[Seminar] Thermophilic Anode Respiring Bacteria

Seminar

Title: Thermophilic Anode Respiring Bacteria

Speaker: Bradley Lusk

Affiliation: Center for Environmental Biotechnology of the Arizona State University (ASU)

Host: Ricardo Louro, Inorganic Biochemistry and NMR Lab

Abstract:

Microbial Electrochemical Cell (MXC) technology harnesses the power stored in wastewater by using anode respiring bacteria (ARB) as a biofilm catalyst to convert the energy stored in waste into hydrogen or electricity. ARB, or exoelectrogens, are able to convert the chemical energy stored in wastes into electrical energy by transporting electrons extracellularly and then transferring them to an electrode. If MXC technology is to be feasible for 'real world' applications, it is essential that diverse ARB are discovered and their unique physiologies elucidated- ones which are capable of consuming a broad spectrum of wastes from different contaminated water sources.

This presentation examines the use of gram-positive thermophilic (60◦C) ARB in MXCs since very little is known regarding the behavior of these microorganisms in this setting. Here, we begin with the draft sequence of the Thermincola ferriacetica genome and reveal the presence of 35 multiheme c-type cytochromes. In addition, we employ electrochemical techniques including cyclic voltammetry (CV) and chronoamperometry (CA) to gain insight into the presence of multiple pathways for extracellular electron transport (EET) and current production (j) limitations in T. ferriacetica biofilms. 

Next, Thermoanaerobacter pseudethanolicus, a fermentative ARB, is investigated for its ability to ferment pentose and hexose sugars prior to using its fermentation products, including acetate and lactate, for current production in an MXC. Using CA, current production is tracked over time with the generation and consumption of fermentation products. Using CV, the midpoint potential of the T. pseudethanolicus EET pathway is revealed.

Lastly, a cellulolytic microbial consortium was employed for the purpose of assessing the feasibility of using thermophilic MXCs for the conversion of solid waste into current production. Here, a highly enriched consortium of bacteria, predominately from the Firmicutes phylum, is capable of generating current from solid cellulosic materials.

Short Biography

Biosketch (where they make me write things about myself in third person):

Scientist, avid runner, businessman, and social entrepreneur, Brad Lusk has spent 7 years of his 11 years at Arizona State University (ASU) as a research scientist in the Swette Center for Environmental Biotechnology researching thermophilic bacteria in microbial electrochemical cells. During his time as a Ph.D. student, he hosted and attended scientific conferences throughout the United States including the North American meeting for the International Society for Microbial Electrochemical Technology (ISMET) at Penn State University, the International meeting for ISMET at ASU, the Association of Environmental Engineering and Science Professors meeting at the Colorado School of Mines, and the general meeting for the American Society for Microbiology in Boston, Massachusetts. His experiences and friendships formed during his graduate studies have enabled him to travel to exotic locations in India and Pakistan, where he has given presentations about his research to a broad, global audience. His has also shared his love for science to live public audiences at local Phoenix events including IGNITE and COMICON.

In his free time, he volunteers with a local non-profit called Camp Sparky -where he served as Chair from 2014-2015- to visit local Title 1 elementary schools through the Phoenix metropolitan area. This volunteer work allows him to spread a message of scientific awareness and emphasize the positive impacts of education to local ‘at-risk’ youth. In 2012, he turned his interest and longtime knack for vintage collectibles into a lucrative online business. He also uses his passion for nutrition and running to conquer 5Ks, 10Ks, and half marathons. With his degree, Brad is looking to travel the world to visit laboratories and industries that are interested in microbial electrochemical research in order to gain a global perspective on his field of interest and to share his experiences to spread cultural awareness.