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WIC Seminar: Professor Hiroshi Takagi
Nov 30, 3:30 pm - 4:30 pm
The Wine Innovation Cluster (WIC) invites you to a seminar:
New metabolic regulation and physiological function of amino acids found in yeast and their application to breeding of industrial yeasts
Professor Hiroshi Takagi, Nara Institute of Science and Technology, Japan
There are two major purposes for breeding of industrial yeasts, improvement of fermentation productivity and diversity of product taste and flavor. For these purposes, we can construct yeast strains by the use of ‘metabolic engineering’ for the optimization of cellular metabolism, with the aid of ‘systems biology’ for the computational and mathematical modeling of cellular metabolism and ‘ synthetic biology’ for the design and introduction of new cellular metabolism. My lab is focusing on novel metabolism and function of amino acids found in Saccharomyces cerevisiae.
During bread-making processes, yeast cells are exposed to baking associated stresses such as freeze-thaw, air-drying, and high sucrose concentrations. Proline (Pro) was found to protect yeast cells from various stresses at least as a ROS scavenger. Removal of the Pro feedback inhibition of γ-glutamyl kinase (GK) enhances Pro accumulation and stress tolerance. We showed that baker’s yeast strains expressing GK variants are tolerant to baking associated stresses and enhance fermentation ability, indicating that Pro accumulation is a suitable method for bread making.
Valine (Val) i s widely used in animal feed, dietary supplements and pharmaceuticals. In S. cerevisiae, VaI biosynthesis is regulated by the Val feedback inhibition of acetohydroxyacid synthase (AHAS), which consists o f the catalytic sub unit llv2 and the regulatory sub unit llv6. We found that several ll v6 variants with desensitization of feedback inhibit ion of AHAS resulted in higher intracellular Val contents compared with those in cells with the wild-type llv6. This could be a practical method for the development of yeast strains with high-level production of VaI or isobutanol.
Friday November 30
3.30pm – 4.30pm
followed by drinks and nibbles
Seminar Rooms, Level 2, WIC Building
About the speaker:
Hiroshi Takagi was awarded the degrees of M.Sc. in immunology at Nagoya University in 1982, then worked at Ajinomoto Co, Inc. as a research scientist from 1982 to 1995. During the time, he studied at State University of New York at Stony Brook under Prof. Masayori Inouye. In 1986 and received his Ph.D. degree at the University of Tokyo under Prof. Takahisha Ohta in 1988 for protein engineering of the Bacillus subtilis subtilisin E. He promoted to Chief Biochemist for protein engineering of microbial enzymes for industrial use and development of frozen dough. In 1995, Dr. Takagi left Ajinomoto and was appointed Associate Professor at Fukui Prefectural University. He then started his major fundamental research on novel stress-tolerant mechanisms of yeast, focusing on amino acid metabolism and ubiquitin system, and their applications to industrial yeast breeding. He promoted to full Professor in 2001 and moved to Nara Institute of Science and Technology (NAIST) in 2006. The Takagi lab is involved in Applied Molecular Microbiology including yeast projects and the bacterial cysteine/sulfur metabolism. He is currently Chair of International Commission on Yeasts (ICY). Also, he received “Achievement Award of the Society for Biotechnology, Japan” last year.