Yang Guiqin, Quan Xiaoyun, Shou Danyang, Guo Xin, Ouyang Dongkun, Zhuang Li
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) and Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, College of Environment and Climate, Jinan University, Guangzhou 511443, China.
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) and Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, College of Environment and Climate, Jinan University, Guangzhou 511443, China.
J Hazard Mater. 2025 Mar 15;486:137061. doi: 10.1016/j.jhazmat.2024.137061. Epub 2024 Dec 31.
Microplastics (MPs) are widely distributed pollutants in various ecosystems, and biodegradation is a crucial process for removal of MPs from environments. Pearl River Estuary, one of the largest estuaries in China, is an important reservoir for MPs with polyethylene MPs (PE-MPs) as the most abundant MPs. Here, biodegradation of PE-MPs and the potential PE-degrading bacteria in sediments of eight major outlets of Pearl River Estuary were firstly investigated. Results showed that biodegradation extent of PE-MPs varied for different sourced sediments, with highest extent for Hongqimen sediment and lowest extent for Jitimen sediment. Selective enrichment of specific bacteria occurred on PE-MPs with Pseudomonadaceae as the predominant family. Potential PE-degrading bacteria of Pseudomonas, Vulcaniibacterium, Cupriavidus, Bacillus were selectively enriched on PE-MPs and their abundance showed positive correlations with degradation extent of PE-MPs, indicating a vital role of them in degrading PE-MPs. Diverse pure cultured strains affiliated to the genera Bacillus, Pseudomonas, Priestia, Lysinibacillus, Marinobacter, Stutzerimonas and Achromobacter isolated from the plastispheres were capable of degrading PE-MPs rapidly, and members in Bacillus showed highest efffeciency of PE-MPs degradation with 6.5 % weight loss of PE-MPs within 40 days. This study provides a new perspective on the natural degradation potential by microbial communities in sediments.
微塑料（MPs）是广泛分布于各种生态系统中的污染物，生物降解是从环境中去除微塑料的关键过程。珠江口是中国最大的河口之一，是微塑料的重要储存地，其中聚乙烯微塑料（PE-MPs）是含量最丰富的微塑料。在此，首次对珠江口八个主要出海口沉积物中PE-MPs的生物降解及潜在的PE降解细菌进行了研究。结果表明，不同来源沉积物中PE-MPs的生物降解程度不同，其中洪奇门沉积物的生物降解程度最高，鸡啼门沉积物的生物降解程度最低。在以假单胞菌科为主要菌科的PE-MPs上发生了特定细菌的选择性富集。假单胞菌、火山硫化叶菌、贪铜菌、芽孢杆菌等潜在的PE降解细菌在PE-MPs上被选择性富集，其丰度与PE-MPs的降解程度呈正相关，表明它们在降解PE-MPs中起着至关重要的作用。从塑料球中分离出的多种纯培养菌株，隶属于芽孢杆菌属、假单胞菌属、Priestia属、赖氨酸芽孢杆菌属、海杆菌属、施氏假单胞菌属和无色杆菌属，能够快速降解PE-MPs，其中芽孢杆菌属成员对PE-MPs的降解效率最高，在40天内PE-MPs的重量损失达6.5%。本研究为沉积物中微生物群落的自然降解潜力提供了新的视角。
