolized and used up by such bacteria when none of the other forms of energy source is available under conditions of stress. The properties of PHB include non toxic, water insoluble, high oxygen permeability and ultra violet resistance, thermostable and biocompatible.

Bacterial fermentation of Alcaligenes eutrophus produces polyhydroxy alkanoates.

The organism is cultured under normal conditions to attain stable growth. The conditions of the medium are then altered so that the bacterium induces production of PHA. This is usually induced in deficiency conditions of macro elements, oxygen etc or due to the excess presence of carbon sources in the medium. Acetyl-coA serves as a precursor in the production of polyhydroxy alkanotaes. The microbial fermentation of Alcaligenes for the production of PHAs is not favourable as the yield is very low. The cost involved in such mechanisms is substantially higher.
Though plants do not produce PHB naturally, they can be programmed to do so. For the production of PHBs by genetic engineering, the two genes involved in the production of enzymes namely, aceto-acetyl-CoA reductase (phbB) and PHB synthase (phbC) are isolated. These two enzymes are pivotal in the PHB synthesis from its precursor. The genes responsible are transferred and expressed in Arabidopsis thaliana plant. These two genes are so targeted so that they are expressed in plastids of plant. The PHB gets accumulated in leaves and can be extracted easily.
Thus synthesis of polyhydroxyl butyrate is a classic example of application of biotechnology in the production of goods of commercial value. Transgenic trees producing phbB and phbC are also produced where the PHB are synthesised in the leaves which can be extracted. Studies shows that plant produce PHB 20 -40% of their dry mass.
This method of production involves many advantages like;
(i) Upstream production (the production of biomass from which the biochemical has to be isolated) costs are much lower than microbial fermentation.
(ii) The post translation modification system of proteins in a plant cell is as advanced as in the animal cell. As a result the PHB which is formed undergo appropriate modification so that when extracted they do not require any further modification.
(iii) The plant seeds of transgenic plants can be stored and transported easily. These seeds could be used to produce transgenic plants to synthesize bioplastic when required.
(iv) Since animal system is not used, it does not face any concerns regarding to ethical issues.

(i) The production levels do not rise to the expected levels.
(ii) The increased level of trangenes in a plant genome results in accumulation of transgenic product. This can effect the plant growth and stability.

Recent Developments:
Several studies involving production of PHB in corn, potato etc has been initiated. Transgenic tobacco plants have also been extensively studied for PHB production. It is also estimated that potatoes can be a good source of PHB production from which PHB can be easily obtained and the resulting yield is also proposed to be higher is such ‘plastic potatoes’. If successful, it will be he most cost effective method involved.
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Bioplastics or the biobased plastic means that the substance or product is either completely or partly derived from the biomass. Biomass utilized for bioplastics comes from plant source for example sugarcane, corn or cellulose. The phrase bioplastics encloses an entire family of materials that vary from conventional plastics to the extent that they are biobased, biodegradable or a combination of both. They are generally promoted as a green alternative to the regular plastics. Bioplastics were initially introduced during the 1980's. The thought behind it was to generate degradable plastics so that they could disintegrate and utilize less space in the landfills. But the idea failed because the modern landfills are usually sealed with impermeable protective liners so that no moisture, air or sunlight could penetrate and not much of the material is degraded. And the other important objective of manufacturing bioplastics was to decrease the utilization of petrochemicals in the production of plastics and replacing them with materials from renewable sources.

Bioplastics are shaping the evolution of plastics. The key advantages of biobased plastic products in comparison to their conventional ones are that they conserve fossil resources by utilizing biomass which annually regenerates and providing the unparallel potential of carbon neutrality (that is net zero carbon emission). Biodegradability is an additional property of certain types of bioplastics and they offer additional advantage of end of life disposals.

Bioplastics are not a single type of polymer but instead a family of materials that can differ significantly from one another. There are mainly 3 groups in the family of bioplastics, each of it with its own distinct features.

Biobased (completely or partially) non-biodegradable plastics: Plastics such as PE, PP or PET which are biobased (so-called drop-ins) and biobased technical performance polymers such as PTT or TPC-ET.

Biobased (completely or partially) and biodegradable plastics: Plastics such as PLA and PHA or PBS come under this category.
Fossil fuel based biodegradable plastics: Plastics that are based on fossil fuels and are biodegradable such as PBAT.

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Increasing and sustainable use of bioplastics is possible in various industrial segments due to the fact that the biodegradable property of the bioplastics doesn’t depend upon the raw materials used but on the molecular structure.

Bioplastics are currently playing important role in the fields of packaging, agriculture/horticulture, gastronomy, consumer electronics/durables and automotive to name a few. In the above mentioned fields, products used for short term or single use like, mulch films or catering products (spoons, plates etc) utilize bioplastics. Even consumer durable products like mobile phone covers or automobile interior parts are increasingly made out of bioplastic materials.

The application of bioplastics is growing steadily. Fields like building and construction, clothing, household items, toys are increasingly made of bioplastic materials. Due to the increasing demand for environmentally friendly and sustainable material is leading to higher growth and capacity addition of bioplastic materials. This is also leading to increase in the variety of the bioplastics being offered in the market. The material properties of the bioplastics such as durability, flexibility, heat resistance, printability, transparency, chemical resistance etc are being improved to match that of current materials.

Bioplastics are improved and sustainable solution to the plastic industry. The bioplastic material can be used in all the fields where plastics are currently being used and even extend to some of the newer fields. Some products produced using bioplastics have an advantage at end of life as they are biodegradable and can be easily disposed confirming to strict environmental laws in some countries. These materials are also environmentally friendly, reducing fossil fuel utilization and hence conserve precious non-renewable resources. These bioplastics also help in reducing green house gas such as carbon dioxide emissions. Another major environmental benefit by switching to bioplastics is the reduction in emissions like dioxins, which are harmful to environment as well as health and are currently being emitted due to burning of the plastics. Use of bioplastics can turn out to be a necessity in regions, such as European countries, which are heavily dependent on imported fossil fuels.
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