P-20
Application of denaturing gradient gel electrophoresis to the inspection of microbes in a brewery
Presenter: Setsuzo Tada, Kirin Brewery Co. Ltd., Yokohama, Kanagawa, Japan
Co-Authors: H. Taguchi and M. Ohkochi, Kirin Brewery Co. Ltd., Yokohama, Kanagawa, Japan

Denaturing gradient gel electrophoresis (DGGE) was developed for directly determining the genetic diversity of complex microbial populations. Kirin applied this technique to the inspection of microbes in a brewery. Kirin has developed a brand named "Yawaraka," brewed by brewer's yeast combined with a specially-selected lactic acid bacterium. DGGE appeared to present a useful tool to guarantee the purity of the lactic acid bacterium strain during production of Yawaraka. We investigated several primers, and the primer corresponding to the position 515 to the position 907 in the 16S rDNA of Escherichia coli proved to be useful for the detection and identification of contaminant microbes. Because the DGGE depends on non-selective PCR-amplification of 16S rDNA and subsequent separation of the amplified DNA fragments by polyacrylamide gel electrophoresis depending on the sequence diversity, we were able to detect contaminant microbes even if they were dead, and only DNA recovered. Moreover, once the amplified DNA was separated and eluted from the gel, we were able to identify the microbes by determining the sequence of amplified DNA.

Setsuzo Tada received his M.S. degree in fermentation technology from Osaka University and began employment with Kirin Brewery Co. Ltd. in 1981. He studied yeast genetics at Massachusetts Institute of Technology as a visiting scientist (1984-1986), and fungal genetics at National Research Institute of Brewing(1987-1990). He received his Ph.D degree from Tokyo University in agricultural chemistry in 1991. At Kirin Brewery, Tada served as project leader for the genetic modification of brewer's yeast (1990-1997), and manager of the Quality Assurance Department at Kirin's Sendai Plant (1997-2000). Since 2000, he has been engaged at the Research Laboratory for Brewing.