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PubMed1967

Survival of microorganisms in a simulated Martian environment. II. Moisture and oxygen requirements for germination of Bacillus cereus and Bacillus subtilis var. niger spores.

The effects of moisture and oxygen concentration on germination of Bacillus cereus and B. subtilis var. niger spores were investigated in a simulated Martian environment. Less moisture was required for germination than for vegetative growth of both organisms. A daily freeze-thaw cycle lowered moisture requirements for spore germination and vegetative growth of both organisms, as compared with a constant 35 C environment. Oxygen had a synergistic effect by lowing the moisture requirements for vegetative growth, and possibly germination, of both organisms. Oxygen was not required for spore germination of either organism, but was required for vegetative growth of B. subtilis and for sporulation of both organisms.

Bacillus cereus↗
PubMed1969

Identification of Bacillus subtilis NRRL B-3275 as a strain of Bacillus pumilus.

The physiological and biochemical properties of a species of Bacillus previously identified as B. subtilis NRRL B-3275 (B-3275) were compared with those of seven strains of B. pumilus and five strains of B. subtilis. The biotin requirement of B-3275, its inability to hydrolyze starch, and its failure to reduce nitrate indicate that the organism is more closely related to the B. pumilus strains than to those of B. subtilis. Hybridization of deoxyribonucleic acid (DNA) from B-3275 with that of the strains of B. pumilus showed a binding efficiency (compared with the homologous reaction) of 58 to 99%, depending on the strain. Hybridization with the DNA from any of the strains of B. subtilis did not exceed 24%. DNA from B-3275 was unable to transform two amino acid auxotrophic markers to prototrophy in a highly competent strain of B. subtilis 168. We conclude that B-3275 is a strain of B. pumilus which we designate as B. pumilus NRRL B-3275.

Amino Acids↗
PubMed1973

Isolation and characterization of cell wall-defective variants of Bacillus subtilis and Bacillus licheniformis.

Quantitative mass conversion of intact bacterial cells of Bacillus subtilis and B. licheniformis to L-phase variants has been effected after lysozyme treatment. After subculture of the unstable L-phase variants for several months in the presence of methicillin, stable L-phase variants were obtained which grew in the absence of the antibiotic and were then unable to revert to the classical bacterial phase under conditions which gave rise to mass reversion of the protoplasts and unstable L-variants. These stable L-phase variants, which retained many of the physiological properties of the bacterium from which they were derived, were capable of growing exponentially and multiplying in liquid medium. Their morphology and apparent modes of reproduction were consistent with that described for other L-phase variants. The morphological events, as monitored by the electron microscope, of the reversion to the intact bacterial phase of an unstable L-phase variant of B. licheniformis are described.

Bacillus↗
PubMed1975

Plasmid deoxyribonucleic acid in Bacillus subtilis and Bacillus pumilus.

Two of eighteen strains of Bacillus subtilis examined contained covalently closed circular duplex deoxyribonucleic acid (DNA) of homogeneous size and buoyant density. Strain ATCC 15841 contained about 16 copies per chromosome of plasmid pPL1, a circular DNA element having a molecular weight of about 4.7 times 10(6) and a buoyant density of 1.700. Strain ATCC 7003 contained about one to two copies per chromosome of plasmid pPL2. pPL2 had a molecular weight of about 46 times 10(6) and a buoyant density of 1.696. Strain ATCC 7003 appeared to be closely related to B. subtilis 168 by genetic, physiological, and biochemical criteria. Strain ATCC 15841 appeared to be much less closely related. B. pumilus ATCC 12140 contained two size classes of covalently closed circular duplex DNA. The plasmids pMB1 and pMB2 had molecular weights of about 6.8 times 10(6) and 5.3 times 10(6), respectively, and were present in several copies per chromosome.

Bacillus↗
PubMed1976

Bacillus pumilus plasmid pPL10: properties and insertion into Bacillus subtilis 168 by transformation.

