The Effect of Hyperosmotic Stress and Nitrogen Starvation on Growth and \beta-Galactosidase Synthesis in Kluyveromyces lactis and Kluyveromyces marxianus

Turkish Journal of Biology

SEZAİ TÜRKEL¹ 

关键词: Kluyveromyces;    \beta-galactosidase;    osmotic stress;    nitrogen regulation;    glucose repression;   

学科分类：生物科学（综合）

来源: Scientific and Technical Research Council of Turkey - TUBITAK

【 摘 要 】

Kluyveromyces lactis and Kluyveromyces marxianus are industrial yeasts widely used in the production of the \beta-galactosidase enzyme. Biosynthesis of \beta-galactosidase is controlled by glucose repression. In this study it was demonstrated that the derepression of \beta-galactosidase biosynthesis in these yeast strains is inhibited by high osmotic stress. It was found that the \beta-galactosidase activity of K. lactis and K. marxianus remained approximately at the repressed level when these yeast cells were subjected to NaCl-, KCl-, or sucrose-induced high osmotic stress. Derepression of \beta-galactosidase biosynthesis seems to be more sensitive to high osmotic stress in K. marxianus than in K. lactis. In addition, it was shown that nitrogen starvation resulted in a significant decrease in the level of \beta-galactosidase biosynthesis in K. lactis, while nitrogen starvation led to a 2-fold increase in \beta-galactosidase biosynthesis in K. marxianus. Results of this study indicated that high levels of NaCl, but not sucrose, inhibited the growth of K. lactis and K. marxianus.

【 授权许可】

Unknown