【摘要】 <正> 我们以前曾经报告过,用紫外线连续二次诱变曲酸生产菌株黄曲霉AS.3.2789的过程,获得变异菌株μV1223①。经过长时间的生产实践证明,变异株μV1223的曲酸产量比原始菌株提高73.8％。为了充分发挥变异株的产酸能力,对其发酵工艺条件作了进一步的研究。本文主要报告发酵工艺条件研究的结果。更多还原

【Abstract】 μV 1233 is the variant strain of Aspergillus flavus AS.3.2789 by two times of ultraviolet light-induced mutation. It is found the optimal conditions for producing kojic acid are an optimal pH of 2.5-3.0, an inoculum culture grown for 17 hours with 5-7% inoculum in the fermentation medium and a greater rate of aeration.The concentration of mineral salts in the medium has no distinct effect, but the concentration of carbon source is important, the yield of kojic acid being in direct proportion to it within certain limits. If no mineral salts are present and sweet potato meal is used as the sole material for fermentation, the quality of kojic acid remains unchanged and further the yield is increased by more than 6%. It is clear that this improved process is much simpler and cheaper than the previous one and it may be used for industrial fermentation.The morphology of the colonies is compared with the variant and the original strains. The time course of kojic acid production together with the changes of the morphology of the mycelia, the pH, and the sugar consumption are examined.更多还原