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At least 19 recordsLinked to original sources
PubMed2005

Heat-stable toxin production by strains of Bacillus cereus, Bacillus firmus, Bacillus megaterium, Bacillus simplex and Bacillus licheniformis.

Strains of Bacillus cereus can produce a heat-stable toxin (cereulide). In this study, 101 Bacillus strains representing 7 Bacillus species were tested for production of heat-stable toxins. Strains of B. megaterium, B. firmus and B. simplex were found to produce novel heat-stable toxins, which showed varying levels of toxicity. B. cereus strains (18 out of 54) were positive for toxin production. Thirteen were of serovar H1, and it was of interest that some were of clinical origin. Two were of serovars 17B and 20, which are not usually implicated in the emetic syndrome. Partial purification of the novel B. megaterium, B. simplex and B. firmus toxins showed they had similar physical characteristics to the B. cereus emetic toxin, cereulide.

Bacillus↗
PubMed1997

beta-Amylase production by some Bacillus cereus, Bacillus megaterium and Bacillus polymyxa [correction of polymaxa] strains.

The production of extracellular beta-amylase by some Bacillus cereus, Bacillus megaterium and Bacillus polymyxa [corrected] strains was investigated, and the maximal yields of the enzyme were 3.6; 9.3 and 20.4 U/mL of the culture fluid, respectively (U, 1 mumol of maltose equivalent per min at 30 degrees C). Several cultivation media were used for beta-amylase production. Bacillus cereus and some strains of Bacillus megaterium gave good yields of beta-amylase only in medium with the addition of nutrient broth. However, beta-amylase produced during growth in protein rich medium (nutrient broth) was highly unstable, probably due to inactivation by proteolytic enzymes co-existing in the culture fluid. Bacillus polymyxa [corrected] strains can produce good yields of beta-amylase on a semi-synthetic medium consisting of inorganic salts, potato starch and inexpensive soybean extract instead of costly peptone and meat extract. The most potential beta-amylase producer was the strain Bacillus polymyxa [corrected] NCIB 8524. The tested Bacillus megaterium and Bacillus polymyxa [corrected] strains were apparently differentiated by temperature cultivation (30 and 37 degrees C) suitable for beta-amylase amylase yield.

Bacillus↗
PubMed2005

Production of natural methyl anthranilate by microbial N-demethylation of N-methyl methyl anthranilate by the topsoil-isolated bacterium Bacillus megaterium.

Bacillus megaterium, isolated in a screening process from topsoil, was used for N-demethylation of natural N-methyl methyl anthranilate to produce natural methyl anthranilate. Maximal productivity of 70 mg/L/day was achieved under laboratory-scale conditions without further optimization. No byproducts were observed. Thus, production of "natural" methyl anthranilate using B. megaterium is a significant improvement over comparable already existing procedures.

Bacillus megaterium↗
PubMed1975

Tryptophan catabolism in Bacillus megaterium.

Bacillus megaterium grows in a medium containing L-tryptophan as the sole carbon, nitrogen, and energy source. Kynurenine, anthranilic acid, and catechol are metabolic intermediates, suggesting that this organism used the anthranilic acid pathway for tryptophan degradation. Cells that grow on L-tryptophan oxidize kynurenine, alanine, and anthranilic acid and the presence of tryptophan oxygenase (EC 1.13.1.12), kynureninase (EC 3.7.1.3), and catechol oxygenase (EC 1.13.1.1) in cell extracts provide additional evidence for the degradative pathway in B. megaterium. Tryptophan oxygenase is inhibited by sodium azide, potassium cyanide, and hydroxylamine, indicating that the enzyme has a functional heme group. D-Tryptophan is not a substrate for tryptophan oxygenase, and the D-isomer does not inhibit this enzyme. Formamidase (EC 3.5.1.9) and anthranilate hydroxylase are not detectable in extracts. Tryptophan catabolism is inducible in B megaterium and is subject to catabolite repression by glucose and glutamate. Arginine does not cause repression, and kynurenine induces both tryptophan oxygenase and kynureninase.

Alanine↗
PubMed1985

Mechanism of action of aflatoxin B1 in Bacillus megaterium.

