INRS-Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Québec, H7V 1B7, Canada.
Microb Ecol. 2017 Nov;74(4):771-775. doi: 10.1007/s00248-017-1011-1. Epub 2017 Jun 17.
While high-affinity H-oxidizing bacteria (HA-HOB) serve as the main sink of atmospheric H, the ecology of this specialist functional group is rather unknown due to its recent discovery. The main purpose of our study is to provide the first extensive survey of HA-HOB in farmland, larch, and poplar soils exposed to 0.5 and 10,000 ppmv H. Using qPCR and qRT-PCR assays along with PCR amplicon high-throughput sequencing of hhyL gene encoding for the large subunit of high-affinity [NiFe]-hydrogenases (HAH), we found that hhyL gene expression ratio explained better variation in measured H oxidation rates than HA-HOB species richness. Carbon, nitrogen, pH, and bacterial species richness appeared as the most important drivers of HA-HOB community structure. Our study also highlights the need to cultivate HA-HOB due to the huge gap in current genomic databases.
虽然高亲和力 H 氧化菌 (HA-HOB) 是大气 H 的主要汇，但其最近才被发现，因此该专门功能群的生态学仍知之甚少。我们研究的主要目的是首次广泛调查农田、落叶松和杨树土壤中 HA-HOB，这些土壤分别暴露于 0.5 和 10000 ppmv H。我们使用 qPCR 和 qRT-PCR 检测以及 hhyL 基因（编码高亲和力 [NiFe]-氢化酶的大亚基）的 PCR 扩增子高通量测序，发现 hhyL 基因表达比率比 HA-HOB 物种丰富度更好地解释了测量的 H 氧化速率的变化。碳、氮、pH 和细菌物种丰富度似乎是 HA-HOB 群落结构的最重要驱动因素。由于当前基因组数据库存在巨大差距，我们的研究还强调了需要培养 HA-HOB。
