A critical review on temperature-mediated marine plastic biodegradation

Biodegradation offers a promising solution to marine plastic pollution. Temperature plays a significant role in biofilm development and microbial dynamics. However, comprehensive studies on the effects of temperature on marine plastic biodegradation remain limited, as most research focuses on individual and moderate temperatures, overlooking how temperature variations across polar to tropical marine environments interact with other ecological factors to influence plastic biodegradation. This review summarizes current research on temperature-induced biofilm formation, microbial succession, and enzymatic depolymerization of plastics. The findings reveal that higher temperatures generally enhance biofilm growth. Notably, cold-tolerant bacteria stimulate the production of extracellular polymeric substances (EPS) to stabilize biofilms and adapt to cold conditions. Microbial succession, particularly within the Proteobacteria phylum, is primarily regulated by temperature, driving shifts in microbial diversity and activity. For different types of plastics, the hydrolyzable ones are degraded via enzymes such as cutinases, lipases, and depolymerases, mostly at mild temperatures. In contrast, non-hydrolyzable plastics are relatively recalcitrant to enzymatic breakdown but can be biodeteriorated by enzyme-generated reactive oxygen species (ROS), with minimal temperature influence due to their slow biodegradation. This review emphasizes the critical role of temperature in biodegradation processes and prospects for promising strategies for improving marine plastic management under the changing climate.