Bacillus megaterium cells from various growth phases were equally susceptible to the lethal effects of aflatoxin B1. Known surfactants (EDTA and Tween-80) accentuated the effects of aflatoxin B1. Viability and inulin uptake in aflatoxin B1-exposed cells decreased considerably. The effect was concentration dependent. A straight-line relationship observed in the death curve indicated a single target for aflatoxin B1 action in B. megaterium. Leakage of intracellular constituents in B. megaterium was also concentration dependent, and this can be related to the extent of cell membrane damage.

Aflatoxin B1↗
PubMed1986

Interference with sporulation can stimulate the rate of a proteinase synthesis in Bacillus megaterium.

Bacillus megaterium, in which sporulation was blocked either by mutation or with netropsin, synthesizes during the stationary phase more exocellular proteinase than the sporulating culture. The asporogenic mutant synthesizes the enzyme at a higher rate and for a longer time than does the sporulating population. The culture, whose sporulation was inhibited by netropsin, produces the proteinase at a higher rate, although for only a limited time interval.

Bacillus megaterium↗
PubMed1991

Cloning and expression of penicillin G acylase gene in Bacillus megaterium.

Bacillus megaterium BM1, which produces penicillin G acylase (PGA), has been isolated. Gene encoding for PGA was cloned into E. coli MC1061 using pBR322 as the vector, obtaining a recombinant plasmid pBmPA4 containing 9.9 kb inserted DNA. Restriction map of the plasmid was analyzed. A pBmPA5 containing 4.9 kb was gained by deletion in vitro. Both pBmPA4 and pBmPA5 clones can be expressed in E.coli MC1061, and their expressions were induced by phenylacetic acid.

Bacillus megaterium↗
PubMed2006

Plant growth promotion and induction of resistance in Camellia sinensis by Bacillus megaterium.

Bacillus megaterium DE BARY TRS-4 was isolated from tea rhizosphere and tested for its ability to promote growth and cause disease reduction in tea plants. In vivo studies revealed the ability of this bacterium to promote growth of tea plants very significantly. Brown root rot disease, caused by Fomes lamaoensis was markedly reduced by application of the bacterium to the soil. Population of F. lamaoensis in soil before and after application of B. megaterium, as determined by ELISA and dot-blot using PAb raised against the pathogen, was shown to be greatly reduced in presence of the bacterium. Biochemical changes induced in tea plants were also examined. Root colonization by B. megaterium and subsequent inoculation with F. lamaoensis also led to an increase in polyphenolics, as well as in defense related enzymes-peroxidase, chitinase, beta -1,3-glucanase and phenyl alanine ammonia lyase. Determination of mechanism of action of this bacterium revealed it to be able to solubilize phosphate, produce IAA, siderophore and antifungal metabolite. The plant growth promotion and reduction of disease intensity have been shown to be due to a combination of several mechanisms.

Antibiosis↗
PubMed1992

spoVG sequence of Bacillus megaterium and Bacillus subtilis.

We have sequenced the stage V sporulation specific gene spoVG in both Bacillus megaterium and Bacillus subtilis. The open reading frames encode polypeptides of 96 and 97 residues, respectively, and have an 88.6% amino acid identity. Both genes have putative rho-independent terminators. No significant amino acid or nucleotide homology of either gene was found when compared with sequences contained in either the Genbank or EMBL data bases.

Amino Acid Sequence↗
PubMed1993

The cortical peptidoglycan from spores of Bacillus megaterium and Bacillus subtilis is not highly cross-linked.

Determination by amino acid analyses of the percentage of diaminopimelic acid in the spore cortex of Bacillus megaterium and Bacillus subtilis which is involved in interpeptide cross-links gave values of 31 to 37%. This finding supports the idea that the cortex volume could undergo significant changes in response to changes in pH or ionic strength and could thus play an active role in reducing the water content of the spore protoplast during sporulation.

Amino Acids↗
PubMed1978

Biochemical studies on glucose initiated germination in Bacillus megaterium.

Bacillus megaterium QM B1551 spores contained the enzymes for the Embden-Meyerhof pathway and the initial reactions in the hexose monophosphate pathway but not the Entner-Doudoroff pathway. With [U-14C]glucose no metabolism was detected until after about 30% of the spores had lost heat resistance. Mutants that lacked either phosphofructokinase or 6-phosphogluconate dehydrogenase were able to initiate germination on glucose like wild type. Purified methyl alpha-D-glucopyranoside, 6-deoxyglucose and 6-deoxy-methyl alpha-D-glucopyranoside were not substrates for spore enzymes yet these compounds still initiated germination. Therefore, metabolism of exogenously added glucose is probably not the primary stimulatory effect in germination.

