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PubMed1993

Injury and repair in biocide-treated spores of Bacillus subtilis.

Bacillus subtilis NCTC 8236 spores exposed to appropriate concentrations of test biocides (glutaraldehyde, two iodine and two chlorine preparations) were able to repair injury if subsequently held in nutrient broth at 37 degrees C but not in broth at 22 degrees C, sterile filtered water at 4, 22 or 37 degrees C or germination medium at 37 degrees C. Repair appeared to occur primarily during outgrowth and was initiated soon for iodine-treated spores and latest for glutaraldehyde-treated ones.

Bacillus subtilis↗

PubMed1991

Inhibition of some mycotoxigenic fungi by iturin A, a peptidolipid produced by Bacillus subtilis.

Bacillus subtilis produces peptidolipid compounds of the iturin group that have been shown to have antifungal properties, but not all fungal species are sensitive to these compounds. In this study, the activity of iturin A, produced by B. subtilis strain B-3, was tested. Paper disks impregnated with various concentrations of iturin A were placed on agar plates seeded with conidia of toxigenic species of Fusarium, Gerlacia, Penicillium or Aspergillus. Most isolates were inhibited at iturin A concentrations as low as 4 micrograms/disk. Penicillium italicum, P. viridicatum, A. ochraceus and A. versicolor were most strongly inhibited by the iturin whereas P. citrinum and A. parasiticus were least sensitive to iturin A.

Anti-Bacterial Agents↗

PubMed1995

Depletion of small cytoplasmic RNA confers fusidic-acid resistance on Bacillus subtilis.

Bacillus subtilis small cytoplasmic RNA (scRNA) is a member of a signal recognition particle (SRP)-like RNA family. To analyze the function of scRNA in protein synthesis, a B. subtilis strain SC201NA was constructed in which the expression of intact scRNA is regulated by an IPTG-inducible promoter. In this strain, depletion of scRNA leads to deficient translation and sporulation as well as morphological changes. In addition, the growth of SC201NA in the absence of IPTG became fusidic-acid resistant. The acquisition of fusidic-acid resistant phenotype by depletion of scRNA suggested that scRNA is associated with elongation factor G (EF-G) in the translation process.

Bacillus subtilis↗

PubMed2005

Simultaneous and selective production of levan and poly(gamma-glutamic acid) by Bacillus subtilis.

Bacillus subtilis(natto) Takahashi, used to prepare the fermented soybean product natto, was grown in a basal medium containing 5% (w/w) sucrose and 1.5% (w/w) L-glutamate and produced 58% (w/w) poly(gamma-glutamic acid) and 42% (w/w) levan simultaneously. After 21 h, 40-50 mg levan ml-1 had been produced in medium containing 20% (w/w) sucrose but without L-glutamate. In medium containing L-glutamic acid but without sucrose, mainly poly(gamma-glutamic acid) was produced.

Bacillus subtilis↗

PubMed1970

Analysis of the multiseptate potential of Bacillus subtilis.

Bacillus subtilis was grown at 30 C in 15 media which produced generation times of between 200 and 40 min. A correlation was observed between the growth rate and the number of septa per cell. The time between the production of a septum and its involvement in cell division was not related to the growth rate, but, for the 15 populations, had a mean value of 138 min. Multiseptate cells became progressively evident when the organism was grown at rates in excess of a 138-min generation time.

Bacillus subtilis↗

PubMed1993

Chloramphenicol acetyltransferase, a cytoplasmic protein is incompatible for export from Bacillus subtilis.

Bacillus subtilis cells expressing a hybrid protein (Lvsss-Cat) consisting of the B. amyloliquefaciens levansucrase signal peptide fused to B. pumilus chloramphenicol acetyltransferase (Cat) are unable to export Cat protein into the growth medium. A series of tripartite protein fusions was constructed by inserting various lengths of the Cat sequences between the levansucrase signal peptide and staphylococcal protein A or Escherichia coli alkaline phosphatase. Biochemical characterization of the various Cat protein fusions revealed that multiple regions in the Cat protein were causing the export defect.

