SEARCH · PubMed Health

Results for “Bacillaceae”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources

PubMed2005

Cloning, sequencing and functional expression in Escherichia coli of the gene for a P-type Na(+)-ATPase of a facultatively anaerobic alkaliphile, Exiguobacterium aurantiacum.

Cloning and sequencing of the gene encoding a P-type Na(+)-ATPase of a facultatively anaerobic alkaliphile, Exiguobacterium aurantiacum, were conducted. The structural gene was composed of 2628 nucleotides. The deduced amino acid sequence (876 amino acid residues; Mr, 96,664) suggested that the enzyme possesses 10 membrane-spanning regions. When the amino acid sequences of the four putative membrane regions, M4, M5, M6 and M8, of BL77/1 ATPase were aligned with those of fungal Na(+)-ATPase, Na(+)/K(+)-ATPase, H(+)-ATPases and sarcoplasmic reticulum Ca(2+)-ATPase, it exhibited the highest homology with Ca(2+)-ATPase except M5 region. By the transformation of Escherichia coli with the expression vector (pQE30) containing the ATPase gene, the enzyme was functionally expressed in E. coli membranes.

Adenosine Triphosphatases↗

PubMed2006

A primary sodium pump gene of the moderate halophile Halobacillus dabanensis exhibits secondary antiporter properties.

The primary sodium pump has been proved to be involved in Na(+) extrusion of bacteria. In our present study, a novel gene encoding a putative primary sodium pump was cloned from chromosomal DNA of moderate halophile Halobacillus dabanensis D-8 by functional complementation, which expression resulted in the growth of antiporter-deficient Escherichia coli strain KNabc in the presence of 0.2 M NaCl. The gene was sequenced and designated nap. The deduced amino acid sequence of Nap has 56% identity to NADH dehydrogenase of Bacillus cereus and 55% to NADH oxidase of Bacillus halodurans C-125. E. coli KNabc carrying nap exhibited resistance to uncoupler CCCP (carbonyl-cyanide m-chlorophenylhydrazone). Everted membrane vesicles prepared from E. coli KNabc carrying nap exhibited secondary Na(+)/H(+) antiporter activity, and nap also supported the growth of respiratory-deficient E. coli ANN0222 lacking NADH dehydrogenase. Based on these results, we proposed that Nap possessed both characteristics of secondary Na(+)/H(+) antiporter and primary sodium pump.

Amino Acid Sequence↗

PubMed2006

Social and sexual behaviours aid transmission of bacteria in birds.

Understanding the behavioural mechanisms that mediate pathogen transmission in social hosts like birds could provide the empirical bases for explaining the epidemiological dynamics of zoonotic infections in vertebrates. By experimentally infecting the feathers and cloaca of captive zebra finches (Taeniopygia guttata), with the bacterium Bacillus licheniformis PWD1 (BL), we examined the self-contamination and horizontal transmission of birds sharing the same environment. We also examined whether sexual transmission of bacteria is gender biased. Our results show that bacteria placed on the plumage of the birds lead to self and allo-infections of the bird guts, possibly through preening behaviours and bacterial ingestion. Furthermore, we found that sexual transmission of the bacteria was asymmetrical, being higher when males are the transmitting sex. Our results suggest the existence of an oral-faecal-genital route of bacterial transmission for avian hosts, wherein bacteria present on feathers infect their host guts through self and allo-preening and bacterial ingestion. Gut bacteria can then be transmitted sexually with transmission rate being higher when males are the infected sex.

Animals↗

PubMed2004

Biochemical characterization of a thermostable cysteine synthase from Geobacillus stearothermophilus V.

