Sang Ho Choi

Sang Ho Choi
Seoul National University, South Korea

Biography

After I graduated from Department of Food Science and Technology, Seoul National University, I decided to study Microbiology at KAIST (Korea Advanced Institute of Science and Technology). While enrolled in the masters program of KAIST, I learned about the physiology and genetics of microorganisms. On graduating from KAIST, I found employment at KIST (Korea Institute of Science and Technology) as a scientist. I worked on the production of novel antibiotics for three and a half years. In 1988, I decided to study the basic mechanisms by which microorganisms sense their environment and respond. I moved with my wife to the University of Iowa in the United States to study for my Ph.D. in microbiology. I studied genetic regulation in a luminous marine bacterium, Vibrio fischeri in Dr. E. P. Greenberg's Lab. Molecular biology and biochemistry were used in the genetic dissection of luxR to elucidate functional domains of the LuxR protein, a luminescence gene activator of V. fischeri. After I got my Ph. D. in 1992, I moved to CalTech (California Institute of Technology) and worked with Dr. M. Lidstrom on the genetics of marine methylotrophic bacteria. I was involved in research projects designed for biochemical and molecular biological characterization of methane assimilation pathways of the bacteria. This research made me realize that molecular biology is an important part of bacterial physiology. In the spring of 1993, I moved to Yale University to further my research on bacterial physiology at the molecular level. I studied the structure of the bacterial chromosome and regulation of genes in Acinetobacter calcoaceticus in Dr. N. Ornston's Lab. For this purpose, recombinants with exogenous genes introduced at different chromosomal sites were constructed and their genetic stability was examined. My work with Dr. N. Ornston also showed me what it takes to be a great human being as well as a great scientist. In August 1993, the Chonnam National University offered me a position and I moved back to Korea. After 11 years in the Chonnam National University as a faculty member in the Department of Food Science and Technology, I moved to the Seoul National University, Department of Food science and Biotechnology. My research interests in Korea are focused on the molecular biology of foodborne pathogenic bacteria, such as Vibrio vulnificus and E. coli O157:H7. I started with the development of methods for direct and rapid detection of the pathogens from food samples, molecular fingerprinting of the natural isolates of the bacteria. I am also cloning and characterizing the toxRS gene, encoding a signal transducer of V. vulnificus. Now, I am struggling to understand the pathogenesis of V. vulnificus at the level of genomics.