Ecofriendly and cost effective Plastic degradation by microorganisms

Abstract

The world is currently grappling with a complex and pervasive issue: the escalating crisis of plastic waste. This crisis presents numerous dimensions that encompass social, technical, and economic challenges, making it an intricate problem to solve. Over the past decades, several corporations have emerged, seeking to utilize innovative processes aimed at tackling this crisis. These approaches encompass diverse methods such as converting plastics back into their monomeric form, with the hope of replacing fossil fuels as the primary feedstock for new materials. Plastics are extremely durable because of their synthetic nature. They are resistant to degradation by natural processes, so they accumulate in the environment. Microorganisms play multifunctional role in human life. They play a significant role in environmental maintenance. Bacteria and fungi are adapted for the role in the management of wastes. Useful compost or organic fertilizers can be produced and used for organic farming. We isolated seven fungal species which were: Aspergillus oryzea, A. flavus, A. fumigatus, A. niger, A. awamori, A. tubingensis and A. carbonarius. Five bacterial species were isolated from different plastic wastes (High-density, Low-density polyethylene and Polyethylene terephthalate): Bacillus altitudinis, Bacillus subtilis, Bacillus velezensis, Micrococcus luteus and Priestia flexa. Bacteria were incubated on nutrient agar medium at 30 °C for 2 days. Fungi were incubated on Sabouraud dextrose agar medium at 25 °C for 5 days. For degradation of plastic, liquid Minimal Salt Medium (MSM) was used for bacteria and Dox medium was used for fungi. Two g of plastic were used as sole carbon source per 100 mL medium. The remaining dry weight of plastic was measured in triplicates. The total protein concentration (µg/100 µL) was measured by Bicinchoninic Acid (BCA) assay. Due to the increasing issue of plastics, biodegradation has been enhanced by including a combination of microorganisms and man-made physical and chemical factors this has shown a higher rate of degradation for approximately two months at 37 °C.