# Biodegradation Mechanisms and Sustainable Governance of Marine Polypropylene Microplastics

## TL;DR

This review explores how marine polypropylene microplastics persist and how they might be degraded using microbes and new materials.

## Contribution

The paper provides a comprehensive overview of biodegradation mechanisms and sustainable strategies for managing polypropylene microplastics in marine environments.

## Key findings

- PP-MPs resist degradation due to their hydrophobic and crystalline nature.
- Microbial communities and environmental factors jointly regulate PP-MP biodegradation.
- Emerging strategies include engineered microbes and AI-based monitoring for pollution control.

## Abstract

Polypropylene microplastics (PP-MPs) represent a persistent class of marine pollutants due to their hydrophobicity, high crystallinity, and resistance to environmental degradation. This review summarizes recent advances in understanding the environmental behavior, physicochemical aging, and ecotoxicological risks of PP-MPs, with emphasis on microbial degradation pathways involving bacteria, fungi, algae, and filter-feeding invertebrates. The biodegradation of PP-MPs is jointly regulated by environmental conditions, polymer properties, and the structure and function of plastisphere communities. Although photo-oxidation and mechanical abrasion enhance microbial colonization by increasing surface roughness and introducing oxygenated functional groups, overall degradation rates remain low in marine environments. Emerging mitigation strategies include biodegradable polymer alternatives, multifunctional catalytic and adsorptive materials, engineered microbial consortia, and integrated photo–biodegradation systems. Key research priorities include elucidating molecular degradation mechanisms, designing programmable degradable materials, and establishing AI-based monitoring frameworks. This review provides a concise foundation for developing ecologically safe and scalable approaches to PP-MP reduction and sustainable marine pollution management.