Genetic analysis of the biosynthesis of non-ribosomal peptide- and polyketide-like antibiotics, iron uptake and biofilm formation by Bacillus subtilis A1/3.
The Bacillus subtilis strain A1/3 shows exceptionally diverse antibiotic capacities compared to other B. subtilis strains. To analyze this phenomenon, mutants for the putative pantotheinyltransferase gene (pptS), and for several genes involved in non-ribosomal peptide synthesis and polyketide synthesis were constructed and characterized, using bioassays with blood cells, bacterial and fungal cells, and mass spectrometry. Among at least nine distinct bioactive compounds, five antibiotics and one siderophore activity were identified. The anti-fungal and hemolytic activities of strain A1/3 could be eliminated by mutation of the fen and srf genes essential for the synthesis of fengycins and surfactins. Both pptS- and dhb -type mutants were defective in iron uptake, indicating an inability to produce a 2,3-dihydroxybenzoate-type iron siderophore. Transposon mutants in the malonyl CoA transacylase gene resulted in the loss of hemolytic and anti-fungal activities due to the inhibition of bacillomycin L synthesis, and this led to the discovery of bmyLD-LA-LB* genes. In mutants bearing disruption mutations in polyketide (pksM- and/or pksR -like) genes, the biosynthesis of bacillaene and difficidins, respectively, was inactivated and was accompanied by the loss of discrete antibacterial activities. The formation of biofilms (pellicles) was shown to require the production of surfactins, but no other lipopeptides, indicating that surfactins serve specific developmental functions.
Hofemeister
J
J
Department of Molecular Genetics, Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstrasse 3, 06466 Gatersleben, Germany. hofemeij@ipk-gatersleben.de
Conrad
B
B
Adler
B
B
Hofemeister
B
B
Feesche
J
J
Kucheryava
N
N
Steinborn
G
G
Franke
P
P
Grammel
N
N
Zwintscher
A
A
Leenders
F
F
Hitzeroth
G
G
Vater
J
J
D051080:Acyl-Carrier Protein S-Malonyltransferase; D000217:Acyltransferases / Q000235:genetics; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D018441:Biofilms; D001681:Biological Assay; D017931:DNA Primers; D004251:DNA Transposable Elements / Q000235:genetics; D040461:Gene Components; D007501:Iron / Q000378:metabolism*; D055666:Lipopeptides; D008074:Lipoproteins; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D046908:Peptide Biosynthesis, Nucleic Acid-Independent / Q000235:genetics*; D010456:Peptides, Cyclic; D010957:Plasmids / Q000235:genetics; D048630:Polyketide Synthases / Q000235:genetics; D013045:Species Specificity; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D017931:DNA Primers; D004251:DNA Transposable Elements; D055666:Lipopeptides; D008074:Lipoproteins; D010456:Peptides, Cyclic; C082662:phosphopantetheinyl transferase; C049972:fengycin; C009365:surfactin peptide; D048630:Polyketide Synthases; D007501:Iron; D000217:Acyltransferases; D051080:Acyl-Carrier Protein S-Malonyltransferase; D017855:Transferases (Other Substituted Phosphate Groups)