Plastic is a broad name given to the different types of organic polymers having high molecular weight and is commonly derived from different petrochemicals. Plastics are generally not biodegradable or few are degradable but in a very slow rate. Day by day, the global demand of these polymers is sharply increasing; however, considering their abundance and potentiality in causing different environmental hazards, there is a great concern in the possible methods of degradation of plastics. Recently, there have been some debates at the world stage about the potential degradation procedures of these synthetic polymers and microbial degradation has emerged as one of the potential alternative ways of degradation of plastics. Alternatively, some scientists have also reported many adverse effects of these polymers in human health, and thus, there is an immediate need of a potential screening of some potential microbes to degrade these synthetic polymers. In this review, we have taken an attempt to accumulate all information regarding the chemical nature along with some potential microbes and their enzymatic nature of biodegradation of plastics along with some key factors that affect their biodegradability.

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The widespread use of chemical pesticides in agriculture has led to the pollution of environmental systems and has caused various health disorders in animals and humans. Biological pest control is one of the most environmentally friendly methods in modern agriscience. Such methods protect crops from pests and do not pollute the environment. A strain of Trichoderma longibrachiatum was isolated and identified from the soil environment of the North 24 Parganas District, eastern India. A spore suspension of this fungus was used to treat Leucinodes orbonalis, one of the major pests of brinjal (eggplant, Solanum melongena). In an in vitro system, fungal antagonism was determined by median lethal dose (LD50) and median lethal time (LT50) tests against insect larvae. The LD50 and LT50 of T. longibrachiatum were 2.87 × 10(7) spores ml(-1) and 11.7 days, respectively. T. longibrachiatum was formulated into a biopesticide, and its performance was evaluated in brinjal field trials in 2012 and 2013. In the field trials, brinjal treated with three spray applications of T. longibrachiatum (10(8) spores/ml) at 15-day intervals showed a 56.02 % higher crop yield than that of the control. This treatment showed similar efficacy to that of the pesticide malathion in the field trials. The results of this study indicate that this formulation may replace malathion to control the insect pest L. orbonalis in brinjal crops. This is the first report of the entomopathogenic property of T. longibrachiatum and its evaluation against an insect pest in field trials.

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