Bacillus pumilus ATCC 12140 harbors 10 or more copies per chromosome of each two small plasmids. Variants of this strain were isolated which were sensitive to a killing activity produced by the plasmid-containing parent. Each of 24 such sensitive (S) variants tested lacked detectable levels of supercoiled deoxyribonucleic acid. Transduction of S variants to the Kill+ phenotype was performed using phage PBP1 propagated on a mutant of ATCC 12140, designated strain L10, that remained Kill+ but retained only a single plasmid species (plasmid pPL10; molecular weight, approximately 4.4 X 10(6), approximately 20 copies per chromosome; RHO = 1.698). Resulting Kill+ transductants of S variants contained a single plasmid species having a size and copy number comparable to that of pPL10. Transfer of pPL10 from strain L10 TO B. pumilus strain NRS 576 was accomplished by transduction with selection for the Kill+ phenotype. Strain NRS 576 naturally harbors about two copies per chromosome of a 28-million-dalton plasmid, pPL576. In Kill + transductants of NRS 576, plasmids pPL10 and pPL576 stably coexisted at a ratio of about 11 molecules of pPL10 to 1 molecule of pPL576. Therefore, pPL576 and pPL10 are compatible plasmids. B. subtilis 168 is naturally resistant to pPl10- determined killing activity. Plasmid pPl10 was therefore inserted into B-subtilis 168 by transformation, using an indirect selection procedure and a spoB mutant as recipient. The plasmid is stably maintained at an estimated 10 copies per chromosome in the spore- recipient and in spore+ transformants. pPL10 is sensitive to cleavage by the endonucleases Hind III and EcoR1.

Bacillus↗
PubMed1978

Spore location patterns in sporulating doublets of Bacillus cereus and Bacillus megaterium, derived from single doublet isolates with differing sporulation geometry.

The distribution of spore loci in pairs of Bacillus cereus and B. megaterium showed different degrees of polarization from random location towards location at the old end of the sporangium. When individual doublets containing both spores at either the old or new ends of the sporangia were isolated by micromanipulation, subsequent culture showed the same spore location patterns.

Bacillus megaterium↗
PubMed1978

Bacteriocin and antibiotic resistance plasmids in Bacillus cereus and Bacillus subtilis.

A number of plasmids have been isolated as covalently closed circular DNAs from strains of Bacillus cereus and B. subtilis. From 12 out of 15 strains of B. cereus, plasmids could be isolated. Most of the B. cereus strains contained two or more plasmids. Their molecular weights ranged from 1.6 X 10(6) to 105 X 10(6). Bacteriocin production could be attributed to a 45 X 10(6)-dalton plasmid (pBC7) from B. cereus DSM 336, and tetracycline resistance to a 2.8 X 10(6) plasmid (pBC16) from B. cereus GP7. Two streptomycin-resistant strains of B. subtilis harbored plasmids of 5.2 X 10(6) and 9 X 10(6), respectively, which were, however, not correlated with the antibiotic resistance. The plasmid carrying resistance to tetracycline, pBC16, which was originally isolated from B. cereus, could be subsequently transformed in B. subtilis, where it is stably maintained.

Anti-Bacterial Agents↗
PubMed1983

Biosynthesis of Bacillus licheniformis penicillinase in Escherichia coli and in Bacillus subtilis.

Modified prepenicillinase was accumulated in both Escherichia coli and Bacillus subtilis treated with globomycin. Although the inhibitions of processings of prepenicillinase and prolipoprotein by globomycin in E. coli are qualitatively similar, they differ in the degree of inhibition at given concentrations of globomycin. The processing of prepenicillinase proceeds much more rapidly in E. coli than in B. subtilis.

Anti-Bacterial Agents↗
PubMed1985

Cloning and sequencing of the beta-lactamase I gene of Bacillus cereus 5/B and its expression in Bacillus subtilis.

The beta-lactamases of Bacillus cereus have attracted interest because they are secreted efficiently, because multiple enzymes are frequently present, and because their regulation has unusual features. beta-Lactamase I of strain 5/B is produced constitutively at a high level, and the exoenzyme appears to be several thousand daltons larger than the corresponding product of strain 569/H. We have cloned the gene for 5/B beta-lactamase I in Escherichia coli and B. subtilis and have sequenced the structural portion and the regulatory regions. The 5/B enzyme is produced at a low level in E. coli RR1(pRWY200) and remains cellbound. In B. subtilis it is formed in large amounts, and over 90% of it is released into the medium. There is a large degree of homology between the promoter and leader peptide regions of the 5/B and 569/H genes; both utilize UUG as the translation initiation codon (P. S. F. Mézes, R. W. Blacher, and J. O. Lampen, (J. Biol. Chem. 260:1218-1223, 1985). Although there are significant differences in the peptide segment where processing would be expected to occur, the NH2 terminus of the major 5/B product from B. subtilis BD170(pRWY215) is His-44, which is the same as the NH2 terminus of the major 569/H product from B. subtilis BD170(pRWM5).

Amino Acid Sequence↗
PubMed1991

Mapping of the gene for a major penicillin-binding protein to a genetically conserved region of the Bacillus subtilis chromosome and conservation of the protein among related species of Bacillus.

