Bacterial diversity and sulfur cycling in a mesophilic sulfide-rich spring
Bacterial diversity and sulfur cycling in a mesophilic sulfide-rich spring
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DOI：
10.1128/aem.69.9.5609-5621.2003
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发表时间：
2003-09-01
影响因子：
4.4
通讯作者：
Krumhoz, LR
中科院分区：
文献类型：
--
作者：
Elshahed, MS;Senko, JM;Krumhoz, LR
俄克拉何马州西南部的一个富含硫化物和硫的自流泉水显示出维持着极其丰富多样的微生物群落。实验室培养和放射自显影研究表明，活跃的硫循环发生在佐德尔顿泉丰富的微生物席上。无氧光养细菌将硫化物氧化为硫酸盐，硫酸盐被硫酸盐还原菌群还原。采用16S rRNA基因克隆和测序的方法，对卓尔顿泉的微生物群落进行了分析。大部分（83%）的微生物克隆属于delta-Proteobacteria、紫色硫γ - proteobacteria、epsilon-Proteobacteria、Chloroflexi和振荡目的丝状蓝藻，以及gamma-Proteobacteria中的一个新类群。在泉源处烃类暴露沉积物中构建的16S克隆文库的多样性高于垫克隆文库（Shannon-Weiner指数为3.84，而垫克隆文库为2.95），属于非光养谱系（如胞食菌、螺旋体、植物菌、厚壁菌门和Verrucomicrobiae）的克隆百分比更高。其中许多克隆与从烃类污染环境和厌氧烃类降解富集中获得的克隆密切相关。此外，18个源克隆没有与任何先前描述的微生物分裂聚类。这18个克隆，加上先前发表的或数据库中从各种环境中检索到的相关序列，可以聚类成至少四个新的候选分类。通过对同化亚硫酸盐还原酶（DSR）基因1.9 kb片段的克隆和测序，初步确定了Zodletone spring硫酸盐还原菌群的特征。DSR无性系属于Desulfococcus-Desulfosarcina-Desulfonema类群、desulobacter类群和Desulfovibrio类群，在DSR树中属于一个深分支类群，没有培养代表。总的来说，这项工作扩大了细菌领域的分裂水平多样性，并突出了参与中温微生物垫中硫循环的微生物群落的复杂性。
An artesian sulfide- and sulfur-rich spring in southwestern Oklahoma is shown to sustain an extremely rich and diverse microbial community. Laboratory incubations and autoradiography studies indicated that active sulfur cycling is occurring in the abundant microbial mats at Zodletone spring. Anoxygenic phototrophic bacteria oxidize sulfide to sulfate, which is reduced by sulfate-reducing bacterial populations. The microbial community at Zodletone spring was analyzed by cloning and sequencing 16S rRNA genes. A large fraction (83%) of the microbial mat clones belong to sulfur- and sulfate-reducing lineages within delta-Proteobacteria, purple sulfur gamma-Proteobacteria, epsilon-Proteobacteria, Chloroflexi, and filamentous Cyanobacteria of the order Oscillatoria as well as a novel group within gamma-Proteobacteria. The 16S clone library constructed from hydrocarbon-exposed sediments at the source of the spring had a higher diversity than the mat clone library (Shannon-Weiner index of 3.84 compared to 2.95 for the mat), with a higher percentage of clones belonging to nonphototrophic lineages (e.g., Cytophaga, Spirochaetes, Planctomycetes, Firmicutes, and Verrucomicrobiae). Many of these clones were closely related to clones retrieved from hydrocarbon-contaminated environments and anaerobic hydrocarbon-degrading enrichments. In addition, 18 of the source clones did not cluster with any of the previously described microbial divisions. These 18 clones, together with previously published or database-deposited related sequences retrieved from a wide variety of environments, could be clustered into at least four novel candidate divisions. The sulfate-reducing community at Zodletone spring was characterized by cloning and sequencing a 1.9-kb fragment of the dissimilatory sulfite reductase (DSR) gene. DSR clones belonged to the Desulfococcus-Desulfosarcina-Desulfonema group, Desulfobacter group, and Desulfovibrio group as well as to a deeply branched group in the DSR tree with no representatives from cultures. Overall, this work expands the division-level diversity of the bacterial domain and highlights the complexity of microbial communities involved in sulfur cycling in mesophilic microbial mats.