Abstract：
Marine distribution of dimethylsulfoniopropionate (DMSP) and its cleavage product dimethyl sulfide (DMS) is greatly affected by the community structures of bacteria, phytoplankton, and zooplankton. Spatial distributions of dissolved and particulate DMSP (DMSPd,p), and DMS were measured and their relationships with DMSP lyase activity (DLA), abundance of DMSP-consuming bacteria (DCB), and the community structures of phytoplankton, zooplankton, and bacteria were determined during summer in the South China Sea (SCS). The depth distributions of DMSPd,p exhibited a similar trend with Chl a, reaching their maxima in the mixing layer. The DMS concentration was positively correlated with DCB abundance and DLA, indicating that DCB and DMSP lyase had a significant effect on DMS production. High DMS concentrations in the horizontal distribution coincided with high DCB abundance and DLA and may be due to the rapid growth of phytoplankton resulting from the high dissolved inorganic nitrogen concentration brought by the cold vortices. Moreover, the highest copepod abundance at station G3 coincided with the highest DMS concentrations there among stations B4, F2, and G3. These results suggest that copepod may play an important role in DMS production. The bacterial SAR11 clade was positively correlated with DLA, indicating its significant contribution to DMSP degradation in the SCS. These findings contribute to the understanding of the effect of the community assemblage on DMSP/DMS distributions in the SCS dominated by mesoscale vortices.
摘要：
二甲基磺丙酸盐(DMSP)及其裂解产物二甲基硫醚(DMS)的海洋分布受细菌群落结构的影响较大,浮游植物,和浮游动物.溶解和颗粒DMSP的空间分布(DMSPd，P),测量和DMS及其与DMSP裂解酶活性（DLA）的关系，丰富的DMSP消耗细菌（DCB），浮游植物的群落结构，浮游动物,并在夏季在南海（SCS）确定了细菌。DMSPd的深度分布，p表现出与Chla相似的趋势，在混合层中达到最大值。DMS浓度与DCB丰度和DLA呈正相关,表明DCB和DMSP裂解酶对DMS的产生有显著影响。水平分布中的高DMS浓度与高DCB丰度和DLA相吻合，这可能是由于冷涡流带来的高溶解无机氮浓度导致浮游植物的快速生长。此外，G3站co足类的最高丰度与B4，F2和G3站中DMS的最高浓度相吻合。这些结果表明，co足类可能在DMS生产中起重要作用。细菌SAR11进化枝与DLA呈正相关,表明其对SCS中DMSP降解的重大贡献。这些发现有助于理解群落组合对中尺度涡旋主导的SCS中DMSP/DMS分布的影响。
