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PubMed1995

Molecular cloning of the genes for pyruvate kinase of two bacilli, Bacillus psychrophilus and Bacillus licheniformis, and comparison of the properties of the enzymes produced in Escherichia coli.

The genes for the pyruvate kinases of a psychrophile, Bacillus psychrophilus, and a mesophile, Bacillus licheniformis, have been cloned in Escherichia coli, and all their nucleotides were sequenced. The two bacterial enzymes each had an extra C-terminal sequence consisting of about 110 amino acid residues, which has been found in the B. stearothermophilus enzyme. Both enzymes were overexpressed in E. coli and the properties of the purified enzymes were compared to those of the B. stearothermophilus enzyme. Both enzymes were less stable than the B. stearothermophilus one. The B. psychrophilus enzyme was more stable than the B. licheniformis one. Similarly to the B. licheniformis and B. stearothermophilus pyruvate kinases, the B. psychrophilus enzyme was activated by AMP or ribose 5-phosphate, and inhibited by ATP or fructose 1,6-bisphosphate. Thus, these enzymes were very similar in the sigmoidal saturation curve for phosphoenolpyruvate and allosteric effectors, but their optimum temperatures and thermostabilities were very different.

Amino Acid Sequence↗

PubMed2002

The effect of composition of parenteral solution on the thermal resistance of Bacillus stearothermophilus and Bacillus subtilis spores.

Large-volume parenteral solutions were submitted to heat treatments after being inoculated with Bacillus stearothermophilus ATCC 7953 (Tr = 121 degrees C) and Bacillus subtilis ATCC 9372 (Tr = 104.5 degrees C) spores. The average decimal reduction time for B. stearothermophilus ranged from a D121 degrees C value of 1.31 to 3.14 min, in glucophysiologic and Ringer's solutions respectively. For B. subtilis, D104.5 degrees C value increased from 0.69 to 1.37 min, in Ringer's (pH=5.91) and 50% glucose (pH 3.05) solutions respectively. The z value ranged from 7.95 degrees C (20% mannitol solution) to 13.14 degrees C (50% glucose solution), corresponding to an activation energy (Ea) of 81.48 and 49.30 kcal/mol, respectively.

Bacillus subtilis↗

PubMed2006

Structure and molecular mechanism of Bacillus anthracis cofactor-independent phosphoglycerate mutase: a crucial enzyme for spores and growing cells of Bacillus species.

Phosphoglycerate mutases (PGMs) catalyze the isomerization of 2- and 3-phosphoglycerates and are essential for glucose metabolism in most organisms. This study reports the production, structure, and molecular dynamics analysis of Bacillus anthracis cofactor-independent PGM (iPGM). The three-dimensional structure of B. anthracis PGM is composed of two structural and functional domains, the phosphatase and transferase. The structural relationship between these two domains is different than in the B. stearothermophilus iPGM structure determined previously. However, the structures of the two domains of B. anthracis iPGM show a high degree of similarity to those in B. stearothermophilus iPGM. The novel domain arrangement in B. anthracis iPGM and the dynamic property of these domains is directly linked to the mechanism of enzyme catalysis, in which substrate binding is proposed to result in close association of the two domains. The structure of B. anthracis iPGM and the molecular dynamics of this structure provide unique insight into the mechanism of iPGM catalysis, in particular the roles of changes in coordination geometry of the enzyme's two bivalent metal ions and the regulation of this enzyme's activity by changes in intracellular pH during spore formation and germination in Bacillus species.

Bacillus anthracis↗

PubMed1998

Bacterial control of mosquito larvae: investigation of stability of Bacillus thuringiensis var. israelensis and Bacillus sphaericus standard powders.

Bacillus thuringiensis var. israelensis and Bacillus sphaericus products were assayed against their respective reference powders IPS82 and SPH88. Since their production in 1982 and 1988, the potency and larvicidal activity of these standard powders have been regularly checked on their test insects Aedes aegypti (for IPS82) or Culex pipiens (for SPH88). Over the 16-year evaluation period of IPS82 and 10-year evaluation period of SPH88, their potencies were considered stable. The global mean of each year's mean showed a coefficient of variation of less than 20%. Larval rearing was the most important factor in the reproducibility of the bioassay, although some variation also originated from the person performing the bioassay. This study demonstrated that the SPH88 standard could be kept in a stock suspension at 4 degrees C for 3 years without loss of potency. Moreover, after 9 years of storage in suspension, only a 2-fold decrease in the potency of SPH88 was detected.

