Saccharomyces mutants with invertase formation resistant to repression by hexoses

Area of Science:

• Biochemistry
• Molecular Biology
• Yeast Genetics

Background:

• Yeast invertase production is often repressed by hexoses, hindering enzyme research.
• This repression complicates studies on enzyme secretion and characterization.

Purpose of the Study:

• To develop yeast mutants resistant to hexose-induced repression of invertase production.
• To investigate the biochemical and genetic basis of this resistance.

Main Methods:

• Saccharomyces strain 303-67 subjected to two-step ultraviolet irradiation.
• Isolation and characterization of hexose-repression-resistant mutants.
• Analysis of cyclic AMP levels and enzyme synthesis in wild-type and mutant strains.

Main Results:

• Mutants with varying degrees of hexose resistance were obtained, with FH4C showing the highest resistance.
• Cyclic AMP levels did not directly correlate with glucose repression sensitivity.
• Mutant FH4C produced high levels of invertase and resistant alpha-glucosidase synthesis.
• Mutants 1016 and 1710 exhibit substantial resistance, sporulate well, and are suitable for genetic analysis.

Conclusions:

• Developed yeast mutants resistant to hexose repression of invertase.
• These mutants, particularly 1016 and 1710, offer valuable tools for studying yeast genetics and enzyme regulation.
• The findings provide insights into the mechanisms of hexose repression in yeast.