Bacterial Regulation of Organic Sulfur Cycling in the Ocean: A Genomic Approach

一笔赠款已授予玛丽安莫兰博士，威廉B。惠特曼和安妮O.这项研究是由格鲁吉亚大学的萨默斯和南亚拉巴马大学的罗纳德P.基恩共同完成的，他们研究了在海洋硫循环中起关键作用的微生物。 二甲基磺基丙酸酯（DMSP）是由海藻合成的一种丰富的有机硫化合物。 当海洋细菌降解DMSP时，它们可以产生二甲硫醚（DMS），这是一种挥发性化合物，是大气中有机硫的最大天然来源。 然而，DMSP存在竞争性的细菌降解途径，其最终产物在有机硫的海洋-大气通量中仅起次要作用。 这些相互竞争的降解途径的遗传基础以及它们在海洋细菌细胞内是如何受到调控的尚不清楚。 此外，海洋环境条件如何影响海洋细菌降解DMSP的途径尚不清楚。 在本项目中，将结合分子生物学方法对DMSP降解海洋细菌（Silicibacter pomeroyi）的基因组序列进行分析，以确定参与DMSP降解的代谢和调控基因。 已识别的基因将用于从沿海和开阔海洋环境表层水的未培养且可能是新型的海洋细菌中检索具有相同功能的基因。沃茨。 该项目的一个重要目标是开发分子工具，用于研究在海水中降解DMSP的海洋细菌，包括它们如何相互作用和与环境相互作用。

A grant has been awarded to Drs. Mary Ann Moran, William B. Whitman, and Anne O. Summers of the University of Georgia, and Ronald P. Kiene of the University of South Alabama to investigate the microbes mediating a key step in the marine sulfur cycle. Dimethylsulfoniopropionate (DMSP) is an abundant organic sulfur compound synthesized by marine algae. When marine bacteria degrade DMSP, they can produce dimethylsulfide (DMS), a volatile compound that is the largest natural source of organic sulfur to the atmosphere. However there are competing bacterial degradation pathways for DMSP, the end products of which play only a minor role in ocean-atmosphere flux of organic sulfur. The genetic basis for these competing degradation pathways and how they are regulated within marine bacterial cells is unknown. Further, it is not understood how environmental conditions in the ocean influence the pathways by which marine bacteria degrade DMSP. In this project, analysis of the genomic sequence of a DMSP-degrading marine bacterium (Silicibacter pomeroyi) will be used in conjunction with molecular biology approaches to identify metabolic and regulatory genes involved in DMSP degradation. Identified genes will be used to retrieve genes with the same function from uncultured and potentially novel marine bacteria from surface waters of coastal and open ocean environments. An important goal of the project is to develop molecular tools for studying the marine bacteria that degrade DMSP in seawater, including how they interact with one another and the environment.