A new fungus (named Geotrichum sp. 38) was discovered from soil by screening. This microorganism possesses a unique reductive property and excellent reactivity. In contrast to Baker's yeast, it catalyzes the reduction of carbonyl group of various substrates according to an anti-Prelog mode. While carrying out the investigation of the synthesis of optically active cyanohydrins catalyzed by oxynitrilase, a new system called micro-aqueous reaction system suitable for use the of raw enzyme preparations was established with good prospects in industry. Three other (R)-oxynitrilase sources with high reactivity have also been obtained by screening.

Key words: GEOTRICHUM CANDIDUM, REDUCIBILTY, SYNTHESIS, BEER, YEAST