[Carbohydrates of the medium and the nature of ontogeny in Aspergillus awamori in relation to glucoamylase biosynthesis].

The biological rhythm of the transition from the processes of blocking and nuclear division to active RNA biosynthesis and growth in submerged culture of Aspergillus awamori producing glucoamylase was studied by the technique of quantitative cytochemistry, and was characterized by distinct daily oscillation in a medium with starch. The rhythm was disturbed when other carbon sources, viz. maltose, sucrose and particularly glucose, were used: the rhythm became longer and uneven, the rate of nuclear blocking decreased, and the de novo formation of the mycelium of the adaptive stage capable of producing glucoamylase was inhibited. As we have shown earlier, such rhythms in fungi are induced at the level of nuclear processes; in this study, they were most affected by the disturbances which led to the inhibition of the enzyme production. It is quite possible therefore that the processes of biochemical adaptation in fungal ontogenesis, particulaly the production of hydrolytic enzymes, are regulated at the molecular-biological level in the initiation of their synthesis rather than at the level of competition between the existing pathways of general metabolism, and are closely related to biorhythms.