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PubMed2001

Regulation of polyglutamic acid synthesis by glutamate in Bacillus licheniformis and Bacillus subtilis.

The synthesis of polyglutamic acid (PGA) was repressed by exogenous glutamate in strains of Bacillus licheniformis but not in strains of Bacillus subtilis, indicating a clear difference in the regulation of synthesis of capsular slime in these two species. Although extracellular gamma-glutamyltranspeptidase (GGT) activity was always present in PGA-producing cultures of B. licheniformis under various growth conditions, there was no correlation between the quantity of PGA and enzyme activity. Moreover, the synthesis of PGA in the absence of detectable GGT activity in B. subtilis S317 indicated that this enzyme was not involved in PGA biosynthesis in this bacterium. Glutamate repression of PGA biosynthesis may offer a simple means of preventing unwanted slime production in industrial fermentations using B. licheniformis.

Bacillus↗
PubMed2001

Lack of cross-resistance to Cry19A from Bacillus thuringiensis subsp. jegathesan in Culex quinquefasciatus (Diptera: Culicidae) resistant to cry toxins from Bacillus thuringiensis subsp. israelensis.

Culex quinquefasciatus mosquitoes with high levels of resistance to single or multiple toxins from Bacillus thuringiensis subsp. israelensis were tested for cross-resistance to the Bacillus thuringiensis subsp. jegathesan polypeptide Cry19A. No cross-resistance was detected in mosquitoes that had been selected with the Cry11A, Cry4A and Cry4B, or Cry4A, Cry4B, Cry11A, and CytA toxins. A low but statistically significant level of cross-resistance, three to fourfold, was detected in the colony selected with Cry4A, Cry4B, and Cry11A. This cross-resistance was similar to that previously detected with B. thuringiensis subsp. jegathesan in the same colony. These data help explain the toxicity of B. thuringiensis subsp. jegathesan against the resistant colonies and indicate that the Cry19A polypeptide might be useful in managing resistance and/or as a component of synthetic combinations of mosquitocidal toxins.

Animals↗
PubMed2003

UV resistance of Bacillus anthracis spores revisited: validation of Bacillus subtilis spores as UV surrogates for spores of B. anthracis Sterne.

Recent bioterrorism concerns have prompted renewed efforts towards understanding the biology of bacterial spore resistance to radiation with a special emphasis on the spores of Bacillus anthracis. A review of the literature revealed that B. anthracis Sterne spores may be three to four times more resistant to 254-nm-wavelength UV than are spores of commonly used indicator strains of Bacillus subtilis. To test this notion, B. anthracis Sterne spores were purified and their UV inactivation kinetics were determined in parallel with those of the spores of two indicator strains of B. subtilis, strains WN624 and ATCC 6633. When prepared and assayed under identical conditions, the spores of all three strains exhibited essentially identical UV inactivation kinetics. The data indicate that standard UV treatments that are effective against B. subtilis spores are likely also sufficient to inactivate B. anthracis spores and that the spores of standard B. subtilis strains could reliably be used as a biodosimetry model for the UV inactivation of B. anthracis spores.

Bacillus anthracis↗
PubMed2006

Occurrence of natural Bacillus thuringiensis contaminants and residues of Bacillus thuringiensis-based insecticides on fresh fruits and vegetables.

A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins visualized by microscopy. Random amplified polymorphic DNA analysis and plasmid profiling indicated that 23 of the 50 B. thuringiensis strains were of the same subtype as B. thuringiensis strains used as commercial bioinsecticides. Fourteen isolates were indistinguishable from B. thuringiensis subsp. kurstaki HD1 present in the products Dipel, Biobit, and Foray, and nine isolates grouped with B. thuringiensis subsp. aizawai present in Turex. The commercial strains were primarily isolated from samples of tomatoes, cucumbers, and peppers. A multiplex PCR method was developed to simultaneously detect all three genes in the enterotoxin hemolysin BL (HBL) and the nonhemolytic enterotoxin (NHE), respectively. This revealed that the frequency of these enterotoxin genes was higher among the strains indistinguishable from the commercial strains than among the other B. thuringiensis and B. cereus-like strains isolated from fruits and vegetables. The same was seen for a third enterotoxin, CytK. In conclusion, the present study strongly indicates that residues of B. thuringiensis-based insecticides can be found on fresh fruits and vegetables and that these are potentially enterotoxigenic.

