Annual DMSP contribution to S and C fluxes through phytoplankton and bacterioplankton in a NW Mediterranean coastal site

Aquatic Microbial Ecology

Josep M. Gasol¹  Laura Alonso-Sáez¹  Maria Vila-Costa¹  Òscar Guadayol¹  Clara Cardelús¹  Rafel Simó¹  Evaristo Vázquez-Domínguez¹ 

关键词: Dimethylsulfide;    Dimethylsulfoniopropionate;    Sulfur;    Food web;    Primary production;    Bacterial production;    Respiration;    Mediterranean;   

DOI  :  10.3354/ame01325

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The contribution of dimethylsulfoniopropionate (DMSP) to the fluxes of carbon and sulfur through phytoplankton and bacterioplankton was investigated throughout an annual cycle in the Blanes Bay Microbial Observatory (coastal NW Mediterranean). DMSP accounted for 0.3 to 7% of biovolume-estimated phytoplankton carbon and 4 to 93% of calculated phytoplankton sulfur, with higher contributions in ‘summer’ (highly irradiated, oligotrophic waters, May to September) and lower in ‘winter’ (October to April). DMSP biosynthesis rates accounted for 0.8 to 7% of carbon fixation and 11 to 88% of sulfur assimilation through primary production, with slightly higher shares in summer. Upon release from the algal cells, DMSP supplied 0.5 to 6% of the total carbon demand of heterotrophic bacteria, and 3 to 100% of the sulfur demand over the year. Uncertainties associated with these calculations are due to a scarce knowledge of C:S ratios in marine bacteria. Bacterial DMSP-sulfur assimilation (measured with ³⁵S-DMSP) was positively correlated with bacterial heterotrophic production rates (measured with ³H-leucine). In summer waters, characterized by higher ratios of particulate DMSP to chlorophyll a (DMSP_p:chl a), DMSP-sulfur assimilation by bacteria was higher and contributed a larger share of the bacterial sulfur demand. We propose that the DMSP:chl a ratio is a good indicator of the relative role of DMSP in the carbon and sulfur fluxes through the first levels of the planktonic food web.

【 授权许可】

Unknown