WorldWideScience

Sample records for bacteria geobacillus stearothermophilus

  1. Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

    Science.gov (United States)

    Hetzer, Adrian; Daughney, Christopher J.; Morgan, Hugh W.

    2006-01-01

    This study reports surface complexation models (SCMs) for quantifying metal ion adsorption by thermophilic microorganisms. In initial cadmium ion toxicity tests, members of the genus Geobacillus displayed the highest tolerance to CdCl2 (as high as 400 to 3,200 μM). The thermophilic, gram-positive bacteria Geobacillus stearothermophilus and G. thermocatenulatus were selected for further electrophoretic mobility, potentiometric titration, and Cd2+ adsorption experiments to characterize Cd2+ complexation by functional groups within and on the cell wall. Distinct one-site SCMs described the extent of cadmium ion adsorption by both studied Geobacillus sp. strains over a range of pH values and metal/bacteria concentration ratios. The results indicate that a functional group with a deprotonation constant pK value of approximately 3.8 accounts for 66% and 80% of all titratable sites for G. thermocatenulatus and G. stearothermophilus, respectively, and is dominant in Cd2+ adsorption reactions. The results suggest a different type of functional group may be involved in cadmium biosorption for both thermophilic strains investigated here, compared to previous reports for mesophilic bacteria. PMID:16751511

  2. Expression and Characterization of Geobacillus stearothermophilus SR74 Recombinant α-Amylase in Pichia pastoris

    OpenAIRE

    Sivasangkary Gandhi; Abu Bakar Salleh; Raja Noor Zaliha Raja Abd. Rahman; Thean Chor Leow; Siti Nurbaya Oslan

    2015-01-01

    Geobacillus stearothermophilus SR74 is a locally isolated thermophilic bacteria producing thermostable and thermoactive α-amylase. Increased production and commercialization of thermostable α-amylase strongly warrant the need of a suitable expression system. In this study, the gene encoding the thermostable α-amylase in G. stearothermophilus SR74 was amplified, sequenced, and subcloned into P. pastoris GS115 strain under the control of a methanol inducible promoter, alcohol oxidase (AOX). Met...

  3. Biotransformation of 2,6-diaminopurine nucleosides by immobilized Geobacillus stearothermophilus.

    Science.gov (United States)

    De Benedetti, Eliana C; Rivero, Cintia W; Britos, Claudia N; Lozano, Mario E; Trelles, Jorge A

    2012-01-01

    An efficient and green bioprocess to obtain 2,6-diaminopurine nucleosides using thermophilic bacteria is herein reported. Geobacillus stearothermophilus CECT 43 showed a conversion rate of 90 and 83% at 2 h to obtain 2,6-diaminopurine-2'-deoxyriboside and 2,6-diaminopurine riboside, respectively. The selected biocatalyst was successfully stabilized in an agarose matrix and used to produce up to 23.4 g of 2,6-diaminopurine-2'-deoxyriboside in 240 h of process. These nucleoside analogues can be used as prodrug precursors or in antisense oligonucleotide synthesis.

  4. FORMALDEHYDE GAS INACTIVATION OF BACILLUS ANTHRACIS, BACILLUS SUBTILIS AND GEOBACILLUS STEAROTHERMOPHILUS SPORES ON INDOOR SURFACE MATERIALS.

    Science.gov (United States)

    Research evaluated the decontamination of Bacillus anthracis, Bacillus subtilis, and Geobacillus stearothermophilus spores on indoor surface material using formaldehyde gas. Spores were dried on seven types of indoor surfaces and exposed to 1100 ppm formaldehyde gas for 10 hr. Fo...

  5. Cold plasma technology: bactericidal effects on Geobacillus stearothermophilus and Bacillus cereus microorganisms.

    Science.gov (United States)

    Morris, Angela D; McCombs, Gayle B; Akan, Tamer; Hynes, Wayne; Laroussi, Mounir; Tolle, Susan L

    2009-01-01

    Cold plasma, also known as Low Temperature Atmospheric Pressure Plasma (LTAPP) is a novel technology consisting of neutral and charged particles, including free radicals, which can be used to destroy or inactivate microorganisms. Research has been conducted regarding the effect of cold plasma on gram-positive bacteria; however, there is limited research regarding its ability to inactivate the spore-formers Geobacillus stearothermophilus and Bacillus cereus. The purpose of this study was to determine if cold plasma inactivates G. stearothermophilus and B. cereus vegetative cells and spores. Nine hundred eighty-one samples were included in this study (762 experimental and 219 controls). Experimental samples were exposed indirectly or directly to cold plasma, before plating and incubating for 16 hours. Control samples were not exposed to cold plasma. The percentage-kill and cell number reductions were calculated from Colony Forming Units (CFU). Data were statistically analyzed at the .05 level using one-way ANOVA, Kruskal Wallis and Tukey's tests. There was a statistically significant difference in the inactivation of G. stearothermophilus vegetative cells receiving indirect and direct exposure (p=0.0001 and p=0.0013, respectively), as well as for B. cereus vegetative cells and spores (p=0.0001 for direct and indirect). There was no statistically significant difference in the inactivation of G. stearothermophilus spores receiving indirect exposure (p=0.7208) or direct exposure (p=0.0835). Results demonstrate that cold plasma exposure effectively kills G. stearothermophilus vegetative cells and B. cereus vegetative cells and spores; however, G. stearothermophilus spores were not significantly inactivated.

  6. DECONTAMINATION ASSESSMENT OF BACILLUS ANTHRACIS, BACILLUS SUBTILIS, AND GEOBACILLUS STEAROTHERMOPHILUS SPORES ON INDOOR SURFACTS USING A HYDROGEN PERIOXIDE GAS GENERATOR

    Science.gov (United States)

    Aims: To evaluate the decontamination of Bacillus anthracis, Bacillus subtilis, and Geobacillus stearothermophilus spores on indoor surface materials using hydrogen peroxide gas. Methods and Results: B. anthracis, B. subtilis, and G. Stearothermophilus spores were dried on seven...

  7. Effects of steam autoclave treatment on Geobacillus stearothermophilus spores.

    Science.gov (United States)

    Huesca-Espitia, L C; Suvira, M; Rosenbeck, K; Korza, G; Setlow, B; Li, W; Wang, S; Li, Y-Q; Setlow, P

    2016-11-01

    To determine the mechanism of autoclave killing of Geobacillus stearothermophilus spores used in biological indicators (BIs) for steam autoclave sterilization, and rates of loss of spore viability and a spore enzyme used in BIs. Spore viability, dipicolinic acid (DPA) release, nucleic acid staining, α-glucosidase activity, protein structure and mutagenesis were measured during autoclaving of G. stearothermophilus spores. Loss of DPA and increases in spore core nucleic acid staining were slower than loss of spore viability. Spore core α-glucosidase was also lost more slowly than spore viability, although soluble α-glucosidase in spore preparations was lost more rapidly. However, spores exposed to an effective autoclave sterilization lost all viability and α-glucosidase activity. Apparently killed autoclaved spores were not recovered by artificial germination in supportive media, much spore protein was denatured during autoclaving, and partially killed autoclave-treated spore preparations did not acquire mutations. These results indicate that autoclave-killed spores cannot be revived, spore killing by autoclaving is likely by protein damage, and spore core α-glucosidase activity is lost more slowly than spore viability. This work provides insight into the mechanism of autoclave killing of spores of an organism used in BIs, and that a spore enzyme in a BI is more stable to autoclaving than spore viability. © 2016 The Society for Applied Microbiology.

  8. Functional characterization of the galactan utilization system of Geobacillus stearothermophilus.

    Science.gov (United States)

    Tabachnikov, Orly; Shoham, Yuval

    2013-02-01

    Type I galactan is a pectic polysaccharide composed of β-1,4 linked units of d-galactose and is part of the main plant cell wall polysaccharides, which are the most abundant sources of renewable carbon in the biosphere. The thermophilic bacterium Geobacillus stearothermophilus T-6 possesses an extensive system for the utilization of plant cell wall polysaccharides, including a 9.4-kb gene cluster, ganREFGBA, which encodes galactan-utilization elements. Based on enzyme activity assays, the ganEFGBA genes, which probably constitute an operon, are induced by short galactosaccharides but not by galactose. GanA is a glycoside hydrolase family 53 β-1,4-galactanase, active on high molecular weight galactan, producing galactotetraose as the main product. Homology modelling of the active site residues suggests that the enzyme can accommodate at least eight galactose molecules (at subsites -4 to +4) in the active site. GanB is a glycoside hydrolase family 42 β-galactosidase capable of hydrolyzing short β-1,4 galactosaccharides into galactose. Applying both GanA and GanB on galactan resulted in the full degradation of the polymer into galactose. The ganEFG genes encode an ATP-binding cassette sugar transport system whose sugar-binding lipoprotein, GanE, was shown to bind galacto-oligosaccharides. The utilization of galactan by G. stearothermophilus involves the extracellular galactanase GanA cleaving galactan into galacto-oligosaccharides that enter the cell via a specific transport system GanEFG. The galacto-oligosaccharides are further degraded by the intracellular β-galactosidase GanB into galactose, which is then metabolized into UDP-glucose via the Leloir pathway by the galKET gene products. Nucleotide sequence data have been deposited in the GenBank database under the accession number JF327803. © 2012 The Authors Journal compilation © 2012 FEBS.

  9. Expression and Characterization of Geobacillus stearothermophilus SR74 Recombinant α-Amylase in Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Sivasangkary Gandhi

    2015-01-01

    Full Text Available Geobacillus stearothermophilus SR74 is a locally isolated thermophilic bacteria producing thermostable and thermoactive α-amylase. Increased production and commercialization of thermostable α-amylase strongly warrant the need of a suitable expression system. In this study, the gene encoding the thermostable α-amylase in G. stearothermophilus SR74 was amplified, sequenced, and subcloned into P. pastoris GS115 strain under the control of a methanol inducible promoter, alcohol oxidase (AOX. Methanol induced recombinant expression and secretion of the protein resulted in high levels of extracellular amylase production. YPTM medium supplemented with methanol (1% v/v was the best medium and once optimized, the maximum recombinant α-amylase SR74 achieved in shake flask was 28.6 U mL−1 at 120 h after induction. The recombinant 59 kDa α-amylase SR74 was purified 1.9-fold using affinity chromatography with a product yield of 52.6% and a specific activity of 151.8 U mg−1. The optimum pH of α-amylase SR74 was 7.0 and the enzyme was stable between pH 6.0–8.0. The purified enzyme was thermostable and thermoactive, exhibiting maximum activity at 65°C with a half-life (t1/2 of 88 min at 60°C. In conclusion, thermostable α-amylase SR74 from G. stearothermophilus SR74 would be beneficial for industrial applications, especially in liquefying saccrification.

  10. Rekombinante Herstellung und Charakterisierung phenoloxidierender Enzyme aus Geobacillus stearothermophilus zur Evaluierung einer biosensorischen Anwendung

    OpenAIRE

    Jäntges, Uwe Konrad

    2006-01-01

    In the current thesis the genetic structure of the phenol hydroxylase of Geobacillus stearothermophilus has been clarified. The single components Phe A1 (oxygenase component), Phe A2 (Flavin reductase component) and a tandem construct consisting of both components were successfully produced with an E. coli host strain. Due to hexahistidin residue, with which all components were provided, all enzymes could be expressed and purified to homogeneity for the first time. The highest specific activi...

  11. Crystal Structure of the Geobacillus stearothermophilus Carboxylesterase Est55 and Its Activation of Prodrug CPT-11

    OpenAIRE

    Liu, Ping; Ewis, Hosam E.; Tai, Phang C.; Lu, Chung-Dar; Weber, Irene T.

    2006-01-01

    Several mammalian carboxylesterases were shown to activate the prodrug irinotecan (CPT-11) to produce SN-38, a topoisomerase inhibitor used in cancer therapy. However, the potential use of bacterial carboxylesterases, which have the advantage of high stability, has not been explored. We present the crystal structure of the carboxyesterase Est55 from Geobacillus stearothermophilus and evaluation of its enzyme activity on CPT-11. Crystal structures were determined at pH 6.2 and 6.8 and resoluti...

  12. Isolation of Glucocardiolipins from Geobacillus stearothermophilus NRS 2004/3a

    Science.gov (United States)

    Schäffer, Christina; Beckedorf, Anke I.; Scheberl, Andrea; Zayni, Sonja; Peter-Katalinić, Jasna; Messner, Paul

    2002-01-01

    Glucose-substituted cardiolipins account for about 4 mol% of total phospholipid extracted from exponentially grown cells of Geobacillus stearothermophilus NRS 2004/3a. Individual glucocardiolipin species exhibited differences in fatty acid substitution, with iso-C15:0 and anteiso-C17:0 prevailing. The compounds were purified to homogeneity by a novel protocol and precharacterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. PMID:12426359

  13. Structural Basis of Substrate Binding in WsaF, a Rhamnosyltransferase from Geobacillus stearothermophilus

    Science.gov (United States)

    Steiner, Kerstin; Hagelueken, Gregor; Messner, Paul; Schäffer, Christina; Naismith, James H.

    2010-01-01

    Carbohydrate polymers are medically and industrially important. The S-layer of many Gram-positive organisms comprises protein and carbohydrate polymers and forms an almost paracrystalline array on the cell surface. Not only is this array important for the bacteria but it has potential application in the manufacture of commercially important polysaccharides and glycoconjugates as well. The S-layer glycoprotein glycan from Geobacillus stearothermophilus NRS 2004/3a is mainly composed of repeating units of three rhamnose sugars linked by α-1,3-, α-1,2-, and β-1,2-linkages. The formation of the β-1,2-linkage is catalysed by the enzyme WsaF. The rational use of this system is hampered by the fact that WsaF and other enzymes in the pathway share very little homology to other enzymes. We report the structural and biochemical characterisation of WsaF, the first such rhamnosyltransferase to be characterised. Structural work was aided by the surface entropy reduction method. The enzyme has two domains, the N-terminal domain, which binds the acceptor (the growing rhamnan chain), and the C-terminal domain, which binds the substrate (dTDP-β-l-rhamnose). The structure of WsaF bound to dTDP and dTDP-β-l-rhamnose coupled to biochemical analysis identifies the residues that underlie catalysis and substrate recognition. We have constructed and tested by site-directed mutagenesis a model for acceptor recognition. PMID:20097205

  14. Modeling the behavior of Geobacillus stearothermophilus ATCC 12980 throughout its life cycle as vegetative cells or spores using growth boundaries.

    Science.gov (United States)

    Mtimet, Narjes; Trunet, Clément; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

    2015-06-01

    Geobacillus stearothermophilus is recognized as one of the most prevalent micro-organism responsible for flat sour in the canned food industry. To control these highly resistant spore-forming bacteria, the heat treatment intensity could be associated with detrimental conditions for germination and outgrowth. The purpose of this work was to study successively the impact of temperature and pH on the growth rate of G. stearothermophilus ATCC 12980, its sporulation ability, its heat resistance in response to various sporulation conditions, and its recovery ability after a heat treatment. The phenotypic investigation was carried out at different temperatures and pHs on nutrient agar and the heat resistance was estimated at 115 °C. The greatest spore production and the highest heat resistances were obtained at conditions of temperature and pH allowing maximal growth rate. The current observations also revealed that growth, sporulation and recovery boundaries are close. Models using growth boundaries as main parameters were extended to describe and quantify the effect of temperature and pH throughout the life cycle of G. stearothermophilus as vegetative cells or as spore after a heat treatment and during recovery.

  15. Cultivo de Geobacillus stearothermophilus ATCC 7953 en un biorreactor de 2.5 litros bajo el sistema “batch”.

    OpenAIRE

    Alvarenga-Venutolo, Silvana; Rivas-Solano, Olga

    2012-01-01

    Informe Final de Proyecto de Investigación. El uso de indicadores biológicos proporciona un medio para examinar directamente la muerte de microorganismos, lo que permite asegurar la calidad y validar procesos de esterilización. El indicador biológico más utilizado contiene endosporas bacterianas de Geobacillus stearothermophilus. En este estudio se cultivó la cepa Geobacillus stearothermophilus ATCC 7953 en medio líquido bajo el sistema de fermentación en lote, para obtener endosporas erm...

  16. Analysis of the tryptophanase expression in Symbiobacterium thermophilum in a coculture with Geobacillus stearothermophilus.

    Science.gov (United States)

    Watsuji, Tomo-O; Takano, Hideaki; Yamabe, Tomoya; Tamazawa, Satoshi; Ikemura, Hiroka; Ohishi, Takanori; Matsuda, Tohyo; Shiratori-Takano, Hatsumi; Beppu, Teruhiko; Ueda, Kenji

    2014-12-01

    The tryptophanase-positive Symbiobacterium thermophilum is a free-living syntrophic bacterium that grows effectively in a coculture with Geobacillus stearothermophilus. Our studies have shown that S. thermophilum growth depends on the high CO2 and low O2 condition established by the precedent growth of G. stearothermophilus. The use of an anoxic atmosphere containing high CO2 allows S. thermophilum to grow independently of G. stearothermophilus, but the cellular yield is ten times lower than that achieved in the coculture. In this study, we characterized the coculture-dependent expression and activity of tryptophanase in S. thermophilum. S. thermophilum cells accumulated a marked amount of indole in a coculture with G. stearothermophilus, but not in the bacterium's pure culture irrespective of the addition of tryptophan. S. thermophilum cells accumulated indole in its pure culture consisting of conditioned medium (medium supplied with culture supernatant of G. stearothermophilus). Proteomic analysis identified the protein specifically produced in the S. thermophilum cells grown in conditioned medium, which was a tryptophanase encoded by tna2 (STH439). An attempt to isolate the tryptophanase-inducing component from the culture supernatant of G. stearothermophilus was unsuccessful, but we did discover that the indole accumulation occurs when 10 mM bicarbonate is added to the medium. RT-PCR analysis showed that the addition of bicarbonate stimulated transcription of tna2. The transcriptional start site, identified within the tna2 promoter, was preceded by the -24 and -12 consensus sequences specified by an alternative sigma factor, σ(54). The evidence suggests that the transcription of some genes involved in amino acid metabolism is σ(54)-dependent, and that a bacterial enhancer-binding protein containing a PAS domain controls the transcription under the presence of high levels of bicarbonate.

  17. Structural Analysis of Xylanase from Marine Thermophilic Geobacillus stearothermophilus in Tanjung Api, Poso, Indonesia

    Directory of Open Access Journals (Sweden)

    BUDI SAKSONO

    2010-12-01

    Full Text Available A xylanase gene, xynA, has been cloned from thermophilic strain Geobacillus stearothermophilus, which was isolated from marine Tanjung Api, Indonesia. The polymerase chain reaction product of 1266 bp of xynA gene consisted of 1221 bp open reading frame and encoded 407 amino acids including 30 residues of signal peptide. The sequence exhibited highest identity of 98.7% in the level of amino acid, with an extracellular endo-1,4-β-xylanase from G. stearothermophilus T-6 (E-GSX T-6 of the glycoside hydrolase family 10 (GH10. A comparative study between the local strain G. stearothermophilus (GSX L and E-GSX T-6 on homology of amino acid sequence indicated five differents amino acids in the gene. They were Threonine/Alanine (T/A, Asparagine/Aspartate (N/D, Lysine/Asparagine (K/N, Isoleucine/Methionine (I/M, Serine/Threonine (S/T at the position 220, 227, 228, 233, and 245, respectively. Protein structural analysis of those differences suggested that those amino acids may play role in biochemical properties such as enzyme stability, in particular its thermostability.

  18. Quantitative assessment of the risk of microbial spoilage in foods. Prediction of non-stability at 55 °C caused by Geobacillus stearothermophilus in canned green beans.

    Science.gov (United States)

    Rigaux, Clémence; André, Stéphane; Albert, Isabelle; Carlin, Frédéric

    2014-02-03

    Microbial spoilage of canned foods by thermophilic and highly heat-resistant spore-forming bacteria, such as Geobacillus stearothermophilus, is a persistent problem in the food industry. An incubation test at 55 °C for 7 days, then validation of biological stability, is used as an indicator of compliance with good manufacturing practices. We propose a microbial risk assessment model predicting the percentage of non-stability due to G. stearothermophilus in canned green beans manufactured by a French company. The model accounts for initial microbial contaminations of fresh unprocessed green beans with G. stearothermophilus, cross-contaminations in the processing chain, inactivation processes and probability of survival and growth. The sterilization process is modeled by an equivalent heating time depending on sterilization value F₀ and on G. stearothermophilus resistance parameter z(T). Following the recommendations of international organizations, second order Monte-Carlo simulations are used, separately propagating uncertainty and variability on parameters. As a result of the model, the mean predicted non-stability rate is of 0.5%, with a 95% uncertainty interval of [0.1%; 1.2%], which is highly similar to data communicated by the French industry. A sensitivity analysis based on Sobol indices and some scenario tests underline the importance of cross-contamination at the blanching step, in addition to inactivation due to the sterilization process.

  19. Kinetics of germination of individual spores of Geobacillus stearothermophilus as measured by raman spectroscopy and differential interference contrast microscopy.

    Directory of Open Access Journals (Sweden)

    Tingting Zhou

    Full Text Available Geobacillus stearothermophilus is a gram-positive, thermophilic bacterium, spores of which are very heat resistant. Raman spectroscopy and differential interference contrast microscopy were used to monitor the kinetics of germination of individual spores of G. stearothermophilus at different temperatures, and major conclusions from this work were as follows. 1 The CaDPA level of individual G. stearothermophilus spores was similar to that of Bacillus spores. However, the Raman spectra of protein amide bands suggested there are differences in protein structure in spores of G. stearothermophilus and Bacillus species. 2 During nutrient germination of G. stearothermophilus spores, CaDPA was released beginning after a lag time (T(lag between addition of nutrient germinants and initiation of CaDPA release. CaDPA release was complete at T(release, and DT(release (T(release - T(lag was 1-2 min. 3 Activation by heat or sodium nitrite was essential for efficient nutrient germination of G. stearothermophilus spores, primarily by decreasing T(lag values. 4 Values of T(lag and T(release were heterogeneous among individual spores, but DT(release values were relatively constant. 5 Temperature had major effects on nutrient germination of G. stearothermophilus spores, as at temperatures below 65°C, average T(lag values increased significantly. 6 G. stearothermophilus spore germination with exogenous CaDPA or dodecylamine was fastest at 65°C, with longer T(lag values at lower temperatures. 7 Decoating of G. stearothermophilus spores slowed nutrient germination slightly and CaDPA germination significantly, but increased dodecylamine germination markedly. These results indicate that the dynamics and heterogeneity of the germination of individual G. stearothermophilus spores are generally similar to that of Bacillus species.

  20. The abp gene in Geobacillus stearothermophilus T-6 encodes a GH27 β-L-arabinopyranosidase.

    Science.gov (United States)

    Salama, Rachel; Alalouf, Onit; Tabachnikov, Orly; Zolotnitsky, Gennady; Shoham, Gil; Shoham, Yuval

    2012-07-30

    In this study we demonstrate that the abp gene in Geobacillus stearothermophilus T-6 encodes a family 27 glycoside hydrolase β-L-arabinopyranosidase. The catalytic constants towards the chromogenic substrate pNP-β-L-arabinopyranoside were 0.8±0.1 mM, 6.6±0.3 s(-1), and 8.2±0.3 s(-1) mM(-1) for K(m), k(cat) and k(cat)/K(m), respectively. (13)C NMR spectroscopy unequivocally showed that Abp is capable of removing β-L-arabinopyranose residues from the natural arabino-polysaccharide, larch arabinogalactan. Most family 27 enzymes are active on galactose and contain a conserved Asp residue, whereas in Abp this residue is Ile67, which shifts the specificity of the enzyme towards arabinopyranoside.

  1. Effects of humidity on sterilization of Geobacillus stearothermophilus spores with plasma-excited neutral gas

    Science.gov (United States)

    Matsui, Kei; Ikenaga, Noriaki; Sakudo, Noriyuki

    2015-06-01

    We investigate the effects of relative humidity on the sterilization process using a plasma-excited neutral gas that uniformly sterilizes both the space and inner wall of the reactor chamber at atmospheric pressure. Only reactive neutral species such as plasma-excited gas molecules and radicals were separated from the plasma and sent to the reactor chamber for chemical sterilization. The plasma source gas is nitrogen mixed with 0.1% oxygen, and the relative humidity in the source gas is controlled by changing the mixing ratio of water vapor. The relative humidity near the sample in the reactor chamber is controlled by changing the sample temperature. As a result, the relative humidity near the sample should be kept in the range from 60 to 90% for the sterilization of Geobacillus stearothermophilus spores. When the relative humidity in the source gas increases from 30 to 90%, the sterilization effect is enhanced by the same degree.

