DIRECTED EVOLUTION OF METABOLIC PATHWAYS IN MICROBIAL POPULATIONS II. A REPEATABLE ADAPTATION IN SACCHAROMYCES CEREVISIAE

[摘要] A selection experiment was conducted for approximately 1,000 generations in a chemostat population of 109 cells of the haploid yeast, S. cerevisiae . The experiment was designed to enhance genetically the rate at which the external enzyme acid phosphatase catalyzed the hydrolysis of very low concentrations of β-glycerophosphate at an unfavorably high pH. The observed genetic adaptation in this experiment consisted of a mutation (ACP-2) in the acid phosphatase structural gene which effected a shift in the pH optimum of the enzyme and incremented its activity. The effects of ACP-2 and a similar mutation, ACP-1, on acid phosphatase substrate specificity are also reported.

[学科分类] 医学（综合）