Interactions between Perchlorate and Nitrate Reductions in the Biofilm of a Hydrogen-Based Membrane Biofilm Reactor
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- 作者：He-Ping Zhao ; Steve Van Ginkel ; Youneng Tang ; Dae-Wook Kang ; Bruce Rittmann ; Rosa Krajmalnik-Brown
- 刊名：Environmental Science & Technology
- 出版年：2011
- 出版时间：December 1, 2011
- 年：2011
- 卷：45
- 期：23
- 页码：10155-10162
- 全文大小：977K
- 年卷期：v.45,no.23(December 1, 2011)
- ISSN：1520-5851
文摘
We studied the microbial functional and structural interactions between nitrate (NO3鈥?/sup>) and perchlorate (ClO4鈥?/sup>) reductions in the hydrogen (H2)-based membrane biofilm reactor (MBfR). When H2 was not limiting, ClO4鈥?/sup> and NO3鈥?/sup> reductions were complete, and the MBfR鈥檚 biofilm was composed mainly of bacteria from the 蔚- and 尾-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 ClO4鈥?/sup> reduction, while Sulfuricurvum and Hydrogenophaga were responsible for NO3鈥?/sup> reduction. When H2 delivery was insufficient to completely reduce both electron acceptors, NO3鈥?/sup> reduction out-competed ClO4鈥?/sup> reduction for electrons from H2, and mixotrophs become important in the MBfR biofilm. 尾-Proteobacteria became the dominant class, and Azonexus replaced Sulfuricurvum as a main genus. The changes suggest that facultative, NO3鈥?/sup>-reducing bacteria had advantages over strict autotrophs when H2 was limiting, because organic microbial products became important electron donors when H2 was severely limiting.