Penicillin-binding protein 5 is the most abundant penicillin-binding protein in the vegetative membranes of Bacillus subtilis and accounts for 95% of the D,D-carboxypeptidase activity of the cell. The structural gene for penicillin-binding protein 5 was mapped to a genetically conserved region near guaB at 0 degrees on the B. subtilis chromosome, and immunoassays revealed that there is conservation of this major penicillin-binding protein among related species.

Bacillus↗
PubMed1994

Induction of surfactin production in Bacillus subtilis by gsp, a gene located upstream of the gramicidin S operon in Bacillus brevis.

The deduced amino acid sequence of the gsp gene, located upstream of the 5' end of the gramicidin S operon (grs operon) in Bacillus brevis, showed a high degree of similarity to the sfp gene product, which is located downstream of the srfA operon in B. subtilis. The gsp gene complemented in trans a defect in the sfp gene (sfpO) and promoted production of the lipopeptide antibiotic surfactin. The functional homology of Gsp and Sfp and the sequence similarity of these two proteins to EntD suggest that the three proteins represent a new class of proteins involved in peptide secretion, in support of a hypothesis published previously (T. H. Grossman, M. Tuckman, S. Ellestad, and M. S. Osburne, J. Bacteriol. 175:6203-6211, 1993).

Amino Acid Sequence↗
PubMed1967

Comparison of the alpha-amylase of Bacillus subtilis and Bacillus amyloliquefaciens.

The alpha-amylase (alpha-1,4-glucan 4-glucanohydrolase, EC 3.2.1.1) of Bacillus subtilis strain W23 is less negatively-charged than the alpha-amylase of B. amyloliquefaciens strain F, as determined by electrophoretic mobility in polyacrylamide gel at pH 8.6. The alpha-amylase of strain W23 is immunologically unrelated to the alpha-amylase of strain F, as judged by lack of cross-reaction in Ouchterlony immunodiffusion studies. The pH range of maximal activity for the enzyme of strain W23 was 5.7 to 6.7, with a maximum at 6.3. The pH range of activity for the alpha-amylase of strain F was 5.5 to 6.5, with a maximum at 5.9. No significant difference was found in the effect of temperature on the activity of the alpha-amylase of strain W23 and strain F. alpha-Amylase production by strain W23 occurs throughout the 7-hr growth period, whereas enzyme production by strain F does not begin until the culture enters the stationary phase of growth. The total amounts of enzyme produced by strains W23 and F after 7 hr of growth were 0.3 and 25.5 units/ml, respectively.

Amylases↗
PubMed1969

Regulated enzymes of aromatic amino acid synthesis: control, isozymic nature, and aggregation in Bacillus subtilis and Bacillus licheniformis.

Several regulated enzymes involved in aromatic amino acid synthesis were studied in Bacillus subtilis and B. licheniformis with reference to organization and control mechanisms. B. subtilis has been previously shown (23) to have a single 3-deoxy-d-arabinoheptulosonate 7-phosphate (DAHP) synthetase but to have two isozymic forms of both chorismate mutase and shikimate kinase. Extracts of B. licheniformis chromatographed on diethylaminoethyl (DEAE) cellulose indicated a single DAHP synthetase and two isozymic forms of chorismate mutase, but only a single shikimate kinase activity. The evidence for isozymes has been supported by the inability to find strains mutant in these activities, although strains mutant for the other activities were readily obtained. DAHP synthetase, one of the isozymes of chorismate mutase, and one of the isozymes of shikimate kinase were found in a single complex in B. subtilis. No such complex could be detected in B. licheniformis. DAHP synthetase and shikimate kinase from B. subtilis were feedback-inhibited by chorismate and prephenate. DAHP synthetase from B. licheniformis was also feedback-inhibited by these two intermediates, but shikimate kinase was inhibited only by chorismate. When the cells were grown in limiting tyrosine, the DAHP synthetase, chorismate mutase, and shikimate kinase activities of B. subtilis were derepressed in parallel, but only DAHP synthetase and chorismate mutase were derepressible in B. licheniformis. Implications of the differences as well as the similarities between the control and the pattern of enzyme aggregation in the two related species of bacilli were discussed.

Bacillus↗
PubMed2006

Characterization of Bacillus cereus isolates associated with fatal pneumonias: strains are closely related to Bacillus anthracis and harbor B. anthracis virulence genes.

