A Novel Ecological Approach to Study Microbial Community Structure in Aggregated Biomass Reactor
Year: 2007
Type: article
Abstract: The objective of this study was to test the hypothesis that the operating conditions of bioreactors could influence the microbial community structure which relates to the bioreactor functional stability.Microbial community structure was studied in bioreactors treating wastewater using an ecology resource competition model.Retention time was varied in order to study the impact of operation condition on the diversity and competition of planktonic and sessile aerobic heterotrophic bacterial species for complementary growth-limiting nutrients in three special cases of biofilm: fully penetrated, internal mass transfer resistance, and external mass transfer resistance biofilm.The results of model simulations showed that for certain values of hydraulic retention time (HRT), competition resulted in oscillations in the abundances of planktonic and sessile species and these oscillations enhanced species diversity.The biofilm model is then extended to describe competition among six aerobic heterotrophs for three complementary growth-limiting nutrients from bioflocs, and incorporates the effects of diffusion limitations and floc propagation.Simulation results show that at certain values of solid retention time (SRT), competition of species favors sustained oscillations in the abundances of species for all three cases of biofloc reactor.The third part of the thesis was to develop a novel denaturing high performance liquid chromatography (DHPLC)-based technique to rapidly separate and identify signature in pre16S rRNA levels among pure cultures.The chromatography results showed the distinct differences in retention time of the individual species for pre 16S ssDNA, thus providing a relative qualitative and quantitative characterization of species in a pre 16S complex.This study is the first to document microbial bacterial response to toxic shock loadings using DHPLC-based quantification of pre16S rRNA levels.
Author: Ting Lu
Institution: University of Cincinnati
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
Funder: University of South Florida
OpenAlex ID: W955672697