Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge
Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge
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DOI：
10.1038/ismej.2011.59
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发表时间：
2011-12-01
期刊：
影响因子：
11
通讯作者：
Okabe, Satoshi
中科院分区：
文献类型：
--
作者：
Ito, Tsukasa;Yoshiguchi, Kazumi;Okabe, Satoshi
通过基于放射性同位素和稳定同位素的功能分析、显微放射自显影-荧光原位杂交 (MAR-FISH) 和 16S rRNA 稳定同位素探测 (RNA-SIP) 来鉴定和定量产甲烷厌氧消化池污泥中的主要利用乙酸盐的细菌和古菌种群，这些方法可以直接将 16S rRNA 系统发育与原位联系起来 代谢功能。首先，使用 C-14-乙酸盐的 MAR-FISH 表明，消化池污泥中只有两个主要群体（未鉴定的细菌细胞和甲烷菌样丝状古菌细胞）对乙酸盐的显着利用。为了鉴定利用乙酸盐的未鉴定细菌，以C-13(6)-葡萄糖和C-13(3)-丙酸作为唯一碳源进行RNA-SIP，随后对16S rRNA进行系统发育分析。我们发现，在源自用 C-13-葡萄糖和 C-13-丙酸盐孵育的污泥的 16S rRNA 克隆文库中，通常检测到属于 Synergistes 第 4 组的细菌。为了确认该细菌群可以利用乙酸盐，新设计了针对 Synergistes 群 4 的特异性 FISH 探针，并将其应用于与 C-14-乙酸盐一起孵育的污泥以进行 MAR-FISH。 MAR-FISH结果显示，属于Synergistes group 4的细菌显着吸收乙酸盐，并且其活跃种群规模与该污泥中的Methanosaeta相当。此外，由于属于 Synergistes group 4 的细菌对乙酸盐具有较高的 K-m 和最大利用率，因此在高乙酸盐浓度（2.5-10mM）下，它们比 Methanosaeta 对乙酸盐更具竞争力。据我们所知，这是首次报道未培养的Synergistes group 4细菌的乙酸利用活性及其与乙酰分解产甲烷菌Methanosaeta的竞争意义。ISME Journal (2011) 5, 1844-1856; doi：10.1038/ismej.2011.59； 2011 年 5 月 12 日在线发布
Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope-and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with C-14-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with C-13(6)-glucose and C-13(3)-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with C-13-glucose and C-13-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with C-14-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high K-m for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5-10mM). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta.The ISME Journal (2011) 5, 1844-1856; doi:10.1038/ismej.2011.59; published online 12 May 2011