bacilysin and fengycin

Probiotics may offer an attractive alternative for standard antibiotic therapy to treat

Topics: Anti-Bacterial Agents; Bacillus amyloliquefaciens; Cell Death; Clostridioides difficile; Dipeptides; DNA, Bacterial; Genome, Bacterial; Lipopeptides; Multigene Family; Oligopeptides; Peptides, Cyclic; Polyketides; Probiotics; Secondary Metabolism; Uronic Acids; Whole Genome Sequencing

Several Bacillus strains are used as biocontrol agents, as they frequently have strong antagonistic effects against microbial plant pathogens. Bacillus strain SZMC 6179J, isolated from tomato rhizosphere, was previously shown to have excellent in vitro antagonistic properties against the most important fungal pathogens of tomato (Alternaria solani, Botrytis cinerea, Phytophthora infestans and Sclerotinia sclerotiorum) as well as several Fusarium species. Taxonomic investigations revealed that it is a member of the B. subtilis subsp. subtilis group and very closely related with the reference type strain B. subtilis subsp. subtilis 168. The sequenced genome of strain SZMC 6179J contains the genes responsible for the synthesis of the extracellular antibiotics surfactin, fengycin and bacilysin. Compared to strain 168, a prophage-like region is missing from the genome of SZMC 6179J, while there are 106 single nucleotide polymorphisms and 23 deletion-insertion polymorphisms. The high biocontrol potential of strain SZMC 6179J may results from a single base deletion in the sfp gene encoding the transcription factor of the surfactin and fengycin operons. Hypermutated regions reflecting short-time evolutionary processes could be detected in SZMC 6179J. The deletion-insertion polymorphism in the sfp gene and the detected hypermutations can be suggested as genetic determinants of biocontrol features in B. subtilis.

Topics: Amino Acid Sequence; Anti-Bacterial Agents; Antifungal Agents; Bacillus subtilis; Bacterial Toxins; Biological Control Agents; Dipeptides; Fungi; Genes, Bacterial; Lipopeptides; Multigene Family; Multilocus Sequence Typing; Mutation; Peptides, Cyclic; Phylogeny; Plant Diseases; Polymorphism, Single Nucleotide; Secondary Metabolism; Solanum lycopersicum; Transcription Factors; Whole Genome Sequencing

Bacillus subtilis XF-1 is a gram-positive, plant-associated bacterium that stimulates plant growth and produces secondary metabolites that suppress soil-borne plant pathogens. In particular, it is especially highly efficient at controlling the clubroot disease of cruciferous crops. Its 4,061,186-bp genome contains an estimated 3853 protein-coding sequences and the 1155 genes of XF-1 are present in most genome-sequenced Bacillus strains: 3757 genes in B. subtilis 168, and 1164 in B. amyloliquefaciens FZB42. Analysis using the Cluster of Orthologous Groups database of proteins shows that 60 genes control bacterial mobility, 221 genes are related to cell wall and membrane biosynthesis, and more than 112 are genes associated with secondary metabolites. In addition, the genes contributed to the strain's plant colonization, bio-control and stimulation of plant growth. Sequencing of the genome is a fundamental step for developing a desired strain to serve as an efficient biological control agent and plant growth stimulator. Similar to other members of the taxon, XF-1 has a genome that contains giant gene clusters for the non-ribosomal synthesis of antifungal lipopeptides (surfactin and fengycin), the polyketides (macrolactin and bacillaene), the siderophore bacillibactin, and the dipeptide bacilysin. There are two synthesis pathways for volatile growth-promoting compounds. The expression of biosynthesized antibiotic peptides in XF-1 was revealed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

Topics: Anti-Bacterial Agents; Antifungal Agents; Bacillus subtilis; Biological Control Agents; Biosynthetic Pathways; Dipeptides; Genes, Bacterial; Genome, Bacterial; Lipopeptides; Molecular Sequence Data; Multigene Family; Oligopeptides; Plant Development; Plant Diseases; Plants; Polyenes; Polyketides; Secondary Metabolism; Sequence Analysis, DNA; Siderophores