Bacillus↗

PubMed2001

Regulation of the acetoin catabolic pathway is controlled by sigma L in Bacillus subtilis.

Bacillus subtilis grown in media containing amino acids or glucose secretes acetate, pyruvate, and large quantities of acetoin into the growth medium. Acetoin can be reused by the bacteria during stationary phase when other carbon sources have been depleted. The acoABCL operon encodes the E1alpha, E1beta, E2, and E3 subunits of the acetoin dehydrogenase complex in B. subtilis. Expression of this operon is induced by acetoin and repressed by glucose in the growth medium. The acoR gene is located downstream from the acoABCL operon and encodes a positive regulator which stimulates the transcription of the operon. The product of acoR has similarities to transcriptional activators of sigma 54-dependent promoters. The four genes of the operon are transcribed from a -12, -24 promoter, and transcription is abolished in acoR and sigL mutants. Deletion analysis showed that DNA sequences more than 85 bp upstream from the transcriptional start site are necessary for full induction of the operon. These upstream activating sequences are probably the targets of AcoR. Analysis of an acoR'-'lacZ strain of B. subtilis showed that the expression of acoR is not induced by acetoin and is repressed by the presence of glucose in the growth medium. Transcription of acoR is also negatively controlled by CcpA, a global regulator of carbon catabolite repression. A specific interaction of CcpA in the upstream region of acoR was demonstrated by DNase I footprinting experiments, suggesting that repression of transcription of acoR is mediated by the binding of CcpA to the promoter region of acoR.

Acetoin↗

PubMed1987

A new mutator strain of Bacillus subtilis.

Bacillus subtilis strain SB1207, widely used in our laboratory, was found to be highly temperature-sensitive and to exhibit a strong SOS-independent mutator phenotype at elevated temperatures. Both chromosomal and plasmid-borne genes were affected by the mutator. Lethality and mutator phenotype could not be attributed to a replication shut off or to thymine starvation. Due to the high frequency of base misincorporation, the mutator phenotype probably results from an editing defect rather than from a post-replication defect (mismatch repair).

Bacillus subtilis↗

PubMed1994

Substrate specificity of an RNase III-like activity from Bacillus subtilis.

Bacillus subtilis bacteriophage SP82 codes for several early RNAs that were shown previously to be cleaved by an RNase III-like enzyme called "Bs-RNase III." Cloning of DNA fragments that encode these RNA sequences downstream of a T7 RNA polymerase promoter allowed the synthesis of substrates that were used to test the cleavage specificity of Bs-RNase III, which was purified from a protease-deficient strain of B. subtilis. Single nucleotide changes at or near the cleavage site and deletions upstream and downstream of the cleavage site were constructed. The effects of these changes on the rate of Bs-RNase III cleavage were measured. The activity of Bs-RNase III and Escherichia coli RNase III on heterologous substrates was also tested. Although the local environment of the site of Bs-RNase III cleavage appears very similar to that of E. coli RNase III, there are important differences in their substrate specificity.

Bacillus subtilis↗

PubMed2006

The GTP-binding protein YlqF participates in the late step of 50 S ribosomal subunit assembly in Bacillus subtilis.

Bacillus subtilis YlqF belongs to the Era/Obg subfamily of small GTP-binding proteins and is essential for bacterial growth. Here we report that YlqF participates in the late step of 50 S ribosomal subunit assembly. YlqF was co-fractionated with the 50 S subunit, depending on the presence of noncleavable GTP analog. Moreover, the GTPase activity of YlqF was stimulated specifically by the 50 S subunit in vitro. Dimethyl sulfate footprinting analysis disclosed that YlqF binds to a unique position in 23 S rRNA. Yeast two-hybrid data revealed interactions between YlqF and the B. subtilis L25 protein (Ctc). The interaction was confirmed by the pull-down assay of the purified proteins. Specifically, YlqF is positioned around the A-site and P-site on the 50 S subunit. Proteome analysis of the abnormal 50 S subunits that accumulated in YlqF-depleted cells showed that L16 and L27 proteins, located near the YlqF-binding domain, are missing. Our results collectively indicate that YlqF will organize the late step of 50 S ribosomal subunit assembly.

