Takuro Nunoura, Senior Scientist at the Institute of Biogeosciences and Group Leader for the Research and Development Center for Marine Biosciences at Japan Agency for Marine-Earth Science & Technology (JAMSTEC), will present a seminar, “Bidirectional TCA Cycle in a Facultatively Chemolithoautotrophic and Thermophilic Deeply-branching Bacteria” at the SP on Wednesday, December 16th. The event will be held in Building N239, Room #B39 from 12:00-1:00pm.
Dr. Nunoura’s brief bio and an abstract of his talk follow below. Questions about this event can be directed to the POC, Peter Minogue. The event is co-hosted by NASA Ames and the SP as part of the SP and Ames Bio Talks and Syn Bio Talks Seminar series.
It has been believed that exergonic citrate synthase function only in the oxidative TCA cycle, and ATP-citrate lyase is necessary for the reductive citrate cleavage reaction. This study revealed a reversible TCA cycle operated by bidirectional reaction of citrate synthase in a chemolithotrophic and thermophilic bacteria that belongs to a deeply-branching bacterial lineage. The previously unseen finding provides novel insights into a primordial central metabolism represented by TCA cycle in early life and chemical evolution on Earth. There is a long history of debate between the heterotrophic and the autotrophic origin of life scenarios. The finding in this study presents another scenario. The versatile TCA cycle that supply essential precursors of the core anabolisms in a deeply-branching chemolithotrophic bacteria suggests the possibility of the mixotrophic origin of life on Earth. The mixotrophic metabolism could occur in both the common ancestor of life and the metabolic networks in chemical evolution. Moreover, this implies that the configuration of autotrophy (carbon fixation) or heterotrophy (decarboxylation) is ecological distinction but not primordial role in the origin of life as theoretically hypothesized by Smith and Morowitz (2010).
About the Speaker:
Dr. Takuro Nunoura is a Senior Scientist at the Institute of Biogeosciences and Group Leader for the Research and Development Center for Marine Biosciences at Japan Agency for Marine-Earth Science & Technology (JAMSTEC). His professional research experience includes: molecular ecological and biochemical techniques using DNA/RNA and protein; sequence analysis, phylogenetic analysis, T-RFLP analysis, DGGE analysis, quantitative real-time-PCR analysis, quantitative competitive-PCR analysis, RT-PCR technique; SDS and 2-dimentional PAGE analysis; gene expression; protein purification; constructing genome library; cultivation techniques both under aerobic and anaerobic conditions; identification of novel microbes; and environmental genomics.