Biomedical subjects

I Tenoux

Publications and source records attributed to I Tenoux.

4 recordsLinked to original sources

PubMed1993

Studies on bacillomycin D biosynthesis by Bacillus subtilis.

The biosynthesis of bacillomycin D, an antibiotic containing a beta-amino fatty acid and a peptide moiety with asparagine, glutamic acid, serine, proline, threonine, and tyrosine, was studied by incubating the Bacillus subtilis producer with various 14C-labelled precursors. Sodium acetate was incorporated into beta-amino fatty acids of bacillomycin D, and asparagine was the best precursor of the peptidic moiety. The kinetics of the incorporation of radioactive substrates into bacillomycin D and into beta-amino fatty acids show that the lipid and the peptide moieties of the antibiotic were synthesized at the same stage of growth of the bacteria. Comparing the effects of different inhibitors on the incorporation of radioactive precursors, the bacillomycin D and beta-amino fatty acids biosyntheses are discussed in relation to the biosyntheses of proteins, lipids and with sporulation.

Acetates↗

PubMed1992

Synthesis of beta-hydroxy fatty acids and beta-amino fatty acids by the strains of Bacillus subtilis producing iturinic antibiotics.

The iturinic antibiotics, which contain long chain beta-amino acids, are produced by Bacillus subtilis. Screening these strains for the presence of a possible precursor of the iturinic antibiotics, we isolated a lipopeptide containing beta-hydroxy fatty acids. The structure of this compound was studied and it appears to be identical or structurally very similar to surfactin. The carbon chain of its beta-hydroxy fatty acids was n C16, iso C16, iso C15 or anteiso C15. The percentages of each beta-hydroxy fatty acids varied according to the strain producing iturinic antibiotics and were influenced by addition of branched-chain alpha-amino acids to the culture medium. These results demonstrate for the first time that iso C14 beta-hydroxy fatty acid is a constituent present in such a surfactin like lipopeptide. Besides, the presence of radioactive beta-hydroxy fatty acids in the phospholipids when the strains were grown in the presence of sodium [14C]acetate seems also characterize the different strains producing iturinic antibiotics.

Amino Acid Sequence↗

PubMed1991

Studies on the antifungal antibiotics: bacillomycin D and bacillomycin D methylester.

Bacillomycin D, an antifungal compound of Bacillus subtilis, was produced during the stationary phase of growth when all the glucose of the medium was exhausted and the pH reached about 8. In addition to bacillomycin D, bacillomycin D methylester was characterized by its antifungal properties and its haemolytic activity.

Anti-Bacterial Agents↗

PubMed1989

Fatty acid and beta-amino acid syntheses in strains of Bacillus subtilis producing iturinic antibiotics.

Iturinic antibiotics, produced by different strains of Bacillus subtilis, contain long-chain beta-amino acids (beta-AA). The regulation of the synthesis of fatty acids (FA) and beta-AA was studied by modifying the culture medium. Addition of possible precursors, branched-chain alpha-amino acids, to the medium affected the FA and beta-AA compositions. According to this, the B. subtilis strains can be divided into two groups. The first contains the producers of mycosubtilin and bacillomycin F which synthesize a high level of iso C16 chains; the second contains the producers of bacillomycin D, bacillomycin L and iturin which synthesize a high level of n carbon chains. The incorporation of radioactive sodium acetate into FA and beta-AA showed rapid FA synthesis followed by a second synthetic step. Although the detailed mechanism has not yet been elucidated, this second step, corresponding to the beta-AA synthesis, seemed to be a key step in determining the alkyl chain of beta-AA.

Amino Acids↗