Bacillus subtilis↗

PubMed1978

Further studies on the competence development in exponentially growing cultures of Bacillus subtilis.

Bacillus subtilis, growing in Bott and Wilson's medium, develops two peaks of competence in batch cultures. The first maximum developed during the exponential growth phase and it has been studied comparatively with the competence level reached in continuous culture at Dt = 2.5 h. In both cases, 100 microgram/ml of arginine inhibited competence. Continuous cultures treated with arginine recovered competence specifically after the addition of Mn2+. In addition, a reduction in the synthesis of aconitase and fumarase was observed in the arginine-inhibited continuous cultures.

Aconitate Hydratase↗

PubMed1977

Purification and comparative properties of the delta and sigma subunits of RNA polymerase from Bacillus subtilis.

Bacillus subtilis delta protein is a 21 500-Mr polypeptide that can be isolated in association with RNA polymerase holoenzyme from uninfected bacteria and with modified forms of RNA polymerase from cells infected with phage SP01 [Pero, J., Nelson, J. and Fox, T. (1975) Proc. Natl Acad. Sci. U.S.A. 72,1589]. Although no function has been assigned to delta protein in uninfected cells, this host polypeptide enhances the specificity of transcription by phage-modified forms of RNA polymerase that contain SP01-coded regulatory subunits. This report describes the purification of delta and sigma proteins from uninfected B. subtilis and examines the comparative effects of these polypeptides on transcription by core RNA polymerase. Purified sigma polypeptide was found to stimulate the transcription of phage DNA while having little effect on RNA synthesis with the synthetic DNA poly(dA-dT) as template. In contrast, purified delta protein markedly depressed the transcription of poly(dA-dT) while having little effect on enzyme activity with phage DNA as template. The inhibitory effect of delta protein on poly (dA-dT) transcription was strongly dependent on the presence of KC1 in the RNA synthesis reaction mixture.

Bacillus subtilis↗

PubMedDate not supplied

Secretion of interferon by Bacillus subtilis.

Bacillus subtilis was transformed with a hybrid gene in which the sequence encoding the alpha-amylase signal peptide was joined by a linker to the sequence encoding mature human interferon alpha 2(IFN-alpha 2). The hybrid preprotein was cleaved precisely following the last amino acid of the alpha-amylase signal sequence and was secreted at 0.5--1 mg per liter. IFN-alpha 2, preceded by either one or six amino acids, has the same specific antiviral activity as IFN-alpha 2 itself.

Amino Acid Sequence↗

PubMed1982

Transport and incorporation of N-acetyl-D-glucosamine in Bacillus subtilis.

Bacillus subtilis 168 has been found to possess a high-affinity transport system for N-acetyl-D-glucosamine (GlcNAC). The Km for uptake was approximately 3.7 microM GlcNAc, regardless of the nutritional background of the cells. Apparent increases in Vmax were noted when the bacteria were grown in the presence of GlcNAc. The uptake of GlcNAc by B. subtilis was highly stereoselective; D-glucose, D-glucosamine, N-acetyl-D-galactosamine, D-galactose, D-mannose, and N-acetylmuramic acid did not inhibit GlcNAc uptake. In contrast, glycerol was an effective inhibitor of [3H]GlcNAc transport and incorporation. Partial inhibition of GlcNAc uptake was observed with azide, fluoride, and cyanide anions, carbonyl cyanide-m-chlorophenyl hydrazone, methyltriphenylphosphonium bromide, N,N'-dicyclohexylcarbodiimide, gramicidin, valinomycin, monensin, and nigericin. Two anions, arsenite and iodoacetate, were potent inhibitors of the uptake of GlcNAc in B. subtilis. Results from paper chromatography showed that there was no intracellular pool of free GlcNAc and that the acetylamino sugar was probably phosphorylated during transport. A modification of the Park-Hancock cell fractionation scheme indicated that cells grown on glycerol or D-glucose incorporated [3H]GlcNAc primarily into the cell wall fraction. When GlcNAc was used as the sole carbon source, label could be demonstrated in fractions susceptible to protease and nuclease, as well as lysozyme, showing that the N-acetylamino sugar was utilized in macromolecular synthesis and energy metabolism.

