Cardman Z, Arnosti C, Durbin A, Ziervogel K, Cox C, Steen A D, Teske A
Department of Marine Sciences, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA.
Department of Marine Sciences, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
Appl Environ Microbiol. 2014 Jun;80(12):3749-56. doi: 10.1128/AEM.00899-14. Epub 2014 Apr 11.
In Arctic marine bacterial communities, members of the phylum Verrucomicrobia are consistently detected, although not typically abundant, in 16S rRNA gene clone libraries and pyrotag surveys of the marine water column and in sediments. In an Arctic fjord (Smeerenburgfjord) of Svalbard, members of the Verrucomicrobia, together with Flavobacteria and smaller proportions of Alpha- and Gammaproteobacteria, constituted the most frequently detected bacterioplankton community members in 16S rRNA gene-based clone library analyses of the water column. Parallel measurements in the water column of the activities of six endo-acting polysaccharide hydrolases showed that chondroitin sulfate, laminarin, and xylan hydrolysis accounted for most of the activity. Several Verrucomicrobia water column phylotypes were affiliated with previously sequenced, glycoside hydrolase-rich genomes of individual Verrucomicrobia cells that bound fluorescently labeled laminarin and xylan and therefore constituted candidates for laminarin and xylan hydrolysis. In sediments, the bacterial community was dominated by different lineages of Verrucomicrobia, Bacteroidetes, and Proteobacteria but also included members of multiple phylum-level lineages not observed in the water column. This community hydrolyzed laminarin, xylan, chondroitin sulfate, and three additional polysaccharide substrates at high rates. Comparisons with data from the same fjord in the previous summer showed that the bacterial community in Smeerenburgfjord changed in composition, most conspicuously in the changing detection frequency of Verrucomicrobia in the water column. Nonetheless, in both years the community hydrolyzed the same polysaccharide substrates.
在北极海洋细菌群落中，疣微菌门的成员在海洋水柱和沉积物的16S rRNA基因克隆文库及焦磷酸测序调查中始终能被检测到，尽管其数量通常并不丰富。在斯瓦尔巴群岛的一个北极峡湾（斯梅伦堡峡湾），在基于16S rRNA基因的水柱克隆文库分析中，疣微菌门的成员与黄杆菌以及较小比例的α-和γ-变形菌一起，构成了最常被检测到的浮游细菌群落成员。对水柱中六种内切多糖水解酶活性的平行测量表明，硫酸软骨素、海带多糖和木聚糖水解占了大部分活性。几个水柱疣微菌系统型与先前测序的、富含糖苷水解酶的单个疣微菌细胞基因组相关，这些细胞能结合荧光标记的海带多糖和木聚糖，因此构成了海带多糖和木聚糖水解的候选者。在沉积物中，细菌群落以疣微菌门、拟杆菌门和变形菌门的不同谱系为主，但也包括在水柱中未观察到的多个门水平谱系的成员。这个群落能高效水解海带多糖、木聚糖、硫酸软骨素和另外三种多糖底物。与前一年夏天同一峡湾的数据比较表明，斯梅伦堡峡湾的细菌群落组成发生了变化，最明显的是水柱中疣微菌检测频率的改变。尽管如此，在这两年中，群落水解的都是相同的多糖底物。
