Microplastic biodegradation and environmental safety: From microbial mechanisms to engineered systems and circular...

Area of Science:

• Environmental Science
• Biotechnology
• Polymer Science

Background:

• Microplastics (<5 mm) are persistent environmental contaminants due to their stability and resistance to conventional removal methods.
• Microbial and enzymatic degradation are emerging as viable strategies for microplastic transformation, but complete mineralization is not consistently achieved.
• Incomplete depolymerization can yield intermediate products with unknown ecological impacts.

Purpose of the Study:

• To provide a mechanistically integrated analysis of microplastic biodegradation.
• To examine factors influencing degradation, including abiotic preconditioning, enzyme-polymer interactions, and microbial community dynamics.
• To critically assess environmental safety and the integration of biodegradation into circular recycling frameworks.

Main Methods:

• Review of current literature on microplastic biodegradation mechanisms.
• Analysis of surface modification, depolymerization, biotransformation, and mineralization processes.
• Examination of microbial systems (single strains, consortia, engineered systems) and their roles.

Main Results:

• Biodegradation outcomes are highly variable, influenced by polymer type, environmental conditions, and microbial consortia.
• Advances in enzyme engineering enhance depolymerization efficiency under controlled settings.
• Environmental safety concerns include byproducts, additive release, and horizontal gene transfer risks.

Conclusions:

• Microbial biodegradation presents a promising avenue for mitigating microplastic pollution.
• Scalability, regulatory compliance, and ecosystem-level risk assessment are critical challenges for practical implementation.
• Integrating mechanistic understanding with environmental realism and regulatory preparedness is essential for safe and effective microplastic biodegradation.