Induction of new proteins synthesis by the yeasts Rhodotorula rubra and Hansenula anomala exposed to fast neutron irradiation

The influence of a low dose [1mGy] of fast neutron irradiation on the molecular structure of proteins extracted from the yeast fungi Rhodotorula rubra and Hansenuala anomala was investigated. The protein characterization was carried out by using the sodium deodecyle sulfate polyacrylamide gel electrophoresis [SDS-PAGE]. The molecular structure of the water soluble protein [WSP]., extracted from R. rubra and H. anomala, was carried out by measuring their dielectric relaxation at the frequency range 0.01 and 0.5 MHz, respectively at 4 +/- 0.5 °C. The absorption spectra, of the extracted protein, were measured at wavelength ranging from 200 to 600 nm. The results indicated that the protein, extracted from the irradiated R. rubera and H. anomala was improved when compared with the unirradiated ones. Such improvement was signified by an increased number of the protein-bands in the irradiated H. anomala [15], and R. rubra [14] in comparison with the unirradiated ones [10 and 9, respectively]. There were remarkable changes in the average molecular radii, shape, relaxation time and the dielectric increment of the WSP molecules, extracted from R. rubra and H. anomala, as a result of the irradiation processes. The intensities of the absorption bands of the R. rubra and H. anomala, irradiated with fast neutrons, were higher than the unirradiated

Factors affecting protoplast isolation and regeneration in Microsporum gypseum

Factors affecting high yields, regeneration frequencies, and viablity of protoplasts from clonal cultures of Microsporum gypseum were investigated. Maximum yields of protoplasts were obtained after 6 hr digestion of 2-4 days old mycelium with Novozyme 234 using CaCl2 [0.4M] as an osmotic stabilizer and glycine [+] HCL [pH 4.5] as the buffer system. Mercaptoetoethanol + dithi-othreitol [0.01 M] proved to be the best pretreatment of mycelium prior to digestion with enzyme. A regeneration frequency of 94.4% was obtained using the top agar method with complete medium [pH 6.5] containing 0.5% agar and 0.4 M CaCl2 as an osmoticum. Colonies from regenerated protoplasts on medium containing were pigmented and completely powdery with high sporulation

Factors affecting the development of the mycelial or yeast forms of Histoplasma duboisii

Culture conditions for the exclusive development of the mycelial and the yeast forms of Histoplasma duboisii 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°, 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°, 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

Comparative enzymatic and histological studies on albino rat organs treated with yeast spp isolated of air spore in Zagazig

The prevalence of yeast spores in the atmosphere of Zagazig City, was investigated over a period of one year. The total count showed seasonal periodicity. Eighteen spp. of yeasts belonging to 10 genera were recovered and identified. Three spp. were chosen in this study as a typical components of air spora due to their host toxic effect [C and ida albicans, C. guilliermondii and C. parapsilosis]. Cell free supernatants from cultures were injected to some rat groups 0.5 ml/BW daily for one week. The treated organs were examined showing enzymatic changes. The level of GOT and GPT under the effect of the three yeast spp. Showed a marked decrease in liver and kidney while there was an increase in the brain tissue. The alkaline phosphatase and LDH concentration were increased significantly in the liver, kidney and brain in the first yeast spp. The results correlated with toxic potency as they cause destructive changes in hepatic, renal tissue as well as in the nervous tissue. Microscopically, the organs injected by C. albicans were the most effected