Showing papers in "Folia Microbiologica in 1978"
TL;DR: Secondary metabolism and cellular differentiation occur within a range of concentrations of phosphate and, in specific taxonomic groups, of zinc, manganese, and/or iron that is much narrower than that permittee for primary metabolism.
Abstract: Secondary metabolism and cellular differentiation occur within a range of concentrations of phosphate and, in specific taxonomic groups, of zinc, manganese, and/or iron that is much narrower than that permittee for primary metabolism. Possible molecular sites of action of the four elements are reviewed.
56 citations
TL;DR: The ability of these yeasts to utilize the wood components (hitherto unknown in the genusCryptococeus) makes them potential producers of microbial proteins from industrial wood wastes containing xylose oligosaccharides, xylan, and hemicelluloses as the major saccharide components without previous saccharification.
Abstract: The ability to grow in liquid media withD-xylose, xylan from deciduous trees, and hemicelluloses from conifers was tested in 95 strains of 35 genera of yeasts and yeast-like organisms Of 54 strains thriving on xylose, only 13 (generaAureobasidium, Cryptococcus andTrichosporon) utilized xylan and hemicelluloses as growth substrates The arowth media of these strains were found to contain xylandegrading enzymes splitting the substrate to xylose and a mixture of xylose oligosaccharides The ability of these yeasts to utilize the wood components (hitherto unknown in the genusCryptococeus) makes them potential producers of microbial proteins from industrial wood wastes containing xylose oligosaccharides, xylan, and hemicelluloses as the major saccharide components without previous saccharification
43 citations
TL;DR: Eurotium repens mycelium cultivated under static conditions was used to isolate and identify metabolities and the highest cytotoxicity towards HeLa cells was found in physcion which caused 50 % growth inhibition at a concentration of 0.1 ώg/ml.
Abstract: Eurotium repens mycelium cultivated under static conditions was used to isolate and identify metabolities—echinulin, physcion, erythroglaucin, flavoglaucin and asperentin; the filtrate of the culture yielded asperentin 8-methylether The broadest biological activity spectrum was displayed by asperentin which had antibacterial and antifungal effects and, at a concentration of 86 ώg/ml, caused 50 % mor7 tality inArtemia saline larvae The highest cytotoxicity towards HeLa cells was found in physcion which caused 50 % growth inhibition at a concentration of 01 ώg/ml
38 citations
TL;DR: Seventy-five species and three varieties which belong to thirty-four genera were identified from 74 soil samples collected from salt marshes in Egypt, with the most frequent fungi being Aspergillus fumigatus, As pergillus niger, Cladosporium herbarum andAlternatia alternata.
Abstract: Seventy-five species and three varieties which belong to thirty-four genera were identified from 74 soil samples collected from salt marshes in Egypt. The most frequent fungi wereAspergillus fumigatus, Aspergillus niger, Cladosporium herbarum andAlternatia alternata, followed byAspergillus terreus,Curvularia spicifera andPenicillium notatum. Six genera were of moderate occurrence:Penicillium, Futarium, Curvularia, Rhizopus, Stachybotrys, andChaetomium. Five genera were of low occurrence:Paecilomyces, Oephalosporium, Epicoccum, Mucor andMyrothecium.
37 citations
TL;DR: The system induced by maltose but not the one induced by α-methyl-d-glucoside was de-induced rapidly by the intervention of a cytoplasmsynthesized protein and Chloramphenicol suppressed all effects of cycloheximide.
