Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.
Sci Total Environ. 2022 Oct 1;841:156468. doi: 10.1016/j.scitotenv.2022.156468. Epub 2022 Jun 2.
Cable bacteria are a group of recently found filamentous sulfide-oxidizing Desulfobulbaceae that significantly impact biogeochemical cycling. However, the limited understanding of cable bacteria distribution patterns and the driving force hindered our abilities to evaluate and maximize their contribution to environmental health. We evaluated cable bacteria assemblages from ten river sediments in the Pearl River Delta, China. The results revealed a clear biogeographic distribution pattern of cable bacteria, and their communities were deterministically assembled through water quality-driven selection. Cable bacteria are diverse in the river sediments with a few generalists and many specialists, and the water quality IV and V environments are the "hot spot." We then provided evidence on their morphology, function, and genome to demonstrate how water quality might shape the cable bacteria assemblages. Reduced cell width, inhibited function, and water quality-related adaptive genomic traits were detected in sulfide-limited water quality III and contaminant-stressed water quality VI environments. Specifically, those genomic traits were contributed to carbon and sulfur metabolism in the water quality III environment and stress resistance in the water quality VI environment. Overall, these findings provided a helpful baseline in evaluating the contribution of cable bacteria in the freshwater ecosystem and suggested that their high diversity and flexibility in phylogeny, morphology, and genome allowed them to adapt and contribute to various environmental conditions.
电缆细菌是一组最近发现的丝状硫氧化脱硫杆菌科，它们对生物地球化学循环有重大影响。然而，对电缆细菌分布模式和驱动因素的了解有限，阻碍了我们评估和最大限度发挥其对环境健康贡献的能力。我们评估了来自中国珠江三角洲的 10 个河流沉积物中的电缆细菌组合。结果表明，电缆细菌具有明显的生物地理分布模式，其群落通过水质驱动的选择而确定性地组装。电缆细菌在河流沉积物中种类繁多，既有少数的通才，也有许多的专家，而水质 IV 和 V 环境是“热点”。然后，我们提供了有关它们的形态、功能和基因组的证据，以证明水质如何塑造电缆细菌组合。在硫化物受限的水质 III 和受污染物胁迫的水质 VI 环境中，检测到细胞宽度减小、功能受到抑制以及与水质相关的适应性基因组特征。具体而言，这些基因组特征有助于水质 III 环境中的碳和硫代谢以及水质 VI 环境中的应激抵抗。总的来说，这些发现为评估电缆细菌在淡水生态系统中的贡献提供了有益的基线，并表明它们在系统发生、形态和基因组方面的高度多样性和灵活性使它们能够适应和为各种环境条件做出贡献。
