Microbial conversion of PHA to bioplastic precursors using anaerobic thermophiles

Overview

This research program develops microbial cultures and consortia of anaerobic thermophilic clostridia capable of breaking down polyhydroxyalkanoate (PHA) biodegradable plastics and converting the resulting monomers into useful bioplastic precursors, including succinate. By working at elevated temperatures, these organisms achieve rapid polymer degradation rates, creating a biological route to recover value from end-of-life biodegradable plastics and feed it back into bioplastic manufacturing. The work supports circular-economy goals for sustainable materials and offers a fermentation-based alternative to conventional chemical recycling.

Technical specifications

Core approach:

• Construction of defined co-cultures from anaerobic thermophilic clostridial isolates sourced from biocompost
• Biological depolymerization of PHA materials followed by fermentation to platform chemicals such as succinate

Key capabilities of the organism collection:

• Thermophilic clostridia with broad catabolic enzyme repertoires confirmed by genome sequencing, enabling degradation of complex biopolymers including lignocellulose and PHA
• Ability to convert polymer-derived sugars into lactic acid, succinic acid, and other useful products
• Preliminary co-culture data showing increased net succinate production without sacrificing cellulose-depolymerization activity

Validation strategy:

• Batch growth experiments across a range of PHA concentrations in two standard media, testing isolates as monocultures and as co-cultures
• PHA "trap" enrichment in thermophilic compost to capture and isolate novel PHA-degrading specialists
• Microbial community analysis to inventory organisms involved in PHA breakdown and guide downstream culturing
• Comparative testing of newly isolated specialists against existing collection isolates

Technology readiness level

The program is at an early-to-mid research stage. Genome sequencing of promising candidate isolates is complete, and preliminary co-culture experiments have demonstrated proof-of-concept for enhanced succinate production alongside polymer degradation. Current and planned work focuses on systematically characterizing isolate capabilities against PHA substrates and expanding the organism collection through targeted enrichment from thermophilic compost, representing validation at the laboratory-bench scale prior to process development.