Genetic determination of polygalacturonase production in wild-type and laboratory strains of Saccharomyces cerevisiae.

The genetic determination of polygalacturonase (PG) production in Saccharomyces cerevisiae was studied by biochemical and classical genetic techniques. Crosses of PG+ strains with PG- strains showed that in the haploid wild-type-derived strain, two structural genes were involved in the production of a hydrolysis halo on plates with polygalacturonic acid. However, in the case of PG+ laboratory strain IM1-8b, the phenotype was controlled by only one structural gene although the analysis of PG- IM1-8b mutants demonstrated the existence of at least two complementation groups. All these genetic results were assessed biochemically by means of cation-exchange chromatography. Two enzymes were separated in the wild-type strain, and only one in the laboratory strain. The three enzymes had different Km values, molecular masses, and optimal pHs for activity.