ELEVATED POLYSACCHARIDE PRODUCTION BY MUTANTS OF THE FUNGUS AUREOBASIDIUM-PULLULANS

Two mutants of the fungus Aureobasidium pullulans ATCC 42023 were isol ated that exhibited elevated polysaccharide production. Both mutants w ere isolated using a combination of chemical mutagenesis and resistanc e to growth inhibitors. It was found that both mutants elaborated high er polysaccharide levels after 7 days of growth on corn syrup or sucro se, respectively, compared to ATCC 42023. The dry weights of the mutan t cells were found not to differ greatly from those of the parent cell s whether corn syrup or sucrose served as the carbon source. The pullu lan content of the polysaccharide synthesized by the mutants or parent cells on sucrose was consistently lower than polysaccharide synthesiz ed on corn syrup. Using corn syrup as a carbon source, the pullulan co ntent of the polysaccharide elaborated by the parent was higher than e ither mutant. The inverse was found to occur with respect to pullulan content when the strains were grown on sucrose as a carbon source.