Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, 18 Jinfeng Road, Xiangzhou Distract, Zhuhai, 519087, Guangdong, China.
School of Environment, Beijing Normal University, Beijing, 100875, China.
Microb Ecol. 2023 Apr;85(3):904-915. doi: 10.1007/s00248-022-02053-1. Epub 2022 Jun 2.
Thermokarst lakes have long been recognized as biogeochemical hotspots, especially as sources of greenhouse gases. On the Qinghai-Tibet Plateau, thermokarst lakes are experiencing extensive changes due to faster warming. For a deep understanding of internal lake biogeochemical processes, we applied metagenomic analyses to investigate the microbial diversity and their biogeochemical roles in sediment and water of thermokarst lakes in the Yellow River Source Area (YRSA). Sediment microbial communities (SMCs) had lower species and gene richness than water microbial communities (WMCs). Bacteria were the most abundant component in both SMCs and WMCs with significantly different abundant genera. The functional analyses showed that both SMCs and WMCs had low potential in methanogenesis but strong in aerobic respiration, nitrogen assimilation, exopolyphosphatase, glycerophosphodiester phosphodiesterases, and polyphosphate kinase. Moreover, SMCs were enriched in genes involved in anaerobic carbon fixation, aerobic carbon fixation, fermentation, most nitrogen metabolism pathways, dissimilatory sulfate reduction, sulfide oxidation, polysulfide reduction, 2-phosphonopropionate transporter, and phosphate regulation. WMCs were enriched in genes involved in assimilatory sulfate reduction, sulfur mineralization, phosphonoacetate hydrolase, and phosphonate transport. Functional potentials suggest the differences of greenhouse gas emission, nutrient cycling, and living strategies between SMCs and WMCs. This study provides insight into the main biogeochemical processes and their properties in thermokarst lakes in YRSA, improving our understanding of the roles and fates of these lakes in a warming world.
热喀斯特湖长期以来一直被认为是生物地球化学热点，尤其是温室气体的源。青藏高原由于变暖速度加快，热喀斯特湖正在发生广泛变化。为了深入了解内部湖泊生物地球化学过程，我们应用宏基因组分析来研究黄河源区（YRSA）热喀斯特湖的沉积物和水中的微生物多样性及其生物地球化学作用。沉积物微生物群落（SMCs）的物种和基因丰富度低于水微生物群落（WMCs）。细菌是 SMCs 和 WMCs 中最丰富的成分，具有明显不同的丰富属。功能分析表明，SMCs 和 WMCs 都具有低产甲烷潜力，但好氧呼吸、氮同化、外多磷酸盐酶、甘油磷酸二酯磷酸二酯酶和多磷酸盐激酶的能力很强。此外，SMCs 富集了参与厌氧碳固定、好氧碳固定、发酵、大多数氮代谢途径、异化硫酸盐还原、硫化物氧化、多硫化物还原、2-膦丙酸盐转运蛋白和磷酸盐调节的基因。WMCs 富集了参与同化硫酸盐还原、硫矿化、膦乙酸水解酶和膦酸盐转运的基因。功能潜力表明 SMCs 和 WMCs 之间在温室气体排放、养分循环和生活策略方面存在差异。本研究深入了解了 YRSA 热喀斯特湖的主要生物地球化学过程及其性质，提高了我们对这些湖泊在变暖世界中的作用和命运的认识。
