Xie Zhen, Li Wei, Yang Kaiwen, Wang Xinze, Xiong Shunzi, Zhang Xiaojun
State Key Laboratory of Microbial Metabolism, and Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
National Observation and Research Station of Erhai Lake Ecosystem in Yunnan, Dali 671000, China.
Microorganisms. 2024 Aug 8;12(8):1617. doi: 10.3390/microorganisms12081617.
The littoral zones of lakes are potential hotspots for local algal blooms and biogeochemical cycles; however, the microbial communities within the littoral sediments of eutrophic plateau lakes remain poorly understood. Here, we investigated the taxonomic composition, co-occurrence networks, and potential functional roles of both abundant and rare taxa within bacterial and archaeal communities, as well as physicochemical parameters, in littoral sediments from Erhai Lake, a mesotrophic lake transitioning towards eutrophy located in the Yunnan-Guizhou Plateau. 16S rRNA gene sequencing revealed that bacterial communities were dominated by Proteobacteria, Bacteroidetes, and Chloroflexi, while Euryarchaeota was the main archaeal phylum. Co-occurrence network analysis revealed that keystone taxa mainly belonged to rare species in the bacterial domain, but in the archaeal domain, over half of keystone taxa were abundant species, demonstrating their fundamental roles in network persistence. The rare bacterial taxa contributed substantially to the overall abundance (81.52%), whereas a smaller subset of abundant archaeal taxa accounted for up to 82.70% of the overall abundance. Functional predictions highlighted a divergence in metabolic potentials, with abundant bacterial sub-communities enriched in pathways for nitrogen cycling, sulfur cycling, and chlorate reduction, while rare bacterial sub-communities were linked to carbon cycling processes such as methanotrophy. Abundant archaeal sub-communities exhibited a high potential for methanogenesis, chemoheterotrophy, and dark hydrogen oxidation. Spearman correlation analysis showed that genera such as , , , , and may serve as potential indicators of eutrophication. Overall, this study provides insight into the distinct roles that rare and abundant taxa play in the littoral sediments of mesotrophic plateau lakes.
湖泊的沿岸带是局部藻类大量繁殖和生物地球化学循环的潜在热点；然而，富营养化高原湖泊沿岸沉积物中的微生物群落仍知之甚少。在此，我们调查了位于云贵高原、正从中营养向富营养转变的洱海沿岸沉积物中细菌和古菌群落内丰富和稀有分类群的分类组成、共现网络及潜在功能作用，以及理化参数。16S rRNA基因测序表明，细菌群落以变形菌门、拟杆菌门和绿弯菌门为主，而广古菌门是主要的古菌门。共现网络分析表明，关键分类群在细菌域主要属于稀有物种，但在古菌域，超过半数的关键分类群是丰富物种，这表明它们在网络持久性中发挥着重要作用。稀有细菌分类群对总丰度贡献很大（81.52%），而一小部分丰富的古菌分类群占总丰度的比例高达82.70%。功能预测突出了代谢潜力的差异，丰富的细菌亚群落富含氮循环、硫循环和氯酸盐还原途径，而稀有细菌亚群落与甲烷营养等碳循环过程有关。丰富的古菌亚群落表现出较高的甲烷生成、化学异养和暗氢氧化潜力。Spearman相关性分析表明，诸如[此处原文缺失具体属名]等属可能是富营养化的潜在指标。总体而言，本研究深入了解了稀有和丰富分类群在中营养高原湖泊沿岸沉积物中所起的不同作用。
