PRODUCTION OF ANTIBACTERIAL COMPOUNDS BY PHYLLOPLANE-INHABITING YEASTS AND YEASTLIKE FUNGI

The production of antibacterial compounds by yeasts and yeastlike fung i isolated from the phylloplane is reported. Aureobasidium pullulans, Citeromyces matritensis, Cryptococcus laurentii, Rhodotorula glutinis, and Sporobolomyces roseus produced antibacterial compounds inhibitory to both Pseudomonas fluorescens and Staphylococcus aureus in an overl ay bioassay. In contrast, isolates of Candida albicans, Filobasidium u niguttulatum, Saccharomyces cerevisiae, Torulaspora delbruckii, Tremel la foliacea, Trichosporon beigelii, and Trichosporon dulcitum obtained from soil or from culture collections did not produce inhibitory comp ounds when screened by the same procedure. The production of antibacte rial compounds was examined in more detail, using several isolates of A. pullulans distinguished by cluster analysis on the basis of biochem ical and physiological tests. They were found to produce a range of an tibacterial compounds with different activities. Two distinct antibiot ics were produced by an isolate of A. pullulans in liquid culture duri ng both the logarithmic and the stationary phases of growth.