Pyrosequencing Analysis Yields Comprehensive Assessment of Microbial Communities in Pilot-Scale Two-Stage Membrane Biofilm Reactors

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• 作者：Aura Ontiveros-Valencia ; Youneng Tang ; He-Ping Zhao ; David Friese ; Ryan Overstreet ; Jennifer Smith ; Patrick Evans ; Bruce E. Rittmann ; Rosa Krajmalnik-Brown
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：July 1, 2014
• 年：2014
• 卷：48
• 期：13
• 页码：7511-7518
• 全文大小：410K
• ISSN：1520-5851

文摘

We studied the microbial community structure of pilot two-stage membrane biofilm reactors (MBfRs) designed to reduce nitrate (NO₃^{鈥?/sup>) and perchlorate (ClO₄鈥?/sup>) in contaminated groundwater. The groundwater also contained oxygen (O₂) and sulfate (SO₄2鈥?/sup>), which became important electron sinks that affected the NO₃鈥?/sup> and ClO₄鈥?/sup> removal rates. Using pyrosequencing, we elucidated how important phylotypes of each 鈥減rimary鈥?microbial group, i.e., denitrifying bacteria (DB), perchlorate-reducing bacteria (PRB), and sulfate-reducing bacteria (SRB), responded to changes in electron-acceptor loading. UniFrac, principal coordinate analysis (PCoA), and diversity analyses documented that the microbial community of biofilms sampled when the MBfRs had a high acceptor loading were phylogenetically distant from and less diverse than the microbial community of biofilm samples with lower acceptor loadings. Diminished acceptor loading led to SO₄2鈥?/sup> reduction in the lag MBfR, which allowed Desulfovibrionales (an SRB) and Thiothrichales (sulfur-oxidizers) to thrive through S cycling. As a result of this cooperative relationship, they competed effectively with DB/PRB phylotypes such as Xanthomonadales and Rhodobacterales. Thus, pyrosequencing illustrated that while DB, PRB, and SRB responded predictably to changes in acceptor loading, a decrease in total acceptor loading led to important shifts within the 鈥減rimary鈥?groups, the onset of other members (e.g., Thiothrichales), and overall greater diversity.}