Diversity of bacterial dimethylsulfoniopropionate degradation genes in surface seawater of Arctic Kongsfjorden

Abstract

Dimethylsulfoniopropionate (DMSP), which is the major source of organic sulfur in the world’s oceans, plays a significant role in the global sulfur cycle. This compound is rapidly degraded by marine bacteria either by cleavage to dimethylsulfide (DMS) or demethylation to 3-methylmercaptopropionate (MMPA). The diversity of genes encoding bacterial demethylation (dmdA) and DMS production (dddL and dddP) were measured in Arctic Kongsfjorden. Both dmdA and dddL genes were detected in all stations along a transect from the outer to the inner fjord, while dddP gene was only found in the outer and middle parts of the fjord. The dmdA gene was completely confined to the Roseobacter clade, while the dddL gene was confined to the genus Sulfitobacter. Although the dddP gene pool was also dominated by homologs from the Roseobacter clade, there were a few dddP genes showing close relationships to both Alphaproteobacter and Gammaproteobacter. The results of this study suggest that the Roseobacter clade may play an important role in DMSP catabolism via both demethylation and cleavage pathways in surface waters of Kongsfjorden during summer.

Differences in free-living and particle-associated bacterial communities and their spatial variation in Kongsfjorden, Arctic

“…Abundance of members of RCA cluster are often highest during phytoplankton blooms and are mainly found associated with organic and inorganic marine particles/surfaces . Recent studies have shown that members of Sulfitobacter and Loktanella genera prefer particle‐associated lifestyle and are involved in the degradation of dimethylsulfoniopropionate (DMSP) . In the present study, members of SAR116 clade (class Alphaproteobacteria ) were enriched in the PA fractions.…”

Metagenomic Insights Into the Cycling of Dimethylsulfoniopropionate and Related Molecules in the Eastern China Marginal Seas

“…The reason for this shift is unknown, but it may be a consequence of the reduction in the abundance of SAR11 in the sediment and an increase in gamma-proteobacteria such as Pseudomonas containing dddP, or perhaps to the increased DMSP levels experienced in these samples. It was noteworthy that BYSS bacteria predicted to contain dddP, Pseudomonas, Mesorhizobium, and Leisingera, are distinct from previous studies that showed the Roseobacter clade to be the major bacteria possessing dddP (Todd et al, 2009;Varaljay, 2012;Zeng et al, 2016).…”

Aerobic Bacterial Catabolism of Dimethylsulfoniopropionate

“…Class III, DddP), with Zn(II) and Ni(II) ions bound. Zeng et al (2016) investigated the diversity of DMSP dethiomethylase genes in surface water of Kongsfjorden, Svalbard (Bokmål, "the king's fjord"), finding all of the dddL clones were allied to the genus Sulfitobacter. The dddL gene was also identified in Bacteria communities associated to corals (Raina et al 2009).…”

“…The dddP gene was found in the genomes of various Alphaproteobacteria and in members of the Ascomycota of the Eukarya, in which functional DMSP dethiomethylase activity was observed (Todd et al 2009). In the Zeng et al (2016) investigation of the diversity of DMSP dethiomethylase genes in surface water of Kongsfjorden, Svalbard, dddP genes were mostly allied to the Rhodobacteraceae, with no specific affiliation to known genera.…”

“…In the analysis of DMSP degradation gene diversity by Zeng et al (2016) in surface water of Kongsfjorden, Svalbard, dmdA genes were mostly affiliated to the Rhodobacteraceae, specifically Sulfitobacter, Ruegeria, Roseobacter, Octadecabacter, and Thalassobius.…”