Abstract: Using incubation in the presence of 0.4 mM cycloheximide the half-lives of the principal membrane transport proteins in baker's yeast were found to be: more than 24 h for the constitutive glucose carrier, 2.2 h for the inducible galactose carrier, 1.2 h for the inducible maltose carrier and 0.8 h for the inducible alpha-methyl-D-glucoside carrier. The distinct nature of the two last-named carriers was thus supported. De-induction of the galactose carrier was enhanced in the presence of glucose plus cycloheximide but not of either substance alone. Chloramphenicol suppressed all effects of cycloheximide. In contrast to the enzymes of galactose metabolism, the induction of the glactose carrier was not under the control of a mitochondrial factor and took place in a rho-mutant. The system induced by maltose but not the one induced by alpha-methyl-D-glucoside was de-induced rapidly by the intervention of a cytoplasm-synthesized protein.
35 citations
TL;DR: Antibiotic compounds do not constitute a homogeneous group and from the chemical point of view they are highly heterogeneous and it is difficult to formulate a general hypothesis that would explain the causes of production of these compounds on the basis of data obtained so far.
Abstract: Antibiotic compounds do not constitute a homogeneous group. From the chemical point of view they are highly heterogeneous and it is difficult to formulate a general hypothesis that would explain the causes of production of these compounds on the basis of data obtained so far (Donovick and Brown, 1965). This difficulty is also reflected by contradictory assumptions concerning the importance of these compounds for production microorganisms.
32 citations
TL;DR: The broad spectrum of animal, plant, and bacterial viruses which had been concentrated by PEG prove the usefulness of this method and different macromolecules will also be mentioned.
Abstract: McClendon (1954) was probably the first to use polyethylene glycol (PEG) for precipitating a fraction of a suspension. Working with isolated chloroplast suspensions he observed that (i) a nucleoprotein-like material precipitates after addition of PEG and (ii) salts promote this precipitation. Later Stocking (1956) added 40% PEGa0o0 to tobacco-leaf homogenate and detected 90% of the phosphorylase activity in the precipitate; thus the protein nature of the PEG precipitate was proved. Similar results were obtained for catalase activity. The first attempts to precipitate viruses with PEG in the presence of NaC1 are due to Hebert (1963). In the following 15 years many publications appeared dealing with the application of PEG to separate and concentrate viruses (Leberman, 1966; Friedmann and Haas, 1970; Wagner et al., 1970; Yamamoto et al., 1970; Hiebert and McDonald, ]973; Polson, 1974; Vajda and Hs 1976). The broad spectrum of animal, plant, and bacterial viruses which had been concentrated by PEG prove the usefulness of this method. This review is focussed on the separation of viruses by PEG, but in some cases different macromolecules will also be mentioned. These will be equally referred to as \"particles\".
32 citations
TL;DR: Substitution with NO2, Cl, Br and I into position 6 of 2-benzthiazoIthiol derivatives increased their antimicrobial efficiency while the SH group is preserved.
Abstract: Substitution with NO2, Cl, Br and I into position 6 of 2-benzthiazoIthiol derivatives increased their antimicrobial efficiency while the SH group is preserved. This increase affected both G+ and G-bacteria, mycobacteria and some fungi The degree of efficiency of the benzthiazol derivatives is also influenced by the substituent in position 2.
27 citations
TL;DR: A new metabolite was isolated from the culture of Penicillium rugulosum and its structure was determined from physico-chemical data.
Abstract: A new metabolite was isolated from the culture ofPenicillium rugulosum and its structure was determined from physico-chemical data. Accompanying metabolites skyrin and rugulosin were characterized by UV, IR, CD, mass and NMR spectra.
26 citations
TL;DR: Of a total of 177 strains of yeasts and yeast-like organisms only 8 were capable of producing α-amylase; most strains were able to utilize 1,4-α-D-glucans by means of enzymes acting on the nonredueing ends of the outer glucan chains.
Abstract: Of a total of 177 strains of yeasts and yeast-like organisms only 8 were capable of producing alpha-amylase; most strains were able to utilize 1,4-alpha-glucans by means of enzymes acting on the non-reducing ends of the outer glucan chains.
25 citations
TL;DR: The molds exhibited lowest enzyme activity but highest cell yields, bacteria produced lowest cell yield and maximum enzyme activity, and strains exhibiting very high activity were Saccharomyces fragilis and Streptococcus cremoris.