The cysK gene encoding a cysteine synthase of Geobacillus stearothermophilus V was overexpressed in E. coli and the recombinant protein was purified and characterized. The enzyme is a thermostable homodimer (32 kDa/monomer) belonging to the beta family of pyridoxal phosphate (PLP)-dependent enzymes. UV-visible spectra showed absorption bands at 279 and 410 nm. The band at 279 nm is due to tyrosine residues as the enzyme lacks tryptophan. The 410 nm band represents absorption of the coenzyme bound as a Schiff base to a lysine residue of the protein. Fluorescence characteristics of CysK's Schiff base were influenced by temperature changes suggesting different local structures at the cofactor binding site. The emission of the Schiff base allowed the determination of binding constants for products at both 20 degrees C and 50 degrees C. At 50 degrees C and in the absence of sulphide the enzyme catalyzes the decomposition of O-acetyl-l-serine to pyruvate and ammonia. At 20 degrees C, however, a stable alpha-aminoacrylate intermediate is formed.

Bacillaceae↗

PubMed2003

The effect of three-dimensional structure on the solid state isotope exchange of hydrogen in polypeptides with spillover hydrogen.

The effect of the three-dimensional structure of polypeptides and proteins on their ability to undergo isotopic exchange under the action of spillover hydrogen (SH) in the high temperature solid state catalytic isotope exchange reaction (HSCIE) was theoretically and experimentally studied. The HSCIE reaction in the beta-galactosidase protein from Thermoanaerobacter ethanolicus (83kDa) was studied. The influence of the beta-galactosidase structure on isotopic exchange as peptide fragments with spillover tritium was studied. The most accessible peptide fragment, which does not contribute to alpha-helix and beta-strand formations (KEMQKE215-220), had the largest relative reactivity. The one located in the contact area between the subunits (YLRDSE417-422) showed the smallest relative reactivity. The relative reactivities of these peptides differ more than 150 times. Data collected during a study devoted to the HSCIE reaction of the beta-galactosidase protein indicate that the HSCIE reaction might be employed for acquiring information about their three-dimensional structure and protein-protein interactions. The results of ab initio calculations have shown that alpha-helix formation in polypeptides decreases the reactivity in HSCIE. Hydrogen exchange in the alpha-helical fragment Trp1-Leu8 of zervamycin IIB was also analyzed using theoretical methods. It was shown by ab initio quantum-chemical calculations that the high degree of substitution of C(alpha)H for tritium in Gln3 might be associated with the participation of electron donor O and N atoms in transition state stabilization in the HSCIE reaction.

Bacillaceae↗

PubMed2005

Characterization of a thermoalkalophilic esterase from a novel thermophilic bacterium, Anoxybacillus gonensis G2.

Poly-3-hydroxybutyrate (P3HB) degradation capabilities of a novel bacterium, Anoxybacillus gonensis G2, were investigated. Both changes on film surfaces of the solution-cast films monitored by scanning electron microscopy (SEM) and weight loss up to 24% after 72 h exposure to A. gonensis G2 cultures indicated secretion of an active esterase responsible for the degradation of P3HB films. Kinetic parameters, Vmax and Km for the esterase activity of crude enzyme from A. gonensis G2 in the presence of p-nitrophenylbutyrate as substrate were observed as 50 U/L and 0.125 mM, respectively, in 50 mM phosphate buffer, pH 7.5 at 60 degrees C. The stimulation of the activity by Ca2+ is an evidence for the requirement of Ca2+ as a cofactor for the enzyme activity which is a characteristic for lipases/esterases. Inhibition of the esterase activity by metal chelating agents such as ethylenediamine tetraacetate, azide and cyanide has also supported the requirement of a metal ion for the activity. The thermal and pH stability profiles for the enzyme showed that the thermophilic bacterium A. gonensis G2 secretes an extracellular thermoalkalophilic PHB depolymerase active at 60 degrees C, and stable at this temperature for 120 min at pH 7.5 and for 24 h at pH 7.5-9.5 range at 4 degrees C by retaining over 75% of its initial activities.

Analysis of Variance↗

PubMed2005

Characterization of sediment bacteria involved in selenium reduction.

