GENETIC-EVIDENCE FOR INDEPENDENCE BETWEEN FERMENTATIVE METABOLISM (ETHANOL ACCUMULATION) AND YEAST-CELL DEVELOPMENT IN THE DIMORPHIC FUNGUSMUCOR-ROUXII

Three allyl-alcohol-resistant mutants were isolated in the dimorphic f ungus Mucor rouxii and characterized with regard to their alcohol dehy drogenase (ADH) activity in vitro and in vivo as well as their ability to execute the morphological alternatives of dimorphism under differe nt environmental stimuli, either in the absence or in the presence of oxygen. These studies indicated that fermentation and yeast-cell devel opment are independent events and that ADH activity is essential for g rowth of the fungus in the absence of oxygen. Heterokaryon constructio n and analysis indicated that in the three mutant strains the correspo nding genetic alterations are recessive nuclear mutations which behave as allelic in complementation tests.