Open Access Poster: Study of enzymatic activities and bacterial communities in two full-scale MBR plants treating wastewaters from municipal solid wastes
Backgrounds: Municipal waste treatment generates wastewaters that have to be treated before their disposal. Membrane bioreactor systems (MBRs) are used for this type of complex wastewater treatment, because of their capacity of working at high concentrations levels of suspended solids and high cell retention times. However, this produces microbial matrixes with limited substrates which reduce the respiratory capability of bacterial communities.
Objectives: The study of enzymatic activities provide important information about the different metabolic processes occurring in the catabolism of proteins, carbohydrates, lipids, inorganic phosphorus assimilation and respiratory capacity of microorganisms.
Methods: Samples from activated sludge were collected monthly during fifteen months from two MBR systems. The enzymatic activities (phosphatases, lipases, glucosidases, proteases and dehydrogenases) were determined spectrophotometrically. The bacterial communities were identified by 16S rRNA gene amplicon sequencing. Multivariate analysis was used to reveal relathionships between the level of enzyme activities, volatile suspended solids (VSS), extracellular polymeric substances (EPS) and bacterial communities.
Conclusions: The activities of all the tested hydrolases were dynamic, showing diverse patterns of variation. Statistically significant relationships have been found between the population of microorganisms and the different enzymatic activities studied. Thus, the relative abundance of Firmicutes, Bacteroidetes and different classes of Proteobacteria has been associated with an increase in glucosidase, acid phosphatase and protease activities in the activated sludge of bioreactors. The simultaneous use of different enzyme activities is useful for the full evaluation of the biodegrading capacity of MBRs treating wastewaters from municipal solid wastes.
Fernández-Navarro, J., Moreno-Mesonero, L., Zornoza, A., Amorós, I., Alonso-Molina, J.L., Muñagorri, F., Álvarez, C. (2017) Study of enzymatic activities and bacterial communities in two full-scale MBR plants treating wastewaters from municipal solid wastes. In: Abstracts of the 7th congress of European microbiologists FEMS 2017, Valencia, Spain, 9-13 July 2017.