Bacterial reduction of selenium (Se) oxyanions (Se[VI] and Se[IV]) to elemental Se (Se[0]) is one of the major biogeochemical processes removing Se from agricultural drainage water and depositing Se in the sediment. This study was conducted to characterize Se-reducing bacterial populations in Lost Hills evaporation pond sediment and to observe their response to Se(VI) and organic C amendments. Se(VI) was removed from the dissolved phase in the sediment slurries amended with organic C with a decrease in redox potential (Eh). Se(VI) concentrations decreased from 2137 to 79 microg L-1 after 9 days of incubation in a 5% soil slurry. Upon our screening process, 9 Se(VI)- and 14 Se(IV)-reducing bacteria were isolated from sediment slurries and identified by amplification and sequencing of 16S rDNA. Bacillus strains appeared to be dominant in the bacterial assemblages active in Se(VI) and Se(IV) reduction in the sediment. Halomonas pacifica and Staphylococcus warneri were also identified as Se(IV)-reducers. Indigenous bacteria have a significant role in the biogeochemical cycling of Se and may be stimulated by addition of a suitable organic source for Se reduction. The bacterial strains isolated from salt-affected and Se-contaminated Lost Hills evaporation pond sediment may have potential application in removing Se from high salt drainage water.

Bacillaceae↗

PubMed2006

Improving production of hyperthermostable and high maltose-forming alpha-amylase by an extreme thermophile Geobacillus thermoleovorans using response surface methodology and its applications.

By cultivating Geobacillus thermoleovorans in shake flasks containing cane molasses medium at 70 degrees C, the fermentation variables were optimized by 'one variable at a time' approach followed by response surface methodology (RSM). The statistical model was obtained by central composite design (CCD) using three variables (cane-molasses, urea and inoculum density). An overall 1.6- and 2.1-fold increase in enzyme production was achieved in the optimized medium in shake flasks and fermenter, respectively. The alpha-amylase titre increased significantly in cane-molasses medium (60 U ml(-1)) as compared to that in the synthetic medium (26 U ml(-1)). Thus the cost of enzyme produced in cane molasses medium (0.823 euros per million U) was much lower than that produced in the synthetic starch-yeast extract-tryptone medium (18.52 euros per million U). The shelf life of bread was improved by supplementing dough with alpha-amylase, and thus, the enzyme was found to be useful in preventing the staling of bread. Reducing sugars liberated from 20% and 30% raw pearl millet starch were fermented to ethanol; ethanol production levels attained were 35.40 and 28.0 g l(-1), respectively.

Bacillaceae↗

PubMed2006

Paenibacillus campinasensis BL11: a wood material-utilizing bacterial strain isolated from black liquor.

In order to search for new thermophilic microorganisms and their enzymes, bacterial strains from black liquor of brownstock at washing stage of kraft pulping process were screened. Therein a multiple glycosyl hydrolase-producing strain, BL11, was isolated as a dominant species in the xylan-degrading bacterial population and identified as Paenibacillus campinasensis. The bacterial strain used all kinds of saccharides and polysaccharides, except lignin as carbon source and produced multiple extracellular polysaccharide-degrading enzymes, including one xylanase (41 kDa), three cellulases (42, 57 and 86 kDa), one pectinase (28 kDa) and one cyclodextrin glucanotransferase (38 kDa). P. campinasensis BL11 lacked lipase and protease activities and was able to grow over a wide range of pH, but it particularly grew well around neutral pH at 55 degrees C. Based on its physiological characteristics, it has strong potential for industrial application and bioresource utilization.

Bacillaceae↗

PubMed2004

Farnesyloxycoumarins, a new class of squalene-hopene cyclase inhibitors.

A few naturally occurring prenyl- and prenyloxycoumarins and several new related synthetic derivatives were evaluated as inhibitors of squalene-hopene cyclase (SHC), a useful model enzyme, to predict their interactions with oxidosqualene cyclase (OSC). Umbelliprenin-10',11'-monoepoxide (IC(50) 2.5 microM) and the corresponding 6',7'-10',11' diepoxide (IC(50) 1.5 microM) were the most active enzyme inhibitors.

Bacillaceae↗

PubMed2004

A convenient synthesis of GDP D-glycero-alpha-D-manno-heptopyranose.

