Impact of oxygen on the coexistence of nitrification, denitrification, and sulfate reduction in oxygen-based membrane aerated biofilm

作者：Liu Hong; Tan Shuying; Sheng Zhiya; Yu Tong; Liu Yang^*

来源：Canadian Journal of Microbiology, 2015, 61(3): 237-242.

DOI：10.1139/cjm-2014-0574

• membrane aerated biofilms
• sulfate-reducing bacteria
• functional diversity
• PCR-DGGE

Membrane aerated biofilms (MABs) are subject to "counter diffusion" of oxygen and substrates. In a membrane aerated biofilm reactor, gases (e.g., oxygen) diffuse through the membrane into the MAB, and liquid substrates pass from the bulk liquid into the MAB. This behavior can result in a unique biofilm structure in terms of microbial composition, distribution, and community activity in the MAB. Previous studies have shown simultaneous aerobic oxidation, nitrification, and denitrification within a single MAB. Using molecular techniques, we investigated the growth of sulfate-reducing bacteria (SRB) in the oxygen-based MAB attached to a flat sheet membrane. Denaturing gradient gel electrophoresis of the amplified 16S rRNA gene fragments and functional gene fragments specific for ammonia-oxidizing bacteria (amoA), denitrifying bacteria (nirK), and SRB (dsrB) demonstrated the coexistence of nitrifiers, denitrifiers, and SRB communities within a single MAB. The functional diversities of SRB and denitrifiers decreased with an increase in the oxygen concentration in the bulk water of the reactor.

• 出版日期2015-3