F Coutte1, V Leclère1, M Béchet1, J-S Guez1, D Lecouturier1, M Chollet-Imbert1, P Dhulster1, P Jacques1. 1. Laboratoire de Procédés Biologiques, Génie Enzymatique et Microbien (ProBioGEM, UPRES EA 1026), Polytech'Lille, IUT A, Université des Sciences et Technologies de Lille, Boulevard Paul, Villeneuve d'Ascq Cedex, France.
Abstract
AIMS: To analyse the effects of plipastatin operon disruption and constitutive expression of surfactin operon in Bacillus subtilis 168 on surfactin productivity, in vitro invasive growth and antagonism against fungi. METHODS AND RESULTS: The srfA native promoter was replaced by the constitutive promoter P(repU) in B. subtilis 168 after integration of a functional sfp gene. Moreover, the plipastatin synthesis was further disrupted in the B. subtilis 168 derivatives. In liquid media, an earlier and higher expression of P(repU), than that found with P(srfA), led to a specific surfactin production fivefold higher after 6 h of culture. On solid media, not only the invasive growth and the haemolytic activity but also the antifungal activity of the constitutive strains were improved when compared to the parental strain BBG111. As expected, the disruption of the plipastatin operon strongly reduced in vitro antifungal properties but, interestingly, enhanced specific surfactin production (1.47 g g(-1) of biomass), spreading behaviour and haemolytic activity of the strains. CONCLUSIONS: This work demonstrates for the first time the interdependency of surfactin and plipastatin regarding their biosynthesis as well as their influence on the biological activities of the producing strain. SIGNIFICANCE AND IMPACT OF THE STUDY: The constitutive overproduction of surfactin enhances the invasive growth and the in vitro antagonistic activity of the mutant strain. Both properties are known to play an important role in the biocontrol of plant diseases. Plipastatin operon disruption increases the surfactin productivity of mutant strains. These mutants are interesting for use in continuous bioprocesses for surfactin production or in bioremediation.
AIMS: To analyse the effects of plipastatin operon disruption and constitutive expression of surfactin operon in Bacillus subtilis 168 on surfactin productivity, in vitro invasive growth and antagonism against fungi. METHODS AND RESULTS: The srfA native promoter was replaced by the constitutive promoter P(repU) in B. subtilis 168 after integration of a functional sfp gene. Moreover, the plipastatin synthesis was further disrupted in the B. subtilis 168 derivatives. In liquid media, an earlier and higher expression of P(repU), than that found with P(srfA), led to a specific surfactin production fivefold higher after 6 h of culture. On solid media, not only the invasive growth and the haemolytic activity but also the antifungal activity of the constitutive strains were improved when compared to the parental strain BBG111. As expected, the disruption of the plipastatin operon strongly reduced in vitro antifungal properties but, interestingly, enhanced specific surfactin production (1.47 g g(-1) of biomass), spreading behaviour and haemolytic activity of the strains. CONCLUSIONS: This work demonstrates for the first time the interdependency of surfactin and plipastatin regarding their biosynthesis as well as their influence on the biological activities of the producing strain. SIGNIFICANCE AND IMPACT OF THE STUDY: The constitutive overproduction of surfactin enhances the invasive growth and the in vitro antagonistic activity of the mutant strain. Both properties are known to play an important role in the biocontrol of plant diseases. Plipastatin operon disruption increases the surfactin productivity of mutant strains. These mutants are interesting for use in continuous bioprocesses for surfactin production or in bioremediation.
Authors: Samara Mejri; Ali Siah; François Coutte; Maryline Magnin-Robert; Béatrice Randoux; Benoit Tisserant; François Krier; Philippe Jacques; Philippe Reignault; Patrice Halama Journal: Environ Sci Pollut Res Int Date: 2017-06-21 Impact factor: 4.223
Authors: Gabriela Mihalache; Tiberius Balaes; Irina Gostin; Marius Stefan; François Coutte; François Krier Journal: Environ Sci Pollut Res Int Date: 2017-05-20 Impact factor: 4.223
Authors: David J Gonzalez; Nina M Haste; Andrew Hollands; Tinya C Fleming; Matthew Hamby; Kit Pogliano; Victor Nizet; Pieter C Dorrestein Journal: Microbiology (Reading) Date: 2011-06-30 Impact factor: 2.777