Event
Bioengineering Seminar Series: Birthe Kjellerup
Friday, September 25, 2015
9:00 a.m.-10:00 a.m.
Pepco Room (1105), Jeong H. Kim Engineering Building
Dr. William Bentley
bentley@umd.edu
Birthe Veno Kjellerup
Assistant Professor, Pedro E. Wasmer Professor in Engineering
Department of Civil & Environmental Engineering
University of Maryland
Activity and diversity of biofilm bacteria involved in enhanced bioremediation of Polychlorinated Biphenyls
Organohalide contaminants such as Polychlorinated Biphenyls (PCBs) have for decades been caused environmental health problems due to anthropogenic activities. Removal of PCBs from contaminated aquatic sediments and soils is a priority because of their ability to enter the food chain and their toxic properties. While in situ microbial degradation of PCBs can represent a significant improvement, previous attempts have failed because of PCB stability, low bioavailability, and the low abundance and activity of indigenous PCB-degrading microorganisms. The high efficiency of activated carbon to quickly sequester PCBs from sediments has been demonstrated. However, this approach leaves the PCBs in the environment only exposed to indigenous organohalide respiring bacteria and limited degradation. The efficiency of PCB degradation can be improved by facilitating the formation of organohalide respiring biofilms. During biofilm colonization, bacteria are encased in an extracellular polymeric substance (EPS) or “slime”, which allows them to share nutrients and remain protected from environmental stresses. In our research, organohalide respiring biofilms are applied for bioremediation enhancement of PCBs by using a novel delivery system with activated carbon as growth surface for biofilm formation. Biofilms of anaerobic Dehalobium chlorocoercia DF1 and enrichments from wastewater were formed and mixed into PCB contaminated sediment.
We apply diverse analytical techniques such as organic solvent extraction and GC-MS analysis for determination of total PCB and individual congener concentrations, anaerobic culturing approaches, molecular biological techniques including DNA extraction, q-PCR, identification by DHPLC and Next Gen Sequencing (Illumina) and microscopy such as fluorescent techniques (Live/Dead staining, Fluorescence In Situ Hybridization, PNA-FISH) and Scanning Electron Microscopy.
