The organosulfur compound dimethylsulfoniopropionate (DMSP) is utilized as an osmoprotectant by Vibrio species.

In this study, we showed that DMSP is used as an osmoprotectant by V. parahaemolyticus and several other Vibrio species including V. cholerae and V. vulnificus Using a V. parahaemolyticus proU double mutant, we demonstrated that these ABC transporters are not required for DMSP uptake. However, a bccT null mutant lacking all four BCCTs had a growth defect compared to wild type in high salinity media supplemented with DMSP. Using mutants possessing only one functional BCCT in growth pattern assays, we identified two BCCT-family transporters, BccT1 and BccT2, which are carriers of DMSP. The only V. parahaemolyticus BccT homolog that V. cholerae and V. vulnificus possess is BccT3 and functional complementation in Escherichia coli MKH13 showed V. cholerae VcBccT3 could transport DMSP. In V. vulnificus strains, we identified and characterized an additional BCCT family transporter, which we named BccT5 that was also a carrier for DMSP.Importance DMSP is present in the marine environment, produced in large quantities by marine phytoplankton as an osmoprotectant, and is an important component of the global geochemical sulfur cycle. This algal osmolyte has not been previously investigated for its role in marine heterotrophic bacterial osmotic stress response. Vibrionaceae are marine species, many of which are halophiles exemplified by V. parahaemolyticus, a species that possesses at least six transporters for the uptake of osmolytes. Here, we demonstrated that V. parahaemolyticus and o...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research