Marine microbial production of dimethylsulfide from dissolved dimethylsulfoniopropionate. Ph. D. Thesis

Technical Report · Mon Feb 01 04:00:00 EST 1993

OSTI ID:6148497

Ledyard, K M

Dimethylsulfide (DMS) plays a central role in the transfer of sulfur from the ocean to the atmosphere and ultimately to land. The most abundant volatile organosulfur compound in seawater, DMS is believed to account for the bulk of the sea-to-air biogenic sulfur flux. DMS has also been implicated as the major precursor of submicron-sized sulfate aerosol over the ocean. This aerosol acts as an effective site for cloud droplet condensation suggesting a possibly important role for DMS in marine cloud formation. In the ocean, the precursor of DMS is presumed to be the zwitterionic sulfonium compound dimethylsulfoniopropionate (DMSP), a common osmoticum in certain classes of marine algae. While some algae can cleave DMSP intracellularly to form DMS, correlation of DMS concentrations with indicators of algal productivity on a local scale is poor. This thesis focuses on an alternative pathway of DMS formation: microbial cleavage of dissolved (extracellular) DMSP. In laboratory studies, bacteria able to cleave DMSP to form DMS were isolated from seawater by a DMSP enrichment technique, and the kinetics of DMSP uptake and DMS production were examined closely in pure cultures of a bacterial isolate from the Sargasso Sea. The isolate could grow with both DMSP and acrylic acid, one of the products of DMSP cleavage, as the sole source of carbon and energy, and the enzyme catalyzing DMSP cleavage appeared to be induced by both of these compounds. Kinetic parameters were estimated for DMSP uptake and cleavage by whole cells. Comparison of the 16S rRNA sequence of this isolate with that of known eubacteria showed that it was most closely related to Erythrobacter longus, an aerobic, bacteriochlorophyll-containing member of the alpha proteobacteria.

• Research Organization: Woods Hole Oceanographic Institution, MA (United States)
• OSTI ID: 6148497
• Report Number(s): N-93-30665; NASA-CR--193278; NAS--1.26:193278; AD-A--264794; WHOI--93-07; CNN: NAGW-606; NSF OCE-90-2532
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540310* -- Environment
Aquatic-- Basic Studies-- (1990-)
AEROSOLS
AIR-WATER INTERACTIONS
ALGAE
BIOSYNTHESIS
CHALCOGENIDES
CLEAVAGE
CLOUDS
COLLOIDS
DIMETHYL SULFIDE
DISPERSIONS
MICROORGANISMS
MICROSTRUCTURE
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PLANTS
SEAS
SOLS
SULFIDES
SULFUR COMPOUNDS
SULFUR CYCLE
SURFACE WATERS
SYNTHESIS