Folia Microbiologica

doi: 10.1007/BF02876391pmid: 6986328

Jirků, V.; Kraxnerová, B.; Krumphanzl, V.

doi: 10.1007/BF02876394pmid: 7188760

During cultivation in a minimal medium with glucoseAlternaria tenuissima andAspergillus vesicolor produce constitutively α- and β-glucanases. Fractions of β-1,3-glucanases exhibiting affinity for laminarin were separated by means of gel filtration chromatography. Two neutral β-1,3-glucanases with affinity for yeast glucan were isolated by affinity chromatography and further characterized.

Hochmannová, J.; Nešvera, J.; Štokrová, J.

doi: 10.1007/BF02876392pmid: 6986329

Minicells ofEscherichia coli P678-54 containing plasmid R1drd19 were submitted to careful controlled lysis. By sedimentation of the resulting lyzate in a sucrose gradient, the material absorbing at 260 nm was separated into three distinct bands. Among the most rapidly sedimenting particles, doublestranded topological circles of DNA attached to patches of membrane were visualized by electron microscopy, while single-stranded molecules (probably RNA) with associated proteins were detected in the medium band. Covalently closed and open circles of the R1drd19 DNA were found at the top of the gradient. Their contour lengths corresponded to the size of the DNA sedimenting together with the membrane in the first peak. This finding implies a direct intracellular interaction between R1drd19 DNA and membrane inE. coli minicells.

Černáková, M.; Kocková-Kratochvílová, A.; Šuty, L.; Zemek, J.; Kuniak, L’.

doi: 10.1007/BF02876399pmid: 7353808

Seventy-seven properties ofAureobasidium pullulans including utilization of various carbon sources, decomposition of the lignin-cellulose complex and the respective enzymes were checked in the present communication. According to these properties the group of 43 strains was separated in three parts, out of which two groups were found to belong to varietiesA. pullulans var.pullulans andA. pullulans var.melanigenum. The third group formed a marginal part. The two varieties differed in numerous biochemical markers, particularly in the absence of monophenol monooxygenase in the varietyA. pullulans var.pullulans.

Zahkadník, F.

doi: 10.1007/BF02876396pmid: 6243600

Purification of streptococcal extracellular NAD+ nucleosidase is associated with changes of kinetio properties. A high-molecular weight component is required for a full activity of the enzyme. The component is not produced by bacteria and is present in the Todd-Hewitt cultivation medium, the beef-heart extract serving primarily as its souroe. In its effect on the enzyme this component can be replaced with bovine albumin. It follows from the time relationship of the NAD decomposition that the mechanism of the studied enzymic reaction is not hydrolytic. In addition to nicotinamide, a product of polymeric character is formed.

Pavlasová, E.; Stejskalová, E.; Novotný, Č.; Sikyta, B.

doi: 10.1007/BF02876393pmid: 6243599

When inducing simultaneously β-galactosidase and tryptophanase in a batch culture either the synthesis of tryptophanase or of both enzymes is decreased due to an insufficient cAMP concentration. The addition of this nucleotide can overcome this decrease. In a continuous culture both enzymes are synthesized at the maximum rate, as the amount of cAMP produced during carbon limitation of growth is probably sufficient for the simultaneous synthesis of both enzymes. In the β-galactosidase hyperproduction mutant cultivated continuously the level of β-galactosidase markedly decreases when tryptophanase is simultaneously induced. Also this decrease is caused by cAMP insufficiency and can be overcome by increasing its concentration. cAMP is thus an important regulatory factor of both enzymes and becomes a limiting factor in their simultaneous synthesis; a competition for this regulatory compound apparently occurs and probably also a different mutual affinity of the regulatory complex with the promoter site of the enzyme opérons is involved.

Deschamps, A.; Plichon, B.; Noel, C.

doi: 10.1007/BF02876397pmid: 6243601

Growth ofSerratia marcescens was not inhibited by high concentrations ofL-lysine and its structural analogues,L-canavanine and S-(2-aminoethyl)-L-cysteine (thialysine). This insensitivity was not caused by deficient transport of basic amino acids, unlike in mutant strains ofEscherichia coli having the same properties. The tested strains showed a lack of regulation at the aspartate kinase level towardL-lysine and thialysine. The data indicate great intraspecific variability for aspartate kinase regulation inS. marcescens.

Lodinová, R.; Haníková, M.; Jouja, V.

doi: 10.1007/BF02876400pmid: 6986330

The cellular immune response (MIF, E-rosette formation and changes in nucleolar morphology of lymphocytes) was followed as related to age and antigenic stimulation. MIF in healthy infants increased from the 2nd to the 12th week of life as compared with the first week, probably due to BCG vaccination. The total and active E-rosette formation did not change during the whole period of investigation. Ring-shaped nucleoli increased gradually from the second week of life. Active nucleoli increased up to the 4th week,i.e. after BCG vaccination and then slowly decreased. Micronucleoli being high in the first week, decreased during 24 weeks of life. After artificial colonization of the intestine the production of MIF was slightly lower in colonized infants than in controls from the 2nd to the 12th week. The other parameters followed were not influenced by colonization.