Phenotypic regulation of the synthesis of carbohydrases by Kluyveromyces yeasts

Abstract

The ability of Kluyveromyces marxianus Y-303 strain to synthesize highly active intracellular β-fructosidases (invertase and inulinase) was studied. The effect of separate sources of carbon, nitrogen, the initial pH of the nutrient medium, temperature and duration of cultivation process on the biosynthesis of enzymes were studied. The optimal composition of the nutrient medium and cultivation conditions that ensure the maximum production of the studied enzymes by K. marxianus yeast were selected. It was found out that the optimal medium for invertase synthesis contains 3% fructose and 0.6% NH4H2PO4, and for inulinase - 0.5% inulin and 0.12% yeast extract of inulinase. Optimal cultivation conditions for the accumulation of invertase - pH 6.0, temperature - 30 ° C, duration - 42 hours; and for inulinase, respectively: pH 5.0, 25 °C, 66 hours. The described cultivation conditions of K. marxianus led to 6-7 fold activity increase for invertaseand 8–9 fold- for inulinase.