Sekiguchi Yuji, Kamagata Yoichi, Syutsubo Kazuaki, Ohashi Akiyoshi, Harada Hideki, Nakamura Kazunori
National Institute of Bioscience and Human-Technology, Agency of Industrial Science and TechnologyTsukuba, Ibaraki 305-8566Japan.
Department of Environmental Systems Engineering, Nagaoka University of TechnologyKamitomioka 1603-1, Nagaoka, Niigata 940-2188Japan.
Microbiology (Reading). 1998 Sep;144 ( Pt 9):2655-2665. doi: 10.1099/00221287-144-9-2655.
The microbial diversity of two types of methanogenic granular sludge, mesophilic (35 degrees C) and thermophilic (55 degrees C), which had been treating sucrose/propionate/acetate-based artificial wastewater were compared. 16S rDNA clone libraries were constructed by PCR with a prokaryote-specific primer set, and partial sequencing of the clonal 16S rDNAs was conducted for phylogenetic analysis. Of 115 mesophilic granule and 110 thermophilic granule clones sequenced, 19 and 22%, respectively, were phylogenetically affiliated with the domain Archaea, and the remainder in each case were assigned to the domain Bacteria. Within the domain Archaea, the 16S rDNA clones in both libraries showed relatively close relationships with those of methanogens. Within the Bacteria, a major group represented in the mesophilic clone library was the delta subclass of the Proteobacteria (27%), in which high degrees of relatedness were observed between the clonal 16S rDNA sequences and those of previously identified syntrophic bacteria and sulfate-reducing bacteria. In contrast, in the thermophilic clone library, the Thermodesulfovibrio group (19%), the green non-sulfur bacteria (18%) and the low G + C subclass of the Gram-positive bacteria (18%) were predominant. A significant difference between the two libraries was that no clone affiliated with the Proteobacteria was detected in the thermophilic clone library, whereas the Proteobacteria was detected in the thermophilic clone library, whereas the Proteobacteria was the most predominant group in the mesophilic clones. Thirty-six and 24 different sequences were found in the mesophilic and thermophilic clones, respectively, suggesting that the microbial diversity of the thermophilic granule was lower than that of the mesophilic granule.
比较了两种处理基于蔗糖/丙酸盐/乙酸盐的人工废水的产甲烷颗粒污泥的微生物多样性，即中温（35摄氏度）和高温（55摄氏度）颗粒污泥。使用原核生物特异性引物对通过PCR构建16S rDNA克隆文库，并对克隆的16S rDNA进行部分测序以进行系统发育分析。在测序的115个中温颗粒和110个高温颗粒克隆中，分别有19%和22%在系统发育上隶属于古菌域，其余的在每种情况下都归为细菌域。在古菌域内，两个文库中的16S rDNA克隆与产甲烷菌的克隆显示出相对密切的关系。在细菌域内，中温克隆文库中代表的一个主要类群是变形菌门的δ亚类（27%），其中克隆的16S rDNA序列与先前鉴定的互营细菌和硫酸盐还原细菌的序列之间观察到高度的相关性。相比之下，在高温克隆文库中，嗜热脱硫弧菌属（19%）、绿色非硫细菌（18%）和革兰氏阳性菌的低G + C亚类（18%）占主导地位。两个文库之间的一个显著差异是，在高温克隆文库中未检测到与变形菌门相关的克隆，而在中温克隆文库中检测到了变形菌门，并且变形菌门是中温克隆中最主要的类群。在中温克隆和高温克隆中分别发现了36个和24个不同的序列，这表明高温颗粒的微生物多样性低于中温颗粒。
