The increase in cell volume and number of nuclei of the Koji-kin Aspergillus oryzae contributes to its high enzyme productivity

We discovered that the hyphae of Aspergillus oryzae thicken, and the number of nuclei in the apical cells increases tenfold. These thick hyphae with increased nuclei emerge through branching, grow more rapidly, and dominate the periphery of colonies, correlating with improved enzyme secretion capacity. We compared transcriptomes of A. oryzae grown in different types of culture media. We also compared transcriptomes of hypha with different numbers of nuclei, which were cut out and collected separately.