Screening and Optimisation of the Biodegradation Potential for Low Density Polyethylene (LDPE) Films by Fusarium Equiseti and Brevibacillus Parabrevis

Abstract

The accumulation of low density polyethylene, used extensively in packaging for industrial and agricultural applications, in the ecosystem is a great threat. This study focuses on the isolation of micro-biota from the plastic polluted sites to screen and optimise their potential for low density polyethylene (LDPE) film biodegradation. Firstly, the plastic samples from soil dumping plastic debris and plastic polluted water were collected; then fungi and bacteria were isolated using potato dextrose agar media and nutrient agar media, respectively, while screening low density polyethylene film biodegradation performed on mineral salt media (MSM) using the isolated micro-biota. The measurement of the potential biodegradation was assessed by visual observation. The most microbial colonization for low density polyethylene films was identifying molecular which was then utilized for optimisation of the biodegradation processes with different parameters such as media type, inoculum size, shaking speed, different incubation temperature and pH at different incubation time. Then the weight loss in the LDPE films percentage was calculated measuring dry mycelium weight and bacterial absorbance. The results revealed that, among the isolated micro-biota fifteenth, the most colonization was Fusarium equiseti and Brevibacillus parabrevis depending on the scanning electron microsope (SEM) and Fourier transform infrared (FTIR) analysis, in addition to optimum media, inoculum size, shaking speed, incubation temperature, pH, MSM, 2 disks and 2 ml, 30˚ C and 35˚C, pH5 and pH7 for 30:20 days for F.equiseti and B.parabrevis, respectively. The overall results confirmed that F.equiseti and B.parabrevis from the plastic polluted sites play an essential role in low density polyethylene films biodegradation.