20 research outputs found
Les biopesticides, compléments et alternatives aux produits phytosanitaires chimiques (synthèse bibliographique).
peer reviewe
Burkholderia genome mining for nonribosomal peptide synthetases reveals a great potential for novel siderophores and lipopeptides synthesis
Burkholderia is an important genus encompassing a variety of species, including pathogenic strains as well as strains that promote plant growth. We have carried out a global strategy, which combined two complementary approaches. The first one is genome guided with deep analysis of genome sequences and the second one is assay guided with experiments to support the predictions obtained in silico. This efficient screening for new secondary metabolites, performed on 48 gapless genomes of Burkholderia species, revealed a total of 161 clusters containing nonribosomal peptide synthetases (NRPSs), with the potential to synthesize at least 11 novel products. Most of them are siderophores or lipopeptides, two classes of products with potential application in biocontrol. The strategy led to the identification, for the first time, of the cluster for cepaciachelin biosynthesis in the genome of Burkholderiaambifaria AMMD and a cluster corresponding to a new malleobactin-like siderophore, called phymabactin, was identified in Burkholderiaphymatum STM815 genome. In both cases, the siderophore was produced when the strain was grown in iron-limited conditions. Elsewhere, the cluster for the antifungal burkholdin was detected in the genome of B.ambifaria AMMD and also Burkholderia sp. KJ006. Burkholderiapseudomallei strains harbor the genetic potential to produce a novel lipopeptide called burkhomycin, containing a peptidyl moiety of 12 monomers. A mixture of lipopeptides produced by Burkholderiarhizoxinica lowered the surface tension of the supernatant from 70 to 27mN center dot m(-1). The production of nonribosomal secondary metabolites seems related to the three phylogenetic groups obtained from 16S rRNA sequences. Moreover, the genome-mining approach gave new insights into the nonribosomal synthesis exemplified by the identification of dual C/E domains in lipopeptide NRPSs, up to now essentially found in Pseudomonas strains
Optimization of an enumeration method to study the efficiency of tomato root colonization by several mutants of Bacillus subtilis having a potential as biopesticide
Optimisation of an enumeration method to study the efficiency of tomato roots colonisation by several mutants of B. subtilis having a potential as biopesticides
Biofilm formation is determinant in tomato rhizosphere colonization by Bacillus velezensis FZB42
In this work, the behavior in tomato rhizosphere of Bacillus velezensis FZB42 was analyzed taking into account the surfactin production, the use of tomato roots exudate as substrates, and the biofilm formation. B. velezensis FZB42 and B. amyloliquefaciens S499 have a similar capability to colonize tomato rhizosphere. Little difference in this colonization was observed with surfactin non producing B. velezensis FZB42 mutant strains. B. velezensis is able to grow in the presence of root exudate and used preferentially sucrose, maltose, glutamic, and malic acids as carbon sources. A mutant enable to produce exopolysaccharide (EPS-) was constructed to demonstrate the main importance of biofilm formation on rhizosphere colonization. This mutant had completely lost its ability to form biofilm whatever the substrate present in the culture medium and was unable to efficiently colonize tomato rhizosphere. © 2017 Springer-Verlag GmbH German
In silico genome mining, a new approach to detect novel lipopeptides potentially involved in biological control
Les lipopeptides de Bacillus spp. : des molécules à haut potentiel pour la lutte biologique contre les champignons phytopathogènes.
Biosurfactants as biopesticides: screening, mode of action and bioprocess development.
Novel biosurfactants with biocontrol activity and low ecotoxicity
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