is a word having a broad class and consist of large molecules or compound or
thousands of atoms. Plastic is classified into synthetic or semi synthetic
plastic. Organic compound like Coal, air carbon dioxide are the main source
component in plastics manufacturing. Some plastics are PP, PE are the example
of non-bio-degradable plastics. The accumulation of plastics in environment in
huge amount due to mismanagement of waste bring about the reduction in the soil
nutrient as well as leading many issues related to environment , health etc.
there are some microorganism that help in degradation of plastics by secreting
enzymes and their other compound under emphasis situation. The enzymes are
protease, lipases, and cutinases help in the degradation of polymer. There is
various mechanism use by microbes first is direct degradation of plastics as
nutrient, second is indirect action of enzymes. Plastics can be classified into
two group according to biodegradability ability. First is non-biodegradable are
mainly those plastics which are mostly used in packaging etc. they are highly
stable high molecular weight PVC, PP, PS are the common example of
non-biodegradable plastics. These plastics are derived from polyolefin e.g.
polyethylene. Biodegradable that include both type of hydrolysis reaction i.e.
aerobic and anaerobic. During biodegradation some enzyme produce called
exoenzymes and breakdown polymer into small units i.e. dimers and monomers.
Biodegradable plastics is further classified into three classes.
based 2. Fossil based 3. Polymer blends
based biodegradable plastic derived from renewable sources. Polylactic acid is
common example of it. Fossil based plastics has many application such as
packaging purposes. However they are non-biodegradable so it cause
environmental pollution or hazardous effect. Its degradation process is very
slow. The common example of polyethylene succinate, polycarpolactic acid are
the common example of fossil based plastics. Biodegradable polymer blend are
those which are the combination of different materials to make plastics
biodegradable, this method is convenient in comparison of copolymerization.
microbes sometimes secrete enzymes outside the cell which can help in
degradation of various type of plastics. In the mechanism of plastic
degradation firstly microbes stick with the polymer with the help of enzyme and
hydrolysis occur into two parts. In the first part hydrolysis division occur
when microbe combine with the substrate of polymer. The products of this reaction
is modified into carbon dioxide and water by transformation. In the presence of
oxygen the oxygen is utilized by microbes as negative atom acceptor and carbon
dioxide and water are the products. In the absence of oxygen microbes breakdown
plastics. Anaerobic bacteria utilized co2, so4, no3, Fe etc. used as electron
acceptor. There are many factors that influence the process of decomposition of
plastics waste. Few factors are moisture, pH, temperature, enzyme
characteristics that are discussed under the heading of vulnerability
situations. Molecular weight, shape, size, additives and bio surfactant are
other factors that influence this process.
treat the huge problem of plastics pollution there is only the way to solve it
that is decomposition of plastics by means of biological organisms. Now a day’s
new microorganism has been isolate which is efficient in breaking down of
polyethylene terephthalate and some other organism also found for degradation
of many kinds of polymer, so it is very beneficial for solving environmental
pollution and developing more compounds that are environmental friendly.
the conclusion is the use of plastic is increasing day by day and it is
unavoidable to public because of their daily life uses. And directly affect the
environment therefore there is a need to synthesize bio based and fossil based
plastics for many application such as continuous safety of environment. Many
microbes are able to modify polymer in to noncomplex compound in the presence
or absence of oxygen. And these biodegradable plastics have industrial and commercial
application and it is one of the best strategy to control environmental
pollution and induced environment safety and sustainability.