Study On The Bio-production Of Dimethyl Sulfur Compounds Of Typical HABs Algae

Dimethylsufide (DMS) is the most abundant volatile biogenic sulfur compound in the surface ocean, which plays an important role in the global sulfur cycle and global climate change. Dimethylsulfoniopropionate (DMSP) is the major precursor of DMS, and DMSP can be degraded to DMS and acrylic acid with DMSP cleavage lyase. Dimethylsulfoxide (DMSO) in seawater is usually considered as the product of photochemical and bacterial oxidation of DMS, and also arises from phytoplankton biosynthesis. This dissertation focuses on the production and turnover rate of dimethyl sulfur compounds in different growth stages of algae through laboratory culture experiment and mesocosm experiment. The detail information is as follows:1) Establishment of analytical methods for DMSP/DMS/DMSOA sequential method for the determination of dimethyl sulfur compounds, including DMS, DMSP and DMSO, in seawater samples had been developed. Detection limit of 2.5pmol of DMS in 25mL sample, corresponding to 0.10nmol/L, was achieved. Recoveries for dimethyl sulfur compounds were in the range of 68.6-78.3%. The relative standard deviations (RSDs) for DMS, DMSP and DMSO determination were 3%, 5.4% and 7.4%, respectively. This method avoids the use of cryogenic trap and shortens the analytical time from hours to minutes.2) Production of dimethyl sulfur compouns in different growth stages of three typical HABs algaeThe productions of dimethyl sulfur compounds were studied in different growth stages of Skeletonema costatum, Phaeocystis sp. and Prorocentrum donghaiense. The results are shown as follows:a) The productions of DMSPp and DMSPd increased with the growth of Skeletonema costatum, and reached their highest concentrations in the stationary growth stage; DMSOp and DMSOd increased with the culture time, and had the highest concentrations in the senescent stage. DMS had low concentration in the exponential growth stage and stationary growth stage,...