Biogeochemical Cycling of Volatile Organosulfur Compounds in a Salt Marsh

海洋环境中挥发性有机硫化合物(VOSCs)的大气排放是全球硫循环的重要组成部分。微生物活动有助于VOSCs的产生，这一点现已得到证实，但微生物消耗的程度尚不清楚。这项研究将检验VOSC的微生物新陈代谢控制其从沉积物和海水中排放的假设。该计划将：(1)开发和使用放射性示踪剂方法来确定盐沼沉积物和海水中二甲基硫(DMS)的周转率；(2)确定对沉积物中VOSC通量的微生物控制；(3)研究沉积物中COS和CS2的产生和消费；(4)分离代谢VOSC的微生物。这项研究将首次直接测量VOSC在沉积物和水柱中的周转率。

Atmospheric emissions of volatile organic sulfur compounds (VOSCs) from the marine environment represent an important component of the global sulfur cycle. It is now well established that microbial activity contributes to the production of VOSCs, but the extent of microbial consumption is unknown. This research will test the hypothesis that microbial metabolism of VOSC controls its emission from sediments and seawater. The program will: (1) develop and employ radiotracer methods to determine turnover rates of dimethylsulfide (DMS) in sediments and seawater in a salt marsh; (2) determine microbial control over VOSC fluxes from sediments; (3) study production and consumption of COS and CS2 in sediments; (4) isolate microbes that metabolize VOSC. This research will provide the first direct measurements of VOSC turnover rates in sediments and in the water column.