Microbial polulation dynamics

Miss Ines Baptista 

This project focuses on the application of novel biomolecular techniq ues in the study of specific strains degrading halogenated compounds within bioreactors. These techniques allow a more detailed investigation into microrganisms and their interactions, providing important information to correlate microbial dynamics to biotreatment efficiency. Currently, we are studying the response of microbial communities to perturbations induced in the biosystem, using two techniques: Fluorescence in situ hybridization -FISH, which allows the detection and quantification of specific strains, and Denaturing Gradient Gel Electrophoresis -DGGE, applied to study the evolution of microbial communities and to trace population shifts.

Fluctuating loads, substrate starvation periods and alternating substrates are ubiquitous in biotreatment of point source chemical industry waste streams containing halogenated solvents. The objectives of this project are, (i) to develop an intensified bioscrubbing process in which an oil-absorption column is used to buffer changes in concentrations and types of substrates; (ii) to establish a series of specific microbial strains degrading specific substrates, for which, through a combination of hybridisation techniques with strain-specific fluorescent probes and analytical tools such as epifluorescence image analysis microscopy and flow cytometry approaches, community composition and dynamics are characterized; (iii) to study how communities containing the specific microbial strains react to dynamic conditions including fluctuating loads, starvation periods and sequentially alternating substrates; (iv) to construct models relating absorber-bioscrubber performance to strain behaviour and use these to optimize the absorber-bioscrubber system.