Department of Marine Sciences, University of Georgia, Athens, Georgia 30602, USA.
Ann Rev Mar Sci. 2012;4:523-42. doi: 10.1146/annurev-marine-120710-100827.
Genomic and functional genomic methods applied to both model organisms and natural communities have rapidly advanced understanding of bacterial dimethylsulfoniopropionate (DMSP) degradation in the ocean. The genes for the two main pathways in bacterial degradation, routing DMSP to distinctly different biogeochemical fates, have recently been identified. The genes dmdA, -B, -C, and -D mediate the demethylation of DMSP and facilitate retention of carbon and sulfur in the marine microbial food web. The genes dddD, -L, -P, -Q, -W, and -Y mediate the cleavage of DMSP to dimethylsulfide (DMS), with important consequences for ocean-atmosphere sulfur flux. In ocean metagenomes, sufficient copies of these genes are present for approximately 60% of surface ocean bacterial cells to directly participate in DMSP degradation. The factors that regulate these two competing pathways remain elusive, but gene transcription analyses of natural bacterioplankton communities are making headway in unraveling the intricacies of bacterial DMSP processing in the ocean.
基因组学和功能基因组学方法既应用于模式生物，也应用于自然群落，这使得人们对海洋中细菌二甲基巯基丙酸酯（DMSP）降解的理解迅速深入。最近，细菌降解过程中两条主要途径的基因已经被确定，这些途径将 DMSP 导向截然不同的生物地球化学命运。基因 dmdA、-B、-C 和 -D 介导 DMSP 的去甲基化，并有助于将碳和硫保留在海洋微生物食物网中。基因 dddD、-L、-P、-Q、-W 和 -Y 介导 DMSP 裂解为二甲硫（DMS），这对海洋-大气硫通量有重要影响。在海洋宏基因组中，这些基因的拷贝数足以使大约 60%的海洋表层细菌细胞直接参与 DMSP 降解。调控这两种竞争途径的因素仍然难以捉摸，但对自然浮游细菌群落的基因转录分析正在深入揭示海洋中细菌 DMSP 处理的复杂性。
