Identification and quantification of Enterococcus spp. species in a
wastewater treatment plant.
Abstract
Faculty: Andrea Silverman
Mentor: Mwanarusi Mwatondo
It was previously observed that wastewater bacteria and laboratory cultured bacteria exhibited different disinfection kinetics. Laboratory cultured Enterococcus spp. had a faster decay rate when exposed to chlorine and monochloramine as compared to wastewater sourced Enterococcus spp., but this differed during sunlight disinfection. Considering that wastewater sourced Enterococcus spp. comprises of over 49 species (Facklam, Carvalho, and Teixeira 2002; Teixeira et al. 2015) whereas the laboratory cultures are typically made up of a single species, this raises the question of whether the genetic variations of species contributed to the disinfection resistance observed in wastewater bacteria. We hypothesize that if the most abundant specie found in wastewater is more resistant to disinfection, then the observed decay rate (k) would be relatively low, however, if the least resistant specie is more prevalent, the observed decay rate would be relatively high. To investigate this, we want to identify and quantify the different enterococci species in wastewater using quantitative polymerase chain reaction (qPCR). This will be conducted quarterly to determine how the seasonal effects influence the bacteria concentration. The significance of this research is that it will provide better insight on how contribution of genetic species’ differences to enhanced disinfectant resistance.