Division of Marine and Atmospheric Chemistry, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149-1098.
Appl Environ Microbiol. 1991 Dec;57(12):3581-4. doi: 10.1128/aem.57.12.3581-3584.1991.
Dimethylsulfoniopropionate (DMSP), an osmolyte in marine plants, is biodegraded by cleavage of dimethyl sulfide (DMS) or by demethylation to 3-methiolpropionate (MMPA) and 3-mercaptopropionate (MPA). Sequential demethylation has been observed only with anoxic slurries of coastal sediments. Bacteria that grew aerobically on MMPA and DMSP were isolated from marine environments and phytoplankton cultures. Enrichments with DMSP selected for bacteria that generated DMS, whereas MMPA enrichments selected organisms that produced methanethiol (CH(3)SH) from either DMSP or MMPA. A bacterium isolated on MMPA grew on MMPA and DMSP, but rapid production of CH(3)SH from DMSP occurred only with DMSP-grown cells. Low levels of MPA accumulated during growth on MMPA, indicating demethylation as well as demethiolation of MMPA. The alternative routes for DMSP biodegradation via MMPA probably impact on net DMS fluxes to the marine atmosphere.
二甲基砜丙酯（DMSP）是海洋植物中的一种渗透调节剂，可通过二甲基硫（DMS）的裂解或通过脱甲基化为 3-巯基丙酸（MMPA）和 3-巯基丙酸（MPA）而被生物降解。只有在沿海沉积物的缺氧泥浆中才观察到顺序脱甲基化。从海洋环境和浮游植物培养物中分离出可在 MMPA 和 DMSP 上有氧生长的细菌。用 DMSP 进行的富集选择产生 DMS 的细菌，而 MMPA 富集选择从 DMSP 或 MMPA 产生甲硫醇（CH(3)SH）的生物体。在 MMPA 上分离出的一种细菌可在 MMPA 和 DMSP 上生长，但只有在 DMSP 生长的细胞中，DMSP 才能快速产生 CH(3)SH。在 MMPA 上生长时会积累少量的 MPA，表明 MMPA 的脱甲基和脱巯基作用。DMSP 通过 MMPA 进行生物降解的替代途径可能会影响到向海洋大气中净 DMS 的通量。