Bacillus thuringiensis↗
PubMed1986

Cloning and expression of the Bacillus anthracis protective antigen gene in Bacillus subtilis.

The gene encoding the protective antigen (PA) moiety of the tripartite exotoxin of Bacillus anthracis was cloned from the recombinant plasmid pSE36 into Bacillus subtilis 1S53 by using the plasmid vector pUB110. Two clones, designated PA1 and PA2, were identified which produced PA in liquid cultures at levels of 20.5 to 41.9 micrograms/ml. This PA was identical to B. anthracis Sterne PA with respect to migration on sodium dodecyl sulfate-polyacrylamide gels and to Western blot antigenic reactivity. Addition of lethal factor or edema factor to PA1 and PA2 supernatants generated biologically active anthrax lethal toxin or edema-producing toxin, respectively. The recombinant plasmid in PA1 (pPA101) was 7.8 kilobases, whereas the PA2 strain plasmid (pPA102) was 6.1 kilobases. Both plasmids had deletions extending into the insert sequence but not into the DNA encoding the PA protein. Immunization with the live recombinant strains protected guinea pigs from lethal challenge with virulent B. anthracis spores, and the immunization partially or completely protected rats from intravenous challenge with anthrax lethal toxin.

Antigens, Bacterial↗
PubMed1990

Immunization against anthrax with aromatic compound-dependent (Aro-) mutants of Bacillus anthracis and with recombinant strains of Bacillus subtilis that produce anthrax protective antigen.

The safety and efficacy of five prototype, live anthrax vaccines were studied in Hartley guinea pigs and CBA/J and A/J mice. Two of the strains, Bacillus anthracis FD111 and FD112, are Aro- mutants derived by Tn916 mutagenesis of B. anthracis UM23-1. Bacillus subtilis PA1 and PA2 contain a recombinant plasmid, pPA101 or pPA102, respectively, that carries the gene from B. anthracis encoding synthesis of protective antigen (PA). The final strain, B. subtilis PA7, was isolated in this study from B. subtilis DB104 transformed with pPA101. All five strains were less virulent in guinea pigs and A/J and CBA/J mice than the toxinogenic, nonencapsulated B. anthracis veterinary vaccine Sterne strain. A/J and CBA/J inbred mice represent strains that are innately susceptible and resistant, respectively, to the Sterne strain. These differences in susceptibility are due to differences in ability to produce complement component 5. In guinea pigs, immunization with PA1 or PA2 vegetative cells or PA7 spores protected greater than or equal to 95% from an intramuscular spore challenge with the virulent, "vaccine-resistant" B. anthracis Ames strain. Strain PA2 vegetative cells and strain PA7 spores were as effective as the Sterne strain in Sterne-resistant CBA/J mice, protecting 70% of the mice from Ames strain spore challenge. Immunization with FD111 or FD112 vegetative cells fully protected guinea pigs from challenge. Immunization with FD111 cells protected up to 100% of CBA/J mice and up to 70% of A/J mice.

Animals↗
PubMed1975

Peptidoglycan synthesis in L-phase variants of Bacillus licheniformis and Bacillus subtilis.

