ABSTRACT: Evolution of bacterial community structure and abundance of nitrifiers during the granulation of aerobic granular sludge in a 70 m3 sequencing batch reactor
Project description:The effect of respiration (aerobic cultivation in the presence of heme and vitamin K2) was compared with unsupplemented aerobic cultivation with Lactobacillus plantarum. Two-condition experiment, aerobic vs respiring cells. Biological replicates: 3 aerobic cultures, 3 respiring cultures, independently grown and harvested. One replicate per array. Respiring cultures are called reactor 1-3; Aerobic cultures are called reactor 4-6 In the subsequent analysis data from reactor 4 were not used. There was likely a mistake made during quenching. This was concluded as new labeling/hybridisation gave same (bad) results (128a); slide 128b was dye-swap.
Project description:Polyphosphate accumulating organisms are responsible for enhanced biological phosphate removal from wastewater, where they grow embedded in a matrix of extracellular polymeric substances. Little is known about the composition and dynamics of those proteins and their production by the different microorganisms. Tomás-Martínez et al., (2022) studied the turnover of proteins and polysaccharides in extracellular polymeric fractions of an enrichment culture of polyphosphate accumulating organisms using an anaerobic-aerobic sequencing batch reactor simulating EBPR conditions. Finally, the carbon source was switched to 13C-labelled acetate to study the protein turnover. Samples were collected at the end of each aerobic phase.
Project description:Different granulation mechanisms between “normal granulation” and “enhanced granulation” revealed by microbial community analysis in a pilot scale sequencing batch reactor treating municipal wastewater
Project description:Effluents from sewage treatment plants contain a mixture of micropollutants with the potential of harming aquatic organisms. Thus, addition of advanced treatment techniques to complement existing conventional methods has been proposed. Some of the advanced techniques could, however, potentially produce additional compounds affecting exposed organisms by unknown modes of action. In the present study the aim was to improve our understanding of how exposure to different sewage effluents affects fish. This was achieved by explorative microarray and quantitative PCR analyses of hepatic gene expression, as well as relative organ sizes of rainbow trout exposed to different sewage effluents (conventionally treated, granular activated carbon, ozonation (5 or 15 mg/L), 5 mg/L ozone plus a moving bed biofilm reactor, or UV-light treatment in combination with hydrogen peroxide). Exposure to the conventionally treated effluent caused a significant increase in liver and heart somatic indexes, an effect removed by all other treatments. Genes connected to xenobiotic metabolism, including cytochrome p450 1A, were differentially expressed in the fish exposed to the conventionally treated effluents, though only effluent treatment with granular activated carbon or ozone at 15 mg/L completely removed this response. The mRNA expression of heat shock protein 70 kDa was induced in all three groups exposed to ozone-treated effluents, suggesting some form of added stress in these fish. The induction of estrogen-responsive genes in the fish exposed to the conventionally treated effluent was effectively reduced by all investigated advanced treatment technologies, although the moving bed biofilm reactor was least efficient. Taken together, granular activated carbon showed the highest potential of reducing responses in fish induced by exposure to sewage effluents.