Aug 2026· Journal of Polymers and the Environment· Vol 34· 0 citations· 86 references
TL;DR
Temperature and inoculum composition jointly shaped bacterial community assembly and predicted PBAT degradation-related functional potential and provide a microbial ecological basis for temperature- and inoculum-guided enrichment strategies to improve PBAT biodegradation and biodegradable plastic waste treatment.
Abstract
Polybutylene adipate terephthalate (PBAT) is a widely used biodegradable plastic, but its microbial degradation mechanisms and environmental responses remain poorly understood. In this study, two compost inocula (K and I) were used to establish PBAT enrichment cultures under mesophilic (35 °C, M) and thermophilic (58 °C, T) conditions, and the effects of temperature and inoculum source on bacterial community structure and PICRUSt2-derived predicted functional profiles were investigated. Surface analyses revealed cracking, erosion, and structural collapse of PBAT under all conditions, with more pronounced degradation in compost I-derived cultures. Microbial diversity decreased during enrichment, accompanied by dominance of specific genera. Under mesophilic conditions, Pseudoxanthomonas dominated (72.6%–91.0%) and showed strong positive correlations with predicted ester bond hydrolysis-related KOs (p < 0.05), suggesting a potential association with initial hydrolysis. Under thermophilic conditions, compost K cultures were dominated by Thermoflavifilum and Rhodothermus, which were mainly associated with predicted hydrolysis-related KOs, whereas compost I cultures were dominated by Thermoflavifilum and Thermopolyspora and showed stronger associations with predicted KOs related to adipate and terephthalic acid metabolism. Predicted aromatic intermediate metabolism-related KOs, including K04101, K01055, and K01607, were also higher in compost I-derived thermophilic cultures. Overall, temperature and inoculum composition jointly shaped bacterial community assembly and predicted PBAT degradation-related functional potential. Thermophilic conditions combined with compost I were associated with functionally differentiated bacterial communities and higher predicted potential for downstream PBAT-derived intermediate metabolism. These findings provide a microbial ecological basis for temperature- and inoculum-guided enrichment strategies to improve PBAT biodegradation and biodegradable plastic waste treatment.
Polybutylene adipate terephthalate (PBAT) is prone to incomplete degradation, leading to environmental pollution and carbon resource waste. Biodegradation and valorization of waste plastics are essential for addressing plastic pollution and promoting a circular economy. Enzymatic degradation offers advantages, but free enzymes suffer from low stability and poor recyclability. Here, surface display technology was used to construct a cutinase Tfcut-DM display system in Escherichia coli BL21(DE3). The results showed that surface display significantly enhanced the stability and reusability of Tfcut-DM. Compared with free enzymes, its thermostability and pH stability increased by 11.9-fold and 42.1-fold, respectively, and approximately 80% of initial activity was retained after seven reuse cycles. Under optimized conditions, the surface-displayed strain released 255.9 µM of terephthalic acid (TPA) from PBAT films over 5 days, with near-complete degradation. To enable TPA valorization , the tph operon was introduced to C. necator H16 (CnH16-tph) for TPA-to-PHB conversion. A co-culture system comprising the surface-displayed strain and CnH16-tph was established for proof-of-concept one-pot conversion of PBAT to PHB. PHB accumulation is indirectly attributed to the TPA derived from PBAT degradation. Under optimized conditions, the maximum PHB yield reached 0.91 g/L. While isotopic tracing would be required for definitive carbon flux assignment, this indirect evidence strongly suggests the successful conversion of PBAT-derived TPA to PHB. This study provides a novel approach for the green degradation and resource utilization of waste PBAT, facilitating the recycling of discarded resources.
Jiali Liu, Jie Yang, Xin Wang et al.· Bioresource Technology· 0 citations
Biodegradable plastics like polybutylene adipate terephthalate (PBAT) are increasingly marketed as alternatives to conventional plastics, yet how soil properties regulate degradation kinetics, how intact films and microplastic fragments differentially affect microbial communities, and which metabolic pathways and functional genes govern mineralization remain unclear. The present study investigated PBAT degradation mechanisms in 10 distinct agricultural soils by integrating metagenomics, microbial community analysis, and strain isolation. The results revealed that the environmental fate of PBAT is critically modulated by soil properties. Neutral-alkaline powdery loam soils exhibited the highest degradation efficiency. Soil physicochemical properties indirectly modulate PBAT weight loss by altering the gene abundance of hydrolases and aromatic-degrading enzymes, with soil nitrogen content serving as a key regulatory factor. Metagenomic correlation analysis suggests that PBAT degradation is associated with specific microbial consortia, including Hydrogenophaga and Ascomycota fungi. Microplastic particles of PBAT induced greater disturbances than intact films, as evidenced by significant reductions in microbial diversity, altered community structure, and shifts in functional gene composition. A complete degradation pathway, including initial polymer cleavage followed by terephthalic acid assimilation via the β-ketoadipate pathway, was elucidated. These results provide mechanistic insights into soil-specific PBAT degradation and facilitate risk assessment and sustainable management of biodegradable plastics.
