title: Production of a novel mixture of mycosubtilins by mutants of Bacillus subtilis.
abstract: Using promoter exchange and gene knock-out strategies, two mutant strains, the so-called BBG116 and BBG125, were constructed from Bacillus subtilis wild-type strain ATCC 6633, a surfactin and mycosubtilin producer. Compared to the parental strain, both mutants overproduced constitutively mycosubtilin, while BBG125 had lost the ability to synthesize surfactin. Surprisingly, BBG125 was found to produce about 2-fold less mycosubtilin than BBG116 despite an expected higher availability of the cytoplasmic precursors and cofactors pool for biosynthesis. Further physiological characterization of BBG125 also highlighted: (i) a strong influence of temperature on mycosubtilin biosynthesis in BBG125 with a maximal productivity observed at 22°C, compared to 15 and 30°C; (ii) substantial changes in fatty acid profiles and thereby in mycosubtilin isoforms, compared to the wild-type strain; and (iii) the presence of five novel mycosubtilin isoforms. The antifungal activities of the new mix were higher than or equal to those of purified isoforms.
authors.affiliation: Laboratoire des Procédés Biologiques, Génie Enzymatique et Microbien-ProBioGEM, UPRES-EA 1026, Polytech'Lille/IUT A, Université Lille Nord de France-Sciences et Technologies, Villeneuve d'Ascq, France.
authors.forename: Max
authors.initials: M
authors.lastname: Béchet
authors.forename: Joany
authors.initials: J
authors.lastname: Castéra-Guy
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Guez
authors.forename: Nour-Eddine
authors.initials: NE
authors.lastname: Chihib
authors.forename: Françoise
authors.initials: F
authors.lastname: Coucheney
authors.forename: François
authors.initials: F
authors.lastname: Coutte
authors.forename: Patrick
authors.initials: P
authors.lastname: Fickers
authors.forename: Valérie
authors.initials: V
authors.lastname: Leclère
authors.forename: Bernard
authors.initials: B
authors.lastname: Wathelet
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacques
mesh_terms: D000935:Antifungal Agents; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli; D055786:Gene Knockout Techniques; D055666:Lipopeptides / Q000235:genetics*; D008074:Lipoproteins / Q000096:biosynthesis; D010456:Peptides, Cyclic / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D020033:Protein Isoforms / Q000096:biosynthesis*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D013696:Temperature
chemical_list: D000935:Antifungal Agents; D055666:Lipopeptides; D008074:Lipoproteins; D010456:Peptides, Cyclic; D020033:Protein Isoforms; C012448:mycosubtiline; C009365:surfactin peptide
keywords: Antifungal activity; Bacillus subtilis; Mycosubtilin; Novel isoforms; Spreading