Concurrent Rapid Identification of Bulking and Foaming Bacteria

Nocardioforms were genetically identified using PCR-REBA. PCR-REBA was able to identify many bacterial genera in one assay. PCR-REBA was able to determine that foams from different WWTPs contain various types of bacteria such as Gordonia spp., Millisia spp., Skermania spp., Tsukamurella spp., and Microthrix parvicella, while light microscopy cannot differentiate amongst them (except M. parvicella). The G. amarae population was detected before foaming event using PCR-REBA, which gives warning sign of the problematic bacteria. The study G. amarae population using qPCR indicated G. amarae were favorable to temperature at 23-26C and during fall and spring (R=0.6011). SRT and F/M were not associated with G. amarae population (R = 0.008 and 0.085 for SRT and F/M, respectively). NH3 in the influent had inverse relationship to numbers of G. amarae, however R was 0.0738. cBOD to nBOD ratio had high R = 0.433. G. amarae were able to uptake high carbon to nitrogen ratio substrate, but G. amarae could not utilize these unbalance nutrients completely. As a result, high biosurfactants were produced, and foams were created during optimum temperature. HRT also had strong relationship to G. amarae population (R= 0.43), which supports this hypothesis that the longer time G. amarae contacted to food, higher G. amarae concentrations were observed.