  2. Keratinous waste decomposition and peptide production by keratinase from Geobacillus stearothermophilus AD-11.

    Science.gov (United States)

    Gegeckas, Audrius; Gudiukaitė, Renata; Debski, Janusz; Citavicius, Donaldas

    2015-04-01

    A keratinolytic proteinase was cloned from thermophilic bacterium Geobacillus stearothermophilus AD-11 and was expressed in Escherichia coli BL21(DE3). Recombinant keratinolytic proteinase (RecGEOker) with an estimated molecular weight of 57 kDa was purified and keratinase activity was measured. RecGEOker showed optimal activity at pH 9 and 60 °C. Recombinant keratinolytic proteinase showed the highest substrate specificity toward keratin from wool > collagen > sodium caseinate > gelatin > and BSA in descending order. RecGEOker is applicable for efficient keratin waste biodegradation and can replace conventional non-biological hydrolysis processes. High-value small peptides obtained from enzymatic biodegradation by RecGEOker are suitable for industrial application in white and/or green biotechnology for use as major additives in various products.

  3. Investigation of Sterilization Mechanism for Geobacillus stearothermophilus Spores with Plasma-Excited Neutral Gas

    Science.gov (United States)

    Matsui, Kei; Ikenaga, Noriaki; Sakudo, Noriyuki

    2015-09-01

    We investigate the mechanism of the sterilization with plasma-excited neutral gas that uniformly sterilizes both the space and inner wall of the reactor chamber at atmospheric pressure. Only reactive neutral species such as plasma-excited gas molecules and radicals are separated from the plasma and sent to the reactor chamber for chemical sterilization. The plasma source gas uses humidified mixture of nitrogen and oxygen. Geobacillus stearothermophilus spores and tyrosine which is amino acid are treated by the plasma-excited neutral gas. Shape change of the treated spore is observed by SEM, and chemical modification of the treated tyrosine is analyzed by HPLC. As a result, the surface of the treated spore shows depression. Hydroxylation and nitration of tyrosine are shown after the treatment. For these reasons, we believe that the sterilization with plasma-excited neutral gas results from the deformation of spore structure due to the chemical modification of amino acid.

  4. In situ investigation of Geobacillus stearothermophilus spore germination and inactivation mechanisms under moderate high pressure.

    Science.gov (United States)

    Georget, Erika; Kapoor, Shobhna; Winter, Roland; Reineke, Kai; Song, Youye; Callanan, Michael; Ananta, Edwin; Heinz, Volker; Mathys, Alexander

    2014-08-01

    Bacterial spores are a major concern for food safety due to their high resistance to conventional preservation hurdles. Innovative hurdles can trigger bacterial spore germination or inactivate them. In this work, Geobacillus stearothermophilus spore high pressure (HP) germination and inactivation mechanisms were investigated by in situ infrared spectroscopy (FT-IR) and fluorometry. G. stearothermophilus spores' inner membrane (IM) was stained with Laurdan fluorescent dye. Time-dependent FT-IR and fluorescence spectra were recorded in situ under pressure at different temperatures. The Laurdan spectrum is affected by the lipid packing and level of hydration, and provided information on the IM state through the Laurdan generalized polarization. Changes in the -CH2 and -CH3 asymmetric stretching bands, characteristic of lipids, and in the amide I' band region, characteristic of proteins' secondary structure elements, enabled evaluation of the impact of HP on endospores lipid and protein structures. These studies were complemented by ex situ analyses (plate counts and microscopy). The methods applied showed high potential to identify germination mechanisms, particularly associated to the IM. Germination up to 3 log10 was achieved at 200 MPa and 55 °C. A molecular-level understanding of these mechanisms is important for the development and validation of multi-hurdle approaches to achieve commercial sterility.

  5. Biochemical and Mutational Characterization of N-Succinyl-Amino Acid Racemase from Geobacillus stearothermophilus CECT49.

    Science.gov (United States)

    Soriano-Maldonado, Pablo; Andújar-Sánchez, Montserrat; Clemente-Jiménez, Josefa María; Rodríguez-Vico, Felipe; Las Heras-Vázquez, Francisco Javier; Martínez-Rodríguez, Sergio

    2015-05-01

    N-Succinyl-amino acid racemase (NSAAR), long referred to as N-acyl- or N-acetyl-amino acid racemase, is an enolase superfamily member whose biotechnological potential was discovered decades ago, due to its use in the industrial dynamic kinetic resolution methodology first known as "Acylase Process". In previous works, an extended and enhanced substrate spectrum of the NSAAR from Geobacillus kaustophilus CECT4264 toward different N-substituted amino acids was reported. In this work, we describe the cloning, purification, and characterization of the NSAAR from Geobacillus stearothermophilus CECT49 (GstNSAAR). The enzyme has been extensively characterized, showing a higher preference toward N-formyl-amino acids than to N-acetyl-amino acids, thus confirming that the use of the former substrates is more appropriate for a biotechnological application of the enzyme. The enzyme showed an apparent thermal denaturation midpoint of 77.0 ± 0.1 °C and an apparent molecular mass of 184 ± 5 kDa, suggesting a tetrameric species. Optimal parameters for the enzyme activity were pH 8.0 and 55-65 °C, with Co(2+) as the most effective cofactor. Mutagenesis and binding experiments confirmed K166, D191, E216, D241, and K265 as key residues in the activity of GstNSAAR, but not indispensable for substrate binding.

  6. Protein engineering applications of industrially exploitable enzymes: Geobacillus stearothermophilus LDH and Candida methylica FDH.

    Science.gov (United States)

    Karagüler, N G; Sessions, R B; Binay, B; Ordu, E B; Clarke, A R

    2007-12-01

    Enzymes have become important tools in several industries due to their ability to produce chirally pure and complex molecules with interesting biological properties. The NAD(+)-dependent LDH (lactate dehydrogenase) [bsLDH [Geobacillus stearothermophilus (formerly Bacillus stearothermophilus) LDH] from G. stearothermophilus and the NAD(+)-dependent FDH (formate dehydrogenase) [cmFDH (Candida methylica FDH)] enzyme from C. methylica are particularly crucial enzymes in the pharmaceutical industry and are related to each other in terms of NADH use and regeneration. LDH catalyses the interconversion of pyruvate (oxo acid) and lactate (alpha-hydroxy acid) using the NADH/NAD(+) pair as a redox cofactor. Employing LDH to reduce other oxo acids can generate chirally pure alpha-hydroxy acids of use in the production of pharmaceuticals. One important use of FDH is to regenerate the relatively expensive NADH cofactor that is used by NAD(+)-dependent oxidoreductases such as LDH. Both LDH and FDH from organisms of interest were previously cloned and overproduced. Therefore they are available at a low cost. However, both of these enzymes show disadvantages in the large-scale production of chirally pure compounds. We have applied two routes of protein engineering studies to improve the properties of these two enzymes, namely DNA shuffling and site-directed mutagenesis. Altering the substrate specificity of bsLDH by DNA shuffling and changing the coenzyme specificity of cmFDH by site-directed mutagenesis are the most successful examples of our studies. The present paper will also include the details of these examples together with some other applications of protein engineering regarding these enzymes.

  7. Plasma Decontamination: A Case Study on Kill Efficacy of Geobacillus stearothermophilus Spores on Different Carrier Materials.

    Science.gov (United States)

    Semmler, Egmont; Novak, Wenzel; Allinson, Wilf; Wallis, Darren; Wood, Nigel; Awakowicz, Peter; Wunderlich, Joachim

    2016-01-01

    A new technology to the pharmaceutical field is presented: surface decontamination by plasmas The technology is comparable to established barrier systems like e-beam, volatile hydrogen peroxide, or radiation inactivation of microbiological contaminations. This plasma technology is part of a fully automated and validated syringe filling line at a major pharmaceutical company and is in production operation. Incoming pre-sterilized syringe containers ("tubs") are processed by plasma, solely on the outside, and passed into the aseptic filling isolator upon successful decontamination. The objective of this article is to present the operating principles and develop and establish a validation routine on the basis of standard commercial biological indicators. Their decontamination efficacies are determined and correlated to the actual inactivation efficacy on the pharmaceutical packaging material.The reference setup is explained in detail and a short presentation of the cycle development and the relevant plasma control parameters is given, with a special focus on the in-process monitor determining the cycle validity. Different microbial inactivation mechanisms are also discussed and evaluated for their contribution and interaction to enhance plasma decontamination. A material-dependent inactivation behavior was observed. In order to be able to correlate the tub surface inactivation of Geobacillus stearothermophilus endospores to metallic biological indicators, a comparative study was performed. Through consistently demonstrating the linear inactivation behavior between the different materials, it becomes possible to develop an effective and time-saving validation scheme. The challenge in new decontamination systems lies in a thorough validation of the inactivation efficacy under different operating regimes. With plasma, as an ionized gas, a new barrier concept is introduced into pharmaceutical aseptic processing of syringes. The presented system operates in vacuum and only

  8. Purification and characterization of cloned alkaline protease gene of Geobacillus stearothermophilus.

    Science.gov (United States)

    Iqbal, Irfana; Aftab, Muhammad Nauman; Afzal, Mohammed; Ur-Rehman, Asad; Aftab, Saima; Zafar, Asma; Ud-Din, Zia; Khuharo, Ateeque Rahman; Iqbal, Jawad; Ul-Haq, Ikram

    2015-02-01

    Thermostable alkaline serine protease gene of Geobacillus stearothermophilus B-1172 was cloned and expressed in Escherichia coli BL21 (DE3) using pET-22b(+), as an expression vector. The growth conditions were optimized for maximal production of the protease using variable fermentation parameters, i.e., pH, temperature, and addition of an inducer. Protease, thus produced, was purified by ammonium sulfate precipitation followed by ion exchange chromatography with 13.7-fold purification, with specific activity of 97.5 U mg(-1) , and a recovery of 23.6%. Molecular weight of the purified protease, 39 kDa, was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was stable at 90 °C at pH 9. The enzyme activity was steady in the presence of EDTA indicating that the protease was not a metalloprotease. No significant change in the activity of protease after addition of various metal ions further strengthened this fact. However, an addition of 1% Triton X-100 or SDS surfactants constrained the enzyme specific activity to 34 and 19%, respectively. Among organic solvents, an addition of 1-butanol (20%) augmented the enzyme activity by 29% of the original activity. With casein as a substrate, the enzyme activity under optimized conditions was found to be 73.8 U mg(-1) . The effect of protease expression on the host cells growth was also studied and found to negatively affect E. coli cells to certain extent. Catalytic domains of serine proteases from eight important thermostable organisms were analyzed through WebLogo and found to be conserved in all serine protease sequences suggesting that protease of G. stearothermophilus could be beneficially used as a biocontrol agent and in many industries including detergent industry.

  9. Structure-Specificity Relationships of an Intracellular Xylanase from Geobacillus stearothermophilus

    Energy Technology Data Exchange (ETDEWEB)

    Solomon,V.; Teplitsky, A.; Shulami, S.; Zolotnitsky, G.; Shoham, Y.; Shoham, G.

    2007-01-01

    Geobacillus stearothermophilus T-6 is a thermophilic Gram-positive bacterium that produces two selective family 10 xylanases which both take part in the complete degradation and utilization of the xylan polymer. The two xylanases exhibit significantly different substrate specificities. While the extracellular xylanase (XT6; MW 43.8 kDa) hydrolyzes the long and branched native xylan polymer, the intracellular xylanase (IXT6; MW 38.6 kDa) preferentially hydrolyzes only short xylo-oligosaccharides. In this study, the detailed three-dimensional structure of IXT6 is reported, as determined by X-ray crystallography. It was initially solved by molecular replacement and then refined at 1.45 {angstrom} resolution to a final R factor of 15.0% and an R{sub free} of 19.0%. As expected, the structure forms the classical ({alpha}/{beta}){sub 8} fold, in which the two catalytic residues (Glu134 and Glu241) are located on the inner surface of the central cavity. The structure of IXT6 was compared with the highly homologous extracellular xylanase XT6, revealing a number of structural differences between the active sites of the two enzymes. In particular, structural differences derived from the unique subdomain in the carboxy-terminal region of XT6, which is completely absent in IXT6. These structural modifications may account for the significant differences in the substrate specificities of these otherwise very similar enzymes.

  10. Crystal Structure of the Geobacillus stearothermophilus Carboxylesterase Est55 and Its Activation of Prodrug CPT-11

    Science.gov (United States)

    Liu, Ping; Ewis, Hosam E.; Tai, Phang C.; Lu, Chung-Dar; Weber, Irene T.

    2007-01-01

    Several mammalian carboxylesterases were shown to activate the prodrug irinotecan (CPT-11) to produce SN-38, a topoisomerase inhibitor used in cancer therapy. However, the potential use of bacterial carboxylesterases, which have the advantage of high stability, has not been explored. We present the crystal structure of the carboxyesterase Est55 from Geobacillus stearothermophilus and evaluation of its enzyme activity on CPT-11. Crystal structures were determined at pH 6.2 and 6.8 and resolution of 2.0 and 1.58 Å, respectively. Est55 folds into three domains, a catalytic domain, an α/β domain and a regulatory domain. The structure is in an inactive form; the side chain of His409, one of the catalytic triad residues, is directed away from the other catalytic residues Ser194 and Glu310. Moreover, the adjacent Cys408 is triply oxidized and lies in the oxyanion hole, which would block the binding of substrate, suggesting a regulatory role. However, Cys408 is not essential for enzyme activity. Mutation of Cys408 showed that hydrophobic side chains were favorable, while polar serine was unfavorable for enzyme activity. Est55 was shown to hydrolyze CPT-11 into the active form SN-38. The mutant C408V provided a more stable enzyme for activation of CPT-11. Therefore, engineered thermostable Est55 is a candidate for use with irinotecan in enzyme-prodrug cancer therapy. PMID:17239398

  11. Inactivation of Geobacillus stearothermophilus spores by alkaline hydrolysis applied to medical waste treatment.

    Science.gov (United States)

    Pinho, Sílvia C; Nunes, Olga C; Lobo-da-Cunha, Alexandre; Almeida, Manuel F

    2015-09-15

    Although alkaline hydrolysis treatment emerges as an alternative disinfection/sterilization method for medical waste, information on its effects on the inactivation of biological indicators is scarce. The effects of alkaline treatment on the resistance of Geobacillus stearothermophilus spores were investigated and the influence of temperature (80 °C, 100 °C and 110 °C) and NaOH concentration was evaluated. In addition, spore inactivation in the presence of animal tissues and discarded medical components, used as surrogate of medical waste, was also assessed. The effectiveness of the alkaline treatment was carried out by determination of survival curves and D-values. No significant differences were seen in D-values obtained at 80 °C and 100 °C for NaOH concentrations of 0.5 M and 0.75 M. The D-values obtained at 110 °C (2.3-0.5 min) were approximately 3 times lower than those at 100 °C (8.8-1.6 min). Independent of the presence of animal tissues and discarded medical components, 6 log10 reduction times varied between 66 and 5 min at 100 °C-0.1 M NaOH and 110 °C-1 M NaOH, respectively. The alkaline treatment may be used in future as a disinfection or sterilization alternative method for contaminated waste.

  12. Structural insights into methanol-stable variants of lipase T6 from Geobacillus stearothermophilus.

    Science.gov (United States)

    Dror, Adi; Kanteev, Margarita; Kagan, Irit; Gihaz, Shalev; Shahar, Anat; Fishman, Ayelet

    2015-11-01

    Enzymatic production of biodiesel by transesterification of triglycerides and alcohol, catalyzed by lipases, offers an environmentally friendly and efficient alternative to the chemically catalyzed process while using low-grade feedstocks. Methanol is utilized frequently as the alcohol in the reaction due to its reactivity and low cost. However, one of the major drawbacks of the enzymatic system is the presence of high methanol concentrations which leads to methanol-induced unfolding and inactivation of the biocatalyst. Therefore, a methanol-stable lipase is of great interest for the biodiesel industry. In this study, protein engineering was applied to substitute charged surface residues with hydrophobic ones to enhance the stability in methanol of a lipase from Geobacillus stearothermophilus T6. We identified a methanol-stable variant, R374W, and combined it with a variant found previously, H86Y/A269T. The triple mutant, H86Y/A269T/R374W, had a half-life value at 70 % methanol of 324 min which reflects an 87-fold enhanced stability compared to the wild type together with elevated thermostability in buffer and in 50 % methanol. This variant also exhibited an improved biodiesel yield from waste chicken oil compared to commercial Lipolase 100L® and Novozyme® CALB. Crystal structures of the wild type and the methanol-stable variants provided insights regarding structure-stability correlations. The most prominent features were the extensive formation of new hydrogen bonds between surface residues directly or mediated by structural water molecules and the stabilization of Zn and Ca binding sites. Mutation sites were also characterized by lower B-factor values calculated from the X-ray structures indicating improved rigidity.

  13. Development of a Multiplex-PCR assay for the rapid identification of Geobacillus stearothermophilus and Anoxybacillus flavithermus.

    Science.gov (United States)

    Pennacchia, Carmela; Breeuwer, Pieter; Meyer, Rolf

    2014-10-01

    The presence of thermophilic bacilli in dairy products is indicator of poor hygiene. Their rapid detection and identification is fundamental to improve the industrial reactivity in the implementation of corrective and preventive actions. In this study a rapid and reliable identification of Geobacillus stearothermophilus and Anoxybacillus flavithermus was achieved by species-specific PCR assays. Two primer sets, targeting the ITS 16S-23S rRNA region and the rpoB gene sequence of the target species respectively, were employed. Species-specificity of both primer sets was evaluated by using 53 reference strains of DSMZ collection; among them, 13 species of the genus Geobacillus and 15 of the genus Anoxybacillus were represented. Moreover, 99 wild strains and 23 bulk cells collected from 24 infant formula powders gathered from several countries worldwide were included in the analyses. Both primer sets were highly specific and the expected PCR fragments were obtained only when DNA from G. stearothermophilus or A. flavithermus was used. After testing their specificity, they were combined in a Multiplex-PCR assay for the simultaneous identification of the two target species. The specificity of the Multiplex-PCR was evaluated by using both wild strains and bulk cells. Every analysis confirmed the reliable identification results provided by the single species-specific PCR methodology. The easiness, the rapidity (about 4 h from DNA isolation to results) and the reliability of the PCR procedures developed in this study highlight the advantage of their application for the specific detection and identification of the thermophilic species G. stearothermophilus and A. flavithermus.

  14. Production of xylan degrading endo-1, 4-β-xylanase from thermophilic Geobacillus stearothermophilus KIBGE-IB29

    Directory of Open Access Journals (Sweden)

    Zainab Bibi

    2014-10-01

    Full Text Available Xylan degrading bacterial strain was isolated from soil and identified as Geobacillus stearothermophilus KIBGE-IB29 on the basis of morphological, biochemical and 16S rDNA sequence analysis. Optimization of medium and culture conditions in submerged fermentation was investigated for maximum endo-1, 4-β-xylanase production. High yield of xylan degrading endo-1, 4-β-xylanase was achieved at 60 °C and pH-6.0 with 24 h of fermentation. Maximum enzyme was produced using 0.5% xylan as a carbon source, 0.5% peptone, 0.2% yeast extract and 0.1% meat extract as nitrogen sources. Di-potassium hydrogen phosphate (0.25%, calcium chloride (0.01%, potassium hydrogen phosphate (0.05% and ammonium sulfate (0.05% were also incorporated in the fermentation medium to enhance the enzyme production.

  15. Plasma sterilization of Geobacillus Stearothermophilus by O{mathsf2}:N{mathsf2} RF inductively coupled plasma

    Science.gov (United States)

    Kylián, O.; Sasaki, T.; Rossi, F.

    2006-05-01

    The aim of this work is to identify the main process responsible for sterilization of Geobacillus Stearothermophilus spores in O{2}:N{2} RF inductively coupled plasma. In order to meet this objective the sterilization efficiencies of discharges in mixtures differing in the initial O{2}/N{2} ratios are compared with plasma properties and with scanning electron microscopy images of treated spores. According to the obtained results it can be concluded that under our experimental conditions the time needed to reach complete sterilization is more related to O atom density than UV radiation intensity, i.e. complete sterilization is not related only to DNA damage as in UV sterilization but more likely to the etching of the spore.

  16. PURIFICATION AND CHARACTERIZATION OF SOLVENT STABLE LIPASE FROM A SOLVENT TOLERANT STRAIN OF GEOBACILLUS STEAROTHERMOPHILUS PS 11

    Directory of Open Access Journals (Sweden)

    Payel Sarkar

    2016-06-01

    Full Text Available An extracellular organic solvent stable lipase produced by solvent tolerant strain of Geobacillus stearothermophilus PS11 was purified and characterised. The overall purification was 8.04 fold with a yield of 22.6%. The molecular weight of purified lipase was approximately 27.5 kDa. The purified lipase activity was stable (745 EU/ml at 72h incubation in presence of toluene, benzene, propanol, methanol etc. The enzyme activity was maximum (764 EU/ml when assayed under optimum temperature and pH of 50⁰C and 10.0, respectively. The enzyme showed stability at a wide range of temperature from 10⁰C to 60⁰C. This solvent stable lipase can be a novel tool for biodiesel industry.

  17. Cloning of araA Gene Encoding L-Arabinose Isomerase from Marine Geobacillus stearothermophilus Isolated from Tanjung Api, Poso, Indonesia

    Directory of Open Access Journals (Sweden)

    DEWI FITRIANI

    2010-06-01

    Full Text Available L-arabinose isomerase is an enzyme converting D-galactose to D-tagatose. D-tagatose is a potential sweetener-sucrose substitute which has low calorie. This research was to clone and sequence araA gene from marine bacterial strain Geobacillus stearothermophilus isolated from Tanjung Api Poso Indonesia. The amplified araA gene consisted of 1494 bp nucleotides encoding 497 amino acids. DNA alignment analysis showed that the gene had high homology with that of G. stearothermophilus T6. The enzyme had optimum activity at high temperature and alkalin condition.

  18. Walking dead: Permeabilization of heat-treated Geobacillus stearothermophilus ATCC 12980 spores under growth-preventing conditions.

    Science.gov (United States)

    Mtimet, Narjes; Trunet, Clément; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

    2017-06-01

    Although heat treatment is probably the oldest and the most common method used to inactivate spores in food processes, the specific mechanism of heat killing of spores is still not fully understood. The purpose of this study is to investigate the evolution of the permeabilization and the viability of heat-treated spores during storage under growth-preventing conditions. Geobacillus stearothermophilus spores were heat-treated under various conditions of temperature and pH, and then stored under conditions of temperature and pH that prevent growth. Spore survival was evaluated by count plating immediately after heat treatment, and then during storage over a period of months. Flow cytometry analyses were performed to investigate the Syto 9 permeability of heat-treated spores. Sub-lethally heat-treated spores of G. stearothermophilus were physically committed to permeabilization after heat treatment. However, prolonged heat treatment may abolish the spore permeabilization and block heat-treated spores in the refractive state. However, viability loss and permeabilization during heat treatment seem to be two different mechanisms that occur independently, and the loss of permeabilization properties takes place at a much slower rate than spore killing. Under growth-preventing conditions, viable heat-treated spores presumably lose their viability due to the permeabilization phenomena, which makes them more susceptible to the action of adverse conditions precluding growth.

  19. Identifying assembly-inhibiting and assembly-tolerant sites in the SbsB S-layer protein from Geobacillus stearothermophilus.

    Science.gov (United States)

    Kinns, Helen; Badelt-Lichtblau, Helga; Egelseer, Eva Maria; Sleytr, Uwe B; Howorka, Stefan

    2010-01-29

    Surface layer (S-layer) proteins self-assemble into two-dimensional crystalline lattices that cover the cell wall of all archaea and many bacteria. We have generated assembly-negative protein variants of high solubility that will facilitate high-resolution structure determination. Assembly-negative versions of the S-layer protein SbsB from Geobacillus stearothermophilus PV72/p2 were obtained using an insertion mutagenesis screen. The haemagglutinin epitope tag was inserted at 23 amino acid positions known to be located on the monomer protein surface from a previous cysteine accessibility screen. Limited proteolysis, circular dichroism, and fluorescence were used to probe whether the epitope insertion affected the secondary and tertiary structures of the monomer, while electron microscopy and size-exclusion chromatography were employed to examine proteins' ability to self-assemble. The screen not only identified assembly-compromised mutants with native fold but also yielded correctly folded, self-assembling mutants suitable for displaying epitopes for biomedical and biophysical applications, as well as cryo-electron microscopy imaging. Our study marks an important step in the analysis of the S-layer structure. In addition, the approach of concerted insertion and cysteine mutagenesis can likely be applied for other supramolecular assemblies.

