A minireview on the bioremediative potential of microbial enzymes as solution to emerging microplastic pollution

Abstract

Accumulating plastics in the biosphere implicates adverse effects, raising serious concern among scientists worldwide. Plastic waste in nature disintegrates into microplastics. Because of their minute appearance, at a scale of <5 mm, microplastics easily penetrate different pristine water bodies and terrestrial niches, posing detrimental effects on flora and fauna. The potential bioremediative application of microbial enzymes is a sustainable solution for the degradation of microplastics. Studies have reported a plethora of bacterial and fungal species that can degrade synthetic plastics by excreting plastic-degrading enzymes. Identified microbial enzymes, such as IsPETase and IsMHETase from Ideonella sakaiensis 201-F6 and Thermobifida fusca cutinase (Tfc), are able to depolymerize plastic polymer chains producing ecologically harmless molecules like carbon dioxide and water. However, thermal stability and pH sensitivity are among the biochemical limitations of the plastic-degrading enzymes that affect their overall catalytic activities. The application of biotechnological approaches improves enzyme action and production. Protein-based engineering yields enzyme variants with higher enzymatic activity and temperature-stable properties, while site-directed mutagenesis using the Escherichia coli model system expresses mutant thermostable enzymes. Furthermore, microalgal chassis is a promising model system for “green” microplastic biodegradation. Hence, the bioremediative properties of microbial enzymes are genuinely encouraging for the biodegradation of synthetic microplastic polymers.

Microplastics in Aquatic and Food Ecosystems: Remediation Coupled with Circular Economy Solutions to Create Resource from Waste

“…In addition, several studies have noted the microalgae's potential for bioremediation. Numerous functional expression investigations on a diatom and a green alga were conducted [80][81][82][83][84][85][86][87][88][89][90][91]. A study by Mohanan et al unveiled that intracellular lipases can be cloned and expressed [92].…”

“…Metagenomicbased research revealed the presence of nearly 800 or more PET hydrolases in the strains of archaea and bacteria from terrestrial and marine environments. Pseudomonas pelagia cutinase is involved in the degradation of polyester [80]. P. pertucinogena can also be used to clean polyesters [81].…”

Advances in Bioremediation Agents and Processes for Removal of Persistent Contaminants From Environment

“…Degradative Enzymes: Bacteria are essential to bioremediation because they produce a range of enzymes that help break down contaminants. As an illustration, certain bacteria produce oxygenases, which initiate the oxidation reactions that degrade hydrocarbons, including PAHs [13]. Formation of Biofilms: Bacterial biofilms improve the efficiency of pollutant decomposition.…”