Regulation of biosynthesis of secondary metabolitesBěhal, V.; Vaněk, Z.
doi: 10.1007/BF02880103pmid: 5480312
AcetylCoA carboxylase (E.C.6.4.1.2) enzymatic activity was studied in high- and low-producing strains ofStreptomyces aureofaciens. Study of the rate of H14CO3
− incorporation into acetylCoA and of CH3
14COO− incorporation into the fatty acids showed that specific activity attained maximum values after about 24 hours' cultivation. AcetylCoA carboxylase activity in the producing strain was approximately double the value in the low-producing strain. The subcellular particles present in the supernatant fractions from cells disintegrated by spinning one hour at 600g and 10,000g did not influence the activity of the enzyme. Avidin inhibited it. The relationship between specific activity of the enzyme and the rate of oligoketide synthesis is discussed.
Organ localization of intravenously administered HSA I131 in chickensKrejčí, J.; Procházka, Z.
doi: 10.1007/BF02880098pmid: 5480307
A study was made on the elimination of heterologous albumin (HSA I131) from the blood of chickens and on its organ distribution. The elimination curve of heterologous antigen followed the typical three-phase pattern. An accelerated elimination of heterologous albumin as compared to the role of elimination of homologous albumin during the second phase is suggestive of specific uptake of antigen. The elimination curve of homologous albumin showed only two phases. The uptake of HSA I131 by organs was evaluated with respect to the amount of antigen present in the circulation. The highest cumulation of antigen was found in the liver and spleen after the 5th day following HSA I131 administration. A mild increase in the antigen content was found already after the 3rd day following injection. The increase in antigen concentration shown by the lung tissue and bone marrow was less marked. The increase in activity found in the bursa of Fabricius and in the thymus is attributed to tissues of other origin which could not be dissected fully from the respective tissue.
A special case of lysogeny inMycobacterium aviumHubáček, J.; Kupková, H.; Mohelská, H.
doi: 10.1007/BF02880100pmid: 5480309
Phage-producing colonies of cells resistant to homologous phage F4II have been isolated after infection ofMycobacterium avium. About one per cent phage-free, sensitive clones can usually be obtained after treatment of the cell suspension with phage antiserum. Because of the relatively high free phage titer in the culture, the presence of very dense particles, probably phage equivalents, in the cytoplasm of many cells and the varied sensitivity of intracellular phage to UV irradiation at different stages of growth, one can assume that a great part of the cells in the population burst and liberate phages. The relationship between phage and the host cell is discussed as a particular case of abortive lysogeny.
Contribution to the morphology of the productive strains ofPenicillium chrysogenum thom from the Wisconsin familyFassatiová, O.
doi: 10.1007/BF02880104pmid: 5480313
The morphology of four productive strains ofPenicillium chrysogenum Thom from the Wisconsin family was studied. The strains Q-176, 47–1564, 49–133, 51–20Z, which were naturally or artificially obtained mutants of thePenicillium chrysogenum NRRL 1951 strain were very variable as to the colony structure and the character of conidiophores. The present study is concerned with the evaluation of their taxonomic position. The macrohabitus of the colonies was not remarkably changed. All different types of colonies (U, D, C, B, rarely A) described by Backus and Stauffer, were found on Czapek agar; they were not recognized on malt agar. Deviations from the normal asymmetric conidiophore were found with every type of colonies, most often with the more floccose or lanose ones showing a higher and a sparser overgrowth. These deviations or changes in the microstructure were divided into three degrees according to their quality and occurrence: (1) A strongly divaricate conidiophore where only metulae and phialides were developed; (2) monoverticilate conidiophore or single phialides on the conidiophore filament; (3) degeneration of phialides or metulae to sterile globose cells or an ultimate reduction of conidiophore to dichotomically branched stump-like hypha. The investigated strains can be involved in the taxonPenicillium chrysogenum Thom; it is necessary, however, to include some additional traits into the characteristics of the taxon: Colonies of the naturally or artificially obtained mutants often have lanose overgrowths sporulating sparsely. Formation of the yellow pigment and the exudate was not obligatory. conidiophores of these strains had a tendency to be more simple. They were scarcer, divaricately open, characterized sometimes by the formation of monoverticilate penicilli. A degeneration was frequently found of the ends of conidiophores (phialides and metulae) to globose enlarged sterile cells as well as the formation of giant cells in the mycelium or reduction of conidiophore to dichotomically branched hypha with stump-like ends.
Contributing factor toMycoplasma pneumoniae produced stimulation of rhinovirus-RNA synthesisFletcher, R.; Milligan, W.; Albertson, J.
doi: 10.1007/BF02880097pmid: 4320382
It has been demonstrated thatRhinovirus ribonucleic acid (RNA) synthesis was greater inMycoplasma pneumoniae inoculated KB (Human Carcinoma of Nasopharynx) cells than in PPLO-free tissue systems (Milligan III & Fletcher, 1969). In this study,Mycoplasma pneumoniae was grown on glass to eliminate the PPLO medium. However, if PPLO medium was added to theMycoplasma pneumoniae inoculum, stimulation of viral-RNA synthesis was greater than in the presence of PPLO alone. Rhinovirus-RNA synthesis, measured by uridine-3H uptake, in the presence ofMycoplasma pneumoniae andMycoplasma pneumoniae plus medium was enhanced 1.2-fold and 1.4-fold respectively, above virus synthesis in untreated KB cell systems. PPLO medium did not appear to significantly stimulate viral RNA synthesis. However, a 5-fold increase in the concentration of the medium or its components resulted in greater viral RNA replication. The medium components, yeast extract and PPLO broth (Difco), stimulated viral RNA synthesis 4-fold and 2-fold, respectively. Our findings also demonstrated that other components, agar, phenol red, and dextrose, inhibited viral replication, whereas horse serum appeared to have no effect.
Antimicrobial agentsČapek, A.; Šimek, A.; Leiner, J.; Weichet, J.
doi: 10.1007/BF02880102pmid: 5480311
In the microbial transformation of 2-chloro-4-nitrophenol and its 2-aminotridecane compound salt, 2-chloro-4-nitrophenol was found to be degraded to four metabolites only on using strains resistant to 2-chloro-4-nitrophenol. Sensitive strains lacked this property. In the case of the 2-amino-tridecane compound salt, the first reaction produced by strains resistant to 2-chloro-4-nitrophenol was dissociation of the compound salt into the two initial components, followed by degradation of 2-chloro-4-nitrophenol. Microbial degradation resulted in diminished antifungal activity. The other antimicrobi-ally active component of the compound salt, i.e. 2-aminotridecane, was not affected by biotransformation and kept its original activity.