  20. Crystallization and preliminary crystallographic analysis of Abp, a GH27 β-L-arabinopyranosidase from Geobacillus stearothermophilus.

    Science.gov (United States)

    Lansky, Shifra; Salama, Rachel; Solomon, Vered H; Belrhali, Hassan; Shoham, Yuval; Shoham, Gil

    2013-06-01

    Geobacillus stearothermophilus T-6 is a thermophilic soil bacterium that possesses an extensive system for the utilization of hemicellulose. The bacterium produces a small number of endo-acting extracellular enzymes that cleave high-molecular-weight hemicellulolytic polymers into short decorated oligosaccharides, which are further hydrolysed into the respective sugar monomers by a battery of intracellular glycoside hydrolases. One of these intracellular processing enzymes is β-L-arabinopyranosidase (Abp), which is capable of removing β-L-arabinopyranose residues from naturally occurring arabino-polysaccharides. As arabino-polymers constitute a significant part of the hemicellulolytic content of plant biomass, their efficient enzymatic degradation presents an important challenge for many potential biotechnological applications. This aspect has led to an increasing interest in the biochemical characterization and structural analysis of this and related hemicellulases. Abp from G. stearothermophilus T-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized in our laboratory, as part of its complete structure-function study. The best crystals obtained for this enzyme belonged to the primitive orthorhombic space group P2(1)2(1)2(1), with average unit-cell parameters a = 107.7, b = 202.2, c = 287.3 Å. Full diffraction data sets to 2.3 Å resolution have been collected for both the wild-type enzyme and its D197A catalytic mutant from flash-cooled crystals at 100 K, using synchrotron radiation. These data are currently being used for a high-resolution three-dimensional structure determination of Abp.

  1. Crystallization and preliminary crystallographic analysis of a family 43 β-d-xylosidase from Geobacillus stearothermophilus T-6

    Energy Technology Data Exchange (ETDEWEB)

    Brüx, Christian; Niefind, Karsten [Institute for Biochemistry, University of Cologne (Germany); Ben-David, Alon; Leon, Maya [Department of Biotechnology and Food Engineering and Institute of Catalysis Science and Technology, Technion-Israel Institute of Technology, Haifa (Israel); Shoham, Gil [Department of Inorganic Chemistry and The Laboratory for Structural Chemistry and Biology, The Hebrew University of Jerusalem, Jerusalem (Israel); Shoham, Yuval [Department of Biotechnology and Food Engineering and Institute of Catalysis Science and Technology, Technion-Israel Institute of Technology, Haifa (Israel); Schomburg, Dietmar, E-mail: d.schomburg@uni-koeln.de [Institute for Biochemistry, University of Cologne (Germany)

    2005-12-01

    The crystallization and preliminary X-ray analysis of a β-d-xylosidase from G. stearothermophilus T-6, a family 43 glycoside hydrolase, is described. Native and catalytic inactive mutants of the enzymes were crystallized in two different space groups, orthorhombic P2{sub 1}2{sub 1}2 and tetragonal P4{sub 1}2{sub 1}2 (or the enantiomorphic space group P4{sub 3}2{sub 1}2), using a sensitive cryoprotocol. The latter crystal form diffracted X-rays to a resolution of 2.2 Å. β-d-Xylosidases (EC 3.2.1.37) are hemicellulases that cleave single xylose units from the nonreducing end of xylooligomers. In this study, the crystallization and preliminary X-ray analysis of a β-d-xylosidase from Geobacillus stearothermophilus T-6 (XynB3), a family 43 glycoside hydrolase, is described. XynB3 is a 535-amino-acid protein with a calculated molecular weight of 61 891 Da. Purified recombinant native and catalytic inactive mutant proteins were crystallized and cocrystallized with xylobiose in two different space groups, P2{sub 1}2{sub 1}2 (unit-cell parameters a = 98.32, b = 99.36, c = 258.64 Å) and P4{sub 1}2{sub 1}2 (or the enantiomorphic space group P4{sub 3}2{sub 1}2; unit-cell parameters a = b = 140.15, c = 233.11 Å), depending on the detergent. Transferring crystals to cryoconditions required a very careful protocol. Orthorhombic crystals diffract to 2.5 Å and tetragonal crystals to 2.2 Å.

  2. Crystallization and preliminary crystallographic analysis of GanB, a GH42 intracellular β-galactosidase from Geobacillus stearothermophilus.

    Science.gov (United States)

    Solomon, Hodaya V; Tabachnikov, Orly; Feinberg, Hadar; Govada, Lata; Chayen, Naomi E; Shoham, Yuval; Shoham, Gil

    2013-10-01

    Geobacillus stearothermophilus T-6 is a Gram-positive thermophilic soil bacterium that contains a multi-enzyme system for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. The bacterium uses a number of endo-acting extracellular enzymes that break down the high-molecular-weight polysaccharides into decorated oligosaccharides. These oligosaccharides enter the cell and are further hydrolyzed into sugar monomers by a set of intracellular glycoside hydrolases. One of these intracellular degrading enzymes is GanB, a glycoside hydrolase family 42 β-galactosidase capable of hydrolyzing short β-1,4-galactosaccharides to galactose. GanB and related enzymes therefore play an important part in the hemicellulolytic utilization system of many microorganisms which use plant biomass for growth. The interest in the biochemical characterization and structural analysis of these enzymes stems from their potential biotechnological applications. GanB from G. stearothermophilus T-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized in our laboratory as part of its complete structure-function study. The best crystals obtained for this enzyme belong to the primitive orthorhombic space group P2₁2₁2₁, with average crystallographic unit-cell parameters of a=71.84, b=181.35, c=196.57 Å. Full diffraction data sets to 2.45 and 2.50 Å resolution have been collected for both the wild-type enzyme and its E323A nucleophile catalytic mutant, respectively, as measured from flash-cooled crystals at 100 K using synchrotron radiation. These data are currently being used for the full three-dimensional crystal structure determination of GanB.

  3. Structural characterization of the acid-degraded secondary cell wall polymer of Geobacillus stearothermophilus PV72/p2.

    Science.gov (United States)

    Petersen, Bent O; Sára, Margit; Mader, Christoph; Mayer, Harald F; Sleytr, Uwe B; Pabst, Martin; Puchberger, Michael; Krause, Eberhard; Hofinger, Andreas; Duus, Jens Ø; Kosma, Paul

    2008-06-09

    The secondary cell wall polymer (SCWP) from Geobacillus stearothermophilus PV72/p2, which is involved in the anchoring of the surface-layer protein to the bacterial cell wall layer, is composed of 2-amino-2-deoxy- and 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-mannose, and 2-acetamido-2-deoxy-D-mannuronic acid. The primary structure of the acid-degraded polysaccharide--liberated by HF-treatment from the cell wall--was determined by high-field NMR spectroscopy and mass spectrometry using N-acetylated and hydrolyzed polysaccharide derivatives as well as Smith-degradation. The polysaccharide was shown to consist of a tetrasaccharide repeating unit containing a pyruvic acid acetal at a side-chain 2-acetamido-2-deoxy-alpha-D-mannopyranosyl residue. Substoichiometric substitutions of the repeating unit were observed concerning the degree of N-acetylation of glucosamine residues and the presence of side-chain linked 2-acetamido-2-deoxy-beta-D-glucopyranosyl units: [Formula: see text].

  4. How to Switch Off a Histidine Kinase: Crystal Structure of Geobacillus Stearothermophilus KinB with the Inhibitor Sda

    Energy Technology Data Exchange (ETDEWEB)

    Bick, M.; Lamour, V; Rajashankar, K; Gordiyenko, Y; Robinson, C; Darst, S

    2009-01-01

    Entry to sporulation in bacilli is governed by a histidine kinase phosphorelay, a variation of the predominant signal transduction mechanism in prokaryotes. Sda directly inhibits sporulation histidine kinases in response to DNA damage and replication defects. We determined a 2.0-Angstroms-resolution X-ray crystal structure of the intact cytoplasmic catalytic core [comprising the dimerization and histidine phosphotransfer domain (DHp domain), connected to the ATP binding catalytic domain] of the Geobacillus stearothermophilus sporulation kinase KinB complexed with Sda. Structural and biochemical analyses reveal that Sda binds to the base of the DHp domain and prevents molecular transactions with the DHp domain to which it is bound by acting as a simple molecular barricade. Sda acts to sterically block communication between the catalytic domain and the DHp domain, which is required for autophosphorylation, as well as to sterically block communication between the response regulator Spo0F and the DHp domain, which is required for phosphotransfer and phosphatase activities.

  5. Semi-Rational Design of Geobacillus stearothermophilus L-Lactate Dehydrogenase to Access Various Chiral α-Hydroxy Acids.

    Science.gov (United States)

    Aslan, Aşkın Sevinç; Birmingham, William R; Karagüler, Nevin Gül; Turner, Nicholas J; Binay, Barış

    2016-06-01

    Chiral α-hydroxy acids (AHAs) are rapidly becoming important synthetic building blocks, in particular for the production of pharmaceuticals and other fine chemicals. Chiral compounds of a variety of functionalities are now often derived using enzymes, and L-lactate dehydrogenase from the thermophilic organism Geobacillus stearothermophilus (bsLDH) has the potential to be employed for the industrial synthesis of chiral α-hydroxy acids. Despite the thorough characterization of this enzyme, generation of variants with high activity on non-natural substrates has remained difficult and therefore limits the use of bsLDH in industry. Here, we present the engineering of bsLDH using semi-rational design as a method of focusing screening in a small and smart library for novel biocatalysts. In this study, six mutant libraries were designed in an effort to expand the substrate range of bsLDH. The eight variants identified as having enhanced activity toward the selected α-keto acids belonged to the same library, which targeted two positions simultaneously. These new variants now may be useful biocatalysts for chiral synthesis of α-hydroxy acids.

  6. Structure-function relationships in Gan42B, an intracellular GH42 β-galactosidase from Geobacillus stearothermophilus.

    Science.gov (United States)

    Solomon, Hodaya V; Tabachnikov, Orly; Lansky, Shifra; Salama, Rachel; Feinberg, Hadar; Shoham, Yuval; Shoham, Gil

    2015-12-01

    Geobacillus stearothermophilus T-6 is a Gram-positive thermophilic soil bacterium that contains a battery of degrading enzymes for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. A 9.4 kb gene cluster has recently been characterized in G. stearothermophilus that encodes a number of galactan-utilization elements. A key enzyme of this degradation system is Gan42B, an intracellular GH42 β-galactosidase capable of hydrolyzing short β-1,4-galactosaccharides into galactose units, making it of high potential for various biotechnological applications. The Gan42B monomer is made up of 686 amino acids, and based on sequence homology it was suggested that Glu323 is the catalytic nucleophile and Glu159 is the catalytic acid/base. In the current study, the detailed three-dimensional structure of wild-type Gan42B (at 2.45 Å resolution) and its catalytic mutant E323A (at 2.50 Å resolution), as determined by X-ray crystallography, are reported. These structures demonstrate that the three-dimensional structure of the Gan42B monomer generally correlates with the overall fold observed for GH42 proteins, consisting of three main domains: an N-terminal TIM-barrel domain, a smaller mixed α/β domain, and the smallest all-β domain at the C-terminus. The two catalytic residues are located in the TIM-barrel domain in a pocket-like active site such that their carboxylic functional groups are about 5.3 Å from each other, consistent with a retaining mechanism. The crystal structure demonstrates that Gan42B is a homotrimer, resembling a flowerpot in general shape, in which each monomer interacts with the other two to form a cone-shaped tunnel cavity in the centre. The cavity is ∼35 Å at the wide opening and ∼5 Å at the small opening and ∼40 Å in length. The active sites are situated at the interfaces between the monomers, so that every two neighbouring monomers participate in the formation of each of the three active

  7. Preliminary crystallographic analysis of Xyn52B2, a GH52 β-D-xylosidase from Geobacillus stearothermophilus T6.

    Science.gov (United States)

    Dann, Roie; Lansky, Shifra; Lavid, Noa; Zehavi, Arie; Belakhov, Valery; Baasov, Timor; Dvir, Hay; Manjasetty, Babu; Belrhali, Hassan; Shoham, Yuval; Shoham, Gil

    2014-12-01

    Geobacillus stearothermophilus T6 is a thermophilic bacterium that possesses an extensive hemicellulolytic system, including over 40 specific genes that are dedicated to this purpose. For the utilization of xylan, the bacterium uses an extracellular xylanase which degrades xylan to decorated xylo-oligomers that are imported into the cell. These oligomers are hydrolyzed by side-chain-cleaving enzymes such as arabinofuranosidases, acetylesterases and a glucuronidase, and finally by an intracellular xylanase and a number of β-xylosidases. One of these β-xylosidases is Xyn52B2, a GH52 enzyme that has already proved to be useful for various glycosynthesis applications. In addition to its demonstrated glycosynthase properties, interest in the structural aspects of Xyn52B2 stems from its special glycoside hydrolase family, GH52, the structures and mechanisms of which are only starting to be resolved. Here, the cloning, overexpression, purification and crystallization of Xyn52B2 are reported. The most suitable crystal form that has been obtained belonged to the orthorhombic P212121 space group, with average unit-cell parameters a = 97.7, b = 119.1, c = 242.3 Å. Several X-ray diffraction data sets have been collected from flash-cooled crystals of this form, including the wild-type enzyme (3.70 Å resolution), the E335G catalytic mutant (2.95 Å resolution), a potential mercury derivative (2.15 Å resolution) and a selenomethionine derivative (3.90 Å resolution). These data are currently being used for detailed three-dimensional structure determination of the Xyn52B2 protein.

  8. Stability engineering of the Geobacillus stearothermophilus alcohol dehydrogenase and application for the synthesis of a polyamide 12 precursor.

    Science.gov (United States)

    Kirmair, Ludwig; Seiler, Daniel Leonard; Skerra, Arne

    2015-12-01

    The thermostable NAD(+)-dependent alcohol dehydrogenase from Geobacillus stearothermophilus (BsADH) was exploited with regard to the biocatalytic synthesis of ω-oxo lauric acid methyl ester (OLAMe), a key intermediate for biobased polyamide 12 production, from the corresponding long-chain alcohol. Recombinant BsADH was produced in Escherichia coli as a homogeneous tetrameric enzyme and showed high activity towards the industrially relevant substrate ω-hydroxy lauric acid methyl ester (HLAMe) with K M = 86 μM and 44 U mg(-1). The equilibrium constant for HLAMe oxidation to the aldehyde (OLAMe) with NAD(+) was determined as 2.16 × 10(-3) from the kinetic parameters of the BsADH-catalyzed forward and reverse reactions. Since BsADH displayed limited stability under oxidizing conditions, the predominant oxidation-prone residue Cys257 was mutated to Leu based on sequence homology with related enzymes and computational simulation. This substitution resulted in an improved BsADH variant exhibiting prolonged stability and an elevated inactivation temperature. Semi-preparative biocatalysis at 60 °C using the stabilized enzyme, employing butyraldehyde for in situ cofactor regeneration with only catalytic amounts of NAD(+), yielded up to 23 % conversion of HLAMe to OLAMe after 30 min. In contrast to other oxidoreductases, no overoxidation to the dodecanoic diacid monomethyl ester was detected. Thus, the mutated BsADH offers a promising biocatalyst for the selective oxidation of fatty alcohols to yield intermediates for industrial polymer production.

  9. Coproduction of thermostable amylase and beta-galactosidase enzymes by Geobacillus stearothermophilus SAB-40: aplication of Plackett-Burman design to evaluate culture requirements affecting enzyme production.

    Science.gov (United States)

    Solimam, Nadia A

    2008-04-01

    A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular beta-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G. stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, CaCl2, the incubation time, MgSO4.7H2O, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote beta-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and beta-galactosidase at 23.29 U/ml/min and 12,958 U/mg biomass, respectively, which was 3- and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

  10. Strain Improvement of Bacillus coagulans and Geobacillus stearothermophilus for Enhanced Thermostable Cellulase Production and the Effect of Different Metal Ions on Cellulase Activity

    Directory of Open Access Journals (Sweden)

    Vikas Sharma

    2012-11-01

    Full Text Available The current study was focused on the strain improvement of Bacillus coagulans and Geobacillus stearothermophilus for thermostable cellulase production with higher enzyme activity. For strain improvement UV radiations, NTG and Sodium azide were used as mutagenic agents.NTG was found to be best mutagenic agent among all in term of highest cellulase activity. Mutant strain C11 exhibited the highest cellulase specific activity at 45 U/mg followed by C15 (39 U/mg in case of B.coagulans while Mutant strain S18 exhibited thehighest cellulase specific activity at 69 U/mg followed by S12 (62 U/mg in case of G. stearothermophilus. Specific activity of cellulase was 92 U/mg in case of B.coagulans C11 and 118 U/mg in case of G. stearothermophilus S18. Ag+, Mg+, Se2+,Ca2+,Co2+,Mn2+,K+, Zn2+ ,Fe3+, Hg2+ and Cu2+ showed positive change in specific activity while Na+, Ni2+ negative change in specific activity of cellulase with respect to specific activity of cellulase in absence of any additive in case of B.coagulans C11 and Ag+, Mg+, Se2+,Co2+,Mn2+ andHg2+ showed positive change in specific activity, Na+, K+ showed no change in specific activity while Ca2+, Zn2+, Ni2+, Fe3+ and Cu2+ showed negative change in specific activity of cellulase with respect to specific activity of cellulase in absence of any additive in case of G. stearothermophilus S18.

  11. Structural basis for thermostability revealed through the identification and characterization of a highly thermostable phosphotriesterase-like lactonase from Geobacillus stearothermophilus

    Energy Technology Data Exchange (ETDEWEB)

    Hawwa, Renda; Aikens, John; Turner, Robert J.; Santarsiero, Bernard D.; Mescar, Andrew D.; (Lybradyn Inc.); (UIC)

    2009-08-31

    A new enzyme homologous to phosphotriesterase was identified from the bacterium Geobacillus stearothermophilus (GsP). This enzyme belongs to the amidohydrolase family and possesses the ability to hydrolyze both lactone and organophosphate (OP) compounds, making it a phosphotriesterase-like lactonase (PLL). GsP possesses higher OP-degrading activity than recently characterized PLLs, and it is extremely thermostable. GsP is active up to 100 C with an energy of activation of 8.0 kcal/mol towards ethyl paraoxon, and it can withstand an incubation temperature of 60 C for two days. In an attempt to understand the thermostability of PLLs, the X-ray structure of GsP was determined and compared to those of existing PLLs. Based upon a comparative analysis, a new thermal advantage score and plot was developed and reveals that a number of different factors contribute to the thermostability of PLLs.

  12. Structure-specificity relationships in Abp, a GH27 β-L-arabinopyranosidase from Geobacillus stearothermophilus T6.

    Science.gov (United States)

    Lansky, Shifra; Salama, Rachel; Solomon, Hodaya V; Feinberg, Hadar; Belrhali, Hassan; Shoham, Yuval; Shoham, Gil

    2014-11-01

    L-Arabinose sugar residues are relatively abundant in plants and are found mainly in arabinan polysaccharides and in other arabinose-containing polysaccharides such as arabinoxylans and pectic arabinogalactans. The majority of the arabinose units in plants are present in the furanose form and only a small fraction of them are present in the pyranose form. The L-arabinan-utilization system in Geobacillus stearothermophilus T6, a Gram-positive thermophilic soil bacterium, has recently been characterized, and one of the key enzymes was found to be an intracellular β-L-arabinopyranosidase (Abp). Abp, a GH27 enzyme, was shown to remove β-L-arabinopyranose residues from synthetic substrates and from the native substrates sugar beet arabinan and larch arabinogalactan. The Abp monomer is made up of 448 amino acids, and based on sequence homology it was suggested that Asp197 is the catalytic nucleophile and Asp255 is the catalytic acid/base. In the current study, the detailed three-dimensional structure of wild-type Abp (at 2.28 Å resolution) and its catalytic mutant Abp-D197A with (at 2.20 Å resolution) and without (at 2.30 Å resolution) a bound L-arabinose product are reported as determined by X-ray crystallography. These structures demonstrate that the three-dimensional structure of the Abp monomer correlates with the general fold observed for GH27 proteins, consisting of two main domains: an N-terminal TIM-barrel domain and a C-terminal all-β domain. The two catalytic residues are located in the TIM-barrel domain, such that their carboxylic functional groups are about 5.9 Å from each other, consistent with a retaining mechanism. An isoleucine residue (Ile67) located at a key position in the active site is shown to play a critical role in the substrate specificity of Abp, providing a structural basis for the high preference of the enzyme towards arabinopyranoside over galactopyranoside substrates. The crystal structure demonstrates that Abp is a tetramer

  13. Three-dimensional structure of a variant `Termamyl-like' Geobacillus stearothermophilus α-amylase at 1.9 Å resolution.

    Science.gov (United States)

    Offen, Wendy A; Viksoe-Nielsen, Anders; Borchert, Torben V; Wilson, Keith S; Davies, Gideon J

    2015-01-01

    The enzyme-catalysed degradation of starch is central to many industrial processes, including sugar manufacture and first-generation biofuels. Classical biotechnological platforms involve steam explosion of starch followed by the action of endo-acting glycoside hydrolases termed α-amylases and then exo-acting α-glucosidases (glucoamylases) to yield glucose, which is subsequently processed. A key enzymatic player in this pipeline is the `Termamyl' class of bacterial α-amylases and designed/evolved variants thereof. Here, the three-dimensional structure of one such Termamyl α-amylase variant based upon the parent Geobacillus stearothermophilus α-amylase is presented. The structure has been solved at 1.9 Å resolution, revealing the classical three-domain fold stabilized by Ca2+ and a Ca2+-Na+-Ca2+ triad. As expected, the structure is similar to the G. stearothermophilus α-amylase but with main-chain deviations of up to 3 Å in some regions, reflecting both the mutations and differing crystal-packing environments.

  14. Study of the influence of sporulation conditions on heat resistance of Geobacillus stearothermophilus used in the development of biological indicators for steam sterilization.

    Science.gov (United States)

    Guizelini, Belquis P; Vandenberghe, Luciana P S; Sella, Sandra Regina B R; Soccol, Carlos Ricardo

    2012-12-01

    Biological indicators are important tools in infection control via sterilization process monitoring. The use of a standardized spore crop with a well-defined heat resistance will guarantee the quality of a biological indicator. Ambient factors during sporulation can affect spore characteristics and properties, including heat resistance. The aim of this study is to evaluate the main sporulation factors responsible for heat resistance in Geobacillus stearothermophilus, a useful biological indicator for steam sterilization. A sequence of a three-step optimization of variables (initial pH, nutrient concentration, tryptone, peptone, beef extract, yeast extract, manganese sulfate, magnesium sulfate, calcium chloride and potassium phosphate) was carried out to screen those that have a significant influence on heat resistance of produced spores. The variable exerting greatest influence on G. stearothermophilus heat resistance during sporulation was found to be the initial pH. Lower nutrient concentration and alkaline pH around 8.5 tended to enhance decimal reduction time at 121 °C (D(121°C)). A central composite design enabled a fourfold enhancement in heat resistance, and the model obtained accurately describes positive pH and negative manganese sulfate concentration influence on spore heat resistance.

  15. A differentially conserved residue (Ile42) of GH42 β-galactosidase from Geobacillus stearothermophilus BgaB is involved in both catalysis and thermostability.

    Science.gov (United States)

    Dong, Yi-Ning; Chen, Hai-Qin; Sun, Yan-Hui; Zhang, Hao; Chen, Wei

    2015-04-01

    The glycoside hydrolase family 42 (GH42) of thermophilic microorganisms consists of thermostable β-galactosidases that display significant variations in their temperature optima and stabilities. In this study, we compared the substrate binding modes of 2 GH42 β-galactosidases, BgaB from Geobacillus stearothermophilus and A4-β-Gal from Thermus thermophilus A4. The A4-β-Gal has a catalytic triad (Glu312-Arg32-Glu35) with an extended hydrogen bond network that has not been observed in BgaB. In this study, we performed site-saturation mutagenesis of Ile42 in BgaB (equivalent to Glu312 in A4-β-Gal) to study the effects of different residues on thermostability, catalytic function, and the extended hydrogen bond network. Our experimental results suggest that substitution of Ile42 with polar AA enhanced the thermostability but decreased the catalytic efficiency of BgaB. Polar AA substitution for Ile42 simultaneously affected thermostability, catalytic efficiency, and the hydrogen bond network, suggesting that Ile42 is responsible for functional discrimination between members of the GH42 family. These observations could lead to a novel strategy for investigating the functional evolution of the GH42 β-galactosidases.

