Research Seminar - Hawkesbury Institute for the Environment

HIE SEMINAR – Thursday 6 September 2012

• Who: Dr Nick Coleman, School of Molecular Bioscience, University of Sydney
• Seminar title: Biodegradation of dichloroethane at the Botany Industrial Park
• When: 3pm, Thursday 6 September
• Where: Lecture Theatre G.21, Building L9, Hawkesbury Campus, UWS

Seminar abstract - The chlorinated hydrocarbon 1,2-dichloroethane (DCA) is a common pollutant of groundwater, and poses both human and environmental health risks. The Botany Industrial Park in south Sydney is heavily contaminated with DCA and other organochlorines. The main user of the site (Orica Ltd) operates a large groundwater treatment plant (GTP) on site to contain and remediate the DCA-contaminated groundwater. At present, remediation is done by air-stripping and thermal oxidation, but this is very costly and energy-intensive. Orica is interested in alternative technologies for treating the groundwater, including bioremediation. In 2010, a pilot scale membrane bioreactor (MBR) was set up to treat a fraction of the groundwater. The aims of our study were to identify DCA-degrading bacteria and genes in the GTP and on the site at large, define the community structure and ecological successions occurring in the MBR, develop a qPCR for catabolic genes in the DCA biodegradation pathway, and field-test this qPCR assay in the MBR and in a survey of groundwater in monitoring wells on the site. We discovered that DCA-degrading bacteria using a hydrolytic pathway (dhlA/dhlB genes) were widespread and diverse at this site, and that the dhlA gene was carried on a catabolic plasmid. The community in the MBR was dominated by alpha- and beta-proteobacteria, and was highly dynamic, changing dramatically in composition as the percentage of raw groundwater in the feed was increased. By combining dhlA qPCR and 16S pyrosequencing data, we found evidence that thus-far-uncultured species of Azoarcus may play a major role in DCA bioremediation in situ in the MBR.

Further information on Dr Coleman can be found via: http://sydney.edu.au/science/molecular_bioscience/people/profiles/ncoleman.php

Further information about the HIE Seminar series and committee can be accessed via: http://www.uws.edu.au/hie/events_and_seminars

No RSVP is required, we hope to see you all there