Microbial communities in plastisphere and free-living microbes for microplastic degradation: A comprehensive review
Surendra Pratap Singh, Pooja Sharma, Ambreen Bano, Ashok Kumar Nadda, Sunita Varjani
Abstract
Plastic plays a crucial role both in people's daily lives as well as in society as a whole. The environment is accumulating plastics, and they have low biodegradability, so this problem will likely persist for a long time. The fragmentation of plastics generates microplastics (MPs). Research on the degradation of synthetic MPs by enzymes or microorganisms has become a prominent topic, which paves the way for the development of biological waste treatment technologies. There are five types of biodegradation processes: (1) colonization, (2) conditional film formation, (3) assimilation, (4) bio-fragmentation, and (5) mineralization. The biodegradation of a variety of polymers has been demonstrated recently by bacteria, bacterial consortia, biofilm-forming bacteria, and fungi. Biodegradation is the microbes-assisted transformation that decomposes the plastic wastes into CO2, methane, biomass, inorganic compounds, and water, depending on organisms, the molecular weight of plastics, polymer type, and environmental conditions. MPs cause inflammation, oxidative stress, and enhanced translocation or absorption in humans, plants, and animals. Humans are susceptible to cancer, neurotoxicity, and metabolic abnormalities, according to various studies. Additionally, we have discussed the metabolic pathways of microbes and our ongoing efforts to use them to reduce microplastic pollution in soil and water. Further investigation is required to determine the critical environmental characteristics and qualities that influence plastic degradation in order to anticipate the destiny of plastics in various contexts and to allow the development of solutions for mitigating plastic waste.