Abstract: Sixty-two strains of yeasts, molds and bacteria were screened for lactase (beta-D-galactosidase) activity. Strains exhibiting the enzyme activity were evaluated for cell yield as well as enzyme units available per litre of the medium, per g cell dry weight and per mg protein of their cell-free extracts. The molds exhibited lowest enzyme activity but highest cell yields, bacteria produced lowest cell yield and maximum enzyme activity. Cultures exhibiting very high activity among yeasts were Saccharomyces fragilis (strain 3217) and among bacteria Streptococcus cremoris (strain H), Lactobacillus bulgaricus (strain RTS and 1373) and Leuconostoc citrovorum (strain 8081).
TL;DR: Torulopsis ingeniosaDi Menna was found to possess an α-amylase strongly attached to the cell wall, its pH optimum being at 5.5, optimum temperature at 50 °C, highly sensitive to thermal inactivation.
Abstract: Torulopsis ingeniosa DI MENNA was found to possess an alpha-amylase strongly attached to the cell wall, its pH optimum being at 5.5, optimum temperature at 50 degrees C, highly sensitive to thermal inactivation. The enzyme was found to be induced by starch but the synthesis is not subject to a glucose effect.
TL;DR: The conidiation of Trichoderma viride colonies grown in the dark had no circadian character and its periodicity depended on the periodicity of photo-induction, and its intensity was influenced by the carbon sources used, a maximum being reached with glucose.
Abstract: After a short irradiation at 366 nm with 200 lx, the intensity of conidiation ofTrichoderma viride colonies grown in the dark increased for the first 10 s proportionally with time. The increase slowed down after 10 s—6 min of exposure and after 10–60 min of irradiation the conidiation intensity began to decrease. When photo-induced by daylight, the conidiation started at a high rate after 25 h and persisted even after 48 h. The conidiation had no circadian character and its periodicity depended on the periodicity of photo-induction. Its intensity was also influenced by the carbon sources used, a maximum being reached with glucose (1–2 %). Higher glucose concentrations inhibited conidiation but had no influence on growth of colonies.
TL;DR: Submerged cultures of the basidiomyceteOudemansiella mucidd, strain III, accumulate D-arabino-2-hexosulose, the enzyme responsible for the C(2)-specific oxidation ofd-glucose acts as an intracellular oxidase with a maximum activity in the exponential phase of growth.
Abstract: Submerged cultures of the basidiomycete Oudemansiella mucida, strain III, accumulate D-arabino-2-hexosulose. The maximum yields during cultivations in shaker flasks or in a laboratory fermentor are 6--12 and 15 mg/ml, respectively (20--50% conversion of substrate glucose). The accumulation is transient, the aldoketose being again utilized after glucose exhaustion. Its production is stimulated by fluoride ions. The enzyme responsible for the C(2)-specific oxidation of D-glucose acts as an intracellular oxidase with a maximum activity in the exponential phase of growth. D-arabino-2-Hexosulose was also detected in the cultivation medium of the wood-rotting fungi Pleurotus ostreatus, Laetiporus sulphureus, and Phellinus abietis.
TL;DR: The profound effect of colicin E3 on mammalian cells could be interpreted in a similar way as in bacteria,viz.
Abstract: The plasma membrane of mammalian cells can mediate the cytotoxic and cytocidal effects of colicin E3. As little as 102 lethal units of purified colicin E3 per cell exert a pronounced cytocidal effect on human epithelial HeLa cells and as little as 104 lethal units per cell also on line L mouse fibroblasts in tissue culture. Cells in complete monolayers are rapidly killed, become spherical and shrink, they are detached from the support and finally autolyzed. The percentage of killed cells in both lines is directly proportional to the multiplicity of colicin used. Theld 50 for HeLa cells is about 30 times lower than for L cells. At the multiplicity of 105 l.u., usually 100 % HeLa cells and 90 % L cells are killed in 2–3 days. Purified colicins E2 and D have no demonstrable cytological effect on HeLa cells, although DNA synthesis in L cells appears to be partly inhibited by colicin E2. The profound effect of colicin E3 on mammalian cells could be interpreted in a similar way as in bacteria,viz. as a specific cleavage of rRNA.
