Microbial community structure in an intermittently aerated submerged membrane bioreactor treating domestic wastewater Original Research Article

The microbial community structure in an intermittently aerated submerged membrane bioreactor treating domestic wastewater was investigated using the respiratory quinone profiling method. The operating cycle consisted of feeding the domestic wastewater into a 90-min oxic condition and a 60-min anoxic condition. A slight difference was observed in the microbial community structure of the suspended microorganisms in anoxic and oxic conditions. The dominant quinone type of anoxic and oxic conditions was ubiquinone (UQ)-8 followed by UQ-10 and menaquinone (MK)-6. The quinone profiles of the suspended microorganisms in the intermittently aerated SMBR with anoxic and oxic cycling showed that Nitrosomonas species, Alcaligenes species, and Thiobacillus, the dominant quinone of there are UQ-8 actively contributed to the biological nitrification/denitrification. The microbial diversities of suspended microorganisms in the anoxic and oxic conditions calculated on the molar fraction basis of all quinone compositions were 8.79–10.38 and 10.03–11.82, respectively.