[Studies on the conidial differentiation of "Neurospora crassa" -- VII. -- Alcoholic regulation and conidiogenous capacity (wild-type and "fluffy" mutant) (authors transl)].

Sucrose consumption by the wild-type Neurospora crassa is quicker, with much more ethanol produced, in the ammonium medium than in nitrate as single N source. On low sugar concentration which is quickly nullified, little alcohol is produced and early conidiation can develop. The higher the initial sugar concentration, the higher is the alcoholigenic coefficient defined as the efficiency of alcoholic glycolysis per unit of sugar consumed, and the more complete is the conidial "repression" in ammonium medium. The nitrate counteracts this catabolic repression effect and, depressing the alcoholigenic coefficients, permits conidiation even on high sugar (8 %) medium. The "fluffy" mutant produces relatively less ethanol (average 2-3 times less) in all cases even though it increases its alcoholigenic coefficient with the increased sugar concentration. Surprisingly, it is not induced to alcoholigenic glycolytic disinhibition by ammonium and produces even more alcohol in nitrate than in ammonium media, thus revealing an inability to benefit from the antiglycolytic, normally conidiogenous, effect of nitrate. Suggestion is made that this amacroconidial mutant is defective in its metabolic regulation related to the Pasteur effect which is required for conidiogenic expression in the wild type.