TL;DR: The strictly aerobic yeastCandida parapsilosis transports the nonmetabolizable monosaccharide 6-deoxy-D-glucose by an active process (inhibition by 2.4-dinitrophenol and other uncouplers but not by iodoacetamide), the accumulation ratio decreasing with increasing substrate concentration, in agreement with those predicted from kinetic constants for influx and efflux.
Abstract: The strictly aerobic yeastCandida parapsilosis transports the nonmetabolizable monosaccharide 6-deoxy-D-glucose by an active process (inhibition by 2.4-dinitrophenol and other uncouplers but not by iodoacetamide), the accumulation ratio decreasing with increasing substrate concentration. Measured accumulation ratios are in agreement with those predicted from kinetic constants for influx and efflux. Energy for transport is probably required in the translocation step. The maximum rate is temperature-dependent with a transition point at 21 °C. the accumulation ratio is not, The uptake is most active at pH 4.5–8.5. It appears not to involve stoichiometric proton symport. The transport system is shared by D-glucose, D-mannose, D-galactose and possibly maltose but not by fructose, sucrose or pentoses. The apparent half-life of the transport system was 3.5–4 h.
TL;DR: The photo-induced conidiation of Trichoderma viride is suppressed by ethidium bromide, acriflavin, lomofungin and 8-quinolinol at concentrations which do not inhibit the colony growth of this deuteromycete.
Abstract: The photo-induced conidiation of Trichoderma viride is suppressed by ethidium bromide, acriflavin, lomofungin and 8-quinolinol at concentrations which do not inhibit the colony growth of this deuteromycete.
TL;DR: Chromatographic analysis of commercial xylan degradation products suggested that the isolates produced either endo-or exo-xylan hydrolases or their mixtures, and mixed additions of culture fluids showed a highly synergistic effect.
Abstract: A good proportion of Sreptomyces isolates from natural sources produced extracellular xylan hydrolase. Nineteen isolated showing high activity were able to completely or partially degrade wheat bran in the growth medium. Chromatographic analysis of commercial xylan degradation products suggested that the isolates produced either endo- or exo-xylan hydrolases or their mixtures. Mixed additions of culture fluids showed a highly synergistic effect, up to an increase by 200%. In a few cases antagonism was seen which, however, could be removed by dialysis of the culture fluid.
TL;DR: In this article, mutants of Streptomyces coeruleorubidus were isolated from the production strains after treatment with UV light, gamma-radiation, nitrous acid, and after natural selection; according to their different biosynthetic activity the mutants were divided into five phenotypic groups.
Abstract: Mutants of Streptomyces coeruleorubidus, blocked in the biosynthesis of anthracycline antibiotics of the daunomycine complex, were isolated from the production strains after treatment with UV light, gamma-radiation, nitrous acid, and after natural selection; according to their different biosynthetic activity the mutants were divided into five phenotypic groups. Mutants of two of these groups produced compounds that had not yet been described in Streptomyces coeruleorubidus (aklavinone, 7-deoxyaklavinone, zeta-rhodomycinone and glycosides of epsilon-rhodomycinone). The mutants differed from the parent strains and also mutually in morphological characteristics but no direct correlation between these changes and the biosynthetic activity could be observed in most cases.
TL;DR: The multiplicity of the structural variation of anthracycline antibiotics can be better reviewed if the substances are differentiated by the number and the positions of the free phenolic groups of the aglycone.
