Thermal Biology Institute Seminar Series
- Monday, March 2, 2015 from 3:10pm to 4:00pm
- Plant Biosciences Building, 108 - view map
Dr. Haluk Beyenal, Associate Professor, Washington State University, is the Thermal Biology Institute's seminar speaker on Monday, March 2. Dr. Beyenal's seminar is, "Electron transfer processes in microbial mats." Seminar is at 3:10pm in 108 Plant Bioscience Building. Dr. Beyenal is a former member of MSU's Center for Biofilm Engineering.
Electron transfer processes in microbial mats
Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. Our research group developed microscale and macroscale electrochemical methods to study local electron transfer processes in microbial mats. For this research, we used a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, to characterize the physicochemical variables influencing electron transfer. Microelectrodes were used to quantify microscale gradients and electron transfer processes. A mat fuel cell consisting of an anode (located near the bottom of the mat) and a cathode (located in the bulk solution) was used to monitor electron transfer rates. In addition, large electrodes located at the bottom of the anodes were anodically or cathodically polarized to understand electron transfer processes and their control on microbial mat structure and activity. Initially, we quantified redox potential, pH and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. To study local electron transfer processes, we deployed a microscale electrode (microelectrode) with tip size ~20 µm. The anodically polarized microelectrode was used to characterize the microelectrode-associated community and compare it to the neighboring mat community. Our results suggested that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared to the neighboring mat community. Finally, our mat fuel cell research suggested that it is possible to electrochemically regulate the structure, community composition, and potentially the function of microbial mats.
- Thermal Biology Institute