Phylogenetic analysis of culturable dimethyl sulfide-producing bacteria from a Spartina-dominated salt marsh and estuarine water
Phylogenetic analysis of culturable dimethyl sulfide-producing bacteria from a Spartina-dominated salt marsh and estuarine water
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DOI：
10.1128/aem.67.3.1210-1217.2001
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发表时间：
2001-03-01
影响因子：
4.4
通讯作者：
Yoch, DC
中科院分区：
文献类型：
--
作者：
Ansede, JH;Friedman, R;Yoch, DC
二甲基磺基丙酸酯（DMSP）是一种存在于海藻和盐沼大米草中的植物保护剂，具有DMSP裂解酶的微生物可将DMSP代谢为二甲基硫醚（DMS）和丙烯酸酯。从盐沼和邻近河口水DMSP琼脂平板上分离的一套产DMS细菌与目前培养的浮游菌株明显不同。虽然许多盐沼和河口分离物产生的甲硫氨酸和二甲亚砜的二甲基硫醚和methanethethernet，似乎没有能够同时产生methanethernet和DMS从DRSP。DMSP及其降解产物丙烯酸酯和β-羟基丙酸酯，而不是甲基-3-巯基丙酸酯或3-巯基丙酸酯，作为所有α-和β-但仅部分γ-变形杆菌分离株生长的碳源. 16 S rRNA基因序列的系统发育分析表明，所有的菌株都在变形菌门组，其中大部分属于α和γ亚类。只有一个分离物被鉴定为β-变形杆菌，并且它与粪产碱杆菌的陆生物种具有>98%的16 S rRNA序列同源性。虽然基于可培养性的细菌种群分析有其局限性，但变形菌门的α和γ亚类细菌是从盐沼沉积物和河口分离出的主要DMS生产者，γ亚类代表80%的分离株。α-变形菌属分离株都属于玫瑰球菌亚群，而许多γ-变形菌属与假单胞菌密切相关;其他的则与海单胞菌属、嗜冷杆菌属或弧菌属物种在遗传学上相关。这些数据表明，DMSP裂解为DMS和丙烯酸酯是一个广泛分布在盐沼河口生态系统的不同类型的藻类的特点。
Dimethylsulfoniopropionate (DMSP), an abundant osmoprotectant found in marine algae and salt marsh cordgrass, can be metabolized to dimethyl sulfide (DMS) and acrylate by microbes having the enzyme DMSP lyase. A suite of DMS-producing bacteria isolated from a salt marsh and adjacent estuarine water on DMSP agar plates differed markedly from the pelagic strains currently in culture. While many of the salt marsh and estuarine isolates produced DMS and methanethiol from methionine and dimethyl sulfoxide, none appeared to be capable of producing both methanethiol and DMS from DRSP. DMSP, and its degradation products acrylate and beta -hydroxypropionate but not methyl-3-mecaptopropionate or 3-mercaptopropionate, served as a carbon source for the growth of all the alpha- and beta- but only some of the gamma -proteobacterium isolates. Phylogenetic analysis of 16S rRNA gene sequences showed that all of the isolates were in the group Proteobacteria, with most of them belonging to the alpha and gamma subclasses. Only one isolate was identified as a beta -proteobacterium, and it had >98% 16S rRNA sequence homology with a terrestrial species of Alcaligenes faecalis. Although bacterial population analysis based on culturability has its limitations, bacteria from the alpha and gamma subclasses of the Proteobacteria were the dominant DMS producers isolated from salt marsh sediments and estuaries, with the gamma subclass representing 80% of the isolates. The alpha -proteobacterium isolates were all in the Roseobacter subgroup, while many of the gamma -proteobacteria were closely related to the pseudomonads; others were phylogenetically related to Marinomonas, Psychrobacter, or Vibrio species. These data suggest that DMSP cleavage to DMS and acrylate is a characteristic widely distributed among different phylotypes in the salt marsh-estuarine ecosystem.