Abstract: The great family of anthracyclines unites under the name proposed by Brockmann (1963) different antibiotics based on tetrahydrotetracene quinone-5,12. The anthracyclines are glycosides, the aglyeone being a derivative of the above quinone linked to one or more identical or different sugar moieties. The differences lie in the substituents at defined positions of the aglycone, e.g. hydroxy, methoxy, earbomethoxy, acetyl, ~-hydroxyacetyl, ethyl or methyl groups. The hydroxy groups are usually found in positions 1, 2, 4, 6, 7, 9, 10 and/or l l; the methoxy group is in position 2 and 4; the earbomethoxy function in position 10, the acetyl, hydroxyacetyl, ethyl or methyl groups in position 9 (Van~k et aL, 1977). The variations within the different types of anthracyclines are based on the kind and sequence of sugars, the number of their molecules, the nature and configuration of the glycosidic bonds and the binding position. The glycosidic bond is usually found in position 7 and 10, occasionally perhaps in position 9. The third type of variability is due to sugars attached through two glycosidic bonds as seen in the aclacinomycins and cinerubins (Van~k et al., 1977). The multiplicity of the structural variation of anthracycline antibiotics can be better reviewed if the substances are differentiated by the number and the positions of the free phenolic groups of the aglycone.
TL;DR: On the basis of the effect of 2-hy-droxy-5 nitrobenzyl bromide, N-bromosuccimmide and N-aeetyhmidazole it may be assumed that trytophan and possibly tyrosine residues influence the enzyme catalysis.
Abstract: Some properties of purified endo-l,4-β-D-xylanase (1,4-β-D-xylan xylanohydrolase, EC 3.2.1.8) from the ligniperdous fungusTrametes hirsuta were investigated. The enzyme was stable between pH 4.0 and 8.0 with optimum activity at pH 5.0–5.5. The temperature optimum was 50 °C and the enzyme was stable for up to 30 min at 45 °C; however, it was denatured at higher temperatures. TheKm for 4-O-methylgluourono-D-xylan was 6.36. 10−3 equivalents ofD-xylose per litre, the activation energy was 28 kJ mol−1. The molecular weight determined by means of gel chromatography was 22000–24000. The enzyme was activated by Ca2+ and inhibited by Ag+ and Hg2+. On the basis of the effect of 2-hy-droxy-5 nitrobenzyl bromide, N-bromosuccimmide and N-aeetyhmidazole it may be assumed that trytophan and possibly tyrosine residues influence the enzyme catalysis.
TL;DR: Cell division was found to induce a pronounced increase in the concentration of sterols and changes in the concentrations of other types of lipids, indicating that changes associated with the division process are only transient.
Abstract: Changes in the concentration of lipids were followed in synchronously dividing cells ofSaccharomyces cerevisiae. Cell division was found to induce a pronounced increase in the concentration of sterols and changes in the concentrations of other types of lipids. The changes associated with the division process are only transient.
TL;DR: The level of lipids was lower as compared to the literature data and their extractability was affected by the manner of preparation of algae and extraction conditions, while the spectrum of fatty acids included both saturated and unsaturated acids from C12 to C22.
Abstract: Fatty acids fromChlorella vulgaris, Scenedesmus obliquus var.acutus and from a mixed culture of the two strains, Melnik, were converted to methyl esters, separated by gas chromatography, and identified by means of standards. The spectrum of fatty acids included both saturated and unsaturated acids (with odd and even numbers of carbon atoms) from C12 to C22. Fatty acids C16:0, C18:0 and C20:3 were the major components in all cultures. Pure strains differed from the mixed culture in the production of C18:1, C12:0 and C19:2 acids; the first of these was present in higher amounts in pure cultures only, the latter two being found in the mixed culture. The level of lipids was lower as compared to the literature data and their extractability was affected by the manner of preparation of algae and extraction conditions.
TL;DR: Functional half-life of the exocellular protease mRNA was determined in exponentially growing and stationary cells of the asporogenic strain ofBacillus megaterium, KM and in the sporogenic strains during sporulation.
