Streptomyces as Potential Synthetic Polymer Degraders: A Systematic Review

Abstract

The inherent resistance of synthetic plastics to degradation has led to an increasing challenge of waste accumulation problem and created a pollution issue that can only be addressed with novel complementary methods such as biodegradation. Since biocontrol is a promising eco-friendly option to address this challenge, the identification of suitable biological agents is a crucial requirement. Among the existing options, organisms of the Streptomyces genus have been reported to biodegrade several complex polymeric macromolecules such as chitin, lignin, and cellulose. Therefore, this systematic review aimed to evaluate the potential of Streptomyces strains for the biodegradation of synthetic plastics. The results showed that although Streptomyces strains are widely distributed in different ecosystems in nature, few studies have explored their capacity as degraders of synthetic polymers. Moreover, most of the research in this field has focused on Streptomyces strains with promising biotransforming potential against polyethylene-like polymers. Our findings suggest that this field of study is still in the early stages of development. Moreover, considering the diverse ecological niches associated with Streptomyces, these actinobacteria could serve as complementary agents for plastic waste management and thereby enhance carbon cycle dynamics.

Heterologous expression and characterization of novel GH12 β-glucanase and AA10 lytic polysaccharide monooxygenase from Streptomyces megaspores and their synergistic action in cellulose saccharification

“…Streptomyces species have been reported to efficiently deconstruct natural polymeric macromolecules using extracellular carbohydrate-active enzymes, including cellulose, lignin, and chitin [ 19 , 20 ]. Herein, two adjacent cellulolytic enzyme genes SmBglu12A and SmLpmo10A were identified from the genome of S. megaspores according to the annotation for carbohydrate-active enzymes against the dbCAN2 database [ 21 ].…”

Bacterial dynamics during the burial of starch-based bioplastic and oxo-low-density-polyethylene in compost soil

“…Furthermore, the abundance of Streptomyces , members of which are known as polyethylene degraders [ 66 , 67 ], was lower in soil exposed to oxo-LDPE than in control soil, albeit that their abundance continued to increase over time in both treatments. To initiate degradation, bacteria first need to colonize the surface of plastic by forming a biofilm layer known as “plastisphere” [ 68 , 69 ].…”

Freshwater-Derived Streptomyces: Prospective Polyvinyl Chloride (PVC) Biodegraders

“…However, this approach has several challenges owing to its inability to discriminate false positives or inconclusive outcomes, such as an increase in the sample weight [ 36 ]. The degradation of a material involves the reduction of molecular weight, release of by-products, and modification of mechanical or physical properties [ 26 ]. We incorporated weight loss, by-product analysis of the supernatant, and thermogravimetric measurements as strategies to obtain orthogonal evidence of PVC degradation/biotransformation.…”

“…Based on a previously conducted systematic review, no studies evaluating PVC biodegradation by Streptomyces have been conducted [ 26 ] despite the positive results of Streptomyces for commodity plastics and biopolymer biodegradation [ 16 ]. Thus, there is an unexplored potential of these bacteria for PVC biodegradation.…”