Surfactin
Mostrando 25-36 de 51 artigos, teses e dissertações.
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25. A new lipopeptide biosurfactant produced by Arthrobacter sp. strain MIS38.
A biosurfactant termed arthrofactin produced by Arthrobacter species strain MIS38 was purified and chemically characterized as 3-hydroxydecanoyl-D-leucyl-D-asparagyl-D-threonyl-D- leucyl-D-leucyl-D-seryl-L-leucyl-D-seryl-L-isoleucyl-L-isoleucyl-L-as paragyl lactone. Surface activity of arthrofactin was examined, with surfactin as a control. Critical micelle
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26. Purification and structural determination of an inhibitor of starfish oocyte maturation from a Bacillus species.
Inhibitors of bacterial origins of starfish oocyte maturation were sought to obtain biologically active substances which act on either hormonal signal transduction or cell cycle regulation. An oocyte maturation-inhibiting substance found in culture fluid of a Bacillus species was purified to homogeneity. This substance possessed the nature of a detergent and
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27. Nucleotide sequence of 5' portion of srfA that contains the region required for competence establishment in Bacillus subtilus.
The nucleotide sequence of the 20,535 base pairs of the 5' end of the srfA operon, containing the region required for competence development, was determined. This included the srfA promoter region, the first open reading frame, srfAA, encoding surfactin synthetase I and part of the second open reading frame, srfAB, encoding surfactin synthetase II. Three ami
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28. Salmonella enterica Serovar Typhimurium Swarming Mutants with Altered Biofilm-Forming Abilities: Surfactin Inhibits Biofilm Formation
Swarming motility plays an important role in surface colonization by several flagellated bacteria. Swarmer cells are specially adapted to rapidly translocate over agar surfaces by virtue of their more numerous flagella, longer cell length, and encasement of slime. The external slime provides the milieu for motility and likely harbors swarming signals. We rec
American Society for Microbiology.
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29. Analysis of Surfactin Synthetase Subunits in srfA Mutants of Bacillus subtilis OKB105
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30. Translation of the open reading frame encoded by comS, a gene of the srf operon, is necessary for the development of genetic competence, but not surfactin biosynthesis, in Bacillus subtilis.
A small open reading frame, comS of the srf operon, is the site of mutations that impair competence development in Bacillus subtilis. comS open reading frame translation was required for competence, as was confirmed by the suppression of a comS amber mutation [comS(Am)] by the nonsense suppressor sup-3. comS(Am), when introduced into the srf operon, eliminat
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31. Comparative Analysis of the Development of Swarming Communities of Bacillus subtilis 168 and a Natural Wild Type: Critical Effects of Surfactin and the Composition of the Medium
The natural wild-type Bacillus subtilis strain 3610 swarms rapidly on the synthetic B medium in symmetrical concentric waves of branched dendritic patterns. In a comparison of the behavior of the laboratory strain 168 (trp) on different media with that of 3610, strain 168 (trp), which does not produce surfactin, displayed less swarming activity, both qualita
American Society for Microbiology.
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32. Identification of comS, a gene of the srfA operon that regulates the establishment of genetic competence in Bacillus subtilis.
Genetic competence (the ability to internalize exogenous DNA) in Bacillus subtilis is dependent on a regulatory pathway that activates the expression of a battery of competence-specific genes. The srfA operon, encoding the subunits of surfactin synthetase, which catalyzes the nonribosomal synthesis of the peptide antibiotic surfactin, also functions in the c
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33. Altered srf Expression in Bacillus subtilis Resulting from Changes in Culture pH Is Dependent on the Spo0K Oligopeptide Permease and the ComQX System of Extracellular Control
The expression of the srf operon of Bacillus subtilis, encoding surfactin synthetase and the competence regulatory protein ComS, was observed to be reduced when cells were grown in a rich glucose- and glutamine-containing medium in which late-growth culture pH was 5.0 or lower. The production of the surfactin synthetase subunits and of surfactin itself was a
American Society for Microbiology.
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34. Induction of surfactin production in Bacillus subtilis by gsp, a gene located upstream of the gramicidin S operon in Bacillus brevis.
The deduced amino acid sequence of the gsp gene, located upstream of the 5' end of the gramicidin S operon (grs operon) in Bacillus brevis, showed a high degree of similarity to the sfp gene product, which is located downstream of the srfA operon in B. subtilis. The gsp gene complemented in trans a defect in the sfp gene (sfpO) and promoted production of the
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35. Analysis of surfactin synthetase subunits in srfA mutants of Bacillus subtilis OKB105.
The srfA operon of Bacillus subtilis functions in the biosynthesis of the lipopeptide antibiotic surfactin. On the basis of nucleotide sequence and genetic analysis, it is believed to encode three enzymes (E1A, E1B, and E2) that catalyze the incorporation of the surfactin substrate amino acids. Insertion, deletion, and amino acid substitution mutations of sr
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36. Structural and immunological characterization of a biosurfactant produced by Bacillus licheniformis JF-2.
Bacillus licheniformis JF-2 produces a very active biosurfactant under both aerobic and anaerobic conditions. We purified the surface-active compound to homogeneity by reverse-phase C18 high-performance liquid chromatography and showed that it is a lipopeptide with a molecular weight of 1,035. Amino acid analysis, fast atom mass and infrared spectroscopy, an