Development of plastic-degrading microbial consortia by induced selection in microcosms

Area of Science:

• Environmental Microbiology
• Polymer Science
• Bioremediation

Background:

• Increasing production of recalcitrant plastics leads to ecosystem accumulation.
• Microbial consortia show potential for enhancing plastic biodegradation.
• Sustainable strategies are needed to mitigate plastic pollution.

Purpose of the Study:

• To select and characterize plastic-degrading microbial consortia.
• To investigate the efficacy of sequential and induced enrichment techniques.
• To identify key microbial players and their enzymatic activities in plastic degradation.

Main Methods:

• Sequential and induced enrichment of microbial consortia from soil microcosms with linear low-density polyethylene (LLDPE).
• Incubation for 105 days with monthly transfers, monitoring microbial diversity and ligninolytic microorganisms.
• Isolation, molecular identification, and enzymatic characterization of consortium members.

Main Results:

• Enrichment with powdered LLDPE yielded a more effective consortium than film form, reducing microplastic weight by 2.5–5.5%.
• Selected consortia exhibited diverse enzymatic activities crucial for degrading recalcitrant polymers.
• Specific strains like *Pseudomonas aeruginosa* REBP5 and *Pseudomonas alloputida* REBP7 demonstrated significant degradation potential.

Conclusions:

• Microbial consortia can be effectively selected for degrading recalcitrant plastics like LLDPE.
• Powdered LLDPE enrichment is more effective for selecting potent plastic-degrading consortia.
• The identified microbial consortia contribute to understanding bioremediation of anthropogenic plastic pollution.