Study on Yeast Lytic Enzyme from Fungi

Eighty-two microorganisms lysing a yeast, Rhodosporidium sp., were separated from soil by the clear zone method. The media containing polypepton and aspartic acid, as the nitrogen source, and cell wall of Rhodosporidium sp. J-5B, as the carbon source, were used for the separation. A strain of Actinomycetes, No.39-B was selected from the isolated microbes for its good growth and lytic activity. When the No.39-B was cultivated in the medium contining 0.5% cell wall of Rhodosporidium and 0.05% glucose as the carbon source, it showed high lytic activity (10 units/ml) on hour 48. This enzyme was proven to be an induced type, because no activity was observed in the culture broth when the carbon source was changed from the cell wall to glucose. The crude enzyme was obtained from the culture broth by salting-out with 80% saturation of ammonium sulfate, dialysis, and lyophilization. The enzyme had lytic activities (degree of reduction in OD of living yeast suspension after incubation with 0.3% enzyme for 3 hr at 30℃) for yeasts; 68% to Rhodosporidium sp. J-5B 48% to Hansenula anomala, 38% to Saccharomyces diastaticus; 8% to Candida utilis, and 0% to Mycotorula japonica and Rhodotorula sa. Z-13. The strain of No. 39-B was estimated to be Actinomadura spadix from the data of morphological observation and chemotaxonomical tests showing existence of 2,6 diamino primeric acid and madurose