Dimorphic fungi isolated from spontaneously fermented juice of soursop, Annona Muricata L.

Two new fungi isolated from fermenting juice of soursop Annona Muricata L., exhibited dimorphism. Aerobic hyphae were coenocytic bearing sporangia while vegetative filaments were septate. Growth in broth was in discrete units. Glucose--yeast extract-peptone broth inoculated with sporangiospores of strain C12 induced arthroconidiospores but it was yeast cells, yeastlike cells, pseudohyphae and pseudomycelia bearing blastospores when strain C13 was inoculated. On the other hand, soursop extract induced arthrospores and yeast cells, yeast like cells and blastospore-bearing pseudomycelia respectively with strain C12 and strain C13 inoculation. Physiological characteristics were distinct. Strain C12 fermented soluble starch and raffinose completely while strain C13 proved weak for both sugars but complete in glucose utilization. The two dimorphic strains along with Saccaharomyces latis were negative in inulin fermentation. The three strains assimilated all carbon and nitrogen sources tested and grew at 37 degrees C. Based on cultural, morphological and biochemical differences, a tentative genus, Dimorphomyces was created for the dimorphic strains. D. diastaticus strain C12 and D. pleomorphis strain C13 were thought to initiate spontaneous fermentation which was brought to completion along with S. latis strain C14.