Selection and study of a Candida molischiana mutant derepressed for beta-glucosidase production.

A mutant strain of Candida molischiana was selected. Analysis of the exocellular activity of Candida molischiana 35M5N grown on different carbon sources revealed that the biosynthesis of beta-glucosidase is derepressed in this yeast strain. The strain is not a hyper-producer mutant. There were no observed differences in the endocellular and parietal activities of the wild and mutant strains. However, the mutant strain produced 35-fold more enzyme than the wild-type in the culture medium with glucose as carbon source. When glucose was used as carbon source, the mutant strain produced 90% more exocellular enzyme than when cellobiose was used as the carbon source.