Xin-Yu Zhang, Jia-Hui Yuan, Lu-Ke Wang et al.· Environmental Science &...· 0 citations
Though biodegradable plastics have been widely developed as sustainable alternatives to petroleum-based plastics, their degradation behavior and microbial interactions in composting environments remain insufficiently understood. In this study, the degradation characteristics of polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS), and the interactions between bacterial communities and functional genes, were evaluated in a 41-day aerobic composting system using anaerobically digested sewage sludge as substrate. Composting parameters were similarly affected by all biodegradable plastics, and the final compost reached a Solvita compost maturity index of 8.0 with no detectable pathogenic bacteria and a CO2 index of 7.83, indicating stable composting. After 41 days of composting, microcracks and microbial attachment were observed on all biodegradable plastic surfaces, with PHB and PBAT showing the most pronounced structural damage and biofilm formation, whereas microbial attachment to PLA was limited. Although biodegradable plastic addition did not greatly alter the overall bacterial community structure, it selectively promoted specific bacterial genera (Symbiobacterium, Paenibacillus, and Psychrobacillus). PICRUSt2-based functional gene prediction revealed that PHB degradation-related genes exhibited the highest predicted abundance, whereas PLA- and PBS-related genes showed low abundance, indicating differences in functional degradation potential among plastic types. Positive correlations among esterase- and hydrolase-related genes under biodegradable plastic-amended conditions suggest that coordinated microbial functional responses to biodegradable plastic addition. Network analysis further indicated that biodegradable plastic addition influenced interactions between specific bacterial genera and degradation-related functional genes. Overall, this study provides insights into bacterial functional adaptation during biodegradable plastic degradation under aerobic composting conditions.
Soo-Ye-On Lee, Subin Hwang, Ian Cho et al.· Biodegradation· 0 citations
An association-based multi-module framework of candidate traits linked to Calditerricola persistence during HC is defined, providing a genome-resolved basis for prioritizing testable thermotolerance targets in engineered high-temperature waste-treatment systems.
Xu Li, Zhengnan Zhu, Youzhao Wang et al.· Bioresource Technology· 0 citations
Soil microbial community dynamics are closely linked to ecosystem functions and responses to environmental stress. This study aimed to investigate the impacts of incubation time and different treatment conditions (CK, CK60, and PLA60) on soil bacterial community structure, diversity, and potential metabolic functions. A 60-day microcosm incubation experiment was conducted, comprising polylactic acid (PLA)-amended soil and blank controls. Metagenomic sequencing revealed that PLA exposure significantly altered both the structure and function of the soil microbial community. Over time, the Pseudomonadota phylum became significantly enriched, and the genus Sphingomonas emerged as the dominant genus. Alpha-diversity (Shannon index) decreased in PLA-treated soils, while beta-diversity (PCA) demonstrated distinct separation among treatment groups.Functional predictions indicate that PLA processing drives functional remodeling of the microbial community to adapt to environmental stress by synergistically activating core energy metabolic pathways such as bacterial glycolysis and the tricarboxylic acid cycle. The time effect and PLA treatment jointly drove the restructuring of the soil bacterial community.
Haoran Liu, Zi-Xuan Zhang, Yani Wang et al.· E3S Web of Conferences· 0 citations
Addressing the limitations of existing studies that predominantly isolate Tetrabromobisphenol A (TBBPA)-degrading bacteria from contaminated environments and focus on degradation characteristics, this study employed multi-omics approaches to systematically elucidate the dynamic succession patterns and metabolic adaptation mechanisms of microbial communities from pristine soil under acute TBBPA stress, and achieved rapid screening of functional degraders. The results showed that TBBPA concentration and exposure time jointly drove community structural reconstruction, in which Methylobacillus and Pannonibacter, owing to their strong tolerance and high abundance, emerged as potential core degraders. Functional analysis indicated that high-concentration TBBPA (200 mg/L) reduced the abundance of the DLD gene by nearly 60%, whereas the community effectively alleviated energy metabolism inhibition through upregulation of upstream tricarboxylic acid cycle genes (CS, IDH3, and ACO) and respiratory chain functional genes (ccoN and ccoO), and formed a more tightly connected interaction network to enhance functional synergy. Metabolomic analysis revealed significant accumulation of membrane repair-related lipids (Gpetn and Lysopa) and amino acids (Norleucine and L-Phenylalanine), while pathways related to ABC transporters were activated, jointly confirming a stress adaptation mechanism centered on membrane repair and defense responses in the microbial community. The degradation process exhibited a multi-enzyme synergistic characteristic, with glutathione S-transferase playing a dominant role. After acclimation, the degradation efficiency of the microbial community was significantly improved, and the key strain Acinetobacter sp. T3 was successfully isolated. This study provides a theoretical basis and soil microbial communities for the development of in situ bioremediation technologies targeting persistent organic pollutants (POPs).
Liangjie Li, Panlin He, Jiawei Jiang et al.· Journal of Hazardous Materia...· 0 citations
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