Microbial degradation of plastics: Biofilms and degradation pathways

Abstract

Plastics are recalcitrant polymers released in the environment through unpredicted use leading to accumulation and increased water and soil pollution. Transportation of these recalcitrant polymers in agricultural soil, sediment, and water has been causing concerns for environmentalists. Biofilm community adhered on plastic polymers have a significant contribution in their degradation as they warrant bioavailability of substrates, sharing of metabolites and increased cell viability thereby accelerating biodegradation. Metabolic enzymes of the microbes can be exploited as a potent tool for polymer degradation. However very little or Chapter contents Introduction …………………………………………………………………………………………………….. Plastic degradation pathways in bacteria …………………………………………………………………… Natural metabolic pathways ……………………………………………………………………………… Engineered pathways ……………………………………………………………………………………… Biofilm forming microbes involved in degradation ……………………………………………………….. Bacteria ………………………………………………………………………………………………………. Fungus ………………………………………………………………………………………………………. Influence of biofilm on plastic degradation ………………………………………………………………... Biofilm-plastic interactions ………………………………………………………………………………….. Conclusion ……………………………………………………………………………………………………... Acknowledgments ……………………………………………………………………………………………. References ……………………………………………………………………………………………………… 185 no reports are available about the influence of biofilm and plastic degradation and vice versa. The present chapter reports the impact of biofilm microbes in the degradation of commonly used plastics. Furthermore, potent microorganisms and their interactions with the plastic surface has been deciphered, which would serve as a better understanding of the utilization of biofilm-based methods in the development of plastic waste management.

Plastic Degradation by Extremophilic Bacteria

“…In natural systems, bacteria serve as primary colonizers that may further entrap other organisms such as fungi, diatoms, etc. [ 20 ]. The result is that the biofilm community differs significantly from the microorganisms in the free-living state in the surrounding environment [ 21 ].…”

“…Combinations of two species of bacteria have been shown to enhance plastic-biodegradation potential. Lately, attention has been drawn to the application of more complicated bacterial consortia isolated from plastic-contaminated natural habitats [ 20 ]. In spite of the apparent correlation between biofilm formation and biodegradation, the molecular mechanisms of the processes remain too vague, and there is no clear-cut link between plastic depolymerization and enzymatic activities specifically originating from biofilm microbes [ 27 ].…”

Metagenomic Exploration of Plastic Degrading Microbes for Biotechnological Application

“…The biodegradation of complex polymeric plastic waste proceeds through an array of oxidation steps to convert into monomers and finally enters into the TCA cycle via assimilation [ 47 ]. All these different stages of biodegradation could not be possible to carry out by any single species [ 98 ]. To resolve it, the genetic engineering tools can be implemented for the complementation of multiple genes of whole plastic metabolic pathways or complete gene circuit into different microbial species.…”

Isolation, characterization and optimization of bacterial isolate SARR1 for biodegradation of pretreated low density polyethylene

“…Plastics are non-biodegradable and a potential xenobiotic compound that can cause impact globally (Ghosh et al, 2019). The wide use of low-density polyethylene (LDPE) is increasing day by day because of its applications in pharmaceuticals industries, agriculture, households, and food packaging industries and due to its inert and durable nature (Erni-Cassola et al, 2019).…”