Isolation and Characterization of a Novel Sulfur-Oxidizing Stutzerimonas Species from Hydrothermal Sediments and Its Adaptation to the Hydrothermal Environment

<i>Stutzerimonas</i>, a genus newly separated from the <i>Pseudomonadaceae</i> family in 2022, has attracted considerable attention due to its diverse metabolic capabilities and environmental adaptability. However, the mechanisms underlying its sulfur-oxidizing capacity and survival strategies in extreme environments remain poorly understood. Clarifying potential sulfur-oxidizing microbial groups contributes to a more accurate understanding of energy flow and elemental cycling in hydrothermal ecosystems. In this study, we isolated and identified a sulfur-oxidizing strain, designated 381-2^T, from sediments in the Tianxiu hydrothermal field of the northwest Indian Ocean, and proposed it as a new species of <i>Stutzerimonas</i>. Physiological characterizations demonstrated that strain 381-2^T could oxidize thiosulfate to tetrathionate and encoded the key sulfur oxidation gene <i>tsdA</i>. Cultivation with sulfide minerals showed that strain 381-2^T could influence sulfide mineral weathering through metabolic activities, such as pH regulation, and potentially promote the reprecipitation of metal ions on the microbial surface. Comparative genomic analysis of 322 <i>Stutzerimonas</i> genomes further revealed the widespread presence of the <i>tsdA</i> gene and metal resistance genes, suggesting potential adaptive strategies for survival in hydrothermal environments. This study expands the understanding of <i>Stutzerimonas</i> species and provides insights into their ecological roles in hydrothermal systems.