Production of sulfur compounds by several yeasts of technological interestfor cheese ripening

Several yeasts, Geotrichum candidum, Yarrowia lipolytica, Kluyveromyces lac tis, Debaryomyces hansenii, and Saccharomyces cerevisiae, were studied for their ability to generate volatile sulfur compounds. These yeasts were cult ivated on a synthetic culture medium supplemented with a biosynthetic precu rsor. With S-methylmethionine, dimethylsulfide (DMS) was the major sulfur c ompound produced. L-methionine promoted the synthesis of a wider spectrum o f volatile sulfur compounds. methanethiol (MTL), DMS, dimethyldisulfide (DM DS), dimethyltrisulfide (DMTS) and S-methylthioacetate (MTA). Enzymatic act ivities possibly involved in sulfur compound synthesis were also investigat ed. Important L-methionine-transaminase activities, and also L-methionine-d emethiolase activities were detected in cellular extracts. Their possible r ole in the generation of sulfur compounds and related biosynthetic pathways are also discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.