Studies on methanol-oxidizing yeasts

A series of yeast strains utilizing methanol as the only source of carbon and energy were isolated both from soil and waste waters. Growth of the yeasts was studied in a mineral medium with yeast extract at 30°C. Growth parameters, Q_{o 2} and composition of biomass were studied in the strain 11Bh producing in shaken flasks highest yields of biomass. The biomass was found to contain 44% of crude proteins, 2% esterified fatty acids, 3% non-esterified fatty acids, 6% RNA and 0.25% DNA. Amino acid analysis revealed a high content of essential amino acids, lysine, leucine, valine and threonine in particular.     

Progesterone transformations as a diagnostic feature in the generaAlternaria,Stemphylium andCladosporium

Various species of the generaAlternaria, Stemphylium andCladosporium were shown to display a specific reaction characteristic for the given genus. In theAlternaria genus this is a 1-2-dehydrogenation of the A ring of the steroid molecule, inStemphylium 14α-hydroxylation and inCladosporium 7β-hydroxylation. This chemotaxonomic feature may supplement morphological and functional criteria in the taxonomy of filamentous fungi (Hyphomycetes).     

The passive anaphylactic reaction in guinea pigs elicited by whole and cathepsin D-degraded antigen

The systemic anaphylactic reaction and thein vitro anaphylactic contraction of the terminal segment of the ileum performed according to the Schultz-Dale technique, were elicited in guinea pigs passively sensitized with rabbit antibodies to human serum albumin, using whole and cathepsin D degraded antigen. The intensity of the systemic anaphylactic response that was evoked by degraded antigen was lower; a highly significant suppression of the response was obtained provided an antigen degraded more than by 70% was injected. With an increasing degradation of antigen, more animals responded with lower or even with no reaction; the number of animals developing severe or lethal shock, decreased at the same time. The number of animals that developed a medium anaphylactic response remained at the same level. The degraded antigen did not evoke the anaphylactic contraction of the terminal segment of the ileumin vitro, and moreover, it blocked the contraction after addition of the whole antigen.     

Protein synthesis by synaptosomes from rat brain. Contribution by the intraterminal mitochondria

(1) The characteristics of protein synthesis in microsomal and synaptosomal fractions from rat brain were examined. A high sensitivity to ribonuclease and to cycloheximide, and the need for the presence of pH5 enzymes distinguished protein synthesis in microsomal fractions from protein synthesis in synaptosomes. (2) Under various conditions of incubation synaptosomal fractions prepared in sucrose showed limited protein synthesis compared with synaptosomal fractions prepared by using Ficoll. Such discrepancies could not be attributed to: (i) animal age, (ii) the metabolic state of the synaptosomal fraction, (iii) the absence of bivalent cations in the incubation medium or (iv) the temperature. (3) Protein synthesis in synaptosomal fractions was inhibited 50-65% by cycloheximide, 38-50% by chloramphenicol, 95% by puromycin, 70% by azide and 40% by deoxyglucose; ribonuclease had only a negligible inhibitory effect. (4) As a first approximation to the localization of the protein-synthetic machinery present in the synaptosomal fraction, the distribution of enzymes and radioactivity in subfractions of prelabelled synaptosomes was determined after osmotic shock with water. Approximately 60% of the total protein synthesis in the synaptosomal fraction occurred in the intraterminal mitochondria. (5) Protein synthesis in the intraterminal mitochondria did not show any fundamental difference from synthesis in somatic mitochondria, with respect to inhibition by cycloheximide and chloramphenicol. (6) It was concluded that if extramitochondrial protein synthesis occurs in synaptosomes, it must be very low.     

Diploids in Microsporum gypseum

The paper studies diploids in dermatophyteMicrosporum gypseum. They were isolated as the more rapidly growing sectors from heterokaryons on minimal medium. They are characterized by their wild morphology, conidiation and growth rate, and they are prototrophic. In their genome they contain all the markers present in both mutant components.     

The problem of carotenoid biosynthesis in the taxonomy of genera Rhodotorula and Rhodosporidium

This report presents results in the composition of major carotenoids of various coloured mutants of the genusRhodotorula and of mating types of the genusRhodosporidium. The separation of carotenoid intermediates was carried out by thin layer chromatography using Silufol 254 Kavalier and the determination of eluated spots by spectrophotometry. There was found no difference in carotenoid composition of both mating typesa and α of individual species of the genusRhodosporidium. The vegetative and sexual reproduction ofRhodotorula andRhodosporidium can be separated from the carotenogenesis using 10^?4 mol diphenylamine. It was concluded that lycopene could be the intermediate to mono- and dicyclic carotenoids; in the case of partial inhibition of the dehydrogenation step the direct cyclization of neurosporene to β-zeacarotene can be expected. An unknown compound, probably lycopersene was found and was considered to be the precursor of phytoene. Phytoene and phytofluene were proved in all studied samples. Nutritional conditions (vitamins, sulfur amino acids, etc.) are able to shift the ratios between major carotenoids. Rhodotorula aurantiaca strains were observed to be auxotrophic mutants of various characters and the existence of this species as independent one, was denied.     

