Fatty acid-oxidizing consortia along a nutrient gradient in the Florida Everglades
Fatty acid-oxidizing consortia along a nutrient gradient in the Florida Everglades
复制标题
DOI：
10.1128/aem.72.4.2400-2406.2006
复制
发表时间：
2006-04-01
影响因子：
4.4
通讯作者：
Ogram, A
中科院分区：
文献类型：
--
作者：
Chauhan, A;Ogram, A
佛罗里达大沼泽地是北美最大的淡水沼泽地之一，几十年来一直受到富营养化的影响。P浓度的梯度延伸到沼泽的北方区域的内部几公里，土壤微生物群落的结构和功能沿着梯度变化。在这项研究中，稳定同位素探测调查碳的命运从发酵产物丙酸和丁酸在土壤中沿着养分梯度。对于丙酸盐微宇宙，来自富营养化和过渡位点的16S rRNA基因克隆文库由与先前描述的丙酸盐氧化剂相关的序列占主导地位，例如1'elotomaculum spp.和互养菌属（Syntrophylspp.）还观察到与丙酸史密斯氏菌（Smithella propionica）相关的序列的显著代表性，所述丙酸史密斯氏菌将丙酸歧化为丁酸。寡营养样品中的优势菌型序列没有与已知的同养生物聚类，但与硫酸盐还原原核生物（SRP）和Pelidae spp。在丁酸盐微宇宙中，与合磷藻属（Syntrophosora spp.）和互养单胞菌属（Syntrophomonas spp.）与Pelospora相关的序列占主导地位的过渡微宇宙。与Pelospora spp.相关的序列和SRP占主导地位的克隆文库从贫营养的缩影。来自不同细菌门和初级发酵物的序列也存在于大多数文库中。来自富营养化微宇宙的微生物序列包括甲烷微生物科、甲烷微藻科和甲烷小球藻科的特征序列。寡营养微宇宙占主导地位的乙酸，包括序列相关的甲烷八叠球菌，这表明积累的乙酸。
The Florida Everglades is one of the largest freshwater marshes in North America and has been subject to eutrophication for decades. A gradient in P concentrations extends for several kilometers into the interior of the northern regions of the marsh, and the structure and function of soil microbial communities vary along the gradient. In this study, stable isotope probing was employed to investigate the fate of carbon from the fermentation products propionate and butyrate in soils from three sites along the nutrient gradient. For propionate microcosms, 16S rRNA gene clone libraries from eutrophic and transition sites were dominated by sequences related to previously described propionate oxidizers, such as 1'elotomaculum spp. and Syntrophobacter spp. Significant representation was also observed for sequences related to Smithella propionica, which dismutates propionate to butyrate. Sequences of dominant phylotypes from oligotrophic samples did not cluster with known syntrophs but with sulfate-reducing prokaryotes (SRP) and Pelobacter spp. In butyrate microcosms, sequences clustering with Syntrophospora spp. and Syntrophomonas spp. dominated eutrophic microcosms, and sequences related to Pelospora dominated the transition microcosm. Sequences related to Pelospora spp. and SRP dominated clone libraries from oligotrophic microcosms. Sequences from diverse bacterial phyla and primary fermenters were also present in most libraries. Archaeal sequences from eutrophic microcosms included sequences characteristic of Methanomicrobiaceae, Methanospirillaceae, and Methanosaetaceae. Oligotrophic microcosms were dominated by acetotrophs, including sequences related to Methanosarcina, suggesting accumulation of acetate.