Project description:Lipopeptide biosurfactant producing Bacillus strains have many useful applications in biotechnology and agriculture, based on their emulsifying, surface activity and antimicrobial properties. In the current study, lipopeptide production kinetics, and biocontrol potentials of two new B. velezensis strains, ES1-02 and EFSO2-04 were analyzed and compared with those of commercial strains QST713 and FZB42. ES1-02 and EFSO2-04 showed higher specific growth rates than FZB42, but lower growth rates than QST713. All strains produced surfactin lipopetides, while fengycin production was not observed in ES1-02 and EFSO2-04. Production of fengycin A, B, X and Y were however confirmed in strains QST713 and FZB42. Significant differences were observed in the production of lipopeptides of the iturin family. While ES1-02 and EFSO2-04 produced bacillomycin L, QST713 produced iturin A, and FZB42 produced bacillomycin D. This was in line with the PCR analysis of corresponding genes encoding the identified lipopeptides. Highest surfactin titer of 97.4 mg/L was observed in ES1-02, while QST713 produced highest amount of iturin/bacillomycin (8.5 mg/L). Surfactin isoforms C12 to C17, and iturin/bacillomycin isoforms C11 to C17 were identified by mass spectrometry. ES1-02 and EFSO2-04 showed biocontrol potentials comparable with that of QST713 against Diaporthe spp., while FZB42 showed superior antifungal potentials. Up to 41%, 43%, 47 % and 68.9 % inhibition of D. caulivora were achieved by ES1-02, EFSO2-04, QST713 and FZB42 respectively. Upon exposure to B. velezensis strains, morphological changes to Diaporthe hyphae in form of swellings, distortion, and complete disruption occurred. Interaction of D. longicolla DPC_HOH20 with ES1-02 and EFSO2-04 induced 10-fold and 5-fold increase in surfactin synthesis, respectively. Antagonist interaction with D. longicolla induced significant changes in the proteome of ES1-02 including an increased abundance of several proteins associated with biosynthesis of antimicrobial compounds and fatty acids, while proteins associated with phosphate uptake were decreased in abundance.
Project description:Two wide type strains of Bacillus subtilis, S-2 and 312, were selected to study their genic differences treated by L-alanine through comparative transcriptomics analysis. The spores of B. subtilis S-2 were selected because of their high germination potential to L-alanine. The spores of B. subtilis 312 without a response to L-alanine were used as the control. The spores with or without L-alanine (100 mm) pretreatment were both cultured in the synthetic medium for 9 h, and then collected for sequencing.
Project description:Lecanicillium fungicola, the causative agent of dry bubble disease on Agaricus bisporus results in significant crop losses for mushroom growers worldwide. Dry bubble disease is treated through strict hygiene control methods and the application of chemical fungicides but an increase in fungicide resistant L. fungicola strains has resulted in a need to develop alternative biocontrol treatment methods. The aim of the work presented here was to evaluate the response of L. fungicola to a Bacillus velezensis isolate to assess its potential as a novel biocontrol agent. The bacterial species in Serenade, a commercially available biocontrol treatment was also included in this analysis. Exposure of 48 hr L. fungicola cultures to 25% v/v 96h B. velezensis culture filtrate resulted in a 45% reduction in biomass (P < 0.0002) and a disruption in hyphal structure and morphology. Characterisation of the proteomic response of L. fungicola following exposure to B. velezensis culture filtrate revealed an increase in the abundance of a variety of proteins associated with stress response (Norsolorinic acid reductase (+8 fold), isocitrate lyase (+7 fold) and MMS19 nucleotide excision repair protein (+4 fold). There was also a decrease in the abundance of proteins associated with transcription (40S ribosomal protein S30 (-33 fold), 60S ribosomal protein L5 (-45 foldThe results presented here indicate that B. velezensis culture filtrate is capable of inhibiting the growth of L. fungicola and inducing a stress response, thus indicating its potential to control this important pathogen of mushrooms.
Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes.
Project description:In the present study, we investigated the effect of Bacillus subtilis var. natto on lifespan using Caenorhabditis elegans as a model animal. The lifespan of the adult C. elegans fed Bacillus subtilis var. natto MI-OMU01 strain was significantly longer than that of animals fed OP50 (control). Transcriptional profiling comparing MI-OMU01- and control-fed animals suggested that genes related to “innate immune system” were upregulated by MI-OMU01.
Project description:This series represents the work described in the publication Bacillus subtilis Genome Diversity by Earl et al. (Journal of Bacteriology, accepted) Keywords: comparative genomic hybridization
Project description:Transcriptional changes occurring at the infection site of 2 weeks old Cabernet sauvignon grapevine cuttings infected with a wood pathogen (Phaeomoniella chlamydospora) in the presence of a root-inoculated biocontrol agent (Pythium oligandrum). Gene expression profiling was done using the Nimblegen whole genome array with 3 biological replicates of 3 pooled wood chunks harvested 0 and 14 d after treatment (pathogen infection, biocontrol agent inoculation, mock treatment).