Factors affecting the development of the mycelial or yeast form of sporothrix shenckii

Culture conditions for the exclusive development of the mycelial and the yeast forms of Sporothrix Schenkii from conidia in a rich, defined medium were established. Only the mycelial morphology developed when the pH of the medium was adjusted between 4.0 and 5.0 and the conidia were incubated at 25 degrees, regardless of aeration. When the pH of the medium was adjusted between 6.5 and 8.0 and the conidia were incubated with aeration at 35 degrees, only the yeast form was obtained. Development of the mycelial form was observed with all of the carbon sources tested [glucose, fructose, mannose, arabinose, sucrose and starch] while the yeast form was developed only when glucose or another hexose was added to the medium. These observations indicated that in the development of conidia into a specific form is depended on the interrelationship between the available nutrients and the culture conditions and that no specific parameter seemed to be exclusively determinant of the morphology obtained

In vitro activity of the killer toxin from the yeast hansenula anomala against some different microorganisms

The killer toxin of Hansenula anomala showed killer activity toward some different microrganisms. The killer toxin produced by this species was purified. This toxin inhibited completely the growth of 2 species of yeasts,. Candida albicans, and CKefyr; three species of dermatophytes, Microsporum gypseum, M. Canis and Trichophyton mentagrophytes; and 2 species of moulds Fusarium solani and Aspergillus terreus tested at concentrations 100 ul/ml or less. The minimum inhibitory concentration [MIC] of the killer toxin against Candida guilliermondii and C. parapsilosis tested was 20 ul/ml or more. [MIC] of the killer toxin against, M. audoiunii, Sepedomium chrysospermun and Penicillium Coryophilum tested was 60 ul/ml or more. Finally the [MIC] of this killer toxin against the following bacterial strains: Proteus Vulgaris. Staphylococcus aureus, Salmonella typh, E. coli and Rhizobium legumnosarum tested was 25 ul/ml or more. But the [MIC] of this toxin against the two species of: Bacillus subtilus and Pseudomonas areuginosa was 50 ul/ml or more. In this paper we found that the purified H. anomala killer toxin used for the determination the [MIC] of a wide range of yeasts, moulds and bacteria including a number of important species

suppressive effect of green tea extract of chromosome aberrations induced by yeast killer toxin [KT 36] in rat bone marrow cells

Soil samples collected from the different sites in Zagazig area yielded isolation of yeast killer fungi [Hansenula anomala]. Yeast killer toxin [KT 36] from Hansenula anomala fungus induced chromosomes aberrations [CA] in rat bone marrow cells. The incidence of aberrant cells were at their maximum level 24 hours after toxin injection. Rats given the hot water extract from green tea [GTE] 24 h before they were injected with [KT 36] displayed considerably suppressed [KT 36] induced [CA] in their bone marrow cells. Rats administered [GTE] 2 h before or after [KT 36] induced [CA] parallel the dose of [GTE] when given in the range between 0.1 and 2 gm/kg body weight; higher doses produced no additional suppression. On the other h and, rats given the hot water extract from black tea or coffee 24 or 2 h before yeast toxin injection showed no suppressive effect