GDP D-glycero-alpha-D-manno-Heptopyranose has been prepared in good overall yield from 2,3,4,6,7-penta-O-acetyl-D-glycero-D-manno-heptopyranose by a short-step synthesis. Phosphitylation using the phosphoramidite procedure afforded the alpha-anomer in high selectivity. Subsequent oxidation and partial deprotection gave the acetylated phosphate derivative, which was subjected to the coupling reaction with GMP-morpholidate to furnish the acetylated heptose nucleoside diphosphate in good yield. De-O-acetylation and final purification afforded the target GDP D-glycero-alpha-D-manno-heptopyranose, which serves as the substrate of the heptosyl transferase in Aneurinibacillus thermoaerophilus DSM 10155 and occurs as an intermediate in the biosynthesis of GDP 6-deoxy-heptose in Yersinia pseudotuberculosis.

Acetylation↗

PubMed2004

The complete structure of the lipooligosaccharide from the halophilic bacterium Pseudoalteromonas issachenkonii KMM 3549T.

Novel lipooligosaccharide components were isolated and identified from the lipooligosaccharide fraction of the halophilic marine bacterium Pseudoalteromonas issachenkonii type strain KMM 3549T. The complete structure was achieved by chemical analysis, 2D NMR spectroscopy and MALDI mass spectrometry as the following: [carbohydrate formula see text] All sugars are d-pyranoses. Hep is L-glycero-D-manno-heptose, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, P is phosphate, residues and substituents in italic are not stoichiometrically linked. In addition, by MALDI mass spectrometry of the intact LOS, the lipid A moiety was also identified as a mixture of penta-, tetra- and triacylated species.

Bacillaceae↗

PubMed2005

An original chemoenzymatic route for the synthesis of beta-D-galactofuranosides using an alpha-L-arabinofuranosidase.

DGalactofuranose is a widespread component of cell wall polysaccharides in bacteria, protozoa and fungi, but is totally absent in mammals. Importantly, galactofuranose is a key constituent of major cell envelope polysaccharides in pathogenic mycobacteria. In this respect, galactofuranose-based glycoconjugates are interesting target molecules for drug design. O-Glycosidases and notably beta-D-galactofuranosidases could be useful tools for the chemoenzymatic synthesis of galactofuranosides, but to date no studies of this type have been reported. Here we report the use of a GH 51 alpha-l-arabinofuranosidase for the synthesis of beta-D-galactofuranosides. We have demonstrated that this enzyme can catalyse both the autocondensation of p-nitrophenyl-beta-D-galactofuranoside and the transgalactofuranosylation of benzyl alpha-D-xylopyranoside, forming p-nitrophenyl beta-D-galactofuranosyl-(1-->2)-beta-D-galactofuranoside and benzyl beta-D-galactofuranosyl-(1-->2)-alpha-D-xylopyranoside, respectively. Both reactions were very regiospecific and the reaction involving benzyl alpha-D-xylopyranoside afforded very high yields (74.8%) of the major product. To our knowledge, this demonstration of chemoenzymatic synthesis of galactofuranosides constitutes the very first use of an O-glycosidase for the synthesis of galactofuranosides.

Bacillaceae↗

PubMed2005

The secondary cell wall polymer of Geobacillus tepidamans GS5-97T: structure of different glycoforms.

Nuclear magnetic resonance spectroscopic studies of the strain-specific secondary cell wall polymer (SCWP) of the Gram-positive, moderately thermophilic organism Geobacillus tepidamans GS5-97T reveal two glycoforms consisting of identical tetrasaccharide repeating units with different chemical modifications of the amide moieties. On the basis of sugar analyses along with 1D and 2D 1H, 13C, 15N, and 31P NMR spectroscopy at natural isotope abundance, the basic backbone structure of the SCWP was established to be [beta-D-Manp-2,3-diNAcANH2-(1-->6)-alpha-D-Glcp-(1-->4)-beta-D-Manp-2,3-diNAcANH2-(1-->3)-alpha-D-GlcpNAc-(1-->]6-(1-->O)-PO2-(O-->6)-MurNAc-, with modifications of the amide groups. In one glycoform, all beta-D-Manp-2,3-diNAcANH2 (2,3-diacetamido-2,3-dideoxy-beta-D-mannopyranuronamide, ManpANH2) residues are substituted with two acetyl groups (glycoform I) at the amide group at C-6; in the other glycoform (glycoform II), only one proton of this amide group is substituted by an acetyl group. The ratio between both the glycoforms approximates 1:1.