  16. Backbone and side chain NMR assignments of Geobacillus stearothermophilus ZapA allow identification of residues that mediate the interaction of ZapA with FtsZ.

    Science.gov (United States)

    Nogueira, Maria Luiza C; Sforça, Mauricio Luis; Chin, Yanni K-Y; Mobli, Mehdi; Handler, Aaron; Gorbatyuk, Vitaliy Y; Robson, Scott A; King, Glenn F; Gueiros-Filho, Frederico J; Zeri, Ana Carolina de Mattos

    2015-10-01

    Bacterial division begins with the formation of a contractile protein ring at midcell, which constricts the bacterial envelope to generate two daughter cells. The central component of the division ring is FtsZ, a tubulin-like protein capable of self-assembling into filaments which further associate into a higher order structure known as the Z ring. Proteins that bind to FtsZ play a crucial role in the formation and regulation of the Z ring. One such protein is ZapA, a widely conserved 21 kDa homodimeric protein that associates with FtsZ filaments and promotes their bundling. Although ZapA was discovered more than a decade ago, the structural details of its interaction with FtsZ remain unknown. In this work, backbone and side chain NMR assignments for the Geobacillus stearothermophilus ZapA homodimer are described. We titrated FtsZ into (15)N(2)H-ZapA and mapped ZapA residues whose resonances are perturbed upon FtsZ binding. This information provides a structural understanding of the interaction between FtsZ and ZapA.

  17. Protein engineering by random mutagenesis and structure-guided consensus of Geobacillus stearothermophilus Lipase T6 for enhanced stability in methanol.

    Science.gov (United States)

    Dror, Adi; Shemesh, Einav; Dayan, Natali; Fishman, Ayelet

    2014-02-01

    The abilities of enzymes to catalyze reactions in nonnatural environments of organic solvents have opened new opportunities for enzyme-based industrial processes. However, the main drawback of such processes is that most enzymes have a limited stability in polar organic solvents. In this study, we employed protein engineering methods to generate a lipase for enhanced stability in methanol, which is important for biodiesel production. Two protein engineering approaches, random mutagenesis (error-prone PCR) and structure-guided consensus, were applied in parallel on an unexplored lipase gene from Geobacillus stearothermophilus T6. A high-throughput colorimetric screening assay was used to evaluate lipase activity after an incubation period in high methanol concentrations. Both protein engineering approaches were successful in producing variants with elevated half-life values in 70% methanol. The best variant of the random mutagenesis library, Q185L, exhibited 23-fold-improved stability, yet its methanolysis activity was decreased by one-half compared to the wild type. The best variant from the consensus library, H86Y/A269T, exhibited 66-fold-improved stability in methanol along with elevated thermostability (+4.3°C) and a 2-fold-higher fatty acid methyl ester yield from soybean oil. Based on in silico modeling, we suggest that the Q185L substitution facilitates a closed lid conformation that limits access for both the methanol and substrate excess into the active site. The enhanced stability of H86Y/A269T was a result of formation of new hydrogen bonds. These improved characteristics make this variant a potential biocatalyst for biodiesel production.

  18. Effect of Dimer Dissociation on Activity and Thermostability of the α-Glucuronidase from Geobacillus stearothermophilus: Dissecting the Different Oligomeric Forms of Family 67 Glycoside Hydrolases

    Science.gov (United States)

    Shallom, Dalia; Golan, Gali; Shoham, Gil; Shoham, Yuval

    2004-01-01

    The oligomeric organization of enzymes plays an important role in many biological processes, such as allosteric regulation, conformational stability and thermal stability. α-Glucuronidases are family 67 glycosidases that cleave the α-1,2-glycosidic bond between 4-O-methyl-d-glucuronic acid and xylose units as part of an array of hemicellulose-hydrolyzing enzymes. Currently, two crystal structures of α-glucuronidases are available, those from Geobacillus stearothermophilus (AguA) and from Cellvibrio japonicus (GlcA67A). Both enzymes are homodimeric, but surprisingly their dimeric organization is different, raising questions regarding the significance of dimerization for the enzymes' activity and stability. Structural comparison of the two enzymes suggests several elements that are responsible for the different dimerization organization. Phylogenetic analysis shows that the α-glucuronidases AguA and GlcA67A can be classified into two distinct subfamilies of bacterial α-glucuronidases, where the dimer-forming residues of each enzyme are conserved only within its own subfamily. It seems that the different dimeric forms of AguA and GlcA67A represent the two alternative dimeric organizations of these subfamilies. To study the biological significance of the dimerization in α-glucuronidases, we have constructed a monomeric form of AguA by mutating three of its interface residues (W328E, R329T, and R665N). The activity of the monomer was significantly lower than the activity of the wild-type dimeric AguA, and the optimal temperature for activity of the monomer was around 35°C, compared to 65°C of the wild-type enzyme. Nevertheless, the melting temperature of the monomeric protein, 72.9°C, was almost identical to that of the wild-type, 73.4°C. It appears that the dimerization of AguA is essential for efficient catalysis and that the dissociation into monomers results in subtle conformational changes in the structure which indirectly influence the active site region

  19. Study of the combined effect of electro-activated solutions and heat treatment on the destruction of spores of Clostridium sporogenes and Geobacillus stearothermophilus in model solution and vegetable puree.

    Science.gov (United States)

    Liato, Viacheslav; Labrie, Steve; Viel, Catherine; Benali, Marzouk; Aïder, Mohammed

    2015-10-01

    The combined effect of heat treatment and electro-activated solution (EAS) on the heat resistance of spores of Clostridium sporogenes and Geobacillus stearothermophilus was assessed under various heating and exposure time combinations. The acid and neutral EAS showed the highest inhibitory activity, indicating that these solutions may be considered as strong sporicidal disinfectants. These EAS were able to cause a reduction of ≥6 log of spores of C. sporogenes at 60 °C in only 1 min of exposition. For G. stearothermophilus spores, a reduction of 4.5 log was observed at 60 °C in 1 min, while in 5 min, ≥7 log CFU/ml reduction was observed. Inoculated puree of pea and corn were used as a food matrix for the determination of the heat resistance of these spores during the treatments in glass capillaries. The inactivation kinetics of the spores was studied in an oil bath. Combined treatment by EAS and temperature demonstrated a significant decrease in the heat resistance of C. sporogenes. The D100°C in pea puree with NaCl solution was 66.86 min while with acid and neutral EAS it was reduced down to 3.97 and 2.19 min, respectively. The spore of G. stearothermophilus displayed higher heat resistance as confirmed by other similar studies. Its D130°C in pea puree showed a decrease from 1.45 min in NaCl solution down to 1.30 and 0.93 min for acid and neutral EAS, respectively. The differences between the spores of these species are attributable to their different sensitivities with respect to pH, Redox potential and oxygen.

  20. Draft Genome Sequences of Seven Thermophilic Spore-Forming Bacteria Isolated from Foods That Produce Highly Heat-Resistant Spores, Comprising Geobacillus spp., Caldibacillus debilis, and Anoxybacillus flavithermus

    NARCIS (Netherlands)

    Berendsen, Erwin M; Wells-Bennik, Marjon H J; Krawczyk, Antonina O; de Jong, Anne; van Heel, Auke; Holsappel, Siger; Eijlander, Robyn T; Kuipers, Oscar P

    2016-01-01

    Here, we report the draft genomes of five strains of Geobacillus spp., one Caldibacillus debilis strain, and one draft genome of Anoxybacillus flavithermus, all thermophilic spore-forming Gram-positive bacteria.

  1. Draft Genome Sequences of Seven Thermophilic Spore-Forming Bacteria Isolated from Foods That Produce Highly Heat-Resistant Spores, Comprising Geobacillus spp., Caldibacillus debilis, and Anoxybacillus flavithermus

    Science.gov (United States)

    Berendsen, Erwin M.; Wells-Bennik, Marjon H. J.; Krawczyk, Antonina O.; de Jong, Anne; van Heel, Auke; Holsappel, Siger; Eijlander, Robyn T.

    2016-01-01

    Here, we report the draft genomes of five strains of Geobacillus spp., one Caldibacillus debilis strain, and one draft genome of Anoxybacillus flavithermus, all thermophilic spore-forming Gram-positive bacteria. PMID:27151781

  2. Optimization of the Fermentation Conditions of 5L Fermenter for Geobacillus stearothermophilus CHB1%嗜热脂肪土芽孢杆菌CHB1的5L发酵罐发酵条件初探

    Institute of Scientific and Technical Information of China (English)

    张慧; 李活孙; 邱宏端; 林新坚

    2012-01-01

    A single-factor method was used to optimize the conditions of Geobacillus stearothermophilus CHB1 such as ventilation volume, speed, temperature, pH and other parameters, and to determine the growth curve of CHB1 in a 5 L fermenter. The best fermentation conditions were: ventilation 6 L/min, speed l80r/min, inoculum 4% and culture temperature 58 ℃. The maximum cell biomass could be achieved by fermentation 21 h. Through the method of auto-fed acetic acid to control the pH of fermentation process, it could achieve a high-density fermentation of CHB1. The cell biology was as high as 6.07x108 cfu/ml. Using fed acid pH control pH8.0, it could achieve the maximum cell biomass up to 6.07x108 cfu/ml.%优化嗜热脂肪芽孢杆菌CHB1的5L发酵罐发酵条件.通过单因素法优化发酵罐的通气量、转速、温度、pH等参数,并测定CHB1在5L发酵罐中的生长曲线.结果表明,最佳发酵条件为:转速180 r/min、通气量6 L/min、发酵温度58℃、接种量4%,发酵过程自动流加乙酸控制pH值为8.0,培养21 h.采用自动流加乙酸控制pH值的方法,效果显著,控制pH值为8.0时,发酵效果最好,细胞生物量高达6.07×108 cfu/mL,约是不控制pH值发酵的对照组(3.5× 108 cfu/mL)的2倍.

  3. Characterization of two novel plasmids from Geobacillus sp. 610 and 1121 strains.

    Science.gov (United States)

    Kananavičiūtė, Rūta; Butaitė, Elena; Citavičius, Donaldas

    2014-01-01

    We describe two cryptic low molecular weight plasmids, pGTD7 (3279bp) and pGTG5 (1540bp), isolated from Geobacillus sp. 610 and 1121 strains, respectively. Homology analysis of the replication protein (Rep) sequences and detection of ssDNA indicate that both of them replicate via rolling circle mechanism. As revealed by sequence similarities of dso region and Rep protein, plasmid pGTD7 belongs to pC194/pUB110 plasmid family. The replicon of pGTD7 was proved to be functional in another Geobacillus host. For this purpose, a construct pUCK7, containing a replicon of the analyzed plasmid, was created and transferred to G. stearothermophilus NUB3621R strain by electroporation. Plasmid pGTG5, based on Rep protein sequence similarity, was found to be related mostly to some poorly characterized bacterial plasmids. Rep proteins encoded by these plasmids contain conservative motifs that are most similar to those of Microviridae phages. This feature suggests that pGTG5, together with other plasmids containing the same motifs, could constitute a new family of bacterial plasmids. To date, pGTG5 is the smallest plasmid identified in bacteria belonging to the genus Geobacillus. The two plasmids described in this study can be used for the construction of new vectors suitable for biotechnologically important bacteria of the genus Geobacillus.

  4. 嗜热脂肪芽孢杆菌羧酸酯酶的异源表达及酶学性质研究%Heterologous Expression and Characterization of The Carboxylesterase From Geobacillus stearothermophilus

    Institute of Scientific and Technical Information of China (English)

    孙锦霞; 刘钟滨

    2010-01-01

    运用生物信息学技术从嗜热脂肪芽孢杆菌(Geobacillus stearothermophilus)CICC 20156中克隆获得羧酸酯酶基因,构建黑曲霉和毕氏酵母表达质粒,将重组质粒分别转化毕氏酵母GS115和黑曲霉pyrG基因缺陷株M54.SDS-PAGE和Westernblot检测显示:携带His标记的外源蛋白在转化真茼宿主中均获得了高效分泌性表达,毕氏酵母和黑曲霉表达的外源蛋白分子质量均约为29ku,蛋白质浓度分别为30.7mg/L和15.3mg/L.生物学活性测定表明,毕氏酵母与黑曲霉表达的羧酸酯酶单位蛋白酶活分别为22 671 U/mg和21 438 U/mg.酶学性质研究显示,两种表达系统表达的重组羧酸酯酶的酶学特性基本一致,它们在40~70℃范围内均显示较好的酶活性,最适反应温度为60℃.70℃处理30min,毕氏酵母和黑曲霉表达重组羧酸酯酶残余酶活分别为76.7%和67.6%,显示出良好的热稳定性.在pH 6.5~8.5的范围内显示较高酶活性,最适pH为8.0.上述研究首次实现了具有良好热稳定性的嗜热脂肪芽孢杆菌羧酸酯酶在黑曲霉和毕氏酵母中高效异源分泌性表达,其中毕氏酵母羧酸酯酶的产量要高于黑曲霉的酶产量,但考虑到重组黑曲霉表达外源性蛋白无需使用任何诱导剂,黑曲霉菌表达热稳定性羧酸酯酶可能具有更好的应用前景.

  5. 嗜热脂肪土芽孢杆菌木聚糖酶基因的合成及其在大肠杆菌中的表达%De novo Synthesis and Expression of a Thermostable Xylanase from Geobacillus stearothermophilus in Escherichia coil

    Institute of Scientific and Technical Information of China (English)

    张志刚; 裴小琼; 吴中柳

    2009-01-01

    The endoxylanase XT6 secreted from Geobacillus stearothermophilus is a particularly attractive candidate for some industrial purposes and was used successfully on an industrial-scale mill trial. The gene was de novo synthesized with the codons adjusted to fit the bias of that of Escherichia coli and constructed into vector pET28a (+). After optimizing the expression conditions, functional xylanase XT6 was over expressed in E. coll with up to 65% of total protein. A maximum xylanase activity of 3,030 U/mL was obtained from cell extract against birchwood xylan. The recombinant XT6 was partly characterized and was similar with those of the native enzyme in G. stearothermophilus. This is the first report on the over expression of a de novo synthesized xylanase XT6 gene from Geobacillus stearothermophilus. Fig 6, Tab 1, Ref 19%来自嗜热脂肪土芽孢杆菌的木聚糖内切酶XT6在工业上有着重要的应用,已经成功应用于工业规模的生产试验.本文作者在合成XT6基因全序列的同时对其密码子进行了优化,且构建重组质粒在大肠杆菌中高表达.通过优化表达条件,功能正常的XT6基因在大肠杆菌中成功过量表达,蛋白表达量占细胞中总蛋白的65%.重组表达的木聚糖内切酶XT6特性和天然酶相似,以桦木木聚糖为底物测定细胞提取物中木聚糖酶活性,最大活性高达3 030 U/mL.本文首次报道了来自嗜热脂肪土芽孢杆菌中木聚糖酶基因全序列的合成和在大肠杆菌中成功过量表达.图6表1参19

  6. The genus Geobacillus and their biotechnological potential.

    Science.gov (United States)

    Hussein, Ali H; Lisowska, Beata K; Leak, David J

    2015-01-01

    The genus Geobacillus comprises a group of Gram-positive thermophilic bacteria, including obligate aerobes, denitrifiers, and facultative anaerobes that can grow over a range of 45-75°C. Originally classified as group five Bacillus spp., strains of Bacillus stearothermophilus came to prominence as contaminants of canned food and soon became the organism of choice for comparative studies of metabolism and enzymology between mesophiles and thermophiles. More recently, their catabolic versatility, particularly in the degradation of hemicellulose and starch, and rapid growth rates have raised their profile as organisms with potential for second-generation (lignocellulosic) biorefineries for biofuel or chemical production. The continued development of genetic tools to facilitate both fundamental investigation and metabolic engineering is now helping to realize this potential, for both metabolite production and optimized catabolism. In addition, this catabolic versatility provides a range of useful thermostable enzymes for industrial application. A number of genome-sequencing projects have been completed or are underway allowing comparative studies. These reveal a significant amount of genome rearrangement within the genus, the presence of large genomic islands encompassing all the hemicellulose utilization genes and a genomic island incorporating a set of long chain alkane monooxygenase genes. With G+C contents of 45-55%, thermostability appears to derive in part from the ability to synthesize protamine and spermine, which can condense DNA and raise its Tm.

  7. 嗜热脂肪芽孢杆菌耐热β-半乳糖苷酶功能位点的累积进化研究%Coevolutionary study on the functionary amino acid residues of Geobacillus stearothermophilus thermostable β-Galactosidase BgaB

    Institute of Scientific and Technical Information of China (English)

    董艺凝; 陈海琴; 张灏; 陈卫

    2015-01-01

    针对嗜热脂肪芽孢杆菌(Geobacillus stearothermophilus)来源耐热p-半乳糖苷酶BgaB底物结合位点构建突变体,研究底物结合位点累积突变的功能进化及水解活性的变化规律.实验结果表明:Y272A与E351R的累积突变体比酶活为野生型酶的3.67倍,为单点突变体Y272A的2倍;Y272A/E351R突变体的Km值增大,其对乳糖的亲和力下降,但由于Kcat值增大,使累积突变体Y272A/E351R催化效率提高为野生型酶催化效率的7.8倍.本研究结果表明底物结合位点间的累积突变可改变底物亲和性,并对水解催化活性进化起到正向促进作用.

  8. Genetic engineering of Geobacillus spp.

    Science.gov (United States)

    Kananavičiūtė, Rūta; Čitavičius, Donaldas

    2015-04-01

    Members of the genus Geobacillus are thermophiles that are of great biotechnological importance, since they are sources of many thermostable enzymes. Because of their metabolic versatility, geobacilli can be used as whole-cell catalysts in processes such as bioconversion and bioremediation. The effective employment of Geobacillus spp. requires the development of reliable methods for genetic engineering of these bacteria. Currently, genetic manipulation tools and protocols are under rapid development. However, there are several convenient cloning vectors, some of which replicate autonomously, while others are suitable for the genetic modification of chromosomal genes. Gene expression systems are also intensively studied. Combining these tools together with proper techniques for DNA transfer, some Geobacillus strains were shown to be valuable producers of recombinant proteins and industrially important biochemicals, such as ethanol or isobutanol. This review encompasses the progress made in the genetic engineering of Geobacillus spp. and surveys the vectors and transformation methods that are available for this genus.

  9. 高产耐热脂肪酶嗜热脂肪地芽孢杆菌的选育%Breeding of Geobacillus stearothermophilus for high producing thermostable lipase

    Institute of Scientific and Technical Information of China (English)

    戚薇; 冯艳蕊; 王海宽; 王建玲; 邵静

    2009-01-01

    采用氮离子注入技术对耐热脂肪酶产生菌嗜热脂肪地芽孢杆菌( Geobacillus stearother mophilus )L4进行诱变,筛选获得酶活力有较大提高且传代稳定的正突变菌株L4-3;再对 L4-3进行紫外线诱变,得到脂肪酶活力提高的正突变菌株L4-3-2,其脂肪酶活力达25.71 U/ mL,较原始菌株L4提高511.9%.高产突变株L4-3-2所产脂肪酶的最适作用温度为50℃,70 ℃保温60min的剩余酶活为82%,最适作用pH为7.0~8.0,为一种耐热碱性脂肪酶.外诱变参考文献胡朝阳, 韦晗宁, 李春苑, 等. 产脂肪酶菌株的筛选及酶学特性研究.

  10. [Regulation of citrate synthese in bacteria: Comparison of the action of various effectors on the enzymes of Rhodospirillum rurbum and Bacillus stearothermophilus].

    Science.gov (United States)

    Higa, A I; Massarini, E; Cazzulo, J J

    1976-01-01

    A comparative study of the citrate synthases purified from the facultatively photosynthetic bacterium Rhodospirillum rubrum (Gram negative) and the thermophile Bacillus stearothermophilus (Gram positive) was made. The citrate synthase from R. rubrum was activated by KCl (6-fold at 0.1 M KCl) and, less effectively, by NaCl and NH4Cl. Its molecular weight was about 300,000. The enzyme was strongly inhibited by NADH, and this inhibition was counteracted by AMP. The citrate synthase from B. stearothermophilus was little affected by KCl, NaCl and NH4Cl, all of which activated by about 25% at 0.1 M. Its molecular weight was ca 100,000. The enzyme was not affected by NADH or AMP. Both citrate synthases were insensitive to alpah-oxoglutarate concentrations up to 5 mM, and were inhibited by ATP; the B. stearothermophilus enzyme was more strongly inhibited than the R. rubrum enzyme. In both cases the ATP inhibition was strictly competitive towards acetyl-CoA and non-competitive towards oxaloacetate. Both enzymes, in spite of the peculiar physiological properties of their bacterial sources, followed the close correlation between the properties of the citrate synthase and the taxonomical position of the microorganism, proposed by Weitzman and his co-workers.

  11. Enhancing the cellulose-degrading activity of cellulolytic bacteria CTL-6 (Clostridium thermocellum) by co-culture with non-cellulolytic bacteria W2-10 (Geobacillus sp.).

    Science.gov (United States)

    Lü, Yucai; Li, Ning; Yuan, Xufeng; Hua, Binbin; Wang, Jungang; Ishii, Masaharu; Igarashi, Yasuo; Cui, Zongjun

    2013-12-01

    The effect of a non-cellulolytic bacterium W2-10 (Geobacillus sp.) on the cellulose-degrading activity of a cellulolytic bacterium CTL-6 (Clostridium thermocellum) was determined using cellulose materials (paper and straw) in peptone cellulose solution (PCS) medium under aerobic conditions. The results indicated that in the co-culture, addition of W2-10 resulted in a balanced medium pH, and may provide the required anaerobic environment for CTL-6. Overall, addition of W2-10 was beneficial to CTL-6 growth in the adverse environment of the PCS medium. In co-culture with W2-10, the CTL-6 cellulose degradation efficiency of filter paper and alkaline-treated wheat straw significantly increased up to 72.45 and 37.79 %, respectively. The CMCase activity and biomass of CTL-6 also increased from 0.23 U ml(-1) and 45.1 μg ml(-1) (DNA content) up to 0.47 U ml(-1) and 112.2 μg ml(-1), respectively. In addition, co-culture resulted in accumulation of acetate and propionate up to 4.26 and 2.76 mg ml(-1). This was a respective increase of 2.58 and 4.45 times, in comparison to the monoculture with CTL-6.

  12. A culture-dependent survey of thermophilic bacteria from hot springs in Xiamen area in China

    Institute of Scientific and Technical Information of China (English)

    YANG Bo; OUYANG Jianping; AO Jingqun; CHEN Xinhua

    2009-01-01

    Microbes are believed to play important roles in ecosystem function in many environments. The hot springs of Xiamen Island are close to the Xiamen Sea, and may have some characteristics different from those of inland hot springs. Microbes living in the hot springs of Xiamen may have new characteristics. However, little is known about microbial communities of hot springs close to the Xiamen Sea. A cuhure-dependent survey of microbial population in the Xiamen hot springs was pcrformed by using an approach combining total cellular protein profile identification and 16S rRNA gene sequencing. A total of 328 isolates of bacteria were obtained from liquid and sediment samples from the Xiamen hot springs, including neutrophilie thermophilic bacteria and moderately thermophilic acidophiles. Neutrophilic thermophilic bacteria, which grow at a temperature range of 55-90℃ including Rhodothermus marinus (Strain 1) , Thermus thermophilus (Strain 2), Thermus thiopara (Strain 3) , Geobacillus stearothermophilus(Strain 4) , Geobacillus thermoleovorans (Strain 5) , and Pseudomonas pseudoal-caligenes (Strain 6), were recovered by 2216E plates. Moderately thermophilic acidophiles, which can grow at temperatures above 50℃ and a pH range of 1. 8-3.5 such as Alicyclobacillus acidoterrestris (Strain 8) , Sul-fobacillus acidophilus (Strain 9), and Sulfobacillus thermosulfidooxidans (Strain 10), were isolated on selective solid medium containing sulfur and Fe2+. Among these strains, Rhodothermus marinus, Thermus thermophilus and Geobacillus stearothermophilus are not only thermophilcs, but also halophiles. One bacterium strain (Strain 6) shared 99% nucleotide sequence homology with Pseudomonas pseudoalcaligenes on the 16S rRNA gene se-quence, but was quite different from Pseudomonas pseudoalcaligenes in biological characteristics, suggesting that it may represent a novel thermophilic species. Results indicated that various species of neutrophilic thermophiles and moderately thermophilic

  13. Genetic toolbox for controlled expression of functional proteins in Geobacillus spp

    DEFF Research Database (Denmark)

    Pogrebnyakov, Ivan; Jendresen, Christian Bille; Nielsen, Alex Toftgaard

    2017-01-01

    Species of genus Geobacillus are thermophilic bacteria and play an ever increasing role as hosts for biotechnological applications both in academia and industry. Here we screened a number of Geobacillus strains to determine which industrially relevant carbon sources they can utilize. One...

