BIODEGRADATION OF LOWDENSITY POLYETHYLENE (LDPE) BY PSEUDOMONAS AERUGINOSA STRAIN P9 ISOLATED FROM POULTRY DROPPINGS

This study aimed to isolate bacteria from poultry droppings for the degradation of lowdensity polyethylene (LDPE). Poultry droppings were collected from the Instructional Livestock Farm Complex (ILFC), Veterinary College, Mhow, Madhya Pradesh, India. LDPE films were treated with UV rays for 48 hours and used for the study. Four isolates were identified by Gram's staining. In M9, K9, P9, and E9; one was identified as Gram-positive, and 3 were found as Gram-negative bacteria. Screening of bacteria for LDPE biodegradation was done by clear zone formation. Out of 4 isolates, P9 was identified as LDPE degrading bacteria. LDPE degradation was analyzed by gravimetric analysis using the weight loss method, the functional group was analyzed by Fourier transform infrared spectroscopy, and the surface was analyzed by scanning electron microscopy. LDPE films with isolate P9 showed significant weight loss (16.98%±0.47) after 60 days. FT-IR analysis showed a decrease (58.8%) in carbonyl index and changes in functional group vibrations indicating LDPE degradation. SEM image examination revealed bacterial colonization, biofilm formation, surface erosions, cracks, and pit formation on the surface of LDPE which was indicative of the degradation of LDPE film. Further, the identification of isolate P9 was done by BD Phoenix M50 automated identification system and 16S rRNA sequencing. Sequencing and phylogenetic analysis of the P9 isolate showed 99.76% similarity with Pseudomonas aeruginosa (OR921266.1). Our findings underscore the potential of strain P9 from poultry droppings to efficiently utilize LDPE as a sole carbon source, thereby contributing to its degradation. This is the first report of isolating LDPE-degrading bacteria from poultry droppings. It is crucial to analyze the poultry gut microbiota for plastic degradation since this discovery highlights the need for further investigation.