Aedes↗

PubMed1989

[Study on Bacillus pumilus as a recipient strain for genetic engineering of Bacillus].

Bacillus pumilus 289 can be transformed easily by plasmid pUB110 through protoplast transformation with the frequency of 10(-5)--10(-3), similar to B. subtilis AS 1.1176, a derivative strain of B. subtilis 168. The regeneration frequency of its protoplast is only slightly lower than B. subtilis AS1.1176 (0.3-12.0% compare to 1.53--24.16%). Plasmid pUB110 can be maintained in both bacterial strains stably. The frequency of loss of the plasmid in both strains is lower than 3% after 45 generations in LB medium. But it is quite different that the hybrid plasmid (pUB110 with 3.9 kb foreign DNA fragment) can be maintained much more stably in B. pumilus 289 than in B. subtilis AS1.1176. The frequency of loss of the plasmid is lower than 5% in B. pumilus 289 and 24% in B. subtilis AS1.1176 after 25 generations when they grown in SH medium. The expression level of foreign gene in B. pumilus 289 is also much higher than that in B. subtilis AS1.1176. Therefore B. pumilus 289 is valuable to be exploited as recipient strain for genetic engineering of Bacillus in the future.

Bacillus↗

PubMed1977

Kinetic evidence for an acyl-enzyme intermediate in D-alanine carboxypeptidases of Bacillus subtilis and Bacillus stearothermophilus.

The kinetics of hydrolysis and transpeptidation of the synthetic substrate diacetyl-L-lysyl-D-alanyl-D-alanine and of the natural substrate UDP-acetylmuramyl pentapeptide and related compounds catalyzed by the D-alanine carboxypeptidases of Bacillus subtilis and Bacillus stearothermophilus in the presence of the nucleophiles hydroxylamine or glycine have been examined. These kinetic data suggest that an acyl-enzyme intermediate is formed in the first step of the reaction and that the transpeptidation is the consequence of the partitioning of this intermediate between water and the nucleophile in the second step.

Alanine↗

PubMed1983

Construction of penP delta 1, Bacillus licheniformis 749/C beta-lactamase lacking site for lipoprotein modification. Expression in Escherichia coli and Bacillus subtilis.

Membrane-bound penicillinases in Gram-positive bacteria are glyceride-cysteine lipoproteins (Nielsen, J. B. K., and Lampen, J. O. (1982) J. Biol. Chem. 257, 4490-4495) that can be, but are not necessarily, intermediates in formation of exocellular enzymes. We have now deleted from the signal region of the Bacillus licheniformis 749/C beta-lactamase gene (penP) 15 base pairs that code for Ala-Leu-Ala-Gly-Cys. This sequence includes the Cys residue that undergoes lipophilic modification and the site of cleavage by signal peptidase and is well conserved in diverse prokaryotic lipoproteins. In the deletion gene, penP delta 1, the remaining Cys is preceded by 8 hydrophobic residues instead of 14 for the original modification site. PenP delta 1 has been cloned in Escherichia coli and Bacillus subtilis and its expression and products compared with penP. Penicillinase synthesis by penP delta 1 clones was greater than or equal to amounts formed by penP clones or B. licheniformis. Lipoprotein production from penP delta 1 was very low in either host and appears physiologically insignificant. In E. coli carrying penP delta 1, 25% of the penicillinase was released into the periplasm as a processed form. The remainder was a membrane-associated form of translation product size and was oriented to the periplasm. In mid-log cultures of B. subtilis carrying penP delta 1, the translation product and 2 protease-shortened species were present both in the cytoplasm and on the outer surface of the membrane. Release began at stationary phase and was dependent on the presence of enzyme processing to exo-small and a pH value greater than 7.5. We conclude that the shortened lipophilic sequence of the penP delta 1 prepenicillinase is adequate for transfer of the nascent chain through the membrane.