Histochemical demonstration of the intestinal hetero-β-galactosidase (glucosidase)

Summary The histochemical demonstration of hetero--galactosidase (glucosidase) has been attempted in sections and zymograms of rabbit, monkey and human intestine and of rat kidney.The leakage of this enzyme from unfixed sections was prevented by the use of cold microtome sections adherent to semipermeable membranes. Methods with -D-glucosides and galactosides of 6-Br-2-naphthol (postincubation azocoupling with Fast Blue B as well as simultaneous azocoupling with hexazonium-p-rosaniline), of -naphthol (simultaneous azocoupling with hexazonium-p-rosaniline) and of 4-Cl-5-Br-3-indolyl (with ferricyanide, phenazonium methosulfate or nitro BT and without any oxidation agent) were used an evaluated concerning the specificity, localization ability and inhibition of enzyme activity. Pretreatment of sections with distilled water or saline and inhibition by p-Cl-mercuribenzoate, glucono- and galactono-lactones were used for the characterization of the demonstrated enzyme activity.6-Br-2-naphthyl--D-glucoside is the most specific substrate for hetero--galactosidase. It is not split by lactase and acid -galactosidase. Only lysosomal -glucosidase can interfere. Because the latter enzyme is membrane-bound the difference in color intensity between untreated and prewashed sections are due to hetero--galactosidase. Only localization on the cellular (not intracellular) level can be achieved, however.The simultaneous azocoupling method with -naphthyl--D-glucoside and hexazonium-p-rosaniline enables a very good localization of hetero--galactosidase in the rabbit intestine. Due to a great inhibition exerted by hexazonium-p-rosaniline on the enzyme activity the method is unsuitable for the detection of hetero--galactosidase in zymograms and in the human intestine. Interference of lactase (or lactase-phlorizine hydrolase complex) is to be considered. The lysosomal -glucosidase does not seem to interfere.Indigogenic methods are not sensitive either. With ferricyanide as an oxidation agent it was not possible to detect the activity of hetero--galactosidase in zymograms and in sections. This is possibly due to overoxidation of indigo. The same holds true for phenazonium methosulfate used for the processing of zymograms. However, it was possible to reveal the activity of hetero--galactosidase in sections of the rabbit and monkey intestine with phenazonium methosulfate as oxidation agent. Nitro BT enhanced the coloration both in zymograms and in sections. In the latter case diffusion artifacts cannot be prevented, however. The interference of lactase, lysosomal -galactosidase and possibly of lysosomal -glucosidase (depending on the glycoside used) is always to be considered.Hetero--galactosidase was localized in the cytoplasm (particularly in the supranuclear region) of differentiated enterocytes covering the villi of the rabbit (the highest activity), monkey and human (the lowest activity) intestine. In crypt enterocytes and in cells of Brunner's glands the activity was lower. The occurrence of a low activity of hetero--galactosidase in the brush border of enterocytes of the rabbit intestine was also demonstrated.A proximodistal gradient was observed in the rabbit and monkey intestine, the upper jejunum displaying the highest activity.In jejunal biopsies of patients with celiac sprue (in the acute stage of the disease) the activity of hetero--galactosidase was lowered. No changes of activity were observed in jejunal biopsies of patients with isolated deficiencies of lactase or sucrase.In the rat kidney the enzyme was demonstrated particularly in the cytoplasm of cells of proximal convoluted tubules.     

Inter-character relationships and heterosis observed in opaque-2 maize crosses and in their normal analogues

Summary Hybrids obtained from two series of diallel crosses made between six o ₂ converted inbred lines on the one hand and their normal analogues on the other were compared for twenty-five characters including yield and several of the yield components, including the parents. Observations on simple inter-character correlation coefficients presented here have shown that the majority of the correlations at the o ₂ level are of the same order as at the normal level. A number of correlations of the o ₂ type are inferior to those of their normal analogues, whereas a few are favoured by the o ₂ gene including the correlation of grain yield with kernels per row. A measure of heterosis for each hybrid over its mid-parent also demonstrated that the o ₂ types show poorer heterosis in more cases than do their normal counterparts. Still, in nearly 40 percent of the cases the o ₂ hybrids were found to be more heterotic than their normal analogues, particularly for the various maturity characters and several of the yield components. Thus, the possibility of improvement exists in breeding maize with the opaque-2 gene.