  14. Large Fragment of DNA Polymerase I from Geobacillus sp. 777: Cloning and Comparison with DNA Polymerases I in Practical Applications.

    Science.gov (United States)

    Oscorbin, Igor P; Boyarskikh, Ulyana A; Filipenko, Maksim L

    2015-10-01

    A truncated gene of DNA polymerase I from the thermophilic bacteria Geobacillus sp. 777 encoding a large fragment of enzyme (LF Gss pol) was cloned and sequenced. The resulting sequence is 1776-bp long and encodes a 592 aa protein with a predicted molecular mass of 69.8 kDa. Enzyme was overexpressed in E. coli, purified by metal-chelate chromatography, and biochemically characterized. The specific activity of LF Gss pol is 104,000 U/mg (one unit of enzyme was defined as the amount of enzyme that incorporated 10 nmol of dNTP into acid insoluble material in 30 min at 65 °C). The properties of LF Gss pol were compared to commercially available large fragments of DNA polymerase I from G. stearothermophilus (LF Bst pol) and Bacillus smithii (LF Bsm pol). Studied enzymes showed maximum activity at similar pH and concentrations of monovalent/divalent ions, whereas LF Gss pol and LF Bst pol were more thermostable than LF Bsm pol. LF Gss pol is more resistant to enzyme inhibitors (SYBR Green I, heparin, ethanol, urea, blood plasma) in comparison with LF Bst pol and LF Bsm pol. LF Gss pol is also suitable for loop-mediated isothermal amplification and whole genome amplification of human genomic DNA.

  15. Modelling of the acid base properties of two thermophilic bacteria at different growth times

    Science.gov (United States)

    Heinrich, Hannah T. M.; Bremer, Phil J.; McQuillan, A. James; Daughney, Christopher J.

    2008-09-01

    Acid-base titrations and electrophoretic mobility measurements were conducted on the thermophilic bacteria Anoxybacillus flavithermus and Geobacillus stearothermophilus at two different growth times corresponding to exponential and stationary/death phase. The data showed significant differences between the two investigated growth times for both bacterial species. In stationary/death phase samples, cells were disrupted and their buffering capacity was lower than that of exponential phase cells. For G. stearothermophilus the electrophoretic mobility profiles changed dramatically. Chemical equilibrium models were developed to simultaneously describe the data from the titrations and the electrophoretic mobility measurements. A simple approach was developed to determine confidence intervals for the overall variance between the model and the experimental data, in order to identify statistically significant changes in model fit and thereby select the simplest model that was able to adequately describe each data set. Exponential phase cells of the investigated thermophiles had a higher total site concentration than the average found for mesophilic bacteria (based on a previously published generalised model for the acid-base behaviour of mesophiles), whereas the opposite was true for cells in stationary/death phase. The results of this study indicate that growth phase is an important parameter that can affect ion binding by bacteria, that growth phase should be considered when developing or employing chemical models for bacteria-bearing systems.

  16. Characteristics of Newly Isolated Geobacillus sp. ZY-10 Degrading Hydrocarbons in Crude Oil.

    Science.gov (United States)

    Sun, Yumei; Ning, Zhanguo; Yang, Fan; Li, Xianzhen

    2015-01-01

    An obligately thermophilic strain ZY-10 was isolated from the crude oil in a high-temperature oilfield, which was capable of degrading heavy crude oil. Phenotypic and phylogenetic analysis demonstrated that the isolate should be grouped in the genus Geobacillus, which shared thd highest similarity (99%) of the 16S rDNA sequence to Geobacillus stearothermophilus. However, the major cellular fatty acid iso-15:0 (28.55%), iso-16:0 (24.93%), iso-17:0 (23.53%) and the characteristics including indole production, tolerance to NaN3 and carbohydrate fermentation showed some difference from the recognized species in the genus Geobacillus. The isolate could use tridecane, hexadecane, octacosane and hexatridecane as sole carbon source for cell growth, and the digesting rate of long-chain alkane was lower than that of short-chain alkane. When the isolate was cultured in the heavy crude oil supplement with inorganic salts and trace yeast extract, the concentration of short-chain alkane was significantly increased and the content of long-chain alkane was decreased, suggesting that the larger hydrocarbon components in crude oil were degraded into shorter-chain alkane. Strain ZY-10 would be useful for improving the mobility of crude oil and upgrading heavy crude oil in situ.

  17. Tracking spore-forming bacteria in food: from natural biodiversity to selection by processes.

    Science.gov (United States)

    Postollec, Florence; Mathot, Anne-Gabrielle; Bernard, Muriel; Divanac'h, Marie-Laure; Pavan, Sonia; Sohier, Danièle

    2012-08-01

    Sporeforming bacteria are ubiquitous in the environment and exhibit a wide range of diversity leading to their natural prevalence in foodstuff. The state of the art of sporeformer prevalence in ingredients and food was investigated using a multiparametric PCR-based tool that enables simultaneous detection and identification of various genera and species mostly encountered in food, i.e., Alicyclobacillus, Anoxybacillus flavithermus, Bacillus, B. cereus group, B. licheniformis, B. pumilus, B. sporothermodurans, B. subtilis, Brevibacillus laterosporus, Clostridium, Geobacillus stearothermophilus, Moorella and Paenibacillus species. In addition, 16S rDNA sequencing was used to extend identification to other possibly present contaminants. A total of 90 food products, with or without visible trace of spoilage were analysed, i.e., 30 egg-based products, 30 milk and dairy products and 30 canned food and ingredients. Results indicated that most samples contained one or several of the targeted genera and species. For all three tested food categories, 30 to 40% of products were contaminated with both Bacillus and Clostridium. The percentage of contaminations associated with Clostridium or Bacillus represented 100% in raw materials, 72% in dehydrated ingredients and 80% in processed foods. In the last two product types, additional thermophilic contaminants were identified (A. flavithermus, Geobacillus spp., Thermoanaerobacterium spp. and Moorella spp.). These results suggest that selection, and therefore the observed (re)-emergence of unexpected sporeforming contaminants in food might be favoured by the use of given food ingredients and food processing technologies.

  18. ISOLATION AND CHARACTERIZATION OF MANNANOLYTIC THERMOPHILIC BACTERIA FROM PALM OIL SHELL AND THEIR MANNANASE ENZYME PRODUCTION PROPERTIES

    Directory of Open Access Journals (Sweden)

    T RESNAWATI P URWADARIA

    2005-01-01

    Full Text Available A mannanolytic thermophilic bacterium (L-07 was isolated from palm oil shell after 2 days of enrichment in liquid medium supplemented with 1% palm kernel meal as mannan source. Sequence analysis of 16S-rRNA indicated that L-07 was similar (98% to Geobacillus stearothermophilus, a species of thermophilic aerobi c bacteria. We found that G. stearothermophilus L-07 produced extracellular β -1,4-mannanases, but no β -manosidase and α -galactosidase activities. The growth of L-07 reached its maximum (3.0 x 106 cell/ml at 12-20 hours, while the highest β -mannanase activity (0.52 U/ml was observed in culture medium after 36 hours of cultivation at 60oC. The medium containing locust bean gum was the best for producing extracellular β -1,4-mannanases compared with kolang kaling , konjak , and palm kernel meal. SDS-PAGE and zymogram analysis demonstrated that crude mannanase complex of L-07 from locust bean gum containing medium comprised three active bands with molecular weight of 85, 73 and 50 kDa.

  19. PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage.

    Science.gov (United States)

    Prevost, S; Andre, S; Remize, F

    2010-12-01

    Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

  20. Effect of Hyperbaric Carbon Dioxide on Spores and Vegetative Cells of Bacillus stearothermophilus

    Science.gov (United States)

    1994-05-01

    retard the growth of spoilage flora in meat , poultry, and fish is well documented (1, 3, 17, 18, 20, 21). The inhibitory effect of C02 increases...high hydrostatic pressure on characteristics of pork slurries and inactivation of microorganisms associated with meat and meat products . Int. J...SUBJECT TERMS BACILLUS STEAROTHERMOPHILUS THERM0PHILIC BACTERIA THERM0PHILIC SPOILAGE 15. NUMBER OF PAGES 39 16 PRICE CODE 17. SECURITY

  1. Antimicrobial Protein Candidates from the Thermophilic Geobacillus sp. Strain ZGt-1: Production, Proteomics, and Bioinformatics Analysis

    Directory of Open Access Journals (Sweden)

    Rawana N. Alkhalili

    2016-08-01

    Full Text Available A thermophilic bacterial strain, Geobacillus sp. ZGt-1, isolated from Zara hot spring in Jordan, was capable of inhibiting the growth of the thermophilic G. stearothermophilus and the mesophilic Bacillus subtilis and Salmonella typhimurium on a solid cultivation medium. Antibacterial activity was not observed when ZGt-1 was cultivated in a liquid medium; however, immobilization of the cells in agar beads that were subjected to sequential batch cultivation in the liquid medium at 60 °C showed increasing antibacterial activity up to 14 cycles. The antibacterial activity was lost on protease treatment of the culture supernatant. Concentration of the protein fraction by ammonium sulphate precipitation followed by denaturing polyacrylamide gel electrophoresis separation and analysis of the gel for antibacterial activity against G. stearothermophilus showed a distinct inhibition zone in 15–20 kDa range, suggesting that the active molecule(s are resistant to denaturation by SDS. Mass spectrometric analysis of the protein bands around the active region resulted in identification of 22 proteins with molecular weight in the range of interest, three of which were new and are here proposed as potential antimicrobial protein candidates by in silico analysis of their amino acid sequences. Mass spectrometric analysis also indicated the presence of partial sequences of antimicrobial enzymes, amidase and dd-carboxypeptidase.

  2. Antimicrobial Protein Candidates from the Thermophilic Geobacillus sp. Strain ZGt-1: Production, Proteomics, and Bioinformatics Analysis

    Science.gov (United States)

    Alkhalili, Rawana N.; Bernfur, Katja; Dishisha, Tarek; Mamo, Gashaw; Schelin, Jenny; Canbäck, Björn; Emanuelsson, Cecilia; Hatti-Kaul, Rajni

    2016-01-01

    A thermophilic bacterial strain, Geobacillus sp. ZGt-1, isolated from Zara hot spring in Jordan, was capable of inhibiting the growth of the thermophilic G. stearothermophilus and the mesophilic Bacillus subtilis and Salmonella typhimurium on a solid cultivation medium. Antibacterial activity was not observed when ZGt-1 was cultivated in a liquid medium; however, immobilization of the cells in agar beads that were subjected to sequential batch cultivation in the liquid medium at 60 °C showed increasing antibacterial activity up to 14 cycles. The antibacterial activity was lost on protease treatment of the culture supernatant. Concentration of the protein fraction by ammonium sulphate precipitation followed by denaturing polyacrylamide gel electrophoresis separation and analysis of the gel for antibacterial activity against G. stearothermophilus showed a distinct inhibition zone in 15–20 kDa range, suggesting that the active molecule(s) are resistant to denaturation by SDS. Mass spectrometric analysis of the protein bands around the active region resulted in identification of 22 proteins with molecular weight in the range of interest, three of which were new and are here proposed as potential antimicrobial protein candidates by in silico analysis of their amino acid sequences. Mass spectrometric analysis also indicated the presence of partial sequences of antimicrobial enzymes, amidase and dd-carboxypeptidase. PMID:27548162

  3. Isolation of the phe-operon from G. stearothermophilus comprising the phenol degradative meta-pathway genes and a novel transcriptional regulator

    Directory of Open Access Journals (Sweden)

    Reiss Monika

    2008-11-01

    Full Text Available Abstract Background Geobacillus stearothermophilus is able to utilize phenol as a sole carbon source. A DNA fragment encoding a phenol hydroxylase catalyzing the first step in the meta-pathway has been isolated previously. Based on these findings a PCR-based DNA walk was performed initially to isolate a catechol 2,3-dioxygenase for biosensoric applications but was continued to elucidate the organisation of the genes encoding the proteins for the metabolization of phenol. Results A 20.2 kb DNA fragment was isolated as a result of the DNA walk. Fifteen open reading frames residing on a low-copy megaplasmid were identified. Eleven genes are co-transcribed in one polycistronic mRNA as shown by reverse transcription-PCR. Ten genes encode proteins, that are directly linked with the meta-cleavage pathway. The deduced amino acid sequences display similarities to a two-component phenol hydroxylase, a catechol 2,3-dioxygenase, a 4-oxalocrotonate tautomerase, a 2-oxopent-4-dienoate hydratase, a 4-oxalocrotonate decarboxylase, a 4-hydroxy-2-oxovalerate aldolase, an acetaldehyde dehydrogenase, a plant-type ferredoxin involved in the reactivation of extradiol dioxygenases and a novel regulatory protein. The only enzymes missing for the complete mineralization of phenol are a 2-hydroxymuconic acid-6-semialdehyde hydrolase and/or 2-hydroxymuconic acid-6-semialdehyde dehydrogenase. Conclusion Research on the bacterial degradation of aromatic compounds on a sub-cellular level has been more intensively studied in gram-negative organisms than in gram-positive bacteria. Especially regulatory mechanisms in gram-positive (thermophilic prokaryotes remain mostly unknown. We isolated the first complete sequence of an operon from a thermophilic bacterium encoding the meta-pathway genes and analyzed the genetic organization. Moreover, the first transcriptional regulator of the phenol metabolism in gram-positive bacteria was identified. This is a first step to elucidate

  4. Extraction of Copper from Malanjkhand Low-Grade Ore by Bacillus stearothermophilus.

    Science.gov (United States)

    Singh, Sradhanjali; Sukla, Lala Behari; Mishra, Baroda Kanta

    2011-10-01

    Thermophilic bacteria are actively prevalent in hot water springs. Their potential to grow and sustain at higher temperatures makes them exceptional compare to other microorganism. The present study was initiated to isolate, identify and determine the feasibility of extraction of copper using thermophilic heterotrophic bacterial strain. Bacillus stearothermophilus is a thermophilic heterotrophic bacterium isolated from hot water spring, Atri, Orissa, India. This bacterium was adapted to low-grade chalcopyrite ore and its efficiency to solubilize copper from Malanjkhand low-grade ore was determined. The low-grade copper ore contains 0.27% Cu, in which the major copper-bearing mineral is chalcopyrite associated with other minerals present as minor phase. Variation in parameters such as pulp-density and temperatures were studied. After 30 days of incubation, it was found that Bacillus stearothermophilus solubilize copper up to 81.25% at pH 6.8 at 60°C.

  5. Isobutanol production at elevated temperatures in thermophilic Geobacillus thermoglucosidasius.

    Science.gov (United States)

    Lin, Paul P; Rabe, Kersten S; Takasumi, Jennifer L; Kadisch, Marvin; Arnold, Frances H; Liao, James C

    2014-07-01

    The potential advantages of biological production of chemicals or fuels from biomass at high temperatures include reduced enzyme loading for cellulose degradation, decreased chance of contamination, and lower product separation cost. In general, high temperature production of compounds that are not native to the thermophilic hosts is limited by enzyme stability and the lack of suitable expression systems. Further complications can arise when the pathway includes a volatile intermediate. Here we report the engineering of Geobacillus thermoglucosidasius to produce isobutanol at 50°C. We prospected various enzymes in the isobutanol synthesis pathway and characterized their thermostabilities. We also constructed an expression system based on the lactate dehydrogenase promoter from Geobacillus thermodenitrificans. With the best enzyme combination and the expression system, 3.3g/l of isobutanol was produced from glucose and 0.6g/l of isobutanol from cellobiose in G. thermoglucosidasius within 48h at 50°C. This is the first demonstration of isobutanol production in recombinant bacteria at an elevated temperature.

  6. Complete genome sequence of Geobacillus thermoglucosidans TNO-09.020, a thermophilic sporeformer associated with a dairy-processing environment

    NARCIS (Netherlands)

    Zhao, Y.; Caspers, M.P.; Abee, T.; Siezen, R.J.; Kort, R.

    2012-01-01

    Thermophilic spore-forming bacteria are a common cause of contamination in dairy products. We isolated the thermophilic strain Geobacillus thermoglucosidans TNO-09.020 from a milk processing plant and report the complete genome of a dairy plant isolate consisting of a single chromosome of 3.75 Mb.

  7. Complete Genome Sequence of Geobacillus thermoglucosidans TNO-09.020, a Thermophilic Sporeformer Associated with a Dairy-Processing Environment.

    NARCIS (Netherlands)

    Zhao, Y.; Caspers, M.P.; Abee, T.; Siezen, R.J.; Kort, R.

    2012-01-01

    Thermophilic spore-forming bacteria are a common cause of contamination in dairy products. We isolated the thermophilic strain Geobacillus thermoglucosidans TNO-09.020 from a milk processing plant and report the complete genome of a dairy plant isolate consisting of a single chromosome of 3.75 Mb.

  8. Complete genome sequence of Geobacillus thermoglucosidans TNO-09.020, a thermophilic sporeformer associated with a dairy-processing environment

    NARCIS (Netherlands)

    Zhao, Y.; Caspers, M.P.; Abee, T.; Siezen, R.J.; Kort, R.

    2012-01-01

    Thermophilic spore-forming bacteria are a common cause of contamination in dairy products. We isolated the thermophilic strain Geobacillus thermoglucosidans TNO-09.020 from a milk processing plant and report the complete genome of a dairy plant isolate consisting of a single chromosome of 3.75 Mb. ©

  9. The Geobacillus paradox: why is a thermophilic bacterial genus so prevalent on a mesophilic planet?

    Science.gov (United States)

    Zeigler, Daniel R

    2014-01-01

    The genus Geobacillus comprises endospore-forming obligate thermophiles. These bacteria have been isolated from cool soils and even cold ocean sediments in anomalously high numbers, given that the ambient temperatures are significantly below their minimum requirement for growth. Geobacilli are active in environments such as hot plant composts, however, and examination of their genome sequences reveals that they are endowed with a battery of sensors, transporters and enzymes dedicated to hydrolysing plant polysaccharides. Although they appear to be relatively minor members of the plant biomass-degrading microbial community, Geobacillus bacteria have achieved a significant population with a worldwide distribution, probably in large part due to adaptive features of their spores. First, their morphology and resistance properties enable them to be mobilized in the atmosphere and transported long distances. Second, their longevity, which in theory may be extreme, enables them to lie quiescent but viable for long periods of time, accumulating gradually over time to achieve surprisingly high population densities.

  10. Proteomic analysis of acetylation in thermophilic Geobacillus kaustophilus.

    Science.gov (United States)

    Lee, Dong-Woo; Kim, Dooil; Lee, Yong-Jik; Kim, Jung-Ae; Choi, Ji Young; Kang, Sunghyun; Pan, Jae-Gu

    2013-08-01

    Recent analysis of prokaryotic N(ε)-lysine-acetylated proteins highlights the posttranslational regulation of a broad spectrum of cellular proteins. However, the exact role of acetylation remains unclear due to a lack of acetylated proteome data in prokaryotes. Here, we present the N(ε)-lysine-acetylated proteome of gram-positive thermophilic Geobacillus kaustophilus. Affinity enrichment using acetyl-lysine-specific antibodies followed by LC-MS/MS analysis revealed 253 acetylated peptides representing 114 proteins. These acetylated proteins include not only common orthologs from mesophilic Bacillus counterparts, but also unique G. kaustophilus proteins, indicating that lysine acetylation is pronounced in thermophilic bacteria. These data complement current knowledge of the bacterial acetylproteome and provide an expanded platform for better understanding of the function of acetylation in cellular metabolism.

  11. Alkane inducible proteins in Geobacillus thermoleovorans B23

    Directory of Open Access Journals (Sweden)

    Kato Tomohisa

    2009-03-01

    Full Text Available Abstract Background Initial step of β-oxidation is catalyzed by acyl-CoA dehydrogenase in prokaryotes and mitochondria, while acyl-CoA oxidase primarily functions in the peroxisomes of eukaryotes. Oxidase reaction accompanies emission of toxic by-product reactive oxygen molecules including superoxide anion, and superoxide dismutase and catalase activities are essential to detoxify them in the peroxisomes. Although there is an argument about whether primitive life was born and evolved under high temperature conditions, thermophilic archaea apparently share living systems with both bacteria and eukaryotes. We hypothesized that alkane degradation pathways in thermophilic microorganisms could be premature and useful to understand their evolution. Results An extremely thermophilic and alkane degrading Geobacillus thermoleovorans B23 was previously isolated from a deep subsurface oil reservoir in Japan. In the present study, we identified novel membrane proteins (P16, P21 and superoxide dismutase (P24 whose production levels were significantly increased upon alkane degradation. Unlike other bacteria acyl-CoA oxidase and catalase activities were also increased in strain B23 by addition of alkane. Conclusion We first suggested that peroxisomal β-oxidation system exists in bacteria. This eukaryotic-type alkane degradation pathway in thermophilic bacterial cells might be a vestige of primitive living cell systems that had evolved into eukaryotes.

  12. Hypervariable pili and flagella genes provide suitable new targets for DNA high-resolution melt-based genotyping of dairy Geobacillus spp.

    Science.gov (United States)

    Chauhan, Kanika; Seale, R Brent; Deeth, Hilton C; Turner, Mark S

    2014-10-01

    Although nonpathogenic in nature, spores of Geobacillus are able to attach to surfaces, germinate, and form biofilms, allowing rapid multiplication and persistence within milk powder processing plants, causing final product contamination, and eventually leading to a loss of revenue in terms of downgraded product quality. As a result, Geobacillus spp. have been found to be common contaminants of milk powder worldwide. Genotyping methods can help in gaining insight into the ecology and transmission of these thermophilic bacteria within and between dairy processing plants. The objective of this study was to use the assembled draft genomes of two Geobacillus spp. to identify and test new hypervariable genotyping targets for differentiating closely related dairy Geobacillus isolates. The two Geobacillus spp. strains obtained from high spore count powders were obtained in 2010 (isolate 7E) and in 1995 (isolate 126) and were previously shown to be of same genotype based on a variable number tandem repeat genotyping method. Significant nucleotide sequence variation was found in genes encoding pili and flagella, which were further investigated as suitable loci for a new high-resolution melt analysis (HRMA)-based genotyping method. Three genes encoding pulG (containing prepilin-type N-terminal cleavage domain), pilT (pili retraction protein), and fliW (flagellar assembly protein) were selected as targets for the new pili/flagella gene (PilFla) HRMA genotyping method. The three-gene-based PilFla-HRMA genotyping method differentiated 35 milk powder Geobacillus spp. isolates into 19 different genotype groups (D = 0.93), which compared favorably to the previous method (which used four variable number tandem repeat loci) that generated 16 different genotype groups (D = 0.90). In conclusion, through comparative genomics of two closely related dairy Geobacillus strains, we have identified new hypervariable regions that prove to be useful targets for highly discriminatory genotyping.

  13. Draft Genome Sequence of Geobacillus subterraneus Strain K, a Hydrocarbon-Oxidizing Thermophilic Bacterium Isolated from a Petroleum Reservoir in Kazakhstan

    Science.gov (United States)

    Poltaraus, Andrey B.; Sokolova, Diyana S.; Grouzdev, Denis S.; Ivanov, Timophey M.; Malakho, Sophia G.; Korshunova, Alena V.; Tourova, Tatiyana P.

    2016-01-01

    The draft genome sequence of Geobacillus subterraneus strain K, a thermophilic aerobic oil-oxidizing bacterium isolated from production water of the Uzen high-temperature oil field in Kazakhstan, is presented here. The genome is annotated for elucidation of the genomic and phenotypic diversity of thermophilic alkane-oxidizing bacteria. PMID:27491973

  14. Rate-limiting steps of stereochemistry retaining ß-D-xylosidase from Geobacillus stearothermophilus acting as substrates

    Science.gov (United States)

    Kinetic experiments of GSXynB2, a ß-xylosidase, acting on 2-nitrophenyl-ß-D-xylopyranoside (2NPX), 4-nitrophenyl-ß-D-xylopyranoside (4NPX), 4-methylumbelliferyl-ß-D-xylopyanoside (MuX) and xylobiose (X2) were conducted at pH 7.0 and 25 °C. Catalysis proceeds in two steps: E + substrate TO E-xylose ...