Bacillaceae↗

PubMed2006

The structures of the cell wall teichoic acids from the thermophilic microorganism Geobacillus thermoleovorans strain Fango.

The structures of two teichoic acid fractions (TA1 and TA2) isolated from the thermophilic gram-positive bacterium Geobacillus thermoleovorans strain Fango were investigated by means of chemical and NMR spectroscopic methods. The most abundant species (TA1) exhibited a rather regular structure comprising two different repeating units of 1,3-glycerol phosphate nonstoichiometrically substituted by terminal-alpha-D-Gal p (t-alpha-D-Gal p). The second molecular species (TA2) presented a higher structural variability and t-alpha-D-Glc p and the disaccharides t-alpha-D-Glc pNAc-(1-->2)-alpha-D-Glc p and t-alpha-D-Glc pNAc-(1-->3)-alpha-D-Glc p were also present as minor substituents at O-2 of the glycerol phosphate residues. Minor substitution by alanine could also be detected.

Bacillaceae↗

PubMed2004

Conversion of squalene to the pentacarbocyclic hopene.

The membrane protein squalene-hopene cyclase was cocrystallized with 2-azasqualene and analyzed by X-ray diffraction to 2.13 A resolution. The conformation of this close analog was clearly established, and it agreed with the common textbook presentation. The bound squalene undergoes only small conformational changes during the formation of rings A through D, thus requiring no intermediate. However, ring E formation is hindered by an entropic barrier, which may explain its absence in the steroids. The structure analysis revealed a mobile region between the active center cavity and the membrane, which may melt, opening a passage for squalene and hopene.

Bacillaceae↗

PubMed2006

Solubilization, solution equilibria, and biodegradation of PAH's under thermophilic conditions.

Biodegradation rates of PAHs are typically low at mesophilic conditions and it is believed that the kinetics of degradation is controlled by PAH solubility and mass transfer rates. Solubility tests were performed on phenanthrene, fluorene and fluoranthene at 20 degrees C, 40 degrees C and 60 degrees C and, as expected, a significant increase in the equilibrium solubility concentration and of the rate of dissolution of these polycyclic aromatic hydrocarbons (PAHs) was observed with increasing temperature. A first-order model was used to describe the PAH dissolution kinetics and the thermodynamic property changes associated with the dissolution process (enthalpy, entropy and Gibb's free energy of solution) were evaluated. Further, other relevant thermodynamic properties for these PAHs, including the activity coefficients at infinite dilution, Henry's law constants and octanol-water partition coefficients, were calculated in the temperature range 20-60 degrees C. In parallel with the dissolution studies, three thermophilic Geobacilli were isolated from compost that grew on phenanthrene at 60 degrees C and degraded the PAH more rapidly than other reported mesophiles. Our results show that while solubilization rates of PAHs are significantly enhanced at elevated temperatures, the biodegradation of PAHs under thermophilic conditions is likely mass transfer limited due to enhanced degradation rates.

Bacillaceae↗

PubMed2004

Umbelliferone aminoalkyl derivatives, a new class of squalene-hopene cyclase inhibitors.

The synthesis is described of several aminoalkyl derivatives of coumarin, obtained in good yields under microwave or high-intensity ultrasound irradiation. These compounds proved uniformly active as inhibitors of squalene-hopene cyclase (SHC) from Alicyclobacillus acidocaldarius. Their design stemmed from our recent finding that the umbelliferone nucleus acquires inhibitory properties towards SHC when functionalized with a suitable chain such as the omega-epoxyfarnesyl group. Under our experimental conditions the most active ones, such as 7-(4'-allylmethylamino-but-2-ynyloxy)chromen-2-one (IC(50) 0.75 mM), approached the potency of anticholesteremic drug Ro 48-8071 (IC(50) 0.35 mM), an effective inhibitor of both squalene- and oxidosqualene-cyclases (OSC). Tests are in progress to determine their efficacy on different eukaryotic OSCs.

Animals↗