Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Department of Microorganisms, Braunschweig, Germany.
Technical University of Braunschweig, Institute of Microbiology, Braunschweig, Germany.
Nat Commun. 2023 Oct 10;14(1):6337. doi: 10.1038/s41467-023-42074-z.
Sulfate-reducing microorganisms represent a globally important link between the sulfur and carbon cycles. Recent metagenomic surveys expanded the diversity of microorganisms putatively involved in sulfate reduction underscoring our incomplete understanding of this functional guild. Here, we use genome-centric metatranscriptomics to study the energy metabolism of Acidobacteriota that carry genes for dissimilation of sulfur compounds in a long-term continuous culture running under alternating anoxic and oxic conditions. Differential gene expression analysis reveals the unique metabolic flexibility of a pectin-degrading acidobacterium to switch from sulfate to oxygen reduction when shifting from anoxic to oxic conditions. The combination of facultative anaerobiosis and polysaccharide degradation expands the metabolic versatility among sulfate-reducing microorganisms. Our results highlight that sulfate reduction and aerobic respiration are not mutually exclusive in the same organism, sulfate reducers can mineralize organic polymers, and anaerobic mineralization of complex organic matter is not necessarily a multi-step process involving different microbial guilds but can be bypassed by a single microbial species.
硫酸盐还原微生物是硫循环和碳循环之间具有全球重要意义的联系。最近的宏基因组调查扩大了可能参与硫酸盐还原的微生物多样性，突出了我们对这一功能类群理解的不完整性。在这里，我们使用基于基因组的宏转录组学来研究在长期连续培养中，在交替缺氧和有氧条件下运行时，携带异化硫化合物基因的 Acidobacteriota 的能量代谢。差异基因表达分析揭示了一种果胶降解嗜酸菌的独特代谢灵活性，当从缺氧条件转变为有氧条件时，它可以从硫酸盐还原切换到氧气还原。兼性厌氧和好氧呼吸的结合扩展了硫酸盐还原微生物的代谢多功能性。我们的结果强调了在同一生物体中，硫酸盐还原和需氧呼吸并非相互排斥的，硫酸盐还原菌可以矿化有机聚合物，复杂有机物的厌氧矿化不一定是一个涉及不同微生物类群的多步过程，而是可以被单个微生物物种绕过。