Acetylglucosamine↗

PubMed1976

Effect of methionine on chemotaxis by Bacillus subtilis.

Bacillus subtilis, like Escherichia coli and Salmonella typhimurium, carries out chemotaxis by modulating the relative frequency of smooth swimming and tumbling. Like these enteric bacteria, methionine auxotrophs starved for methionine show an abnormally long-period of smooth swimming after addition of attractant. This "hypersensitive" state requires an hour of starvation for its genesis, which can be hastened by including alanine, a strong attractant, in starvation medium. Susceptibility to repellent, which causes transient tumbling when added, if anything, increases slightly by starvation for methionine. The results are interpreted by postulating the existence of a methionine-derived structure that hastens recovery of attractant-stimulated bacteria back to normal.

Alanine↗

PubMed2004

Bottlenecks in the expression and secretion of heterologous proteins in Bacillus subtilis.

Bacillus subtilis is an alternative host for expression and secretion of heterologous proteins. However, low yields of protein production limit its use on a wide scale. The secretory pathway of proteins can be divided into three functional stages: the early stage, involving the synthesis of secretory pre-proteins, their interaction with chaperones and binding to the secretory translocase; the second stage, translocation across the cytoplasmic membrane; and the last stage, including removal of the signal peptide, protein refolding and passage through the cell wall. Five bottlenecks for expression and secretion of heterologous proteins are described in this review: transcription, protein folding, translocation, signal peptide processing and proteolysis.

Bacillus subtilis↗

PubMed2000

Analysis of tnrA alleles which result in a glucose-resistant sporulation phenotype in Bacillus subtilis.

Bacillus subtilis cells cannot sporulate in the presence of catabolites such as glucose. During the analysis of Tn10-generated mutants, we found that deletion of the C-terminal region of the tnrA gene, which encodes a global regulator that positively regulates a number of genes in response to nitrogen limitation, results in a catabolite-resistant sporulation phenotype. Analyses of nrg-lacZ and nasB-lacZ, which are activated by TnrA under nitrogen limitation, showed that C-terminally truncated TnrA activates nitrogen-regulated genes constitutively. The relief of catabolite repression of sporulation may result from the uncontrolled expression of the TnrA-regulated genes.

Alleles↗

PubMedDate not supplied

Utilization of one promoter by two forms of RNA polymerase from Bacillus subtilis.

Bacillus subtilis possesses several forms of RNA polymerase, each differing in its sigma subunit and its specificity of promoter recognition. The sequential appearance of sigma subunits, which change the promoter recognition specificity of RNA polymerase, may have a key role in controlling the temporal pattern of gene expression required for endospore development in B. subtilis. Several genes that are expressed over relatively long periods of time during the developmental cycle are transcribed by more than one form of RNA polymerase, which initiate transcription from either tandem or overlapping promoter. The promoter region for the ctc gene is interesting because transcription is initiated at or near the same position by both sigma 37 RNA polymerase (E sigma 37), a minor form in growing cells, and sigma 29 RNA polymerase (E sigma 29), a form which appears approximately 2 h after the initiation of sproulation. Here we report that several base substitutions in the ctc promoter differentially affect the utilization of the promoter by E sigma 37 or E sigma 29.

Bacillus subtilis↗