The effects of gene disruption of Kre6-like proteins on the phenotype of β-glucan-producing Aureobasidium pullulans

This genetic study identified two Kre6-like proteins in Aureobasidium pullulans M-2 and created single and double gene-disruption mutants. Disruption changed cell morphology and reduced extracellular-polysaccharide production and beta-glucan branching relative to the wild type, without producing the severe viability defect seen in comparable Saccharomyces mutants. The findings help explain biosynthesis and cell-wall biology in this strain. They do not demonstrate that the mutations optimize molecular weight, immunological potency, commercial production, or health effects.