Bacillus megaterium↗
PubMed1996

Induction of cytochrome P-450 BM-3 (CYP 102) by non-steroidal anti-inflammatory drugs in Bacillus megaterium.

Bacillus megaterium contains a cytochrome P-450 fatty acid mono-oxygenase which is inducible with barbiturate drugs. We have demonstrated that this enzyme system is inducible with peroxisome proliferators. In mammals, peroxisome proliferators also induce mono-oxygenases in the CYP4A gene family. In this paper we demonstrate that the non-steroidal anti-inflammatory drugs ibuprofen, ketoprofen and indomethacin are potent inducers of fatty acid mono-oxygenase activity as well as of P-450BM-3 protein in B. megaterium. The levels of induction of P-450 protein were 11.8-, 3.9- and 3.0-fold respectively. In addition, we demonstrate that these inducing agents interact with a transcriptional repressor, Bm3R1, which leads to its dissociation from its operator sequence. This provides a rational mechanism for the induction process. This is the first report which demonstrates that non-steroidal anti-inflammatory drugs can interact directly with a transcription factor to initiate gene expression, and further substantiates the structure-activity relationships that identify inducers of cytochrome P-450BM-3 and compounds that have the potential to act as peroxisome proliferators and induce CYP4A expression in mammals.

Animals↗
PubMed1975

Microbiological assay of patulin, using Bacillus megaterium.

Bacillus megaterium NRRL 1368 was found to be sensitive to patulin and a suitable test organism for an accurate, quantitative bioassay of the toxin. The optimum conditions for the test were determined. The response of the organism to patulin was found to be linear between 2 and 80 mug. When compared to thin layer chromatographic and spectrophotometric assay methods, the bioassay was found to be comparable in accuracy, but less sensitive. The test was found to be sensitive to 1.7 mug patulin. The assay is rapid (12-15 hr), simple, and inexpensive and can be used to verify the toxicity of samples, as well as to quantitatively measure patulin in samples of liquid media, apple juice, and corn.

Bacillus megaterium↗
PubMed1978

Purification and properties of glutamate synthase and glutamate dehydrogenase from Bacillus megaterium.

Bacillus megaterium N.C.T.C. no. 10342 exhibits glutamate synthetase (EC 2.6.1.53) and glutamate dehydrogenase (EC 1.4.1.4) activities. Concentrations of glutamate synthase were high when the bacteria were grown on 3mM-NH4Cl and low when they were grown on 100mM-NH4Cl, whereas glutamate dehydrogenase concentrations were higher when the bacteria were grown on 100mM-NH4Cl than on 3mM-NH4Cl. Glutamate synthase and glutamate dehydrogenase were purified to homogeneity from B. megaterium grown in 10mM-glucose/10mM-NH4Cl. The purified enzymes had mol.wts. 840000 and 270000 for glutamate synthase and glutamate dehydrogenase respectively. The Km values for substrates with NADPH and coenzyme were (glutamate synthase activity shown first) 9 micron and 360 micron for 2-oxoglutarate, 7.1 micron and 8.7 micron for NADPH, and 0.2 mM for glutamine and 22 mM for NH4Cl, similar values to those of enzymes from Escherichia coli. Glutamate synthase contained NH3-dependent activity (different from authentic glutamate dehydrogenase), which was enhanced 4-fold during treatment at pH 4.6 NH3-dependent activity was generally about 2% of the glutamine-dependent activity. Amidination of glutamate synthase by the bi-functional cross-linking reagent dimethyl suberimidate inactivated glutamine-dependent glutamate synthase activity, but increased NH3-dependent activity. A cross-linked structure of mol.wt. approx 200000 was the main product formed.

Amino Acids↗
PubMed1974

Requirement of deoxyribonucleic acid synthesis for microcycle sporulation in Bacillus megaterium.

Bacillus megaterium cells have been examined during outgrowth for their macromolecular content, ability to undergo microcycle sporulation, the time of their growth division, the time of deoxyribonucleic acid (DNA) replication initiation, and their ability to synthesize DNA after transfer to sporulation medium. The increase in total DNA content of the cells increased discontinuously beginning at 90 min. Thymidine incorporation became insensitive to chloramphenicol between 90 and 105 min of outgrowth. At 90 min the cells acquired the ability to undergo microcycle sporulation and the degree of sporulation depended on the time spent in outgrowth, with maximal sporulation occurring at 180 min. During outgrowth, cells underwent one synchronous growth division beginning at 225 min and ending at 270 min. Outgrowing cells were not able to continue DNA synthesis after transfer to sporulation medium. The data suggest that DNA replication starts before cells are able to undergo microcycle sporulation; however, the initiation of replication may not be the only requirement for microcycle sporulation.

