Impact of hydraulic retention time on MBR and hybrid MBBR-MBR systems through microbiological approach: TGGE and enzyme activities

Abstract

The microbial community structure and the enzyme activities of a MBR and two hybrid MBBR-MBR systems were analyzed at two different hydraulic retention times. The TGGE fingerprinting showed that the microbial community structure was deeply dependent on the operational HRT. The activities of acid phosphatase, basic phosphatase and α-glucosidase enzyme activities also were affected by the different HRT. A multivariate redundancy analysis showed that the first of these was positively correlated with the HRT, while the other two were negatively correlated. In this sense, the microbiological approach could successfully explain the influence of the HRT over the bacterial communities and activities in the MBR and hybrid MBBR-MBR systems analyzed.