Wim Vermaas's Talk

Aug 07, 2014 - 17:00

Aug 07, 2014 - 18:00

Creativity Hall Room 118 Chemical Engineering

Seminars

Wim Vermaas Foundation Professor School of Life Sciences and Center for Bioenergy and Photosynthesis Arizona State University USA

Abstract : Cyanobacteria are a promising platform for solar-powered CO2-consuming production of biofuels petroleum substitutes and other useful products using photosynthesis. Transformation of selected cyanobacteria resulting in targeted gene replacement deletion or addition is relatively facile and consequently metabolic steps or even pathways can be introduced or enhanced in the cyanobacterium. The organism that is the focus of our research is Synechocystis sp. PCC 6803 which is a well-studied model organism that can use a variety of carbon sources (and thereby employ several different growth modes) and that is amenable to outdoor cultivation in enclosed photobioreactors. Examples of metabolic modifications that we have analyzed in our group are introduction of genes enabling production of isoprene and free fatty acids. Efficiencies and rate limitations will be discussed. In the case of fatty acid production the amount of energy stored in the fatty acid can be up to 28% of the energy of the light if one were to excite with 680 nm light and all absorbed light was used for fatty acid production. Making adjustments for solar illumination (only ~50% of the energy can be used for photosynthesis) blue-photon utilization and losses due to non-photochemical quenching and the requirements for maintenance energy the solar energy conversion efficiency may still be in the range of ~7% which is superior to most other bio-based approaches.Biosketch: Wim Vermaas received his doctorate from the Agricultural University in Wageningen The Netherlands and worked at Du Pont before joining Arizona State University in 1986. His research work over the years has focused on cyanobacteria particularly on photosynthesis and molecular physiology in Synechocystis sp. PCC 6803. Early work involved tool development and molecular-genetic approaches to determine the function of individual subunits and protein complexes in photosynthetic electron transport and as this work matured he included more applied work on cyanobacteria as solar-powered biocatalysts to produce useful compounds in the scientific repertoire. This work includes molecular-genetic metabolic and physiological components as well as larger-scale productivity approaches. In larger multidisciplinary projects the Vermaas group is using Synechocystis strains that have been genetically modified to produce and excrete fatty acids or other useful organic compounds. Dr. Vermaas is Foundation Professor in the School of Life Sciences founding member of the Center for Bioenergy and Photosynthesis director of an NSF-funded interdisciplinary graduate training program in solar energy IGERT-SUN and is Fellow of the American Association for the Advancement of Science.