Evaluation of Polyethylene Degrading Potential of Isolated Soil Bacteria

Abstract

The present study aimed to isolate and identify a potent polyethylene degrading bacterial strain newlinefrom the petrochemical oil contaminated soil and plastic waste disposal soil and to study its degrading newlineefficiency in a laboratory scale. The bacterial strains were isolated by enrichment technique and were newlineidentified based on the morphological and biochemical characteristics. Cell surface hydrophobicity of newlinethe isolated bacterial strains was assessed. Further, they were screened individually for their low newlinedensity polyethylene (LDPE) degrading efficiency by in vitro biodegradation assay. Among the newlineisolated bacterial strains, the more potent strain was selected and its phylogeny was analyzed by 16S newlinerDNA sequencing studies. The efficiency of the potent strain to colonize on the LDPE surface and its newlinebiodegradation ability were investigated. The degraded products of low density polyethylene were newlineanalyzed by HPLC and GC- MS after the biodegradation study. The selected strain was further newlinescreened for the presence of enzymes such as laccase, manganese peroxidase and lignin peroxidase newlineactivity and biosurfactant production during polyethylene degradation. The bioremediation potential of newlinethe selected strain in low density polyethylene (LDPE) polluted soil under laboratory conditions using newlinebioaugmentation strategy was investigated. Totally five different bacterial strains were isolated from newlinethe polluted soil. The bacterial strain PE3 showed maximum growth, more cell surface hydrophobicity newlineand weight loss and it was selected for further studies. The 16S rDNA sequence of PE3 shared 93% newlinesequence similarity with Bacillus cytotoxicus. Hence the strain was designated as Bacillus sp.PE3. The newlinedegraded products were identified as carboxylic acids, alkanes and alkenes. The strain Bacillus Sp.PE3 newlinewas able to produce laccase, manganese peoxidase, lignin peroxidase and biosurfactants. The results newlineinferred that the exogenous addition of Bacillus Sp.PE3 to LDPE contaminated soil causes an newlineenhanced degradation. The data generated in the present