Amino Acid Sequence↗

PubMed1984

Synthesis of peptidoglycan by high molecular weight penicillin-binding proteins of Bacillus subtilis and Bacillus stearothermophilus.

The high molecular weight penicillin-binding proteins (PBP(s) ) Bacillus subtilis PBPs 1, 2, and 4 and Bacillus stearothermophilus PBPs 1-4 were shown to catalyze peptidoglycan synthesis from the undecaprenol-containing lipid intermediate substrate in two assay systems. In a filter paper assay system, high levels of substrate polymerization occurred when reaction mixtures were incubated on Whatman 3MM filter paper. The pH optimum for peptidoglycan synthesis was 7.5 for B. subtilis PBPs 1, 2, and 4 and 8.5 for B. stearothermophilus PBPs 1-4. Polymerization was Mg2+-independent and was unaffected by sulfhydryl reagents. Reconstitution with membrane lipids or addition of detergent (optimal concentration, 0.1%) was necessary for synthesis to occur. Bacitracin, penicillin, and cephalothin did not affect polymerization while vancomycin, ristocetin, moenomycin, and macarbomycin were strong inhibitors. In a test tube assay system, optimal synthesis occurred either in the presence of 10% ethylene glycol, 10% glycerol, and 8% methanol or in the presence of 10% N-acetylglucosamine. The products of lysozyme digestion of the synthesized peptidoglycan were analyzed by gel filtration and paper chromatography. B. stearothermophilus PBPs 1-4 synthesized a peptidoglycan product that was 5-7% cross-linked. No evidence for cross-linking was apparent in the peptidoglycan product of B. subtilis PBPs 1, 2, and 4.

Bacillus subtilis↗

PubMedDate not supplied

[The effect of Bacillus intermedius RNAase on the growth and development of Bacillus mucilaginosus].

The effect of Bacillus intermedius RNAase on vegetative cells and spores of siliceons bacteria Bacillus mucilaginosus was investigated. It is shown that the enzyme stimulates the growth of vegetative cells of B. mucilaginosus at a concentration of 10 mkg/ml and promotes germination of spores at a 1000-fold lesser concentration (0.1 mkg/ml). The spores at stages of activation and initiation appear to be most susceptible to the enzyme action. The effect of RNAase on B. mucilaginosus multiplication correlates with intensification of bacterial leaching of bauxites.

Bacillus↗

PubMedDate not supplied

[Cloning and expression of the Bacillus stearothermophilus neutral proteinase gene in Bacillus subtilis cells].

Gene of thermostable Bacillus stearothermophilus metalloprotease was cloned and expressed in mesophilic Bacillus subtilis cells. It was demonstrated that this gene is closely related by its restriction map to B. stearothermophilus T metalloprotease gene cloned earlier. Thermostability level and thermal optimum of activity of metalloprotease, the product of cloned gene expression, were estimated.

Bacillus subtilis↗

PubMed1997

[Suitability of Bacillus subtilis and Bacillus stearothermophilus spores as test organism bioindicators for detecting superheating of steam].

