Arthrobacter globiformis - a new yeast-lysing bacterium

Abstract

A bacterium capable to lyse viable yeast cells was isolated from compost enriched with baker's yeast cells and was identified as Arthrobacter globiformis. The yeast lytic enzyme complex produced by shaking culture was precipitated with ammonium sulfate, dialyzed and lyophilized. The crude residue contained beta-glucanase and alpha-mannanase, yet not chitinase. Optimale carbon sources in the culture medium for a high enzyme synthesis were 0.5% beta-glucan for the production of beta-glucanase, resp., 3% alpha-mannan for the production of alpha-mannanase. Addition of 10% whole died baker's yeast cells to the culture medium effected similar results. The crude enzyme residue released among other things spheroplasts from cells of the yeast Pichia membranaefaciens, Metschnikowia pulcherrima, Hansenula anomala and Candida guilliermondii "H". However, it did not or only weakly lyse viable cells of the yeasts Rhodotorula rubra, Rhodosporidium toruloides and Sporobolomyces roseus. The mutants of Candida guilliermondii "H" with modified glucan, resp., mannan concentrations in the cell walls did not indicate differences in their susceptibility to lysis.