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Updated: Jun 17, 2025

Bioprospecting of Extremophilic Microorganisms to Address Environmental Pollution
Published on: December 30, 2021
Enhancing biodegradation efficiency of PLA/PBAT-ST20 bioplastic using thermophilic bacteria co-culture system: New
Yizhan Qiu1, Pan Wang2, Luxi Zhang3
1School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing 100048, China; Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing 100048, China; Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Abstract:
The rising utilization of PLA/PBAT-ST20 presents potential ecological risks stemming from its casual disposal and incomplete degradation. To solve this problem, this study investigated the degradation capabilities of PLA/PBAT-ST20 by a co-culture system comprising two thermophilic bacteria, Pseudomonas G1 and Kocuria G2, selected and identified from the thermophilic phase of compost. Structural characterization results revealed that the strains colonized the PLA/PBAT-ST20's surface, causing holes and cracks, with an increase in the carbonyl index (CI) and polydispersity index (PDI), indicating oxidative degradation. Enzyme activity results demonstrated that the co-culture system significantly enhanced the secretion and activity of proteases and lipases, promoting the breakdown of ester bonds. LC-QTOF-MS results showed that various intermediate products were obtained after degradation, ultimately participating in the TCA cycle (ko00020), further completely mineralized. Additionally, after 15-day compost, the co-culture system achieved a degradation rate of 72.14 ± 2.1 wt% for PBAT/PLA-ST20 films, with a decrease in the abundance of plastic fragments of all sizes, demonstrating efficient degradation of PLA/PBAT-ST20 films. This study highlights the potential of thermophilic bacteria to address plastic pollution through biodegradation and emphasizes that the co-culture system could serve as an ideal solution for the remediation of PLA/PBAT plastics.

