Identification of putative benzene-degrading bacteria in methanogenic enrichment cultures
Identification of putative benzene-degrading bacteria in methanogenic enrichment cultures
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DOI：
10.1016/j.jbiosc.2009.06.005
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发表时间：
2009-12-01
影响因子：
2.8
通讯作者：
Yamamoto, Kazuo
中科院分区：
文献类型：
--
作者：
Sakai, Nahoko;Kurisu, Futoshi;Yamamoto, Kazuo
从未受污染的莲田土壤中获得了产甲烷的厌氧降解苯富集菌。采用C-13苯稳定同位素探针法对苯降解菌进行检测。分离样品的变性梯度凝胶电泳(DGGE)显示一些DGGE条带明显向较重的DNA部分移动。通过构建重组份的克隆文库，获得了与DCGE带相对应的几乎全长的16S rRNA基因序列，即Hasda-A。Hasda-A序列与最近鉴定的龙胆突触线虫的同源性仅为85.1%。Hasda-A可能是一种重要的细菌，参与了产甲烷条件下苯降解的初始步骤，因为它是在苯降解过程中早期吸收标记苯的最突出的细菌。设计了一套定量聚合酶链式反应对Hasda-A基因拷贝数进行定量的方法。Hasda-A的浓度为(3.5+/-0.8)×10(6)拷贝/毫升，占增菌培养中细菌间基因拷贝数的8.4%。增菌培养由三个优势菌群组成：Hasda-A，以及醋酸菌和产氢产甲烷菌。甲烷被认为是由苯通过发酵细菌、产氢产乙酸菌和产甲烷菌顺序降解苯而产生的。(C)2009年，日本生物技术学会。版权所有。
Anaerobic benzene-degrading enrichment cultures performing methanogenesis were obtained from non-contaminated lotus field soil. Stable isotope probing with C-13 benzene was used to detect the bacteria that were involved in benzene degradation. Denaturing gradient gel electrophoresis (DGGE) of fractionated samples exhibited an obvious shift of some DGGE bands to a heavier DNA fraction. An almost full-length 16S rRNA gene sequence corresponding to the DCGE band, namely Hasda-A, was obtained by constructing a clone library of the heavier fraction. The Hasda-A sequence showed only 85.1% identity with the closest identified bacterium, Syntrophus gentianae. Hasda-A may be an important bacterium involved in the initial steps of benzene degradation under methanogenic conditions, as it was the most prominent bacterium that assimilated labeled benzene early in the process of benzene degradation. A primer set was designed to quantify the gene copies of Hasda-A by quantitative PCR. Hasda-A was present at a concentration of (3.5 +/- 0.8) x 10(6) copies/mL and represented 8.4% of gene copies among bacteria in the enrichment culture. The enrichment culture consisted of three dominant bacterial groups: Hasda-A and both aceticlastic and hydrogenotrophic methanogens. Methane is believed to be produced from benzene by the sequential degradation of benzene by fermenting bacteria, hydrogen-producing acetogens, and methanogens. (C) 2009, The Society for Biotechnology, Japan. All rights reserved.