Cloning of a Gene Suppressing Hydrogen Sulfide Production by Saccharomyces cerevisiae and Its Expression in a Brewing Yeast. Hidetoshi Tezuka, Toshio Mori, Yasushi Okumura, Katsuaki Kitabatake, and Yoshihiro Tsumura, Central Research Laboratories, Asahi Breweries, Ltd., 2-13-1 Omori-kita, Ota-ku, Tokyo 143, Japan. J. Am. Soc. Brew. Chem. 50:0130, 1992.

NHS₅, a gene suppressing formation of hydrogen sulfide (H₂S), was cloned from a Saccharomyces cerevisiae X2180-1A gene library. The gene was inserted into suitable vectors and introduced into bottom-fermentation yeasts. We verified that the strain with the inserted gene was effective in beer production because the gene reduced H₂S content in green beer and did not affect other fermentation characters. We also proved that the function of the gene was related to production of cystathionine β-synthase.

Keywords: Bottom-fermentation yeast, Hydrogen sulfide