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R Süssmuth

Publications and source records attributed to R Süssmuth.

At least 55 records · Page 3Linked to original sources
PubMed1980

Induction of prophage and mutagenic effects by alkyl alkylaminosulfonates, ethyl aminosulfonate and alkyl methanesulfonates.

Prophage induction and mutation by alkylaminosulfonates, ethyl aminosulfonate and alkyl methanesulfonates were examined comparatively. Prophage induction was carried out with a lysozyme lysis technique on the lysogenic strain Micrococcus lysodeikticus 53-40 (N5). The sulfonic ester derivatives show a slight lysogenic induction. At higher concentrations their toxicity seems to mask phage detection. Only methyl isopropylaminosulfonate and ethyl aminosulfonate exhibit no or negligible toxic effects, and with these compounds at higher concentrations a strong prophage induction is found. Alkyl sulfonate derivatives induce mutations in the tester strain of Salmonella typhimurium TA1535. Methyl methylaminosulfonate and ethyl N-methyl-N-2-chloroethyl aminosulfonate show a mutagenicity comparable to that of the well-known methyl methanesulfonate or ethyl methanesulfonate. With ethyl aminosulfonate, however, which does not show inactivation, no significant mutagenic effect was observed. DNA alterations were found in the polymerase-deficient strain E. coli P3478. The results of prophage induction and mutagenicity are compared and discussed.

Alkanesulfonates↗
PubMed1980

[Growth inhibition by phenylalanine and tyrosine--metabolism of phenylalanine in Flavobacterium devorans (author's transl)].

Growth of a chloramphenicol-resistant mutant of Flavobacterium devorans (F. devorans r) was inhibited by L-phenylalanine and L-tyrosine and furthermore by L-tryptophan, 4-amino-benzoate, anthranilate and homogentisate. The inhibitionwas reversed partially by simultaneous addition of aromatic amino acids and 4-amino-benzoate. After cultivating F. devorans r in a glucose-minimal medium containing L-phenylalanine, the metabolites L-tyrosine, 4-hydroxyphenylpyruvate, 4-hydroxyphenylacetate, 4-hydroxybenzaldehyd, 4-hydroxybenzoate, homogentisate and anthranilate were found. Growth inhibition and a hypothetical degrading pathway of phenylalanine are discussed.

Aminobenzoates↗
PubMed1980

[A prephenate dehydratase from Flavobacterium devorans stimulated by aromatic amino acids (author's transl)].

Isolation and properties of prephenate dehydratase from Flavobacterium devorans r are described. The enzyme was enriched 43-fold by ammonium sulfate precipitation, by gel chromatography on ultrogel ACA-34 and by hydrophobic chromatography on decylagarose. The molecular weight was estimated to be 1.35 x 10(5). The enzyme was activated in 1mM solutions of L-tyrosine 4,4-fold, of L-phenylalanine 3.9fold and by L-tryptophan 1.9-fold in 0.02M Tris/HCl buffer at pH 7.7. The Km values were, when adding the activator, at L-tyrosine 1.5 x 10(-5) M, at L-phenylalanine 1.3 x 10(-5) M and at L-tryptophan 1 x 10(-5) M. Regulation of aromatic amino acid is discussed in connection with the prephenate dehydratase.

Chorismate Mutase↗
PubMed1979

Chloramphenicol resistance of three different flavobacteria.

The chloramphenicol resistance of some flavobacteria was investigated comparatively. This resistance can be explained either by acetylation of chloramphenicol to O-acetylchloramphenicol via constitutively formed acetyltransferases, followed by cometabolic degradation (strain CB 60), or by limited uptake and total degradation (strain CB 6) by inducible enzymes or by other mechanisms (F. devorans). The mechanisms of resistance, CM-acetylation, CM-degradation and limited uptake are discussed.

Acetylation↗
PubMed1979

[gamma-Irradiated ribosomes from Micrococcus radiodurans in a cell-free protein synthesizing system (author's transl)].

gamma-irradiation inactivation of isolated ribosomes of Micrococcus radiodurans was studied by examining poly U directed synthesis of polyphenylalanine. Ribosomes of M. radiodurans did not show significant gamma-radiation sensitivity up to a dose of approx. 11.6 k Gy. Cells of M. radiodurans take up more magnesium than E. coli cells unter the same conditions. The magnesium content of ribosomes of M. radiodurans was 18% higher than that of E. coli ribosomes. A possible relation between Mg2+-content and gamma-resistance is discussed.

Dose-Response Relationship, Radiation↗
PubMed1976

Mutagenic and inactivating effects of methyl alkylaminosulfonates on Escherichia coli.

Methyl alkylamino methanesulfonates are mutagenic agents as shown by treating several strains of E. coli at pH 7. Methyl methylaminosulfonate (CH3-NH-SO3-CH3) was more efficient than methyl ethylaminosulfonate (C2H5-NH-SO3-CH3) which itself was more efficient than methyl isopropylaminosulfonate (C3H7-NH-SO3-CH3). Methyl methylaminosulfonate seemed to be at least as effective as methyl methanesulfonate (CH3-SO3-CH3). Methyl methylaminosulfonate produced a yield of up to 1% of auxotrophic mutants. All three new mutagens appeared to react according to the same mechanism by ester fission and methylation of nucleophilic groups as is known for methyl methanesulfonate. The reaction mechanism seems to be of the SN2 type.

Amino Acids↗
PubMedDate not supplied

Weak light emission patterns from lactic acid bacteria.

Distinct low level chemiluminescence patterns during aerobic growth of a selection of bacterial strains of the lactic acid group were recorded in on-line measurements. These patterns may be specific for the strain and the medium employed for cultivation. The patterns are oxygen-dependent and consist in the case of Enterococcus faecalis of three basic patterns, which reflect different mechanisms leading to both the generation and depletion of initiators of the chemiluminescence, particularly hydrogen peroxide and superoxide radical. The influence of catalase and superoxide dismutase on the patterns was examined. We could demonstrate the sensitivity of chemiluminescence measurements for the detection of both exogenous oxidative stress, which is imposed to the cells by reactive species formed in the medium, as well as endogenous oxidative stress, which is due to products of the cellular oxygen metabolism, the latter being often the reason for growth restriction.

Animals↗