Novel Insights into Dimethylsulfoniopropionate Catabolism by Cultivable Bacteria in the Arctic Kongsfjorden

• Published in: Applied and environmental microbiology Vol. 88; no. 2; p. e0180621
• Main Authors: Zhang, Shan, Cao, Hai-Yan, Zhang, Nan, Teng, Zhao-Jie, Yu, Yang, Wang, Zhi-Bin, Wang, Peng, Fu, Hui-Hui, Chen, Xiu-Lan, Zhang, Yu-Zhong, Li, Chun-Yang
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 25.01.2022
• Subjects: Alteromonas; Bacteria; Carbon sources; Carbon-Sulfur Lyases - genetics; Catabolism; Catabolites; Cleavage; Demethylation; Dimethyl sulfide; Environmental Microbiology; Humans; Methanethiol; Oceans; Organosulfur compounds; Polar environments; Pseudoalteromonas; Psychrobacter; Strains (organisms); Sulfides - metabolism; Sulfonium Compounds - metabolism; Sulfur; Sulfur - metabolism; Sulfur compounds; Sulfur cycle; Vibrio; Arctic region; the Arctic; catabolic pathways; marine bacteria; DMSP; Gammaproteobacteria
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.01806-21

Dimethylsulfoniopropionate (DMSP) is one of the most abundant organic sulfur compounds in the oceans, which is mainly degraded by bacteria through two pathways, a cleavage pathway and a demethylation pathway. Its volatile catabolites dimethyl sulfide (DMS) and methanethiol (MT) in these pathways play important roles in the global sulfur cycle and have potential influences on the global climate. Intense DMS/DMSP cycling occurs in the Arctic. However, little is known about the diversity of cultivable DMSP-catabolizing bacteria in the Arctic and how they catabolize DMSP. Here, we screened DMSP-catabolizing bacteria from Arctic samples and found that bacteria of four genera ( , , and ) could grow with DMSP as the sole carbon source, among which and are predominant. Four representative strains ( sp. K31L, sp. K222D, sp. K632G, and sp. G41H) from different genera were selected to probe their DMSP catabolic pathways. All these strains produce DMS and MT simultaneously during their growth on DMSP, indicating that all strains likely possess the two DMSP catabolic pathways. On the basis of genomic and biochemical analyses, the DMSP catabolic pathways in these strains were proposed. Bioinformatic analysis indicated that most and bacteria have the potential to catabolize DMSP via the demethylation pathway and that only a small portion of strains may catabolize DMSP via the cleavage pathway. This study provides novel insights into DMSP catabolism in marine bacteria. Dimethylsulfoniopropionate (DMSP) is abundant in the oceans. The catabolism of DMSP is an important step of the global sulfur cycle. Although are widespread in the oceans, the contribution of in global DMSP catabolism is not fully understood. Here, we found that bacteria of four genera belonging to ( , , and ), which were isolated from Arctic samples, were able to grow on DMSP. The DMSP catabolic pathways of representative strains were proposed. Bioinformatic analysis indicates that most and bacteria have the potential to catabolize DMSP via the demethylation pathway and that only a small portion of strains may catabolize DMSP via the cleavage pathway. Our results suggest that novel DMSP dethiomethylases/demethylases may exist in , and and that may be important participants in the marine environment, especially in polar DMSP cycling.