班公湖水体细菌多样性和群落分布格局

Diversity and distribution patterns of bacteria in Bangong Lake

摘要:

【背景】 细菌是湖泊生态系统中的主要驱动者，其群落结构会对湖泊的环境变化产生高度响应。班公湖地区特殊的地理位置和高海拔环境造就了其独特的微生物生态系统，目前鲜见对班公湖细菌的研究。【目的】 探究班公湖水体细菌多样性和群落分布格局，于2023年9月对阿里地区班公湖东岸、西岸、湖心、湖底4个区域共计20个样点进行采样。【方法】 基于16S rRNA基因高通量测序技术进行样品分析，通过α多样性分析认识细菌群落之间的差异，利用Spearman相关系数衡量班公湖水体理化因子与α多样性指数之间的相关性。【结果】 共得到14 886条OTU，已注释的OTU分别属于47门470属。班公湖水体细菌群落主要由变形菌门(Proteobacteria)、放线菌门(Actinomycetota)、拟杆菌门(Bacteroidota)和疣微菌门(Verrucomicrobiota)组成。α多样性指数分析显示，班公湖水体细菌群落多样性和丰富度均较高，群落结构较为复杂。Spearman相关系数表明，总磷(total phosphorus, TP)与电导率(electric conductivity, EC)是影响班公湖水体细菌的主要环境因子。【结论】 阐明了班公湖水体细菌群落多样性和分布格局，并揭示了水体理化因子对细菌群落的影响，为未来班公湖的收缩或扩张变化后的水体细菌群落动态研究提供参考依据。

关键词:高原湖泊;班公湖;细菌;多样性;群落结构

Abstract:

[Background] Bacteria are the main drivers in lake ecosystems, and their community structure is highly responsive to the environmental changes in the lake. The special geographical location and high altitude environment of Bangong Lake have shaped a unique microbial ecosystem. However, little is known about the bacteria in this lake. [Objective] To explore the bacterial diversity and distribution pattern in Bangong Lake in the Ali region, we collected samples at 20 sites in the east bank, west bank, center, and bottom of this lake in September 2023. [Methods] The 16S rDNA high-throughput sequencing was performed for the samples, and the α diversity of the microorganisms was measured. The Spearman’s correlation analysis was conducted between the physicochemical properties of water and the α diversity of microorganisms. [Results] A total of 14 886 operational taxonomic units (OTUs) were yielded, indicating 470 genera of 47 phyla. The bacterial community in Bangong Lake was mainly composed of Proteobacteria, Actinomycetota, Bacteroidota, and Verrucomicrobiota. The community had high diversity and richness, with a complex structure. The Spearman correlation coefficient indicated that total phosphorus and electrical conductivity were the main environmental factors affecting the bacteria in Bangong Lake. [Conclusion] This paper clarifies the diversity and distribution pattern of bacteria in Bangong Lake and reveals the water physicochemical factors influencing the bacterial community. The findings provide a reference for studying the dynamics of bacteria after the narrowing or expansion of Bangong Lake in the future.

Key words:plateau lakes;Bangong Lake;bacteria;diversity;community structure