  15. Thermostable, Raw-Starch-Digesting Amylase from Bacillus stearothermophilus

    OpenAIRE

    Kim, Jaeyoung; Nanmori, Takashi; Shinke, Ryu

    1989-01-01

    An endospore-forming thermophilic bacterium, which produced amylase and was identified as Bacillus stearothermophilus, was isolated from soil. The amylase had an optimum temperature of 70°C and strongly degraded wheat starch granules (93%) and potato starch granules (80%) at 60°C.

  16. Gene cloning and functional analysis of triple alkane monooxygenases from Geobacillus thermoleovorans B23

    OpenAIRE

    2014-01-01

    An extremely thermophilic bacterium, Geobacillus thermoleovorans B23 which was isolated from a deep subterranean oil reservoir at Niigata, Japan, is capable of degrading broad range alkanes (C11-C32) at 70℃ by terminal oxidation pathway, followed by β-oxidation pathway. Whole genome sequence analysis revealed that B23 did not have alkB-type alkane monooxygenases genes like most alkane degrading bacteria but it carried three gene homologs namely ladAαB23, ladAβB23 and ladBB23 on its chromosome...

  17. BIOPHYSICAL CHARACTERIZATION OF A THERMOALKALOPHILIC ESTERASE FROM Geobacillus sp.

    Directory of Open Access Journals (Sweden)

    Liam M. Longo

    2013-12-01

    Full Text Available Esterases are a class of enzyme with broad industrial applications in stereo-specific synthetic approaches to metabolic processing of drugs and antimicrobial agents. As such, preparation of an efficient esterase that is robust to denaturation under a wide range of temperatures and solvent conditions would be of great practical utility. To this end, an esterase cloned from the thermophilic bacteria Geobacillus sp. was subjected to biophysical characterization. In the presence of reducing agents (e.g., dithiothreitol, equilibrium studies of heat- and chemicalinduced denaturation were apparently two-state and reversible. Derived parameters from unfolding studies using fluorescence and circular dichroism were similar, indicating that unfolding is largely cooperative. As predicted, the esterase is highly stable, with Tm app = 75.8 °C and delta Gunf app = –69.8 kJ/mol at 25°C. Refolding studies carried out at 25°C reveal the presence of one or more folding intermediates. Taken together, these results suggest that this esterase is an excellent candidate for use in industrial applications, and indicate that the systematic removal of Cys to recover reversible folding in the absence of reducing agents will be a feasible approach to further improving the utility of this enzyme.

  18. Cloning, overexpression, and characterization of a novel alkali-thermostable xylanase from Geobacillus sp. WBI.

    Science.gov (United States)

    Mitra, Suranjita; Mukhopadhyay, Bidhan Chandra; Mandal, Anisur Rahaman; Arukha, Ananta Prasad; Chakrabarty, Kuheli; Das, Gourab Kanti; Chakrabartty, Pran Krishna; Biswas, Swadesh Ranjan

    2015-04-01

    An endo-β-1,4-xylanase gene xynA of a thermophilic Geobacillus sp. WBI from "hot" compost was isolated by PCR amplification. The gene encoding 407 residues were overexpressed in E. coli and purified by Ni-NTA chromatography. The purified enzyme (47 kDa) had a broad pH optimum of 6.0 to 9.0, and was active between 50 and 90 °C. The enzyme retained 100% of its activity when incubated at 65 °C for 1 h under alkaline condition (pH 10.0) and retained 75% activity at pH 11.0. The K(m) and V(max) of the enzyme were 0.9 mg ml(-1) and 0.8 µmol ml(-1) min(-1), respectively. In molecular dynamics simulation at 338 K (65 °C), the enzyme was found to be stable. At an elevated temperature (450 K) specific α-helix and β-turns of the proteins were most denatured. The denaturation was less in WBI compared with its highest homolog G. stearothermophilus T-6 xylanase with difference of six residues. The results predict that these regions are responsible for the improved thermostability observed over related enzymes. The present work encourages further experimental demonstration to understand how these regions contribute thermostability to WBI xylanase. The study noted that WBI produces a xylanase with unique characteristics, specifically alkali-thermostability.

  19. Cloning and sequence analysis of the heat-stable acrylamidase from a newly isolated thermophilic bacterium, Geobacillus thermoglucosidasius AUT-01.

    Science.gov (United States)

    Cha, Minseok; Chambliss, Glenn H

    2013-02-01

    A thermophilic bacterium capable of degrading acrylamide, AUT-01, was isolated from soil collected from a hot spring area in Montana, USA. The thermophilic strain grew with 0.2 % glucose as the sole carbon source and 1.4 mM acrylamide as the sole nitrogen source. The isolate AUT-01 was identified as Geobacillus thermoglucosidasius based on 16S rDNA sequence. An enzyme from the strain capable of transforming acrylamide to acrylic acid was purified by a series of chromatographic columns. The molecular weight of the enzyme was estimated to be 38 kDa by SDS-PAGE. The enzyme activity had pH and temperature optima of 6.2 and 70 ºC, respectively. The influence of different metals and amino acids on the ability of the purified protein to transform acrylamide to acrylic acid was evaluated. The gene from G. thermoglucosidasius encoding the acrylamidase was cloned, sequenced, and compared to aliphatic amidases from other bacterial strains. The G. thermoglucosidasius gene, amiE, encoded a 38 kDa, monomeric, heat-stable amidase that catalysed the cleavage of carbon-nitrogen bonds in acrylamide. Comparison of the amino acid sequence to other bacterial amidases revealed 99 and 82 % similarity to the amino acid sequences of Bacillus stearothermophilus and Pseudomonas aeruginosa, respectively.

  20. 21 CFR 184.1012 - α-Amylase enzyme preparation from Bacillus stearothermophilus.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true α-Amylase enzyme preparation from Bacillus... preparation from Bacillus stearothermophilus. (a) α-Amylase enzyme preparation is obtained from the culture... Bacillus stearothermophilus. Its characterizing enzyme activity is α-amylase (1,4 α-D...

  1. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this

  2. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this alpha-amylas

  3. Characterization of a new Bacillus stearothermophilus isolate : a highly thermostable α-amylase-producing strain

    NARCIS (Netherlands)

    Wind, R.D.; Buitelaar, R.M.; Eggink, G.; Huizing, H.J.; Dijkhuizen, L.

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known α-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable α-amylase. The half-time of inactivation of this α-amylase was 5.1 h

  4. Preliminary Characterization of the Probiotic Properties of Candida Famata and Geobacillus Thermoleovorans

    Directory of Open Access Journals (Sweden)

    A Bakhrouf

    2011-12-01

    Full Text Available Background and Objective: Probiotics are live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance, producing metabolites which inhibit the colonization or growth of other microorganisms or by competing with them for resources such as nutrients or space. The aim of this study was to investigate the probiotic properties of Candida famata and Geobacillus thermoleovorans.Material and Methods: In this study, yeast and bacterial strains isolated from pure oil waste were identified using Api 50 CHB and Api Candida Systems and their probiotic properties were studied through antimicrobial activity, biofilm production, adherence assay and enzymatic characterization.Results and Conclusion: According to biochemical analyses, these strains corresponded to Geobacillus thermoleovorans and Candida famata. Antagonism assay results showed that the tested strains have an inhibitory effect against tested pathogenic bacteria. The yeast Candida famata was unable to produce biofilm on Congo Red Agar (CRA, while the bacterial strain was a slime producer. Adherence assays to abiotic surfaces revealed that the investigated strains were fairly adhesive to polystyrene with values ranging from 0.18 to 0.34 at 595 nm. The enzymatic characterization revealed that the tested strains expressed enzymes such as phosphatase alkaline, esterase lipase (C8, amylase, lipase, lecitenase and caseinase. The obtained results may allow the isolated strains to be considered as having the potential to be candidate probiotics.

  5. Characterization of aerobic spore-forming bacteria associated with industrial dairy processing environments and product spoilage.

    Science.gov (United States)

    Lücking, Genia; Stoeckel, Marina; Atamer, Zeynep; Hinrichs, Jörg; Ehling-Schulz, Monika

    2013-09-02

    Due to changes in the design of industrial food processing and increasing international trade, highly thermoresistant spore-forming bacteria are an emerging problem in food production. Minimally processed foods and products with extended shelf life, such as milk products, are at special risk for contamination and subsequent product damages, but information about origin and food quality related properties of highly heat-resistant spore-formers is still limited. Therefore, the aim of this study was to determine the biodiversity, heat resistance, and food quality and safety affecting characteristics of aerobic spore-formers in the dairy sector. Thus, a comprehensive panel of strains (n=467), which originated from dairy processing environments, raw materials and processed foods, was compiled. The set included isolates associated with recent food spoilage cases and product damages as well as isolates not linked to product spoilage. Identification of the isolates by means of Fourier-transform infrared spectroscopy and molecular methods revealed a large biodiversity of spore-formers, especially among the spoilage associated isolates. These could be assigned to 43 species, representing 11 genera, with Bacillus cereus s.l. and Bacillus licheniformis being predominant. A screening for isolates forming thermoresistant spores (TRS, surviving 100°C, 20 min) showed that about one third of the tested spore-formers was heat-resistant, with Bacillus subtilis and Geobacillus stearothermophilus being the prevalent species. Strains producing highly thermoresistant spores (HTRS, surviving 125°C, 30 min) were found among mesophilic as well as among thermophilic species. B. subtilis and Bacillus amyloliquefaciens were dominating the group of mesophilic HTRS, while Bacillus smithii and Geobacillus pallidus were dominating the group of thermophilic HTRS. Analysis of spoilage-related enzymes of the TRS isolates showed that mesophilic strains, belonging to the B. subtilis and B. cereus

  6. Transglycosylation of neohesperidin dihydrochalcone by Bacillus stearothermophilus maltogenic amylase.

    Science.gov (United States)

    Cho, J S; Yoo, S S; Cheong, T K; Kim, M J; Kim, Y; Park, K H

    2000-02-01

    Neohesperidin dihydrochalcone (NHDC), a sweet compound derived from citrus fruits, was modified to a series of its oligosaccharides by transglycosylation activity of Bacillus stearothermophilus maltogenic amylase (BSMA). Maltotriose as a donor was reacted with NHDC as an acceptor to glycosylate for the purpose of increasing the solubility of NHDC. Maltosyl-NHDC was a major transglycosylation product among the several transfer products by TLC analysis. The structure of the major transglycosylation product was determined to be maltosyl-alpha-(1,6)-neohesperidin dihydrochalcone by MALDI-TOF/MS and (1)H and (13)C NMR. Maltosyl-NHDC was 700 times more soluble in water and 7 times less sweet than NHDC.

  7. An improved agar medium for growth of Geobacillus thermoglucosidarius strains.

    Science.gov (United States)

    Javed, M; Baghaei-Yazdi, N; Qin, W; Amartey, S

    2017-01-01

    Geobacillus species have potential applications in many biotechnological processes. They are fastidious in their vitamin and amino acid requirements. A new semi-defined agar medium (SDM) was developed which gave consistently high viable cell counts of various G. thermoglucosidasius strains (5×10(8)-6×10(8)cfu/ml) under aerobic conditions at 70°C.

  8. Phylogenomic re-assessment of the thermophilic genus Geobacillus.

    Science.gov (United States)

    Aliyu, Habibu; Lebre, Pedro; Blom, Jochen; Cowan, Don; De Maayer, Pieter

    2016-12-01

    Geobacillus is a genus of Gram-positive, aerobic, spore-forming obligate thermophiles. The descriptions and subsequent affiliations of the species in the genus have mostly been based on polyphasic taxonomy rules that include traditional sequence-based methods such as DNA-DNA hybridization and comparison of 16S rRNA gene sequences. Currently, there are fifteen validly described species within the genus. The availability of whole genome sequences has provided an opportunity to validate and/or re-assess these conventional estimates of genome relatedness. We have applied whole genome approaches to estimate the phylogenetic relatedness among the sixty-three Geobacillus strains for which genome sequences are currently publicly available, including the type strains of eleven validly described species. The phylogenomic metrics AAI (Average Amino acid Identity), ANI (Average Nucleotide Identity) and dDDH (digital DNA-DNA hybridization) indicated that the current genus Geobacillus is comprised of sixteen distinct genomospecies, including several potentially novel species. Furthermore, a phylogeny constructed on the basis of the core genes identified from the whole genome analyses indicated that the genus clusters into two monophyletic clades that clearly differ in terms of nucleotide base composition. The G+C content ranges for clade I and II were 48.8-53.1% and 42.1-44.4%, respectively. We therefore suggest that the Geobacillus species currently residing within clade II be considered as a new genus. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Genome sequencing and annotation of Geobacillus sp. 1017, a hydrocarbon-oxidizing thermophilic bacterium isolated from a heavy oil reservoir (China

    Directory of Open Access Journals (Sweden)

    Vitaly V. Kadnikov

    2017-03-01

    Full Text Available The draft genome sequence of Geobacillus sp. strain 1017, a thermophilic aerobic oil-oxidizing bacterium isolated from formation water of the Dagang high-temperature oilfield, China, is presented here. The genome comprised 3.6 Mbp, with the G + C content of 51.74%. The strain had a number of genes responsible for numerous metabolic and transport systems, exopolysaccharide biosynthesis, and decomposition of sugars and aromatic compounds, as well as the genes related to resistance to metals and metalloids. The genome sequence is available at DDBJ/EMBL/GenBank under the accession no MQMG00000000. This genome is annotated for elucidation of the genomic and phenotypic diversity of new thermophilic alkane-oxidizing bacteria of the genus Geobacillus.

  10. Effect of Essential Oils on Germination and Growth of Some Pathogenic and Spoilage Spore-Forming Bacteria.

    Science.gov (United States)

    Voundi, Stève Olugu; Nyegue, Maximilienne; Lazar, Iuliana; Raducanu, Dumitra; Ndoye, Florentine Foe; Marius, Stamate; Etoa, François-Xavier

    2015-06-01

    The use of essential oils as a food preservative has increased due to their capacity to inhibit vegetative growth of some bacteria. However, only limited data are available on their effect on bacterial spores. The aim of the present study was to evaluate the effect of some essential oils on the growth and germination of three Bacillus species and Geobacillus stearothermophilus. Essential oils were chemically analyzed using gas chromatography and gas chromatography coupled to mass spectrometry. The minimal inhibitory and bactericidal concentrations of vegetative growth and spore germination were assessed using the macrodilution method. Germination inhibitory effect of treated spores with essential oils was evaluated on solid medium, while kinetic growth was followed using spectrophotometry in the presence of essential oils. Essential oil from Drypetes gossweileri mainly composed of benzyl isothiocyanate (86.7%) was the most potent, with minimal inhibitory concentrations ranging from 0.0048 to 0.0097 mg/mL on vegetative cells and 0.001 to 0.002 mg/mL on spore germination. Furthermore, essential oil from D. gossweileri reduced 50% of spore germination after treatment at 1.25 mg/mL, and its combination with other oils improved both bacteriostatic and bactericidal activities with additive or synergistic effects. Concerning the other essential oils, the minimal inhibitory concentration ranged from 5 to 0.63 mg/mL on vegetative growth and from 0.75 to 0.09 mg/mL on the germination of spores. Spectrophotometric evaluation showed an inhibitory effect of essential oils on both germination and outgrowth. From these results, it is concluded that some of the essential oils tested might be a valuable tool for bacteriological control in food industries. Therefore, further research regarding their use as food preservatives should be carried out.

  11. Complete genome sequence of Geobacillus thermoglucosidasius C56-YS93, a novel biomass degrader isolated from obsidian hot spring in Yellowstone National Park.

    Science.gov (United States)

    Brumm, Phillip J; Land, Miriam L; Mead, David A

    2015-01-01

    Geobacillus thermoglucosidasius C56-YS93 was one of several thermophilic organisms isolated from Obsidian Hot Spring, Yellowstone National Park, Montana, USA under permit from the National Park Service. Comparison of 16 S rRNA sequences confirmed the classification of the strain as a G. thermoglucosidasius species. The genome was sequenced, assembled, and annotated by the DOE Joint Genome Institute and deposited at the NCBI in December 2011 (CP002835). The genome of G. thermoglucosidasius C56-YS93 consists of one circular chromosome of 3,893,306 bp and two circular plasmids of 80,849 and 19,638 bp and an average G + C content of 43.93 %. G. thermoglucosidasius C56-YS93 possesses a xylan degradation cluster not found in the other G. thermoglucosidasius sequenced strains. This cluster appears to be related to the xylan degradation cluster found in G. stearothermophilus. G. thermoglucosidasius C56-YS93 possesses two plasmids not found in the other two strains. One plasmid contains a novel gene cluster coding for proteins involved in proline degradation and metabolism, the other contains a collection of mostly hypothetical proteins.

  12. PRODUCTION AND CHARACTERIZATION OF AN ALKALOTHERMOSTABLE, ORGANIC SOLVENT TOLERANT AND SURFACTANT TOLERANT ESTERASE PRODUCED BY A THERMOPHILIC BACTERIUM GEOBACILLUS SP. AGP-04, ISOLATED FROM BAKRESHWAR HOT SPRING, INDIA

    Directory of Open Access Journals (Sweden)

    Amit Ghati

    2013-10-01

    Full Text Available A thermophilic bacteria, Geobacillus sp. AGP-04, isolated from Surya Kund hot spring, Bakreshwar, West Bengal, India was studied in terms of capability of tributyrin hydrolysis and characterization of its thermostable esterase activity using p-nitrophenyl butyrate (PNPB as substrate. The extracellular crude preparation was characterized in terms of pH and temperature optima and stability, organic solvent tolerance capacity and stability, substrate specificity, surfactant tolerance capacity, kinetic parameters and activation/inhibition behavior towards some metal ions and chemicals. Tributyrin agar assay exhibited that Geobacillus sp. AGP-04 secretes an extracellular esterase. The Vmax and Km values of the esterase were found to be 5099 U/Land 103.5µM, respectively in the presence of PNPB as substrate. The optimum temperature and pH, for Geobacillus sp. AGP-04 esterase was 60oC and 8.0, respectively. Although the enzyme activity was not significantly altered by incubating crude extract solution at 20-70oC for 1 hour, the enzyme activity was fully lost at 90oC for same incubation period. The pH stability profile showed that original crude esterase activity is stable at a broad range (pH 5.0-10.0. Moreover, the enzyme was highly organic solvent and surfactant tolerant. The effect of some chemical on crude esterase activity indicated that Geobacillus sp. AGP-04 produce an esterase which contains a serine residue in active site and for its activity -SH groups are essential. Besides, enzyme production was highly induced if fermentation medium contain polysaccharides and oil as carbon source.

  13. The Geobacillus Pan-Genome: Implications for the Evolution of the Genus.

    Science.gov (United States)

    Bezuidt, Oliver K; Pierneef, Rian; Gomri, Amin M; Adesioye, Fiyin; Makhalanyane, Thulani P; Kharroub, Karima; Cowan, Don A

    2016-01-01

    The genus Geobacillus is comprised of a diverse group of spore-forming Gram-positive thermophilic bacterial species and is well known for both its ecological diversity and as a source of novel thermostable enzymes. Although the mechanisms underlying the thermophilicity of the organism and the thermostability of its macromolecules are reasonably well understood, relatively little is known of the evolutionary mechanisms, which underlie the structural and functional properties of members of this genus. In this study, we have compared 29 Geobacillus genomes, with a specific focus on the elements, which comprise the conserved core and flexible genomes. Based on comparisons of conserved core and flexible genomes, we present evidence of habitat delineation with specific Geobacillus genomes linked to specific niches. Our analysis revealed that Geobacillus and Anoxybacillus share a high proportion of genes. Moreover, the results strongly suggest that horizontal gene transfer is a major factor deriving the evolution of Geobacillus from Bacillus, with genetic contributions from other phylogenetically distant taxa.

  14. Bacillus stearothermophilus contains a plasmid-borne gene for alpha-amylase.

    Science.gov (United States)

    Mielenz, J R

    1983-01-01

    The gene for thermostable alpha-amylase from the thermophilic bacterium Bacillus stearothermophilus has been cloned and expressed in Escherichia coli. Each alpha-amylase-producing colony contained at least a 9.7-kilobase-pair (kb) chimeric plasmid composed of the vector pBR322 and a common 5.4-kb HindIII fragment of DNA. B. stearothermophilus contains four plasmids with sizes from 12 kb to over 108 kb. Restriction endonuclease analysis of these naturally occurring plasmids showed they also contain a 5.4-kb HindIII fragment of DNA. Cloning experiments with the four plasmids yielded alpha-amylase-producing E. coli that contained the same 9.7-kb chimeric plasmid. Restriction endonuclease analysis and further recombinant DNA experiments identified a 26-kb plasmid that contains the gene for alpha-amylase. A spontaneous mutant of B. stearothermophilus unable to produce alpha-amylase was missing the 26-kb plasmid but contained a 20-kb plasmid. A 6-kb deletion within the region of the 5.4-kb HindIII fragment yielded the 20-kb plasmid unable to code for alpha-amylase. A nick-translated probe for the alpha-amylase coding region did not hybridize to either plasmid or total cellular DNA from this mutant strain of B. stearothermophilus. These results demonstrate the gene for alpha-amylase is located exclusively on a 26-kb plasmid in B. stearothermophilus with no genetic counterpart present on the chromosome. Images PMID:6193526

  15. Enzymatic production of fructose 1,6-diphosphate using crude cell extract of Bacillus stearothermophilus.

    Science.gov (United States)

    Widjaja, A; Yasuda, M; Ogino, H; Nakajima, H; Ishikawa, H

    1999-01-01

    The enzymatic production of fructose 1,6-diphosphate (FDP) from glucose was performed in a batch reactor and a semibatch reactor using the crude cell extract of Bacillus stearothermophilus which contains all four enzymes required for the synthesis. The experimental results of the yield and the time courses of FDP production obtained using various enzyme concentrations were in good agreement with the theoretical predictions calculated based on the differential equations including the rate equations of the four enzymes, which were determined using the purified enzymes of B. stearothermophilus.

  16. A model for the interaction of the G3-subdomain of Geobacillus stearothermophilus IF2 with the 30S ribosomal subunit

    NARCIS (Netherlands)

    Dongre, Ramachandra; Folkers, Gert E; Gualerzi, Claudio O; Boelens, Rolf; Wienk, Hans

    2016-01-01

    Bacterial translation initiation factor IF2 complexed with GTP binds to the 30S ribosomal subunit, promotes ribosomal binding of fMet-tRNA, and favors the joining of the small and large ribosomal subunits yielding a 70S initiation complex ready to enter the translation elongation phase. Within the I

  17. Cloning and expression of three ladA-type alkane monooxygenase genes from an extremely thermophilic alkane-degrading bacterium Geobacillus thermoleovorans B23

    OpenAIRE

    2014-01-01

    An extremely thermophilic bacterium, Geobacillus thermoleovorans B23, is capable of degrading a broad range of alkanes (with carbon chain lengths ranging between C11 and C32) at 70 A degrees C. Whole-genome sequence analysis revealed that unlike most alkane-degrading bacteria, strain B23 does not possess an alkB-type alkane monooxygenase gene. Instead, it possesses a cluster of three ladA-type genes, ladA alpha(B23), ladA beta(B23), and ladB (B23), on its chromosome, whose protein products sh...

  18. Purification and reconstitution of the glutamate carrier GltT of the thermophilic bacterium Bacillus stearothermophilus

    NARCIS (Netherlands)

    Gaillard, Isabelle; Slotboom, Dirk-Jan; Knol, Jan; Lolkema, Juke S.; Konings, Wil N.