Bacillus cereus is ubiquitous in nature, and while most isolates appear to be harmless, some are associated with food-borne illnesses, periodontal diseases, and other more serious infections. In one such infection, B. cereus G9241 was identified as the causative agent of a severe pneumonia in a Louisiana welder in 1994. This isolate was found to harbor most of the B. anthracis virulence plasmid pXO1 (13). Here we report the characterization of two clinical and one environmental B. cereus isolate collected during an investigation of two fatal pneumonia cases in Texas metal workers. Molecular subtyping revealed that the two cases were not caused by the same strain. However, one of the three isolates was indistinguishable from B. cereus G9241. PCR analysis demonstrated that both clinical isolates contained B. anthracis pXO1 toxin genes. One clinical isolate and the environmental isolate collected from that victim's worksite contained the cap A, B, and C genes required for capsule biosynthesis in B. anthracis. Both clinical isolates expressed a capsule; however, neither was composed of poly-D-glutamic acid. Although most B. cereus isolates are not opportunistic pathogens and only a limited number cause food-borne illnesses, these results demonstrate that some B. cereus strains can cause severe and even fatal infections in patients who appear to be otherwise healthy.

Adult↗
PubMed2003

Identification of genomic islands in the genome of Bacillus cereus by comparative analysis with Bacillus anthracis.

Horizontal gene transfer has been recognized as a universal event throughout bacterial evolution. The availability of both complete genome sequences of Bacillus cereus and B. anthracis provides the possibility to perform comparative analysis based on their genomes. By using a windowless method to display the distribution of the genomic GC content of B. cereus and B. anthracis, we have found three genomic islands in the genome of B. cereus, i.e., BCGI-1, BCGI-2, and BCGI-3, respectively, which are absent in the genome of B. anthracis. All the genomic islands have abrupt changes in GC content compared with that of surrounding regions. BCGI-1 has many conserved features of genomic islands, e.g., a Val-tRNA gene is utilized as the integration site, and a site-specific recombinase gene is located at the 3' end. BCGI-2 has a large percentage of phage protein, suggesting a phage-related recombination is involved. BCGI-3 contains a ferric anguibactin transport system, which is likely to be involved in the iron transport that enables the bacterium to overcome the iron limitation in the host. In addition, BCGI-3 also contains a cluster of genes related to lantibiotics, which may play a role during the evolution of the genome. Furthermore, the integrations of the genomic islands, BCGI-1 and BCGI-3, result in deletions of DNA sequence fragments; therefore, such integrations lead to both gene gain and gene loss simultaneously.

Bacillus anthracis↗
PubMed2000

Human cell exposure assays of Bacillus thuringiensis commercial insecticides: production of Bacillus cereus-like cytolytic effects from outgrowth of spores.

Most contemporary bioinsecticides are derived from scaled-up cultures of Bacillus thuringiensis subspecies israelensis (Bti) and kurstaki (Btk), whose particulate fractions contain mostly B. thuringiensis spores (> 10(12)/L) and proteinaceous aggregates, including crystal-like parasporal inclusion bodies (PIB). Based on concerns over relatedness to B. cereus-group pathogens, we conducted extensive testing of B. thuringiensis (BT) products and their subfractions using seven human cell types. The Bti/Btk products generated nonspecific cytotoxicities involving loss in bioreduction, cell rounding, blebbing and detachment, degradation of immunodetectable proteins, and cytolysis. Their threshold dose (Dt approximately equal.5 times 10(-14)% BT product/target cell) equated to a single spore and a target cell half-life (tLD(50)) of approximately 16 hr. At Dts > 10(4), the tLD(50) rapidly shifted to < 4 hr; with antibiotic present, no component, including PIB-related [delta]-endotoxins, was cytolytic up to an equivalent of approximately 10(9 )Dt. The cytolytic agent(s) within the Bti/Btk-vegetative cell exoprotein (VCP) pool is an early spore outgrowth product identical to that of B. cereus and acting possibly by arresting protein synthesis. No cytolytic effects were seen with VCP from B. subtilis and Escherichia coli. These data, including recent epidemiologic work indicate that spore-containing BT products have an inherent capacity to lyse human cells in free and interactive forms and may also act as immune sensitizers. To critically impact at the whole body level, the exposure outcome would have to be an uncontrolled infection arising from intake of Btk/Bti spores. For humans, such a condition would be rare, arising possibly in equally rare exposure scenarios involving large doses of spores and individuals with weak or impaired microbe-clearance capacities and/or immune response systems.

Bacillus cereus↗
PubMed2000

[study of the virulence of a recombinant strain of Bacillus anthracis, obtained as a result of transductive transfer of chromosomal genes from a strain of Bacillus cereus].

Auxotrophic markers of B. anthracis strains differing them from other Bacillus representatives have been determined. Chromosome genes from prototrophic B. cereus strain were transduced into auxotrophic B. anthracis strain. The properties of transductants were studied in order to establish common transfer of chromosomal determinants responsible for realization of various signs. Transduction mating between species resulted in construction of prototroph B. anthracis strains (pX01- pX02+), whose derivatives are characterized by decreased virulence for laboratory animals.

Animals↗