DEGRADATION OF POLYETHYLENE PLASTIC WASTE BY INDIGENOUS MICROBIAL CONSORTIUM AND FUNGI

Abstract

Aim: This research aims to determine the ability of indigenous microbial consortium in degrading Low Density Polyethylene (LDPE) plastics. The research start by preparing plastic into 1 x 1 cm2 size which was cut mechanically because the smaller the size of the plastic, the larger the surface area. The plastic is placed in a petri dish containing Nutrient Broth (NB) media. The variations used were bacterial composition (%) 10, 50, and 75, variations in temperature (°C) 25, 30, 35, variations in acidity values (pH) 5, 7, 9, and variations in contact time (Td) 10 days. LDPE plastic degradation was analyzed by gravimetric method, Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). Both types of bacteria were resistant or insensitive to the presence of plastic compounds as xenobiotic substrates because there was no inhibition zone around the plastic samples and they were able to grow on Nutrient Agar (NA) media added with plastic samples. Based on the results of gravimetric and FTIR analysis, the highest removal value was at a temperature variation of 30°C and pH 7 with a bacterial composition of 75% (v/v) which was incubated for 10 days. Methodology and Results:The results of the gravimetric analysis showed that the weight loss in LDPE plastic was 0.1548 gr to 0.1464 gr or 5.47%, while the FTIR analysis showed the intensity removal result was 70.67%. Conclusion, significance, and impact of study: These results were confirmed again using Scanning Electron Microscope (SEM) analysis which showed morphological changes on the surface of LDPE plastic samples. Changes that occur in LDPE plastic samples incubated with indigenous microbial consortium are influenced by several factors, including temperature, pH, contact time, and the presence of bacteria as biodegradators.