Biological indicators used to test sterilisation procedures for their efficacy consist of a so-called germ carrier to which the microorganisms used as test organisms adhere. In previous papers we demonstrated that carriers made of filter paper on contact with saturated steam show superheating while carriers made of glass fibre fleece as well as wetted filter paper do not. Using spores of Bacillus subtilis and Bacillus stearothermophilus as test organisms we have now investigated whether and to what extent carrier superheating affects the characteristic values (t50%) of these biological indicators. The indicators were exposed to saturated steam at 100 degrees C (B. subtilis) or 120 degrees C (B. stearothermophilus) under three different exposure conditions: 1. dry (i.e. conditioned to 45% relative humidity before introduction into the sterilising chamber), freely accessible; 2. dry with a substratum and a cover of filter card-board; 3. wet (moistened with twice distilled water before introduction into the sterilising chamber), freely accessible. For previously selected exposure periods, the incidence of indicators with surviving test organisms was determined. The reaction pattern of bioindicators with spores of B. stearothermophilus was different from that of bioindicators with spores of B. subtilis. For B. subtilis, the incidence of bioindicators exhibiting surviving test organisms depended on the nature of the carries as well as on the exposure conditions. On filter paper carriers, t50% increased in the order "wet, freely accessible", "dry, freely accessible", "dry, between filter card-board". On dry and wetted glass fibre fleece, resistance was approximately the same; when the indicators were sandwiched between layers of filter card-board, t50% increased. For B. stearothermophilus, t50% was largely dependent on the carrier material alone. The values obtained for filter paper were invariably much lower than those for glass fibre fleece. As the results show, using spores of B. subtilis it is possible to detect superheating, but the steam resistance of the spores is relatively low. Spores of B. stearothermophilus are of high steam resistance but they are practically unsuitable for detecting superheating. It is imperative to search for a test organism the resistance of which against steam is sufficiently high and which at the same time is capable of reacting to superheating (equivalent to reduced humidity) by a sufficiently large increase in resistance.

Bacillus subtilis↗

PubMed2001

Comparative sensitivity to UV-B radiation of two Bacillus thuringiensis subspecies and other Bacillus sp.

Susceptibility of Bacillus thuringiensis spores and toxins to the UV-B range (280--330 nm) of the solar spectrum reaching Earth's surface may be responsible for its inactivation and low persistence in nature. Spores of the mosquito larvicidal B. thuringiensis subsp. israelensis were significantly more resistant to UV-B than spores of the lepidopteran-active subsp. kurstaki. Spores of subsp. israelensis were as resistant to UV-B as spores of B. subtilis and more resistant than spores of the closely related B. cereus and another mosquito larvicidal species B. sphaericus. Sensitivity of B. thuringiensis subsp. israelensis spores to UV-B radiation depended upon their culture age; 24-h cultures, approaching maximal larvicidal activity, were still sensitive. Maximal resistance to UV-B was achieved only at 48 h.

Bacillus↗

PubMed2003

Recombinant strain of Bacillus thuringiensis producing Cyt1A, Cry11B, and the Bacillus sphaericus binary toxin.

A novel recombinant Bacillus thuringiensis subsp. israelensis strain that produces the B. sphaericus binary toxin, Cyt1Aa, and Cry11Ba is described. The toxicity of this strain (50% lethal concentration [LC(50)] = 1.7 ng/ml) against fourth-instar Culex quinquefasciatus was higher than that of B. thuringiensis subsp. israelensis IPS-82 (LC(50) = 7.9 ng/ml) or B. sphaericus 2362 (LC(50) = 12.6 ng/ml).

Animals↗

PubMed2005

Comparison of minisatellite polymorphisms in the Bacillus cereus complex: a simple assay for large-scale screening and identification of strains most closely related to Bacillus anthracis.

Polymorphism of five tandem repeats that are monomorphic in Bacillus anthracis was investigated in 230 isolates of the B. cereus group and in 5 sequenced B. cereus genomes in search for markers allowing identification of B. cereus and B. thuringiensis strains most closely related to B. anthracis. Using this multiple-locus variable number of tandem repeat analysis (MLVA), a cluster of 30 strains was selected for further characterization. Eventually, six of these were characterized by multilocus sequence type analysis. One of the strains is only six point mutations (of almost 3,000 bp) away from B. anthracis and was also proposed to be closest to B. anthracis by MLVA analysis. However, this strain remains separated from B. anthracis by a number of significant genetic events observed in B. anthracis, including the loss of the hemolysin activity, the presence of four prophages, and the presence of the two virulence plasmids, pXO1 and pXO2. One particular minisatellite marker provides an efficient assay to identify the subset of B. cereus and B. thuringiensis strains closely related to B. anthracis. Based on these results, a very simple assay is proposed that allows the screening of hundreds of strains from the B. cereus complex, with modest equipment and at a low cost, to eventually fill the gap with B. anthracis and better understand the origin and making of this dangerous pathogen.

