Activity of Aspergillus and Pseudomonas in the biodegradation of polyethylene

Abstract

Plastics containing polyethylene, a polymer integral to myriad aspects of modern life, have become indispensable in our day-to-day routines. From the packaging that safeguards our groceries to the components in our electronic devices, the omnipresence of polyethylene-based plastics underscores their indispensability. However, this pervasive reliance on plastics has ushered in a host of challenges, chief among them being the degradation of these materials. The degradation of plastics represents a multifaceted dilemma, exacerbated by the sheer scale of their consumption. Conventional degradation methods, including physical, chemical, landfilling, and pyrolysis, are intricate processes fraught with complexities. These methods, while attempting to mitigate the environmental burden posed by plastics, often introduce new challenges, including toxicity to the air, water, and land. Moreover, the consequences of plastic accumulation reverberate throughout ecosystems, with wildlife ingesting plastics and water systems clogged by their persistent presence. In response to these pressing environmental concerns, the pursuit of biodegradation solutions has emerged as an imperative. Bacteria and fungi, nature’s recyclers, offer promising avenues for the degradation of plastics. The biodegradation of plastics by microbial organisms represents a burgeoning field of research, with ongoing efforts aimed at elucidating the mechanisms underlying this process. The focal point of this study revolves around the biodegradation of polyethylene fragments, spearheaded by the microbial prowess of Pseudomonas and Aspergillus species. To simulate real-world conditions, low-density polyethylene fragments are meticulously prepared, sterilized, and then introduced into cultures teeming with these microbial agents. Over a span of 30 days, at a temperature conducive to microbial activity, the fate of these polyethylene fragments is meticulously monitored. Quantifying the biodegradation process necessitates a multifaceted approach, incorporating various analytical techniques. Viable cell counts, conducted using sophisticated colony counters, provide insights into microbial proliferation. Gas chromatography–mass spectrometry analysis enables the identification of degradation by-products, shedding light on the intricate biochemical pathways at play. Moreover, morphological changes in the polyethylene fragments are scrutinized using compound microscopy and scanning electron microscopy, offering visual cues to the degradation process. The determination of fragment weight loss serves as a tangible marker of biodegradation efficacy, offering quantitative data to complement qualitative observations. In tandem with this study, parallel investigations delve into additional facets of plastic biodegradation. Fourier transform infrared (FTIR) spectroscopy, a powerful analytical tool, unveils chemical transformations occurring during the degradation process. These complementary analyses enrich our understanding of plastic biodegradation dynamics, laying the groundwork for more comprehensive strategies to combat plastic pollution. The findings of this study underscore the remarkable biodegradation capabilities exhibited by both Aspergillus and Pseudomonas species, albeit to varying extents. Looking ahead, the synergistic potential of harnessing multiple microbial species to form consortia holds promise for enhancing biodegradation efficiency. As such, future research endeavors are poised to explore novel avenues, leveraging microbial communities to tackle the pervasive challenge of plastic pollution head-on.