Stable L-phase variants isolated from Bacillus licheniformis and Bacillus subtilis, when grown in osmotically stabilized media, do not synthesize peptidoglycan but have been found to accumulate the nucleotide precursors of this polymer. The enzymes involved in the synthesis of these precursors and the later membrane-bound stages of peptidoglycan synthesis have been investigated, and the L-phase variants have been shown to contain lesions, which provide a rational explanation for the absence of peptidoglycan and for the nature of the precursor accumulated. The majority of the L-phase variants contained a single enzymic defect, but two strains were isolated with double lesions. Five out of seven strains examined accumulated uridine 5'-diphosphate (UDP)-MurAc-L-ala-D-glu and were unable to synthesize diaminopimelic acid as a consequence of a defect in aspartate-beta-semialdehyde dehydrogenase activity. Two strains were deficient in UDP-MurAc: L-alanine ligase and accumulated UDP-MurAc. One strain accumulated the complete nucleotide precursor UDP-MurAc-L-ala-D-glu-mA2pm-D-ala-D-ala and was deficient in phospho-N-acetylmuramyl pentapeptide translocase. A second strain also had this lesion, together with defective aspartate-beta-semialdehyde dehydrogenase activity. The other enzymes of peptidoglycan synthesis were present in the L-phase variants, with activities similar to those found in the parent bacilli grown under identical conditions. Membrane preparations from certain of the L-phase variants were also capable of synthesizing the secondary polymers poly(glycerol phosphate) teichoic acid and teichuronic acid and also a polymer of N-acetylglucosamine.

Alanine↗
PubMed1980

Regulation of a glutamine amidotransferase subunit from Bacillus subtilis by a cloned trpE gene from Bacillus pumilus.

The influence of a cloned trpE (trpE+p) gene from Bacillus pumilus on the expression of the gat locus in Bacillus subtilis was examined. The trpE gene was regulated by tryptophan and the mtr locus, which specifies the presumed aporepressor. The specific activity of subunit G varied directly with the level of subunit Ep, and the heterologous EpG complex that was formed was stable to gel filtration.

Anthranilate Synthase↗
PubMed1981

Molecular cloning and expression of Bacillus licheniformis beta-lactamase gene in Escherichia coli and Bacillus subtilis.

The chromosomal beta-lactamase (penicillinase, penP) gene from Bacillus licheniformis 749/C has been cloned in Escherichia coli. The locations of the target sites for various restriction enzymes on the 4.2-kilobase EcoRI fragment were determined. By matching the restriction mapping data with the potential nucleotide sequences of the penP gene deduced from known protein sequence, we established the exact position of the penP gene on the fragment. A bifunctional plasmid vector carrying the penP gene, plasmid pOG2165, was constructed which directs the synthesis of the heterologous beta-lactamase in both E. coli and Bacillus subtilis hosts. The protein synthesized in E. coli and B. subtilis is similar in size to the processed beta-lactamase made in B. licheniformis. Furthermore, the beta-lactamase made in B. subtilis is efficiently secreted by the host into the culture medium, indicating that B. subtilis is capable of carrying out the post-translational proteolytic cleavage(s) to convert the membrane-bound precursor enzyme into the soluble extracellular form.

Bacillus↗
PubMed1981

Distribution of bacteriophage phi 3T homologous deoxyribonucleic acid sequences in Bacillus subtilis 168, related bacteriophages, and other Bacillus species.

The Bacillus subtilis 168 chromosome was found to share extensive homology with the genome of bacteriophage phi 3T. At least three different regions of the bacterial genome hydridized to ribonucleic acid complementary to phi 3T deoxyribonucleic acid (DNA). The thymidylate synthetase gene, thyA, of B. subtilis and the sequences adjacent to it were shown to be homologous to the region in the phi 3T DNA containing the phage-encoded thymidylate synthetase gene, thyP3. SP beta, a temperate bacteriophage known to be integrated into the B. subtilis 168 chromosome, was demonstrated to be closely related to phi 3T. Other regions of the bacterial genome were also found to hybridize to the phi 3T probe. The nature and location of these sequences in the bacterial and phage chromosomes were not identified. It was shown however, that they were not homologous to either the thyP3 gene or the DNA surrounding the thyP3 gene. The chromosomes of other Bacillus species were also screened for the presence of phi 3T homologous sequences, and the thyP3 gene was localized in the linear genomes of phages phi 3T and rho 11 by heteroduplex mapping. It is suggested that the presence of sequences of phage origin in the B. subtilis 168 chromosome might contribute to the restructuring and evolution of the viral and bacterial DNAs.

