State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
Peking University Shenzhen Institute, Shenzhen, Guangdong 518057, China; PKU-HKUST Shenzhen-Hongkong Institution, Shenzhen, Guangdong 518057, China.
Sci Total Environ. 2024 Dec 1;954:176576. doi: 10.1016/j.scitotenv.2024.176576. Epub 2024 Sep 27.
Plastisphere, characterized by microbial colonization on plastic debris, has attracted concern with its adverse environmental effects. The microbial features have been increasingly investigated; however, there lacks direct evidence for microplastics serving as carbon sources and enriching plastic-degrading microorganisms. Here, we obtained microbial communities from soil microplastics, analyzed the dissimilarity compared with soil, and characterized the plastic-degrading potential of isolates from plastisphere. Results showed the plastisphere communities significantly differed from soil communities and exhibited a higher relative abundance of Nocardia and Rhodococcus. To verify the selective enrichment of plastic-degrading microorganisms in the plastisphere, culture-based strategies were employed to evaluate the polyethylene (PE) degradation potential of two isolates Nocardia asteroides No.11 and Rhodococcus hoagii No.17. They could grow solely on PE and led to significant weight loss. FTIR and SEM analysis revealed the formation of new functional groups and the destruction of structural integrity on PE surfaces. Genes related to PE biodegradation were identified by genome-wide sequencing thus recognizing relevant enzymes and elucidating potential pathways. Overall, this report combined culture-free and culture-based approaches to confirm the plastic degradation potential of selectively enriched microorganisms in soil plastisphere, providing a positive perspective toward promoting microplastic biodegradation in farmland soil by enhancing natural microbial processes.
塑膠球層，特徵為微生物在塑膠碎片上的定殖，因其對環境的不良影響而引起關注。微生物的特徵已越來越受到研究；然而，缺乏微塑膠作為碳源並富集塑膠降解微生物的直接證據。在本研究中，我們從土壤微塑膠中獲取微生物群落，分析其與土壤的差異，並特徵化源自塑膠球層的塑膠降解菌的潛力。研究結果表明，塑膠球層群落明顯有別於土壤群落，並表現出更高相對豐度的節球菌和紅球菌。為了驗證塑膠球層中塑膠降解微生物的選擇性富集，我們採用基於培養的策略來評估兩株分離菌節球菌（Nocardia asteroides No.11）和紅球菌（Rhodococcus hoagii No.17）對聚乙烯（PE）的降解潛力。它們只能在 PE 上生長，並導致明顯的重量減輕。FTIR 和 SEM 分析揭示了新功能團的形成和 PE 表面結構完整性的破壞。透過全基因組測序識別與 PE 生物降解相關的基因，從而識別相關酶並闡明潛在途徑。總之，本報告結合無培養和基於培養的方法來確認土壤塑膠球層中選擇性富集微生物的塑膠降解潛力，為通過增強自然微生物過程來促進農田土壤中的微塑膠生物降解提供了積極的觀點。
