Proteomic examination of polyester-polyurethane degradation by Streptomyces sp. PU10: Diverting polyurethane intermediates to secondary metabolite production

Omic-driven strategies to unveil microbiome potential for biodegradation of plastics: a review

Plastic waste accumulation has lately been identified as the leading and pervasive environmental concern, harming all living beings, natural habitats, and the global market. Given this issue, developing ecologically friendly solutions, such as biodegradation instead of standard disposal, is critical. To effectively address and develop better strategies, it is critical to understand the inter-relationship between microorganisms and plastic, the role of genes and enzymes involved in this process. However, the complex nature of microbial communities and the diverse mechanisms involved in plastic biodegradation have hindered the development of efficient plastic waste degradation strategies. Omics-driven approaches, encompassing genomics, transcriptomics and proteomics have revolutionized our understanding of microbial ecology and biotechnology. Therefore, this review explores the application of omics technologies in plastic degradation studies and discusses the key findings, challenges, and future prospects of omics-based approaches in identifying novel plastic-degrading microorganisms, enzymes, and metabolic pathways. The integration of omics technologies with advanced molecular technologies such as the recombinant DNA technology and synthetic biology would guide in the optimization of microbial consortia and engineering the microbial systems for enhanced plastic biodegradation under various environmental conditions.

Understanding visible light and microbe-driven degradation mechanisms of polyurethane plastics: Pathways, property changes, and product analysis

The accumulation of polyurethane plastics (PU-PS) in the environment is on the rise, posing potential risks to the health and function of ecosystems. However, little is known about the degradation behavior of PU-PS in the environment, especially water environment. To address this knowledge gap, we investigated and isolated a degrading strain of Streptomyces sp. B2 from the surface of polyurethane coatings. Subsequently, a photoreactor was employed to simulate the degradation process of bio-based polyurethane (BPU) and petroleum-based polyurethane (PPU) under three conditions, including single microorganism (SM), single light exposure (SL), and combined light exposure/microorganism action (ML) in aqueous solution. The results indicated that PU-PS mainly relies on biodegradation, with the highest degradation rate observed after 28 d under SM condition (BPU 5.69 %; PPU 5.25 %). SL inhibited microbial growth and degradation, with the least impact on plastic degradation. Microorganisms colonized the plastic surface, secreting relevant hydrolytic enzymes and organic acids into the culture medium, providing a negative charge. The carbon chains were broken and aged through hydrogen peroxide induction or attack by oxygen free radicals. This process promoted the formation of oxidized functional groups such as OH and CO, disrupting the polymer's structure. Consequently, localized fragmentation and erosion of the microstructure occurred, resulting in the generation of secondary microplastic (MPs) particles, weight loss of the original plastic, increased surface roughness, and enhanced hydrophilicity. Additionally, BPU exhibited greater degradability than PPU, as microorganisms could utilize the produced fatty acids, which promoted their reproduction. In contrast, PPU degradation generated a large amount of isocyanate, potentially toxic to cells and inhibiting biodegradation. This study unveils the significant role of microorganisms in plastic degradation and the underlying degradation mechanisms of BPU, providing a novel strategy for polyurethane degradation and valuable information for comprehensive assessment of the behavior and fate of MPs in the environment.