    1996-01-01

    An affinity tag consisting of six adjacent histidine residues followed by an enterokinase cleavage site was genetically engineered at the N-terminus of the glutamate transport protein GltT of the thermophilic bacterium Bacillus stearothermophilus. The fusion protein was expressed in Escherichia coli

  19. The caa(3) terminal oxidase of Bacillus stearothermophilus - Transient spectroscopy of electron transfer and ligand binding

    NARCIS (Netherlands)

    Giuffre, A; DItri, E; Giannini, S; Brunori, M; UbbinkKok, T; Konings, WN; Antonini, G

    1996-01-01

    The thermophilic bacterium Bacillus stearothermophilus possesses a caa(3)-type terminal oxidase, which was previously purified (De Vrij, W., Heyne, R. I. HL, and Konings, W. N. (1989) Ear. J. Biochem. 178, 763-770). We have carried out extensive kinetic experiments on the purified enzyme by stopped-

  20. Draft Genome Sequences of Four Thermophilic Spore Formers Isolated from a Dairy-Processing Environment

    Science.gov (United States)

    Caspers, Martien P. M.; Boekhorst, Jos; de Jong, Anne; Kort, Remco; Nierop Groot, Masja

    2016-01-01

    Spores of thermophilic spore-forming bacteria are a common cause of contamination in dairy products. Here, we report draft genome sequences of four thermophilic strains from a milk-processing plant or standard milk, namely, a Geobacillus thermoglucosidans isolate (TNO-09.023), Geobacillus stearothermophilus TNO-09.027, and two Anoxybacillus flavithermus isolates (TNO-09.014 and TNO-09.016). PMID:27516503

  1. Identification and characterization of a novel Geobacillus thermoglucosidasius bacteriophage, GVE3.

    Science.gov (United States)

    van Zyl, Leonardo Joaquim; Sunda, Falone; Taylor, Mark Paul; Cowan, Don Arthur; Trindade, Marla Iris

    2015-09-01

    The study of extremophilic phages may reveal new phage families as well as different mechanisms of infection, propagation and lysis to those found in phages from temperate environments. We describe a novel siphovirus, GVE3, which infects the thermophile Geobacillus thermoglucosidasius. The genome size is 141,298 bp (G+C 29.6%), making it the largest Geobacillus spp-infecting phage known. GVE3 appears to be most closely related to the recently described Bacillus anthracis phage vB_BanS_Tsamsa, rather than Geobacillus-infecting phages described thus far. Tetranucleotide usage deviation analysis supports this relationship, showing that the GVE3 genome sequence correlates best with B. anthracis and Bacillus cereus genome sequences, rather than Geobacillus spp genome sequences.

  2. The Geobacillus pan-genome: implications for the evolution of the genus

    Directory of Open Access Journals (Sweden)

    Oliver Keoagile Ignatius Bezuidt

    2016-05-01

    Full Text Available The genus Geobacillus is comprised of a diverse group of spore-forming Gram-positive thermophilic bacterial species and is well known for both its ecological diversity and as a source of novel thermostable enzymes. Although the mechanisms underlying the thermophilicity of the organism and the thermostability of its macromolecules are reasonably well understood, relatively little is known of the evolutionary mechanisms, which underlie the structural and functional properties of members of this genus. In this study, we have compared 29 Geobacillus genomes, with a specific focus on the elements, which comprise the conserved core and flexible genomes. Based on comparisons of conserved core and flexible genomes, we present evidence of habitat delineation with specific Geobacillus genomes linked to specific niches. Interestingly, our analysis has shown that horizontal gene transfer is a major factor deriving the evolution of Geobacillus from Bacillus, with genetic contributions from other phylogenetically distant taxa.

  3. Characterization of a thermophilic bacteriophage of Geobacillus kaustophilus.

    Science.gov (United States)

    Marks, Timothy J; Hamilton, Paul T

    2014-10-01

    GBK2 is a bacteriophage, isolated from a backyard compost pile, that infects the thermophile Geobacillus kaustophilus. GBK2 has a circularly permuted genome of 39,078 bp with a G+C content of 43 %. Annotation of the genome reveals 62 putative open reading frames (ORFs), 25 of which (40.3 %) show homology to known proteins and 37 of which (59.7 %) are proteins with unknown functions. Twelve of the identified ORFs had the greatest homology to genes from the phage SPP1, a phage that infects the mesophile Bacillus subtilis. The overall genomic arrangement of GBK2 is similar to that of SPP1, with the majority of GBK2 SPP1-like genes coding for proteins involved in DNA replication and metabolism.

  4. [Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

    Science.gov (United States)

    Liu, Qing-kun; Wang, Jun; Li, Guo-qiang; Ma, Ting; Liang, Feng-lai; Liu, Ru-lin

    2008-12-01

    A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that Geobacillus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.0, high temperature in the range of 45-70 degrees C and saline concentration ranging from 0.2% to 3.0%. Furthermore, the optimal temperature and pH value for utilizing hydrocarbons by the strain were 60 degrees C and 7.0, respectively. Under such optimal conditions, the strain utilized liquid paraffine emulsified by itself as its carbon source for growth; further analysis by gas chromatography (GC) and infrared absorption spectroscopy demonstrated that it was able to degrade n-alkanes (C14-C30), branched-chain alkanes and aromatic hydrocarbons in crude oil and could also utilize long-chain n-alkanes from C16 to C36, among of which the degradation efficiency of C28 was the highest, up to 88.95%. One metabolite of the strain oxidizing alkanes is fatty acid.While utilizing C16 as carbon source for 5 d, only one fatty acid-acetic acid was detected by HPLC and MS as the product, with the amount of 0.312 g/L, which indicated that it degraded n-alkanes with pathway of inferior terminal oxidation,and then followed by a beta-oxidation pathway. Due to its characters of efficient emulsification, high-performance degradation of hydrocarbons and fatty-acid production under high temperature and anoxic condition, the strain DM-2 may be potentially applied to oil-waste treatment and microbial enhanced heavy oil recovery in extreme conditions.

  5. A commensal symbiotic interrelationship for the growth of Symbiobacterium toebii with its partner bacterium, Geobacillus toebii

    Directory of Open Access Journals (Sweden)

    Masui Ryoji

    2011-10-01

    Full Text Available Abstract Background Symbiobacterium toebii is a commensal symbiotic thermophile that absolutely requires its partner bacterium Geobacillus toebii for growth. Despite development of an independent cultivation method using cell-free extracts, the growth of Symbiobacterium remains unknown due to our poor understanding of the symbiotic relationship with its partner bacterium. Here, we investigated the interrelationship between these two bacteria for growth of S. toebii using different cell-free extracts of G. toebii. Results Symbiobacterium toebii growth-supporting factors were constitutively produced through almost all growth phases and under different oxygen tensions in G. toebii, indicating that the factor may be essential components for growth of G. toebii as well as S. toebii. The growing conditions of G. toebii under different oxygen tension dramatically affected to the initial growth of S. toebii and the retarded lag phase was completely shortened by reducing agent, L-cysteine indicating an evidence of commensal interaction of microaerobic and anaerobic bacterium S. toebii with a facultative aerobic bacterium G. toebii. In addition, the growth curve of S. toebii showed a dependency on the protein concentration of cell-free extracts of G. toebii, demonstrating that the G. toebii-derived factors have nutrient-like characters but not quorum-sensing characters. Conclusions Not only the consistent existence of the factor in G. toebii during all growth stages and under different oxygen tensions but also the concentration dependency of the factor for proliferation and optimal growth of S. toebii, suggests that an important biosynthetic machinery lacks in S. toebii during evolution. The commensal symbiotic bacterium, S. toebii uptakes certain ubiquitous and essential compound for its growth from environment or neighboring bacteria that shares the equivalent compounds. Moreover, G. toebii grown under aerobic condition shortened the lag phase of S

  6. Geobacillus zalihae sp. nov., a thermophilic lipolytic bacterium isolated from palm oil mill effluent in Malaysia

    Directory of Open Access Journals (Sweden)

    Salleh Abu

    2007-08-01

    Full Text Available Abstract Background Thermophilic Bacillus strains of phylogenetic Bacillus rRNA group 5 were described as a new genus Geobacillus. Their geographical distribution included oilfields, hay compost, hydrothermal vent or soils. The members from the genus Geobacillus have a growth temperatures ranging from 35 to 78°C and contained iso-branched saturated fatty acids (iso-15:0, iso-16:0 and iso-17:0 as the major fatty acids. The members of Geobacillus have similarity in their 16S rRNA gene sequences (96.5–99.2%. Thermophiles harboring intrinsically stable enzymes are suitable for industrial applications. The quest for intrinsically thermostable lipases from thermophiles is a prominent task due to the laborious processes via genetic modification. Results Twenty-nine putative lipase producers were screened and isolated from palm oil mill effluent in Malaysia. Of these, isolate T1T was chosen for further study as relatively higher lipase activity was detected quantitatively. The crude T1 lipase showed high optimum temperature of 70°C and was also stable up to 60°C without significant loss of crude enzyme activity. Strain T1T was a Gram-positive, rod-shaped, endospore forming bacterium. On the basic of 16S rDNA analysis, strain T1T was shown to belong to the Bacillus rRNA group 5 related to Geobacillus thermoleovorans (DSM 5366T and Geobacillus kaustophilus (DSM 7263T. Chemotaxonomic data of cellular fatty acids supported the affiliation of strain T1T to the genus Geobacillus. The results of physiological and biochemical tests, DNA/DNA hybridization, RiboPrint analysis, the length of lipase gene and protein pattern allowed genotypic and phenotypic differentiation of strain T1T from its validly published closest phylogenetic neighbors. Strain T1T therefore represents a novel species, for which the name Geobacillus zalihae sp. nov. is proposed, with the type strain T1T (=DSM 18318T; NBRC 101842T. Conclusion Strain T1T was able to secrete extracellular

  7. High Production of Thermostable β-Galactosidase of Bacillus stearothermophilus in Bacillus subtilis

    OpenAIRE

    1985-01-01

    By cloning the β-galactosidase gene of Bacillus stearothermophilus IAM11001 (ATCC 8005) into Bacillus subtilis, enzyme production was enhanced 50 times. β-Galactosidase could be purified to 80% homogeneity by incubating the cell extract of B. subtilis at 70°C for 15 min, followed by centrifugation to remove the denatured proteins. Because of its heat stability and ease of production, β-galactosidase is suitable for application in industrial processes.

  8. SODIUM ION-DEPENDENT AMINO-ACID-TRANSPORT IN MEMBRANE-VESICLES OF BACILLUS-STEAROTHERMOPHILUS

    NARCIS (Netherlands)

    HEYNE, RIR; DEVRIJ, W; CRIELAARD, W; KONINGS, WN

    1991-01-01

    Amino acid transport in membrane vesicles of Bacillus stearothermophilus was studied. A relatively high concentration of sodium ions is needed for uptake of L-alanine (K(t) = 1.0 mM) and L-leucine (K(t) = 0.4 mM). In contrast, the Na+-H+-L-glutamate transport system has a high affinity for sodium io

  9. Complete genome sequences of Geobacillus sp. WCH70, a thermophilic strain isolated from wood compost.

    Science.gov (United States)

    Brumm, Phillip J; Land, Miriam L; Mead, David A

    2016-01-01

    Geobacillus sp. WCH70 was one of several thermophilic organisms isolated from hot composts in the Middleton, WI area. Comparison of 16 S rRNA sequences showed the strain may be a new species, and is most closely related to G. galactosidasius and G. toebii. The genome was sequenced, assembled, and annotated by the DOE Joint Genome Institute and deposited at the NCBI in December 2009 (CP001638). The genome of Geobacillus species WCH70 consists of one circular chromosome of 3,893,306 bp with an average G + C content of 43 %, and two circular plasmids of 33,899 and 10,287 bp with an average G + C content of 40 %. Among sequenced organisms, Geobacillus sp. WCH70 shares highest Average Nucleotide Identity (86 %) with G. thermoglucosidasius strains, as well as similar genome organization. Geobacillus sp. WCH70 appears to be a highly adaptable organism, with an exceptionally high 125 annotated transposons in the genome. The organism also possesses four predicted restriction-modification systems not found in other Geobacillus species.

  10. Effects of iron-reducing bacteria on carbon steel corrosion induced by thermophilic sulfate-reducing consortia.

    Science.gov (United States)

    Valencia-Cantero, Eduardo; Peña-Cabriales, Juan José

    2014-02-28

    Four thermophilic bacterial species, including the iron-reducing bacterium Geobacillus sp. G2 and the sulfate-reducing bacterium Desulfotomaculum sp. SRB-M, were employed to integrate a bacterial consortium. A second consortium was integrated with the same bacteria, except for Geobacillus sp. G2. Carbon steel coupons were subjected to batch cultures of both consortia. The corrosion induced by the complete consortium was 10 times higher than that induced by the second consortium, and the ferrous ion concentration was consistently higher in iron-reducing consortia. Scanning electronic microscopy analysis of the carbon steel surface showed mineral films colonized by bacteria. The complete consortium caused profuse fracturing of the mineral film, whereas the non-iron-reducing consortium did not generate fractures. These data show that the iron-reducing activity of Geobacillus sp. G2 promotes fracturing of mineral films, thereby increasing steel corrosion.

  11. Cloning and expression of three ladA-type alkane monooxygenase genes from an extremely thermophilic alkane-degrading bacterium Geobacillus thermoleovorans B23.

    Science.gov (United States)

    Boonmak, Chanita; Takahashi, Yasunori; Morikawa, Masaaki

    2014-05-01

    An extremely thermophilic bacterium, Geobacillus thermoleovorans B23, is capable of degrading a broad range of alkanes (with carbon chain lengths ranging between C11 and C32) at 70 °C. Whole-genome sequence analysis revealed that unlike most alkane-degrading bacteria, strain B23 does not possess an alkB-type alkane monooxygenase gene. Instead, it possesses a cluster of three ladA-type genes, ladAαB23, ladAβB23, and ladB B23, on its chromosome, whose protein products share significant amino acid sequence identities, 49.8, 34.4, and 22.7 %, respectively, with that of ladA alkane monooxygenase gene found on a plasmid of Geobacillus thermodetrificans NG 80-2. Each of the three genes, ladAαB23, ladAβB23, and ladB B23, was heterologously expressed individually in an alkB1 deletion mutant strain, Pseudomonas fluorescens KOB2Δ1. It was found that all three genes were functional in P. fluorescens KOB2Δ1, and partially restored alkane degradation activity. In this study, we suggest that G. thermoleovorans B23 utilizes multiple LadA-type alkane monooxygenases for the degradation of a broad range of alkanes.

  12. Influence of N- and/or C-terminal regions on activity, expression, characteristics and structure of lipase from Geobacillus sp. 95.

    Science.gov (United States)

    Gudiukaitė, Renata; Gegeckas, Audrius; Kazlauskas, Darius; Citavicius, Donaldas

    2014-01-01

    GD-95 lipase from Geobacillus sp. strain 95 and its modified variants lacking N-terminal signal peptide and/or 10 or 20 C-terminal amino acids were successfully cloned, expressed and purified. To our knowledge, GD-95 lipase precursor (Pre-GD-95) is the first Geobacillus lipase possessing more than 80% lipolytic activity at 5 °C. It has maximum activity at 55 °C and displays a broad pH activity range. GD-95 lipase was shown to hydrolyze p-NP dodecanoate, tricaprylin and canola oil better than other analyzed substrates. Structural and sequence alignments of bacterial lipases and GD-95 lipase revealed that the C-terminus forms an α helix, which is a conserved structure in lipases from Pseudomonas, Clostridium or Staphylococcus bacteria. This work demonstrates that 10 and 20 C-terminal amino acids of GD-95 lipase significantly affect stability and other physicochemical properties of this enzyme, which has never been reported before and can help create lipases with more specific properties for industrial application. GD-95 lipase and its modified variants GD-95-10 can be successfully applied to biofuel production, in leather and pulp industries, for the production of cosmetics or perfumes. These lipases are potential biocatalysts in processes, which require extreme conditions: low or high temperature, strongly acidic or alkaline environment and various organic solvents.

  13. Isolation and characterization of a potential paraffin-wax degrading thermophilic bacterial strain Geobacillus kaustophilus TERI NSM for application in oil wells with paraffin deposition problems.

    Science.gov (United States)

    Sood, Nitu; Lal, Banwari

    2008-02-01

    Paraffin deposition problems, that have plagued the oil industry, are currently remediated by mechanical and chemical means. However, since these methods are problematic, a microbiological approach has been considered. The bacteria, required for the mitigation of paraffin deposition problems, should be able to survive the high temperatures of oil wells and degrade the paraffins under low oxygen and nutrient conditions while sparing the low carbon chain paraffins. In this study, a thermophilic paraffinic wax degrading bacterial strain was isolated from a soil sample contaminated with paraffinic crude oil. The selected strain, Geobacillus TERI NSM, could degrade 600mg of paraffinic wax as the sole carbon source in 1000ml minimal salts medium in 7d at 55 degrees C. This strain was identified as Geobacillus kaustophilus by fatty acid methyl esters analysis and 16S rRNA full gene sequencing. G. kaustophilus TERI NSM showed 97% degradation of eicosane, 85% degradation of pentacosane and 77% degradation of triacontane in 10d when used as the carbon source. The strain TERI NSM could also degrade the paraffins of crude oil collected from oil wells that had a history of paraffin deposition problems.

  14. A thiostrepton resistance gene and its mutants serve as selectable markers in Geobacillus kaustophilus HTA426.

    Science.gov (United States)

    Wada, Keisuke; Kobayashi, Jyumpei; Furukawa, Megumi; Doi, Katsumi; Ohshiro, Takashi; Suzuki, Hirokazu

    2016-01-01

    Effective utilization of microbes often requires complex genetic modification using multiple antibiotic resistance markers. Because a few markers have been used in Geobacillus spp., the present study was designed to identify a new marker for these thermophiles. We explored antibiotic resistance genes functional in Geobacillus kaustophilus HTA426 and identified a thiostrepton resistance gene (tsr) effective at 50 °C. The tsr gene was further used to generate the mutant tsr(H258Y) functional at 55 °C. Higher functional temperature of the mutant was attributable to the increase in thermostability of the gene product because recombinant protein produced from tsr(H258Y) was more thermostable than that from tsr. In fact, the tsr(H258Y) gene served as a selectable marker for plasmid transformation of G. kaustophilus. This new marker could facilitate complex genetic modification of G. kaustophilus and potentially other Geobacillus spp.

  15. Construction of Geobacillus thermoglucosidasius cDNA library and analysis of genes expressed in response to heat stress.

    Science.gov (United States)

    Tripathy, S; Maiti, N K

    2014-03-01

    Thermophiles exhibit various kinds of molecular mechanisms to survive in extreme environment, but their behavioral responses to long duration stress is poorly understood until date. In the present study, we have prospected for the genes differentially expressed in response to long duration heat stress in thermophilic bacteria. A cDNA library was constructed from Geobacillus thermoglucosidasius grown with a temperature upshift of 10 °C from optimum growth temperature of 45 °C for 16 h. A total of 451 clones from the library were sequenced with accurate base calling that generated 257 high quality sequences with an average read length of 350 bp. We queried our collection of single pass sequences against the NCBI non-redundant database using the BLASTX algorithm and obtained sequences that showed significant similarity (>60%) with heat shock proteins, metabolic proteins and hypothetical proteins. The expressed sequence tags (ESTs) expressed in response to heat stress were annotated that further commuted a strong interaction network among one another. The ESTs based on the best hits were validated by RT-PCR. Di- and tri-nucleotide repeat motifs were also found to be associated with 17 genes involved in heat shock response, metabolism, transport and transcriptional regulation. The present results provide the novel identification of the putative genes responsible for imparting tolerance to bacteria under heat stress and unveil their role for survival of life in environmental extremes.

  16. 1H, 13C, and 15N backbone and side chain resonance assignments of thermophilic Geobacillus kaustophilus cyclophilin-A.

    Science.gov (United States)

    Holliday, Michael J; Zhang, Fengli; Isern, Nancy G; Armstrong, Geoffrey S; Eisenmesser, Elan Z

    2014-04-01

    Cyclophilins catalyze the reversible peptidyl-prolyl isomerization of their substrates and are present across all kingdoms of life from humans to bacteria. Although numerous biological roles have now been discovered for cyclophilins, their function was initially ascribed to their chaperone-like activity in protein folding where they catalyze the often rate-limiting step of proline isomerization. This chaperone-like activity may be especially important under extreme conditions where cyclophilins are often over expressed, such as in tumors for human cyclophilins (Lee Archiv Pharm Res 33(2): 181-187, 2010), but also in organisms that thrive under extreme conditions, such as theromophilic bacteria. Moreover, the reversible nature of the peptidyl-prolyl isomerization reaction catalyzed by cyclophilins has allowed these enzymes to serve as model systems for probing the role of conformational changes during catalytic turnover (Eisenmesser et al. Science 295(5559): 1520-1523, 2002; Eisenmesser et al. Nature 438(7064): 117-121, 2005). Thus, we present here the resonance assignments of a thermophilic cyclophilin from Geobacillus kaustophilus derived from deep-sea sediment (Takami et al. Extremophiles 8(5): 351-356, 2004). This thermophilic cyclophilin may now be studied at a variety of temperatures to provide insight into the comparative structure, dynamics, and catalytic mechanism of cyclophilins.

  17. 1H, 13C, and 15N backbone and side chain resonance assignments of thermophilic Geobacillus kaustophilus cyclophilin-A

    Energy Technology Data Exchange (ETDEWEB)

    Holliday, Michael; Zhang, Fengli; Isern, Nancy G.; Armstrong, Geoffrey S.; Eisenmesser, Elan Z.

    2014-04-01

    Cyclophilins catalyze the reversible peptidyl-prolyl isomerization of their substrates and are present across all kingdoms of life from humans to bacteria. Although numerous biological roles have now been discovered for cyclophilins, their function was initially ascribed to their chaperone-like activity in protein folding where they catalyze the often rate-limiting step of proline isomerization. This chaperone-like activity may be especially important under extreme conditions where cyclophilins are often over expressed, such as in tumors for human cyclophilins {Lee, 2010 #1167}, but also in organisms that thrive under extreme conditions, such as theromophilic bacteria. Moreover, the reversible nature of the peptidyl-prolyl isomerization reaction catalyzed by cyclophilins has allowed these enzymes to serve as model systems for probing the role of conformational changes during catalytic turnover {Eisenmesser, 2002 #20;Eisenmesser, 2005 #203}. Thus, we present here the resonance assignments of a thermophilic cyclophilin from Geobacillus kaustophilus derived from deep-sea sediment {Takami, 2004 #1384}. This thermophilic cyclophilin may now be studied at a variety of temperatures to provide insight into the comparative structure, dynamics, and catalytic mechanism of cyclophilins.

  18. Genome shuffling enhances lipase production of thermophilic Geobacillus sp.

    Science.gov (United States)

    Chalopagorn, Pornchanok; Charoenpanich, Jittima; Choowongkomon, Kiattawee

    2014-10-01

    Thermostable lipases are potential enzymes for biocatalytic application. In this study, the lipase production of Geobacillus sp. CF03 (WT) was improved by genome shuffling. After two rounds of genome shuffling, one fusant strain (FB1) achieved increase lipase activity from the populations generated by ultraviolet irradiation and ethyl methylsulfonate (EMS) mutagenesis. The growth rate and lipase production of FB1 increased highest by 150 and 238 %, respectively, in comparison to the wild type. The fusant enzyme had a significant change in substrate specificity but still prefers the long-chain length substrates. It had an optimum activity at 60 °C, pH at 7.0-8.0, with p-nitrophenyl palmitate (C16) as a substrate and retained about 50 % of their activity after 15 min at 70 °C, pH 8.0. Furthermore, the fusant lipase showed the preference of sesame oil, waste palm oil, and canola oil. Therefore, the genome shuffling strategy has been successful to strain improvement and selecting strain with multiple desirable characteristics.

  19. Geobacillus icigianus sp. nov., a thermophilic bacterium isolated from a hot spring.

    Science.gov (United States)

    Bryanskaya, Alla V; Rozanov, Alexey S; Slynko, Nikolay M; Shekhovtsov, Sergey V; Peltek, Sergey E

    2015-03-01

    A Gram-reaction-positive, motile, thermophilic spore-forming strain, G1w1(T), was isolated from a hot spring of the Valley of Geysers, Kamchatka (Russia). Based on data from the present polyphasic taxonomic study, including phylogenetic analysis of 16S rRNA and spo0A gene sequences, the strain is considered to represent a novel species of the genus Geobacillus, for which the name Geobacillus icigianus sp. nov. is proposed. The type strain is G1w1(T) ( = VKM B-2853(T) = DSM 28325(T)).

  20. Study on the Optimization of Bio-emulsifier Production by Geobacillus sp.XS2 Based on Response Surface Methodology

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the optimization of bio-emulsifier production by Geobacillus sp.XS2 based on response surface methodology.[Method] Firstly,single factor experiment was conducted to find out the main medium components influencing bio-emulsifier production by Geobacillus sp.XS2,and then response surface model was established by using response surface methodology and Design-Expert 7.0,so as to optimize the fermentation medium for bio-emulsifier production by Geobacillus sp.XS2.[Result] Glucose...

