CONIDIATION OF ASPERGILLUS NIDULANS IN SUBMERGED LIQUID CULTURE

Submerged shake cultures of Aspergillus nidulans produce conidia within 33hr of incubation under optimal growth conditions. Although the conidia are viable and are formed on normal structures, they lack the green pigment. Conidiating shake cultures turn the media yellowish brown. Although conidia germinate even in the absence of inorganic salts in the minimal medium, mycelium formation is inhibited. In a medium deficient in KCl, small hard ball-like colonies are formed. On being transferred to a normal medium, all the germinated conidia or abnormal colonies give rise to normal colonies with normal conidial heads. Colonies grown in liquid media for a long time are capable of producing cleistothecia very quickly. The importance of these observations has been discussed.