Abstract: Functional half-life of the exocellular protease mRNA was determined in in exponentially growing and stationary cells of the asporogenic strain of Bacillus megaterium KM and in the sporogenic strain of B. megaterium 27 during sporulation. No reserve of the protease mRNA could be detected in the cells and the half-lives were determined to be 6--7 min in the exponential and stationary cells of B. megaterium KM and 7.5--8.5 min in B. megaterium 27. The mean half-life of mRNA for cell proteins was determined to be 3.5--4.5 min. Thus, as compared with the mean half-life of mRNA for cell proteins that of mRNA for the exocellular protease is slightly longer.
TL;DR: The mutant strainClaviceps purpurea 244 forming hyphae composed mainly from sclerotiumlike cells was found to sporulate both in liquid and solid media, particularly in the form of terminal chlamydospores.
Abstract: The mutant strainClaviceps purpurea 244 forming hyphae composed mainly from sclerotiumlike cells was found to sporulate both in liquid and solid media, particularly in the form of terminal chlamydospores (4.0 × 6.5 μm). Chlamydospores produced during submerged cultivation germinated, new chlamydospores being formed directly from germ tubes, or, occasionally, conidia (the so-called microcycle) or new vegetative mycelium were formed. The ultrastructures of the chlamydospores and vegetative cells was identical. The cytoplasm was filled with ribosomes and contained lipid inclusions and vacuoles with membrane invaginations. Strain 244 cultivated under submerged conditions produced 150 μg/ml clavins, with elymoclavin predominating (82 %). The parent strainClaviceps purpurea 129 only produced chlamydospores on the vegetative mycelium, whereas no microcycle was detected; under submerged conditions it produced mainly agroclavin (85 %) at a concentration of 4 mg/ml.
TL;DR: The cellulolytic activity of some soil fungi isolated from soil and decomposing pieces of plant material was observed to depend upon the genera of fungi, the nature of substrate and the temperature.
Abstract: The cellulolytic activity of some soil fungi isolated from soil and decomposing pieces of plant material was observed to depend upon the genera of fungi, the nature of substrate and the temperature. The cellulase produced in the presence of cellulose powder was active against CMC and vice versa.
TL;DR: The method of mutagenesis of the replication point by N-methyl-N-nitroso-N’-nitroguanidine in synchronously dividing populations and the method of analysis of gene frequency were applied to construct the replication map of the chromosome of Mycobacterium phlei.
Abstract: It was the aim of the present work to construct the replication map of the chromosome ofMycobacterium phlei. The method of mutagenesis of the replication point by N-methyl-N-nitroso-N’-nitroguanidine in synchronously dividing populations and the method of analysis of gene frequency were applied. The order of replication of 19 genes on the chromosome was determined by means of induction of back mutations and forward mutations in auxotrophic mutants PAleu and PAmet and in double auxotrophic mutants with methionine as a reference marker.
TL;DR: Streptomyces coeruleorubidus JA 10092 was found to segregate into two spontaneous morphological variants (spo-1 andbld-1) with a different ability to form aerial mycelium in media with glucose as the main carbon source.
Abstract: The wild strain Streptomyces coeruleorubidus JA 10092 was found to segregate into two spontaneous morphological variants (spo-1 and bld-1) with a different ability to form aerial mycelium in media with glucose as the main carbon source. Six new types of developmental mutants were obtained from the bald variant bld-1 after treatment with mutagens (UV light, gamma radiation, nitrous acid) and after natural selection. Formation of the aerial mycelium was fully suppressed in the bld-2 type growing on media both with glucose and with starch. The other types were bald only on starch media, forming the aerial mycelium on media with glucose; types spo-2, spo-3, spo-4 and spo-5 differed in size, shape and surface structure of spores, the type whi formed asporogenous aerial hyphae.