Bacillus↗
PubMed1983

Cloning and expression in Escherichia coli and Bacillus subtilis of the hemolysin (cereolysin) determinant from Bacillus cereus.

From a cosmid gene bank of Bacillus cereus GP4 in Escherichia coli we isolated clones which, after several days of incubation, formed hemolysis zones on erythrocyte agar plates. These clones contained recombinant cosmids with B. cereus DNA insertions of varying lengths which shared some common restriction fragments. The smallest insertion was recloned as a PstI fragment into pJKK3-1, a shuttle vector which replicates in Bacillus subtilis and E. coli. When this recombinant plasmid (pJKK3-1 hly-1) was transformed into E. coli, it caused hemolysis on erythrocyte agar plates, but in liquid assays no external or internal hemolytic activity could be detected with the E. coli transformants. B. subtilis carrying the same plasmid exhibited hemolytic activity at levels comparable to those of the B. cereus donor strain. The hemolysin produced in B. subtilis seemed to be indistinguishable from cereolysin in its sensitivity to cholesterol, activation by dithiothreitol, and inactivation by antibodies raised against cereolysin. When the recombinant DNA carrying the cereolysin gene was used as a probe in hybridization experiments with chromosomal DNA from a streptolysin O-producing strain of Streptococcus pyogenes or from listeriolysin-producing strains of Listeria monocytogenes, no positive hybridization signals were obtained. These data suggest that the genes for these three SH-activated cytolysins do not have extended sequence homology.

Bacillus cereus↗
PubMed1983

Expression of a Bacillus megaterium sporulation-specific gene during sporulation of Bacillus subtilis.

The gene for the Bacillus megaterium spore C protein, a sporulation-specific gene, has been transferred into Bacillus subtilis. The B. megaterium gene was expressed little, if at all, during log-phase and early-stationary-phase growth, but was expressed during sporulation with the same kinetics as and at a level similar to that of the analogous B. subtilis genes. This finding is most consistent with the regulation of this class of genes by a mechanism of positive control.

Bacillus megaterium↗
PubMed1984

Expression of Bacillus megaterium and Bacillus subtilis small acid-soluble spore protein genes during stationary-phase growth of asporogenous B. subtilis mutants.

The small acid-soluble spore proteins alpha and beta were not detected during stationary-phase growth of asporogenous Bacillus subtilis mutants blocked in stages 0, II, or III, but mutants blocked in stages IV or V accumulated nearly wild-type levels of these small acid-soluble spore proteins. Similar results were obtained when production of Bacillus megaterium C protein (also a small acid-soluble spore protein), as well as alpha and beta, were monitored in these mutants containing a recombinant plasmid carrying the B. megaterium C protein gene. The only exception was a spo0H mutant which synthesized a small amount of C protein, but no alpha or beta.

Bacillus megaterium↗
PubMed1984

Molecular cloning of a major cell wall protein gene from protein-producing Bacillus brevis 47 and its expression in Escherichia coli and Bacillus subtilis.

Bacillus brevis 47 contains two major cell wall proteins. Each protein forms a hexagonal array in the cell wall. A 4.8-kilobase HindIII fragment of B. brevis 47 DNA cloned into Escherichia coli with pBR322 as a vector directed the synthesis of polypeptides cross-reactive with antibody to the middle wall protein. A 700-base-pair BamHI-HpaI fragment was shown to be the essential region for the synthesis of immunoreactive polypeptides. Furthermore, this fragment appeared to contain the promoter activity. The 3.5-kilobase BamHI fragment covering the essential region as well as its downstream sequence was subcloned into the corresponding restriction site of pUB110 by using Bacillus subtilis as the cloning host. Both E. coli and B. subtilis carrying the cloned DNA synthesized several immunoreactive polypeptides which were mainly found in the cytoplasm. B. subtilis secreted polypeptides cross-reactive with antibody to the middle wall protein. These extracellular polypeptides were degraded upon prolonged culture.

