Distribution and metabolism of dimethylsulfoniopropionate (DMSP) and phylogenetic affiliation of DMSP-assimilating bacteria in northern Baffin Bay/Lancaster Sound
Distribution and metabolism of dimethylsulfoniopropionate (DMSP) and phylogenetic affiliation of DMSP-assimilating bacteria in northern Baffin Bay/Lancaster Sound
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DOI：
10.1029/2011jc007330
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发表时间：
2012-02-03
影响因子：
3.6
通讯作者：
Lovejoy, C.
中科院分区：
文献类型：
--
作者：
Motard-Cote, J.;Levasseur, M.;Lovejoy, C.
2008年9月，我们测定了巴芬湾/兰开斯特湾北部两个主要地表水团中二甲基磺酰丙酸盐（DMSP）和二甲基硫化物（DMS）的分布和细菌代谢。DMSP颗粒浓度（DMSPp; 5 ~ 70 nmol L-1）和DMSPp: Chl a比值（15 ~ 229 nmol mu g(-1)）较高，提示存在富含DMSP的浮游植物类群。巴芬湾地表水（BBS）光合微真核生物和总原核生物的丰度分别是北极地表水（AS）的10倍和3倍。与之前报道的温暖和高产环境相比，异养细菌产量（0.07-2.5 μ C L-1 d(-1)）和溶解DMSP （DMSPd）的细菌周转速率常数（0.03-0.11 h(-1)）较低。尽管如此，被细菌代谢的DMSP转化为DMS的比例相对较大（12%-31%）。此外，40%至65%的细菌细胞从DMSPd中吸收硫，其中γ变形菌和非玫瑰杆菌α变形菌（Alf(R-)）对总dmsp结合细胞的贡献比例更高。在BBS中，Alf（R-）对总原核生物群落的贡献比在AS中高50%，而在BBS中，DMSPd的细菌转化率常数比在AS中高78%。这些结果表明，两种不同的北极水体拥有特定的微生物组合，导致对DMSP的不同亲和力。
We determined the distribution and bacterial metabolism of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) in the two dominant surface water masses in northern Baffin Bay/Lancaster Sound during September 2008. Concentrations of particulate DMSP (DMSPp; 5-70 nmol L-1) and the DMSPp: Chl a ratios (15-229 nmol mu g(-1)) were relatively high, suggesting the presence of DMSP-rich phytoplankton taxa. Photosynthetic picoeukaryotes and total prokaryotes were tenfold and threefold more abundant in Baffin Bay surface water (BBS) than in Arctic surface water (AS), respectively. Heterotrophic bacterial production (0.07-2.5 mu C L-1 d(-1)) and bacterial turnover rate constants for dissolved DMSP (DMSPd) were low (0.03-0.11 h(-1)) compared with the values previously reported in warmer and more productive environments. Nonetheless, a relatively large proportion (12%-31%) of the DMSP metabolized by the bacteria was converted into DMS. Additionally, between 40% and 65% of the total bacterial cells incorporated sulfur from DMSPd, with Gammaproteobacteria and non-Roseobacter Alphaproteobacteria (Alf(R-)) contributing proportionally more to total DMSP-incorporating cells. The contribution of Alf(R-) to the total prokaryotic community was 50% higher in BBS than in AS, while the bacterial rate constants for DMSPd turnover were 78% higher in BBS than in AS. These results show that the two different Arctic water masses host specific microbial assemblages that result in distinct affinity for DMSP.