MONITORING NITRIFYING MICROBIAL COMMUNITIES IN WASTEWATER TREATMENT PROCESSES: APPLICATION OF FATTY ACID ANALYSIS

The purpose of this research is to evaluate the use of fatty acid methyl ester (FAME) analysis to monitor nitrifying microbial populations in biological treatment systems. This research investigates the potential application of FAME analysis to monitor nitrifying organisms in activated sludge processes. By extracting FAMEs from the microorganisms in a nitrifying activated sludge sample, we were able to produce a “fingerprint” of the entire microbial community. We also used the combination of FAME analysis and principal component analysis (PCA) to detect shifts in microbial community structure after two chemical inhibitors, nitrapyrin and thiourea, were added to upset the nitrification process. Shifts in fatty acid composition could be detected just a few hours after inhibition. In addition to performing batch inhibition experiments, pure- and mixed-culture studies were used to identify a potential signature fatty acid (19:0 cyclo ω11c) for Nitrobacter sp.