Surfactin
Mostrando 13-24 de 51 artigos, teses e dissertações.
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13. Study of process variables and scale-up of the production of biosurfactant by Bacillus subtilis in cassava wastewater. / Estudo das variaveis de processo e ampliação de escala na produção de biossurfactante por Bacillus subtilis em manipueira.
The bacteria Bacillus subtilis is well known by their capacity of production surfactants lipopeptides. Among these, the most studied is surfactin, a powerfull surfactant that reduces the superficial tension of the water from 72 to 27 mN/m in concentrations less than 20_M. The application of industrial wastewaters as substrate for production of biosurfactant
Publicado em: 2007
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14. Biosurfactant, Bacillus subtilis, lipopeptides, antimicrobial activity / ProduÃÃo, extraÃÃo e caracterizaÃÃo de surfactante por Bacillus subtilis R14
Lipopeptides represent a class of microbial surfactants with increasing scientific, therapeutic and biotechnological interests. The genus Bacillus is a producer of these active compounds, and among them B. subtilis produces surfactin, the most potent biosurfactant known. These compounds can act as antibiotics, antivirals, antitumorals, immunomudulators and e
Publicado em: 2006
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15. Biotechnological production of surfactante of Bacillus subtilis in agro-industrial residue, characterization and applications. / Produção biotecnologica de surfatante de Bacillus subtilis em residuo agroindustrial, caracterização e aplicações.
Biosurfactants are amphypatic compounds from biologycal source showing both hydrophilic and lipophilic groups. Due to this feature, the biosurfactants acts decreasing the surface and interfacial tension of a liquid. The byproducts of agricola and industrial processing are an underexplored new sources to the production of biotechnological interesting compound
Publicado em: 2005
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16. Gene yerP, Involved in Surfactin Self-Resistance in Bacillus subtilis
Surfactin is a cyclic lipopeptide biosurfactant. Transposon mutagenesis was performed in Bacillus subtilis strain 168, and a surfactin-susceptible mutant, strain 801, was isolated. Analysis of the region of insertion revealed that yerP was the determinant of surfactin self-resistance. YerP had homology with the resistance, nodulation, and cell division (RND)
American Society for Microbiology.
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17. Enhanced Production of Surfactin from Bacillus subtilis by Continuous Product Removal and Metal Cation Additions
The lipopeptide, surfactin, is produced by Bacillus subtilis. A study has been made on large-scale production of this surfactant. A good yield was obtained from a glucose substrate fermentation by continuously removing the product by foam fractionation. The surfactin could be easily recovered from the collapsed foam by acid precipitation. The yield was also
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18. Identification of a genetic locus required for biosynthesis of the lipopeptide antibiotic surfactin in Bacillus subtilis.
Surfactin is a lipopeptide antibiotic produced by the cells of Bacillus subtilis ATCC 21332. A genetic locus responsible for surfactin production (sfp) was transferred from ATCC 21332 to JH642, a derivative of the standard B. subtilis 168. To study the sfp locus at the molecular level, a Tn917 insertion mutant that was blocked in surfactin production (srf) w
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19. Biocontrol of Bacillus subtilis against Infection of Arabidopsis Roots by Pseudomonas syringae Is Facilitated by Biofilm Formation and Surfactin Production1
Relatively little is known about the exact mechanisms used by Bacillus subtilis in its behavior as a biocontrol agent on plants. Here, we report the development of a sensitive plant infection model demonstrating that the bacterial pathogen Pseudomonas syringae pv tomato DC3000 is capable of infecting Arabidopsis roots both in vitro and in soil. Using this in
The American Society for Plant Biologists.
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20. Rapid Surface Motility in Bacillus subtilis Is Dependent on Extracellular Surfactin and Potassium Ion
Motility on surfaces is an important mechanism for bacterial colonization of new environments. In this report, we describe detection of rapid surface motility in the wild-type Bacillus subtilis Marburg strain, but not in several B. subtilis 168 derivatives. Motility involved formation of rapidly spreading dendritic structures, followed by profuse surface col
American Society for Microbiology.
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21. Amino-acylation site mutations in amino acid-activating domains of surfactin synthetase: effects on surfactin production and competence development in Bacillus subtilis.
The part of the srfA operon of Bacillus subtilis that contains the region required for competence development is composed of the first four amino acid-activating domains which are responsible for the incorporation of Glu, Leu, D-Leu, and Val into the peptide moiety of the lipopeptide surfactin. Ser-to-Ala substitutions were made in the amino-acylation site o
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22. Cloning and characterization of srfB, a regulatory gene involved in surfactin production and competence in Bacillus subtilis.
A Tn917 insertion mutation srfB impairs the production of the lipopeptide antibiotic surfactin in Bacillus subtilis. srfB is located between aroG and ald in the B. subtilis genome, as determined by phage PBS1 transduction mapping, and is not linked to the previously described surfactin loci sfp or srfA. A srfB mutant was found to be also deficient in the est
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23. srfA is an operon required for surfactin production, competence development, and efficient sporulation in Bacillus subtilis.
The srfA locus of Bacillus subtilis is defined by a transposon Tn917 insertion and is required for production of the peptide secondary metabolite surfactin. The srfA locus was isolated by cloning the DNA flanking srfA::Tn917 insertions followed by chromosome walking. The cloned region is an operon of over 25 kb which covers the transcription initiation regio
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24. Antimycoplasma properties and application in cell culture of surfactin, a lipopeptide antibiotic from Bacillus subtilis.
Surfactin, a cyclic lipopeptide antibiotic and biosurfactant produced by Bacillus subtilis, is well-known for its interactions with artificial and biomembrane systems (e.g., bacterial protoplasts or enveloped viruses). To assess the applicability of this antiviral and antibacterial drug, we determined the cytotoxicity of surfactin with a 50% cytotoxic concen