Studies on Isolation and Identification of Active Microorganisms during Degradation of Polyethylene / Starch Film

Abstract

Low density polyethylene is a vital cause of environmental pollution. It occurs by choking sewer line through mishandling thus posing an everlasting ecological threat. Biodegradable plastics are eco-friendly; they accumulate great potential applications in various industries. Biodegradable polymers degrade upon disposal by the action of active microorganisms in the soil. The result of degradation can be interpreted with physical changes through biological force. Microbial degradation of plastics convert polymer into oligomers and monomers. This microbial degradation may be based on aerobic and anaerobic metabolisms. The main objective of present study is to isolate and identify the microorganisms from soil during biodegradation testing of polyethylene/starch film. The isolation is been carried out through soil serial dilution method. An isolated microorganism is cultivated in culture media. After growth of microorganisms at 37 C identification of microorganisms was carried out by macroscopic/microscopic examination. During identification it is found that bacteria (Pseudomonas spp, Streptococcus spp, Staphylococcus spp, Micrococcus spp and Moraxella spp etc), fungi (Aspergillus niger, Aspergillus glaucus etc), and Actinomycetes are present on the surface of polyethylene/starch film. Surface morphology of polyethylene/starch film has been analyzed by scanning electron microscopy (SEM) before and after degradation. Physico - mechanical properties has also been determined before and after degradation of film in order to understand the rate as well as the mechanism of degradation.