Impact of different substrates on biomass protein composition during wastewater treatment investigated by two-dimensional electrophoresis
The influence of different influent substrates on biomass protein composition was examined by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Activated sludge from six sequencing batch reactors (SBRs) was investigated; four reactors were fed with model substrates and two received effluents from a wood milling process and a paper production process, respectively. Our investigations showed that in 2D-PAGE complex substrates caused a less diverse protein pattern than model wastewater composed of simple and low molecular weight compounds. This may be caused by complex formation by high molecular weight compounds of substrate with proteins. A more likely explanation is the presence of a more diversified microbial population resulting in a lower concentration of individual proteins, so that detection limits after staining were too high to observe discrete spots.