Bacillus↗
PubMed1984

Construction of a promoter-probe vector for a Bacillus subtilis host by using the trpD+ gene of Bacillus amyloliquefaciens.

The trp gene cluster of Bacillus amyloliquefaciens was found to be structurally similar to that of the Enterobacteriaceae. The translation termination codon of the putative trpE gene and the initiation codon for the putative trpD gene overlap at the trpE-trpD junction, and a promoter for the putative trpC gene is suggested to exist. A promoter-probe vector of Bacillus subtilis, pFTB281, was constructed with a DNA fragment of B. amyloliquefaciens, complementing the trpC and trpD mutations of B. subtilis, a 42-base-pair DNA fragment of M13mp7, and the larger EcoRI-PvuII fragment of pUB110, which confers an autonomous replication function and the kanamycin-resistance phenotype to the chimeric plasmid. pFTB281 has BamHI, EcoRI, and SalI cloning sites in the 5'-upstream portion of the protein-coding region of the putative trpD gene, and the insertion of a certain DNA fragment at any of these sites allowed the plasmid to transform a trpD mutant of B. subtilis to the TrpD+ phenotype. DNA fragments showing the promoter function for the trpD gene were obtained from B. amyloliquefaciens and Saccharomyces cerevisiae chromosomes and rho 11 and lambda phage DNAs, but rarely from the DNAs of Escherichia coli and pBR322.

Amino Acid Sequence↗
PubMed1986

Expression of the staphylococcal protein A gene in Bacillus subtilis by gene fusions utilizing the promoter from a Bacillus amyloliquefaciens alpha-amylase gene.

Gene fusions of DNA sequences encoding protein A from Staphylococcus aureus (spa) with expression elements from an alpha-amylase gene from Bacillus amyloliquefaciens (amyEBamP) directed the synthesis and efficient secretion of protein A in Bacillus subtilis. The fusions were established on multicopy pUB110-based plasmid vectors, in contrast to the intact spa gene, which could not be stably established on plasmids in B. subtilis. Some of the resulting B. subtilis strains secreted protein A at levels in excess of 1 g/liter, demonstrating that a foreign protein encoded by an engineered gene can be secreted by B. subtilis at levels comparable to endogenous exoproteins.

Bacillus↗
PubMed1986

Molecular cloning and nucleotide sequence of a DNA fragment from Bacillus natto that enhances production of extracellular proteases and levansucrase in Bacillus subtilis.

A DNA fragment from Bacillus natto IFO3936 has been cloned which enhances the production of both extracellular alkaline and neutral proteases in Bacillus subtilis. The DNA sequence analysis around the gene responsible for the hyperproduction, prtR, revealed one open reading frame (comprising 60 amino acid residues) which was bounded by potential transcriptional and translational regulatory signals in its preceding and following regions. This open reading frame was not homologous to the published sequences of the structural genes of the two proteases. The calculated molecular weight (7,109) of the polypeptide predicted from the DNA sequence is much smaller than those of the two proteases, indicating that the gene product is distinct from those enzymes. In-frame fusion between the N-terminal region of the coding sequence and the lacZ gene of Escherichia coli demonstrated that the coding region was indeed translated in vivo. By deletion analysis it was suggested that prtR was the structural gene for the 60-amino-acid polypeptide. Cells carrying a prtR plasmid secreted both proteases 40 to 400 times more than the cells carrying the vector alone. Furthermore, it was found that prtR also enhanced the production of levansucrase by 1 or 2 orders of magnitude. There was no difference, however, in the amount of the other extracellular enzymes such as alpha-amylase, RNase, and alkaline phosphatase. These results indicate that prtR is specific for the hyperproduction of the proteases and levansucrase.

Bacillus↗