Animals↗

PubMed1996

Evaluation of Bacillus thuringiensis and Bacillus sphaericus Strains from Chinese Soils Toxic to Mosquito Larvae

During our research to isolate and screen microbial agents, eight Bacillus thuringiensis isolates and five Bacillus sphaericus isolates were shown to have high toxicity to mosquito larvae. Comparing the LC50 values, four B. sphaericus isolates with LC50 values ranging from 0.50 to 1.47 ng/ml were about two to six times more toxic than strain 1593 (LC50 3.00 ng/ml) against larvae of Culex quinquefasciatus. Four B. thuringiensis isolates (LC50 values ranging from 3.80 to 7.54 ng/ml) and four B. sphaericus isolates with LC50 of 17.0 to 43.7 ng/ml were more toxic to Aedes aegypti than strain 1897 (LC50 8.46 ng/ml) and strain 1593 (LC50 67.3 ng/ml). As to Anopheles hyrcanus, the LC50 values of three B. sphaericus isolates ranging from 3.63 to 5.73 ng/ml were three to five times smaller than that of strain 1593 (LC50 16.1 ng/ml). Two B. sphaericus isolates showed high toxicity against mosquito larvae in the three genera Culex, Aedes, and Anopheles.

Journal Article↗

PubMed1998

Expression of chromosomally inserted bacillus thuringiensis israelensis toxin genes in bacillus sphaericus

Bacillus thuringiensis israelensis delta-endotoxin genes were inserted into transposon Tn917 in plasmid pTV51Ts and cloned into the chromosome of Bacillus sphaericus 2362. Many of the transformants reacted with antibody to the 135-, 128-, 65-, and 28-kDa B.t.israelensis toxin proteins and were approximately 10 times more toxic to A. aegypti larvae than the untransformed host. Some of the transformants differed physiologically and morphologically from the wild-type B. sphaericus. The toxicity of the transformed phenotype was maintained through many transfers in the absence of selective pressure. Copyright 1998 Academic Press.

Journal Article↗

PubMed2004

Fusion of Bacillus stearothermophilus leucine aminopeptidase II with the raw-starch-binding domain of Bacillus sp. strain TS-23 alpha-amylase generates a chimeric enzyme with enhanced thermostability and catalytic activity.

Bacillus stearothermophilus leucine aminopeptidase II (LAPII) was fused at its C-terminal end with the raw-starch-binding domain of Bacillus sp. strain TS-23 alpha-amylase. The chimeric enzyme (LAPsbd), with an apparent molecular mass of approximately 61 kDa, was overexpressed in IPTG-induced Escherichia coli cells and purified to homogeneity by nickel-chelate chromatography. The purified enzyme retained LAP activity and adsorbed raw starch. LAPsbd was stable at 70 degrees C for 10 min, while the activity of wild-type enzyme was completely abolished under the same environmental condition. Compared with the wild-type enzyme, the twofold increase in the catalytic efficiency for LAPsbd was due to a 218% increase in the k(cat) value.

Binding Sites↗

PubMed1994

Over-expression of membrane-bound cytochrome c-551 from thermophilic Bacillus PS3 in Bacillus stearothermophilus K1041.

Cytochrome c-551 is a lipoprotein of about 10500 Da, found in thermophilic Bacillus PS3 grown under air-limited conditions. An expression vector was constructed from a structural gene of PS3 cytochrome c-551, synthetic oligonucleotide as a promoter for Bacillus stearothermophilus and a shuttle vector for Escherichia coli and B. stearothermophilus. The transformed cells of B. stearothermophilus K1041 expressed cytochrome c-551 as much as 5 nmol/mg membrane protein. The effects of over-expression on the host cells are analyzed; a slightly slower growth rate and an increased synthesis of cytochrome oxidase (about twofold) occurred. Over-expressed (4-10-fold) cytochrome c-551 were purified and its properties were examined to know whether the protein is processed as in PS3 cells grown under air-limited conditions. The molecular mass determination and treatment with Rhizopus lipase suggested that the same processes, cleavage of signal peptidase, blocking of the N-terminal group and acylation of glycerol residue by two fatty acids, took place in the over-expression system. Fatty acylation seems useful for the cytochrome c to be effectively oxidized.

Acylation↗