Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, Arizona 85287-5701, United States.
Environ Sci Technol. 2011 Dec 1;45(23):10155-62. doi: 10.1021/es202569b. Epub 2011 Nov 7.
We studied the microbial functional and structural interactions between nitrate (NO(3)(-)) and perchlorate (ClO(4)(-)) reductions in the hydrogen (H(2))-based membrane biofilm reactor (MBfR). When H(2) was not limiting, ClO(4)(-) and NO(3)(-) reductions were complete, and the MBfR's biofilm was composed mainly of bacteria from the ε- and β-proteobacteria classes, with autotrophic genera Sulfuricurvum, Hydrogenophaga, and Dechloromonas dominating the biofilm. Based on functional-gene and pyrosequencing assays, Dechloromonas played the most important role in ClO(4)(-) reduction, while Sulfuricurvum and Hydrogenophaga were responsible for NO(3)(-) reduction. When H(2) delivery was insufficient to completely reduce both electron acceptors, NO(3)(-) reduction out-competed ClO(4)(-) reduction for electrons from H(2), and mixotrophs become important in the MBfR biofilm. β-Proteobacteria became the dominant class, and Azonexus replaced Sulfuricurvum as a main genus. The changes suggest that facultative, NO(3)(-)-reducing bacteria had advantages over strict autotrophs when H(2) was limiting, because organic microbial products became important electron donors when H(2) was severely limiting.
我们研究了在基于氢气的膜生物膜反应器（MBfR）中硝酸盐（NO3-）和高氯酸盐（ClO4-）还原之间的微生物功能和结构相互作用。当 H2不受到限制时，ClO4-和 NO3-的还原完全进行，并且 MBfR 的生物膜主要由 ε-和 β-变形菌纲的细菌组成，自养属 Sulfuricurvum、 Hydrogenophaga 和 Dechloromonas 主导生物膜。基于功能基因和焦磷酸测序分析，Dechloromonas 在 ClO4-还原中起着最重要的作用，而 Sulfuricurvum 和 Hydrogenophaga 则负责 NO3-还原。当 H2的供应不足以完全还原两种电子受体时，NO3-还原会从 H2中竞争电子，而混合营养体在 MBfR 生物膜中变得重要。β-变形菌纲成为优势类群，Azonexus 取代 Sulfuricurvum 成为主要属。这些变化表明，在 H2受到限制时，兼性、NO3-还原细菌比严格的自养菌具有优势，因为当 H2严重受到限制时，有机微生物产物成为重要的电子供体。
