Metaproteomics to investigate the response of the biomass of a membrane bioreactor to a decrease of organic supply

Bacteria of activated sludge for wastewater treatment degrade and oxidize the polluting matter. They can also select and adapt to metabolize complex substrates. The knowledge of metabolic pathways for pollutant degradation becomes decisive to manage wastewater treatment plants. These pathways are strongly related to the bacterial enzymatic activity, that can be revealed through protein measurement. The protein set of a cell represents its functional picture in a given situation, and differently from the gene set it may change significantly according to environmental conditions. In biological wastewater treatment plants, metaproteomics can be applied to find the key enzymes or proteins of a process, and can reveal unexpected biochemical pathways. In every case it can show the metabolic dynamics of an entire consortium in different or targeted conditions. In order to evaluate the behavior of microbial consortia under well determined operating conditions, metaproteomics has been applied for the characterization of the biomass of a membrane bioreactor (MBR) treating an industrial wastewater (Salerno et al., 2016). The present work reports on the effects of changes in wastewater composition/supply on the biomass in terms of its functional response as measured through metaproteomics.