Xu Fei, Zhu Lanping, Wang Jiaying, Xue Yuqin, Liu Kunhe, Zhang Fubin, Zhang Tuo
College of Environmental Science and Engineering, China West Normal University, Nanchong, 637002, China.
Institute of Nature and Ecology, Heilongjiang Academy of Sciences, Harbin, 150040, China.
Microb Ecol. 2023 May;85(4):1308-1322. doi: 10.1007/s00248-022-02009-5. Epub 2022 Apr 13.
Nonpoint source pollution (NPSP) from human production and life activities causes severe destruction in river basin environments. In this study, three types of sediment samples (A, NPSP tributary samples; B, non-NPSP mainstream samples; C, NPSP mainstream samples) were collected at the estuary of the NPSP tributaries of the Jialing River. High-throughput sequencing of the fungal-specific internal transcribed spacer (ITS) gene region was used to identify fungal taxa. The impact of NPSP on the aquatic environment of the Jialing River was revealed by analysing the community structure, community diversity, and functions of sediment fungi. The results showed that the dominant phylum of sediment fungi was Rozellomycota, followed by Ascomycota and Basidiomycota (relative abundance > 5%). NPSP caused a significant increase in the relative abundances of Exosporium, Phialosimplex, Candida, Inocybe, Tausonia, and Slooffia, and caused a significant decrease in the relative abundances of Cercospora, Cladosporium, Dokmaia, Setophaeosphaeria, Paraphoma, Neosetophoma, Periconia, Plectosphaerella, Claviceps, Botrytis, and Papiliotrema. These fungal communities therefore have a certain indicator role. In addition, NPSP caused significant changes in the physicochemical properties of Jialing River sediments, such as pH and available nitrogen (AN), which significantly increased the species richness of fungi and caused significant changes in the fungal community β-diversity (P < 0.05). pH, total phosphorus (TP), and AN were the main environmental factors affecting fungal communities in sediments of Jialing River. The functions of sediment fungi mainly involved three types of nutrient metabolism (symbiotrophic, pathotrophic, and saprotrophic) and 75 metabolic circulation pathways. NPSP significantly improved the pentose phosphate pathway, pentose phosphate pathway, and fatty acid beta-oxidation V metabolic circulation pathway functions (P < 0.05) and inhibited the chitin degradation to ethanol, super pathway of heme biosynthesis from glycine, and adenine and adenosine salvage III metabolic circulation pathway functions (P < 0.05). Hence, NPSP causes changes in the community structure and functions of sediment fungi in Jialing River and has adversely affected for the stability of the Jialing River Basin ecosystem.
人类生产生活活动产生的非点源污染（NPSP）对流域环境造成了严重破坏。本研究在嘉陵江NPSP支流河口采集了3种类型的沉积物样本（A，NPSP支流样本；B，非NPSP干流样本；C，NPSP干流样本）。利用真菌特异性内部转录间隔区（ITS）基因区域的高通量测序来鉴定真菌分类群。通过分析沉积物真菌的群落结构、群落多样性和功能，揭示了NPSP对嘉陵江水环境的影响。结果表明，沉积物真菌的优势门为罗兹菌门，其次是子囊菌门和担子菌门（相对丰度>5%）。NPSP导致外生孢子菌属、简单瓶梗霉属、念珠菌属、丝盖伞属、陶氏菌属和斯洛菲属的相对丰度显著增加，导致尾孢菌属、枝孢属、多克迈属、顶球腔菌属、拟茎点霉属、新拟茎点霉属、佩里壳属、褶丝孢属、麦角菌属、葡萄孢属和帕皮利奥曲霉属的相对丰度显著降低。因此，这些真菌群落具有一定的指示作用。此外，NPSP导致嘉陵江沉积物的理化性质发生显著变化，如pH值和有效氮（AN），显著增加了真菌的物种丰富度，并导致真菌群落β多样性发生显著变化（P<0.05）。pH值、总磷（TP）和AN是影响嘉陵江沉积物中真菌群落的主要环境因素。沉积物真菌的功能主要涉及三种营养代谢类型（共生营养、致病营养和腐生营养）和75条代谢循环途径。NPSP显著改善了磷酸戊糖途径、磷酸戊糖途径和脂肪酸β氧化V代谢循环途径的功能（P<0.05），并抑制了几丁质降解为乙醇、甘氨酸血红素生物合成的超级途径以及腺嘌呤和腺苷补救III代谢循环途径的功能（P<0.05）。因此，NPSP导致嘉陵江沉积物真菌的群落结构和功能发生变化，对嘉陵江流域生态系统的稳定性产生了不利影响。