Bacillus megaterium↗
PubMed1997

Production and characterization of xylanase from a beta-amylolytic strain of Bacillus megaterium.

Bacillus megaterium B6 ATCC 51946, a potent beta-amylase producing strain produced extracellular xylanase (EC 3.2.1.8) when cultivated in the presence of xylan as sole carbon source. The strain showed maximum xylanolytic activity after 12 h growth, and was capable of fermenting various agricultural wastes, of which under-utilized jute stalk proved to be best for production of xylanase. The ultrafiltered xylanase showed temperature and pH optima at 85 degrees C and 7.5, respectively. The enzyme was stable at 50 degrees C for 20 min and in the pH range of 7-9. The stability of the enzyme in the presence of thiol inhibitors revealed the absence of thiols at its active site. The enzyme was inactivated in the presence of Hg2+. Absence of substrate cross specificity and high temperature optima of the enzyme made it applicable to pulp and bleaching processes. The high saccharifying potential and ability to hydrolyse lignocellulosic residues favour its application in the commercial production of xylose, a sugar of food and pharmaceutical importance.

Bacillus megaterium↗
PubMed1971

Iron requirements and aluminum sensitivity of an hydroxamic acid-requiring strain of Bacillus megaterium.

Bacillus megaterium strain ATCC 19213 secretes a ferric-chelating secondary hydroxamic acid, whereas a mutant (strain SK11) derived from it cannot produce a hydroxamate. Strain SK11 could be cultivated in a sucrose-mineral salts medium (treated with Chelex 100 to reduce trace metals) in the absence of added hydroxamate, if the inoculum was high. The lowest iron supplements necessary for maximal growth of both strains were equivalent (0.01 to 0.04 mug of iron per ml). Addition of either aluminum (0.5 mug/ml) or chromium (0.1 mug/ml) to the medium prevented full growth of strain SK11 at the minimal iron concentration, although elevated iron (1 mug/ml) reversed this inhibition. The iron-free secondary hydroxamate, Desferal, also abolished aluminum and chromium inhibition of strain SK11, producing maximal population densities at the low iron concentration. Growth of the hydroxamate-producing strain 19213 was not altered significantly by the aluminum or chromium levels which inhibited strain SK11. However, strain 19213 responded to these metals by increasing its secretion of a secondary hydroxamate. It was concluded that aluminum and chromium interfered with iron incorporation, either directly or by formation of nonutilizable aggregates with iron. The secondary hydroxamates may have overcome this interference by solubilization of iron for delivery to a single uptake process, or the ferric-hydroxamate chelate may enter the cell by an alternate route.

Aluminum↗
PubMed1967

Iron-chelating hydroxamic acid (schizokinen) active in initiation of cell division in Bacillus megaterium.

Bacillus megaterium ATCC 19213 secretes a cell division-initiating "schizokinen" (SK) which accumulates during its culture cycle to a concentration inversely proportional to the iron added to a sucrose-mineral salts medium. Secreted SK was purified from culture filtrates as a red Fe (III) chelate, and a fraction with similar biological properties was obtained from whole cells. Infrared spectra of SK, and analyses of unhydrolyzed and acid-hydrolyzed preparations indicated it to be a secondary hydroxamate; visible absorption maxima of the ferric complex showed pH dependency typical of ferric monohydroxamates. Schizokinen preparations from cultures grown at "normal" and at low Fe concentrations were similar biologically and in certain of their chemical properties, but their R(F) values and infrared spectra suggested nonidentity. Significant lag reduction of B. megaterium was effected by 0.2 mmug of SK per ml; the Fe (III)-SK chelate and "iron-free" SK were equally effective. A 50-mmug amount produced half-maximal growth response of the siderochrome auxotroph, Arthrobacter JG-9. Schizokinen also overcame ferrimycin A inhibition of three Bacillus species. These properties relate the B. megaterium schizokinen to the trihydroxamate siderochromes, although SK appears to be a monohydroxamate.

Bacillus megaterium↗