Shao Keqiang, Qin Boqiang, Chao Jianying, Gao Guang
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Ministry of Environmental Protection, Nanjing Institute of Environmental Sciences, Nanjing 210042, China.
Microorganisms. 2023 Oct 30;11(11):2669. doi: 10.3390/microorganisms11112669.
Bacterial communities inhabiting alpine lakes are essential to our understanding of ecosystem processes in a changing climate, but little has been reported about the vertical patterns of sediment bacterial communities in alpine lakes. To address this knowledge gap, we collected the 100 cm long sediment core from the center of Lake Sayram, the largest alpine lake in Xinjiang Uygur autonomous area, China, and used 16S rRNA gene-targeted amplicon sequencing to examine the bacterial populations. The results showed that bacterial diversity, as estimated by the Shannon index, was highest at the surface (6.9849 at 0-4 cm) and gradually decreased with depth up to 3.9983 at 68-72 cm, and then increased to 5.0927 at 96-100 cm. A total of 56 different phyla and 1204 distinct genera were observed in the sediment core of Lake Sayram. The bacterial community structure in the sediment samples from the various layers was dissimilar. The most abundant phyla in alpine Lake Sayram were , , and , accounting for 73%, 6%, and 4% of the total reads, respectively; the most abundant genera were , , and , accounting for 18%, 12%, and 8% of the total reads, respectively. Furthermore, the relative abundance of increased with sediment depth, while the relative abundance of and decreased with sediment depth. Our findings indicated that the nitrate-reducing bacteria (, , and ) may be prevalent in the sediment core of Lake Sayram. Canonical correspondence analysis showed that carbonate and total organic carbon (TOC) may be the main environmental factors affecting the vertical patterns of bacterial community composition (BCC) in the sediment of Lake Sayram. This work significantly contributes to our understanding of the BCC of sediments from alpine lakes in arid and semiarid regions.
栖息在高山湖泊中的细菌群落对于我们理解气候变化下的生态系统过程至关重要，但关于高山湖泊沉积物细菌群落的垂直分布模式的报道却很少。为了填补这一知识空白，我们从中国新疆维吾尔自治区最大的高山湖泊赛里木湖中心采集了100厘米长的沉积物岩芯，并使用靶向16S rRNA基因的扩增子测序来检测细菌种群。结果表明，以香农指数估算的细菌多样性在表层最高（0 - 4厘米处为6.9849），并随深度逐渐降低，在68 - 72厘米处降至3.9983，然后在96 - 100厘米处又升至5.0927。在赛里木湖的沉积物岩芯中共观察到56个不同的门和1204个不同的属。不同层沉积物样品中的细菌群落结构不同。高山赛里木湖沉积物中最丰富的门分别是 、 和 ，分别占总读数的73%、6%和4%；最丰富的属分别是 、 和 ，分别占总读数的18%、12%和8%。此外， 的相对丰度随沉积物深度增加，而 和 的相对丰度随沉积物深度降低。我们的研究结果表明，硝酸盐还原细菌（ 、 和 ）可能在赛里木湖的沉积物岩芯中普遍存在。典范对应分析表明，碳酸盐和总有机碳（TOC）可能是影响赛里木湖沉积物中细菌群落组成（BCC）垂直分布模式的主要环境因素。这项工作对于我们理解干旱和半干旱地区高山湖泊沉积物的BCC有显著贡献。
