Quantification of in Situ Growth Activity: A Novel Approach to Study Response of Activated Sludge to Toxic Shock Loadings

A novel denaturing high performance liquid chromatography (DHPLC)-based technique was developed to rapidly separate and identify signature in pre16S rRNA levels among pure cultures of E.coli and A. calcoaceticus as well as activated sludge samples. The chromatography results showed the distinct differences in retention time of the individual species for pre 16S ssDNA, thus providing a qualitative and quantitative characterization of species in a mixture of pre 16S ssDNA. This study is an expansion of previous results reporting the development of a reverse transcription and primer extension assay, and it is the first to document activated sludge response to toxic shock loadings using DHPLC-based quantification of pre16S rRNA levels. The anticipated outcome is to demonstrate the effectiveness of ribosome genesis as a sensitive indicator of toxic loading.