  1. PURIFICATION AND CHARACTERIZATION OF A HIGHLY THERMOSTABLE ALPHA-L-ARABINOFURANOSIDASE FROM GEOBACILLUS CALDOXYLOLYTICUS TK4

    Science.gov (United States)

    The gene encoding an alpha-L-arabinofuranosidase from Geobacillus caldoxylolyticus TK4, AbfATK4, was isolated, cloned, and sequenced. The deduced protein had a molecular mass of about 58 kDa, and analysis of its amino acid sequence revealed significant homology and conservation of different catalyt...

  2. Genome sequence of Geobacillus thermoglucosidasius DSM2542, a platform hosts for biotechnological applications with industrial potential.

    Science.gov (United States)

    Chen, Jingyu; Zhang, Zhengzhi; Zhang, Caili; Yu, Bo

    2015-12-20

    Thermophilic Geobacillus thermoglucosidasius could ferment a wide range of substrates with low nutrient requirements for growth. Here, the first released the complete genome sequence of G. thermoglucosidasius DSM2542 may facilitate the design of rational strategies for further strain improvements and provide information for exploring industrially interesting enzymes with thermotolerant properties.

  3. Draft Genome Sequence of a Thermophilic Desulfurization Bacterium, Geobacillus thermoglucosidasius Strain W-2

    Science.gov (United States)

    Zhu, Lin; Li, Mingchang; Guo, Shuyi

    2016-01-01

    Geobacillus thermoglucosidasius strain W-2 is a thermophilic bacterium isolated from a deep-subsurface oil reservoir in northern China, which is capable of degrading organosulfur compounds. Here, we report the draft genome sequence of G. thermoglucosidasius strain W-2, which may help to elucidate the genetic basis of biodegradation of organosulfur pollutants under heated conditions. PMID:27491977

  4. Complete Genome Sequence of Geobacillus thermoglucosidasius NCIMB 11955, the Progenitor of a Bioethanol Production Strain

    Science.gov (United States)

    Sheng, Lili; Zhang, Ying

    2016-01-01

    The industrially important thermophile Geobacillus thermoglucosidasius has the potential to produce chemicals and fuels from biomass-derived sugar feedstocks. Here, we present the genome sequence of strain NCIMB 11955, the progenitor of an ethanologenic industrial strain, revealing 11 single-nucleotide polymorphisms and 2 indels compared to strain DSM 2542 and two novel plasmids. PMID:27688322

  5. Genomic analysis of six new Geobacillus strains reveals highly conserved carbohydrate degradation architectures and strategies

    Directory of Open Access Journals (Sweden)

    Phillip eBrumm

    2015-05-01

    Full Text Available In this work we report the whole genome sequences of six new Geobacillus xylanolytic strains along with the genomic analysis of their capability to degrade carbohydrates.. The six sequenced Geobacillus strains described here have a range of GC contents from 43.9% to 52.5% and clade with named Geobacillus species throughout the entire genus. We have identified a ~200 kb unique super-cluster in all six strains, containing five to eight distinct carbohydrate degradation clusters in a single genomic region, a feature not seen in other genera. The Geobacillus strains rely on a small number of secreted enzymes located within distinct clusters for carbohydrate utilization, in contrast to most biomass-degrading organisms which contain numerous secreted enzymes located randomly throughout the genomes. All six strains are able to utilize fructose, arabinose, xylose, mannitol, gluconate, xylan, and α-1,6-glucosides. The gene clusters for utilization of these seven substrates have identical organization and the individual proteins have a high percent identity to their homologs. The strains show significant differences in their ability to utilize inositol, sucrose, lactose, α-mannosides, α-1,4-glucosides and arabinan.

  6. Detection and characterization of chlorinated-dioxin ether cleavage function in the bacterium geobacillus midousuji SH2B-J2

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Y.; Hoshina, S. [Jikei Univ. School of Medicine, Tokyo (Japan). Dept. of Laboratory Medicine; Nakamura, M.; Hishiyama, S. [Forestry and Forest Products Research Institute, Ibaraki (Japan); Katayama, Y. [Tokyo Univ. of Agriculture and Technology, Koganei (Japan)

    2004-09-15

    As of now, there are no dioxin degrading microorganism reported that can be applied to bioremediation. The reasons for this are that degrading function acquired from comprehensive screening of bacteria that can be grown with a single carbon source using non-chlorinated dioxin does not function against highly chlorinated dioxins, and that although white rot fungus capable of degrading lignin, a plant polyphenol substance, have been reported to reduce chlorinated dioxins, degrading enzyme remain unclear. Geobacillus midousuji SH2B-J2 (J2 strain) that have been separated by Hoshina et al. have shown to reduce highly chlorinated dioxins in incineration fly ash, as well as octa-chlorinated dioxins (OCDD). However, details of its degrading mechanisms remain unclear. Since the J2 strain is capable of reducing even OCDD, it was hypothesized that the initial degradation reaction is intramolecular ether bond cleavage, so J2 strain dioxin degradation mechanism was analyzed for verification.

  7. A new process for obtaining hydroxytyrosol using transformed Escherichia coli whole cells with phenol hydroxylase gene from Geobacillus thermoglucosidasius.

    Science.gov (United States)

    Orenes-Piñero, Esteban; García-Carmona, Francisco; Sánchez-Ferrer, Alvaro

    2013-08-15

    Phenol hydroxylase gene cloning from the thermophilic bacteria Geobacillus thermoglucosidasius was used to develop an effective method to convert tyrosol into the high-added-value compound hydroxytyrosol by hydroxylation. Phenol hydroxylase is a two-component enzyme encoded by pheA1 and pheA2 genes and strictly dependent on NADH and FAD. These two genes were subcloned together as a 2 kb fragment into Escherichia coli Rosetta cells, and the transformants were able to grow and effectively transform up to 5 mM of phenol and tyrosol using IPTG (isopropyl-β-D-thiogalactopyranoside) as inducer. In addition, when a new fragment with a 340 pb upstream pheA1 gene was subcloned, a similar biotransformation rate was attained without IPTG, confirming that this fragment encodes for a phenol hydroxylase promoter that can be recognised by E. coli. Both transformants brought about the total bioconversion of monophenols at a high concentration (5 mM), which represents an increase, both in concentration and in yield, compared with that previously described in the bibliography. The use of the transformant with its constitutive promoter was more interesting from a biotechnological point of view, since it is not necessary to use IPTG. It also gave rise to greater operational stability.

  8. Overexpression and characterization of dimeric and tetrameric forms of recombinant serine hydroxymethyltransferase from Bacillus stearothermophilus

    Indian Academy of Sciences (India)

    Venkatakrishna R Jala; V Prakash; N Appaji Rao; H S Savithri

    2002-06-01

    Serine hydroxymethyltransferase (SHMT), a pyridoxal-5′-phosphate (PLP) dependent enzyme catalyzes the interconversion of L-Ser and Gly using tetrahydrofolate as a substrate. The gene encoding for SHMT was amplified by PCR from genomic DNA of Bacillus stearothermophilus and the PCR product was cloned and overexpressed in Escherichia coli. The purified recombinant enzyme was isolated as a mixture of dimer (90%) and tetramer (10%). This is the first report demonstrating the existence of SHMT as a dimer and tetramer in the same organism. The specific activities at 37°C of the dimeric and tetrameric forms were 6.7 U/mg and 4.1 U/mg, respectively. The purified dimer was extremely thermostable with a m of 85°C in the presence of PLP and L-Ser. The temperature optimum of the dimer was 80°C with a specific activity of 32.4 U/mg at this temperature. The enzyme catalyzed tetrahydrofolate-independent reactions at a slower rate compared to the tetrahydrofolate-dependent retro-aldol cleavage of L-Ser. The interaction with substrates and their analogues indicated that the orientation of PLP ring of B. stearothermophilus SHMT was probably different from sheep liver cytosolic recombinant SHMT (scSHMT).

  9. KINETIC EVALUATION OF ETHANOL-TOLERANT THERMOPHILE Geobacillus thermoglucosidasius M10EXG FOR ETHANOL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Eny Ida Riyanti

    2016-10-01

    Full Text Available Thermophiles are challenging to be studied for ethanol production using agricultural waste containing lignocellulosic materials rich in hexose and pentose. These bacteria have many advantages such as utilizing a wide range of substrates, including pentose (C5 and hexose (C6. In ethanol production, it is important to use ethanol tolerant strain capable in converting lignocellulosic hydrolysate. This study was aimed to investigate the growth profile of ethanol-tolerant thermophile Geobacillus thermoglucosidasius M10EXG using a defined growth medium consisted of single carbon glucose (TGTV, xylose (TXTV, and a mixture of glucose and xylose (TGXTV, together with the effect of yeast extract additionto the media. The experiments were conducted at the School of Biotechnology and Biomolecular Sciences of The University of New South Wales, Australia on a shake flask fermentation at 60°C in duplicate experiment. Cultures were sampled every two hours and analised for their kinetic parameters including the maximum specific growth rate (µmax, biomass yield (Yx/s, ethanol and by-product yields (acetate and L-lactate (Yp/s, and the doubling time (Td. Results showed that this strain was capable of growing on minimal medium containing glucose or xylose as a single carbon source. This strain utilized glucose and xylose simultaneously (co-fermentation, although there was glucose repression of xylose at relatively low glucose concentration (0.5% w/v, particularly when yeast extract (0.2% w/v was added to the medium. The highest biomass yield was obtained at 0.5 g l-1 on glucose medium; the yield increased when yeast extract was added (at 0.59 g l-1. The highest specific growth rate of 0.25 was obtained in the phase I growth when the strain was grown on a mixture of glucose and xylose (0.5% : 0.5% w/v medium. Diauxic growth was shown on the mixture of glucose, xylose, and yeast extract. The strain produced low level of ethanol (0.1

  10. The quorum-quenching lactonase from Geobacillus caldoxylosilyticus : purification, characterization, crystallization and crystallographic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bergonzi, Celine; Schwab, Michael; Elias, Mikael

    2016-08-09

    Lactonases are enzymes that are capable of hydrolyzing various lactones such as aliphatic lactones or acyl-homoserine lactones (AHLs), with the latter being used as chemical signaling molecules by numerous Gram-negative bacteria. Lactonases therefore have the ability to quench the chemical communication, also known as quorum sensing, of numerous bacteria, and in particular to inhibit behaviors that are regulated by this system, such as the expression of virulence factors or the production of biofilms. A novel representative from the metallo-β-lactamase superfamily, dubbed GcL, was isolated from the thermophilic bacteriumGeobacillus caldoxylosilyticus. Because of its thermophilic origin, GcL may constitute an interesting candidate for the development of biocontrol agents. Here, we show that GcL is a thermostable enzyme with a half-life at 75°C of 152.5 ± 10 min. Remarkably, it is also shown that GcL is among the most active lactonases characterized to date, with catalytic efficiencies (kcat/Km) against AHLs of greater than 106 M$-$1 s$-$1. The structure of GcL is expected to shed light on the catalytic mechanism of the enzyme and the molecular determinants for the substrate specificity in this class of lactonases. Here, the expression, purification, characterization, crystallization and X-ray diffraction data collection to 1.6 Å resolution of GcL are reported.

  11. Expression, purification, and characterization of a thermophilic neutral protease from Bacillus stearothermophilus in Bacillus subtilis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.8-fold, with a specific activity of 16530 U mg-1. As analyzed by SDS-PAGE, the molecular mass of the expressed protease was about 35 kDa, and the optimal temperature and pH of the protease were 65℃ and 7.5, respectively. Moreover, it still had about 80% activity after 1 h reaction at 65 ℃ .

  12. Expression, purification, and characterization of a thermophilic neutral protease from Bacillus stearothermophilus in Bacillus subtilis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.8-fold, with a specific activity of 16530 U mg-1. As analyzed by SDS-PAGE, the molecular mass of the expressed protease was about 35 kDa, and the optimal temperature and pH of the protease were 65℃ and 7.5, respectively. Moreover, it still had about 80% activity after 1 h reaction at 65℃.

  13. Graphical procedure for comparing thermal death of Bacillus stearothermophilus spores in saturated and superheated steam.

    Science.gov (United States)

    SHULL, J J; ERNST, R R

    1962-09-01

    The thermal death curve of dried spores of Bacillus stearothermophilus in saturated steam was characterized by three phases: (i) a sharp initial rise in viable count; (ii) a low rate of death which gradually increased; and (iii) logarithmic death at maximal rate. The first phase was a reflection of inadequate heat activation of the spore population. The second and third phases represented the characteristic thermal death curve of the spores in saturated steam. A jacketed steam sterilizer, equipped with a system for initial evacuation of the chamber, was examined for superheat during normal operation. Measurements of spore inactivation and temperature revealed superheat in surface layers of fabrics being processed in steam at 121 C. The high temperature of the fabric surfaces was attributed to absorption of excess heat energy from superheated steam. The superheated steam was produced at the beginning of the normal sterilizing cycle by transfer of heat from the steam-heated jacket to saturated steam entering the vessel.

  14. Kinetic model of Bacillus stearothermophilus. cap alpha. -amylase under process conditions

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, W.E.; Teague, W.M.

    1988-11-01

    A model is presented describing starch hydrolysis by Bacillus stearothermophilus ..cap alpha..-amylase at temperatures of 90 to 115/sup 0/C and substrate concentrations of 24 to 36% solids. First order kinetics adequately describe both the enzyme decay and starch hydrolysis reactions. Quantitation of temperature, pH, added calcium and substrate concentration interactive effects on the first order rate constants is aided by applying standard statistical techniques of experimental design and data analysis. A method for determining residual ..cap alpha..-amylase activity in liquefact based on the Phadebas dye release assay, and an osmometry method for determining degree of liquefact hydrolysis are described. Computer implementation of the model allows rapid graphical visualization as well as screening of ideas for improved starch hydrolysis processes.

  15. Optimized culture condition for enhancing lytic performance of waste activated sludge by Geobacillus sp. G1.

    Science.gov (United States)

    Yang, Chunxue; Zhou, Aijuan; Hou, Yanan; Zhang, Xu; Guo, Zechong; Wang, Aijie; Liu, Wenzong

    2014-01-01

    Hydrolysis is known as the rate-limiting step during waste activated sludge (WAS) digestion. The optimization of the culture conditions of Geobacillus sp. G1 for enhancing WAS hydrolysis was conducted in this study with uniform design and response surface methodology. Taking the lysis rate of Escherichia coli as the response, the Plackett-Burman design was used to screen the most important variables. Experimental results showed that the maximum predicted lysis rate of E. coli was 50.9% for 4 h treatment time with concentrations of skim milk, NaCl and NH4SO4 at 10.78, 4.36 and 11.28 g/L, respectively. The optimized dosage ratio of Geobacillus sp. G1 to WAS was 35%:65% (VG1:VWAS). Under this condition, soluble protein was increased to 695 mg chemical oxygen demand (COD)/L, which was 5.0 times higher than that obtained in the control (140 mg COD/L). The corresponding protease activity reached 1.1 Eu/mL. Scanning electron microscopy showed that abundant cells were apparently lysed with treatment of Geobacillus sp. G1.

  16. Biotransformation of eugenol via protocatechuic acid by thermophilic Geobacillus sp. AY 946034 strain.

    Science.gov (United States)

    Giedraityte, Gražina; Kalėdienė, Lilija

    2014-04-01

    The metabolic pathway of eugenol degradation by thermophilic Geobacillus sp. AY 946034 strain was analyzed based on the lack of data about eugenol degradation by thermophiles. TLC, GC-MS, and biotransformation with resting cells showed that eugenol was oxidized through coniferyl alcohol, and ferulic and vanillic acids to protocatechuic acid before the aromatic ring was cleaved. The cell-free extract of Geobacillus sp. AY 946034 strain grown on eugenol showed a high activity of eugenol hydroxylase, feruloyl-CoA synthetase, vanillate-O-demethylase, and protocatechuate 3,4-dioxygenase. The key enzyme, protocatechuate 3,4- dioxygenase, which plays a crucial role in the degradation of various aromatic compounds, was purified 135-fold to homogeneity with a 34% overall recovery from Geobacillus sp. AY 946034. The relative molecular mass of the native enzyme was about 450 ± 10 kDa and was composed of the non-identical subunits. The pH and temperature optima for enzyme activity were 8 and 60°C, respectively. The half-life of protocatechuate 3,4-dioxygenase at the optimum temperature was 50 min.

  17. Cloning and sequence analysis of novel DNA polymerases from thermophilic Geobacillus species isolated from hot springs in Turkey: characterization of a DNA polymerase I from Geobacillus kaue strain NB.

    Science.gov (United States)

    Çağlayan, Melike; Bilgin, Neş'e

    2011-11-01

    The complete coding sequences of the polA genes from seven thermophilic Geobacillus species, isolated from hot springs of Gönen and Hisaralan in Turkey, were cloned and sequenced. The polA genes of these Geobacillus species contain a long open reading frame of 2,637 bp encoding DNA polymerase I with a calculated molecular mass of 99 kDa. Amino acid sequences of these Geobacillus DNA polymerases are closely related. The multiple sequence alignments show all include the conserved amino acids in the polymerase and 5'-3' exonuclease domains, but the catalytic residues varied in 3'-5' exonuclease domain of these Geobacillus DNA polymerases. One of them, DNA polymerase I from Geobacillus kaue strain NB (Gkaue polI) is purified to homogeneity and biochemically characterized in vitro. The optimum temperature for enzymatic activity of Gkaue polI is 70 °C at pH 7.5-8.5 in the presence of 8 mM Mg(2+) and 80-100 mM of monovalent ions. The addition of polyamines stimulates the polymerization activity of the enzyme. Three-dimensional structure of Gkaue polI predicted using homology modeling confirmed the conservation of all the functionally important regions in the polymerase active site.

  18. A comparative study of fatty acid profile and formation of biofilm in Geobacillus gargensis exposed to variable abiotic stress.

    Science.gov (United States)

    Al-Beloshei, Noor Essa; Al-Awadhi, Husain; Al-Khalaf, Rania A; Afzal, Mohammad

    2015-01-01

    Understanding bacterial fatty acid (FA) profile has a great taxonomic significance as well as clinical importance for diagnosis issues. Both the composition and nature of membrane FAs change under different nutritional, biotic and (or) abiotic stresses, and environmental stress. Bacteria produce both odd-carbon as well as branched-chain fatty acids (BCFAs). This study was designed to examine the effect of abiotic pressure, including salinity, temperature, pH, and oxinic stress on the growth, development, and FA profile in thermophilic Geobacillus gargensis. Under these stresses, 3 parametric ratios, 2-methyl fatty acids/3-methyl fatty acids (iso-/anteiso-FAs), BCFAs/straight-chain saturated fatty acids (SCSFA), and SCSFAs/straight-chain unsaturated fatty acids (SCUFA), in addition to total lipids affected by variable stresses were measured. Our results indicate that the ratio of total iso-/anteiso-FAs increased at the acidic pH range of 4.1-5.2 and decreased with increasing pH. The reverse was true for salt stress when iso-/anteiso-FAs ratio increased with salt concentration. The BCFAs/SCSFAs and SCSFAs/SCUFAs ratios increased at neutral and alkaline pH and high salt concentration, reduced incubation time, and comparatively high temperature (55-65 °C) of the growth medium. The bacterial total lipid percentage deceased with increasing salt concentration, incubation period, but it increased with temperature. The formation of extracellular polymeric substances was observed under all stress conditions and with the addition of sodium dodecyl sulfate (2 and 5 mmol/L) to the growth medium. The membrane phospholipid composition of the bacterium was analyzed by thin-layer chromatography.

  19. Characterisation of a new thermoalkaliphilic bacterium for the production of high-quality hemp fibres, Geobacillus thermoglucosidasius strain PB94A.

    Science.gov (United States)

    Valladares Juárez, A G; Dreyer, J; Göpel, P K; Koschke, N; Frank, D; Märkl, H; Müller, R

    2009-06-01

    Novel thermophilic and alkaliphilic bacteria for the processing of bast fibres were isolated using hemp pectin as substrate. The strain PB94A, which showed the highest growth rate (micro = 0.5/h) was identified as Geobacillus thermoglucosidasius (DSM 21625). The strain grew optimally at 60 degrees C and pH 8.5. During growth on citrus pectin, the strain produced pectinolytic lyases, which were excreted into the medium. In contrast to the commercially available pectinase Bioprep 3000 L, the enzymes from G. thermoglucosidasius PB94A converted pectin isolated from hemp fibres. In addition to hemp pectin, the culture supernatant also degraded citrus, sugar beet and apple pectin and polygalacturonic acid. When hemp fibres were incubated with the cell-free fermentation broth of G. thermoglucosidasius PB94A, the fineness of the fibres increased. The strain did not produce any cellulases, which is important in order to avoid damaging the fibres during incubation. Therefore, these bacteria or their enzymes can be used to produce fine high-quality hemp fibres.

  20. Changes in Sodium, Calcium, and Magnesium Ion Concentrations That Inhibit Geobacillus Biofilms Have No Effect on Anoxybacillus flavithermus Biofilms.

    Science.gov (United States)

    Somerton, B; Lindsay, D; Palmer, J; Brooks, J; Flint, S

    2015-08-01

    This study investigated the effects of varied sodium, calcium, and magnesium concentrations in specialty milk formulations on biofilm formation by Geobacillus spp. and Anoxybacillus flavithermus. The numbers of attached viable cells (log CFU per square centimeter) after 6 to 18 h of biofilm formation by three dairy-derived strains of Geobacillus and three dairy-derived strains of A. flavithermus were compared in two commercial milk formulations. Milk formulation B had relatively high sodium and low calcium and magnesium concentrations compared with those of milk formulation A, but the two formulations had comparable fat, protein, and lactose concentrations. Biofilm formation by the three Geobacillus isolates was up to 4 log CFU cm(-2) lower in milk formulation B than in milk formulation A after 6 to 18 h, and the difference was often significant (P ≤ 0.05). However, no significant differences (P ≤ 0.05) were found when biofilm formations by the three A. flavithermus isolates were compared in milk formulations A and B. Supplementation of milk formulation A with 100 mM NaCl significantly decreased (P ≤ 0.05) Geobacillus biofilm formation after 6 to 10 h. Furthermore, supplementation of milk formulation B with 2 mM CaCl2 or 2 mM MgCl2 significantly increased (P ≤ 0.05) Geobacillus biofilm formation after 10 to 18 h. It was concluded that relatively high free Na(+) and low free Ca(2+) and Mg(2+) concentrations in milk formulations are collectively required to inhibit biofilm formation by Geobacillus spp., whereas biofilm formation by A. flavithermus is not impacted by typical cation concentration differences of milk formulations.

  1. Absorption, steady-state fluorescence, fluorescence lifetime, and 2D self-assembly properties of engineered fluorescent S-layer fusion proteins of Geobacillus stearothermophilus NRS 2004/3a.

    Science.gov (United States)

    Kainz, Birgit; Steiner, Kerstin; Möller, Marco; Pum, Dietmar; Schäffer, Christina; Sleytr, Uwe B; Toca-Herrera, José L

    2010-01-11

    S-layer fusion protein technology was used to design four different fluorescent fusion proteins with three different GFP mutants and the red fluorescent protein mRFP1. Their absorption spectra, steady-state fluorescence, and fluorescence lifetime were investigated as a function of pH. It was found that fluorescence intensities and lifetime of the GFP mutant S-layer fusion proteins decreased about 50% between pH 6 and pH 5. The spectral properties of the red S-layer fusion protein were minimally affected by pH variations. These results were compared with His-tagged reference fluorescent proteins, demonstrating that the S-layer protein did not change the general spectral properties of the whole fusion protein. In addition, the pK(a) values of the fluorescent S-layer fusion proteins were calculated. Finally, it was shown that the S-layer fusion proteins were able to self-assemble forming 2D nanostructures of oblique p2 symmetry with lattice parameters of about a = 11 nm, b = 14 nm, and gamma = 80 degrees . The fluorescence tag did not hinder the natural self-assembly process of the S-layer protein. The combination of the fluorescence properties and the self-assembly ability of the engineered fusion proteins make them a promising tool to generate biomimetic surfaces for future applications in nanobiotechnology at a wide range of pH.

  2. Genome Sequence of Geobacillus sp. Strain ZGt-1, an Antibacterial Peptide-Producing Bacterium from Hot Springs in Jordan.

    Science.gov (United States)

    Alkhalili, Rawana N; Hatti-Kaul, Rajni; Canbäck, Björn

    2015-07-23

    This paper reports the draft genome sequence of the firmicute Geobacillus sp. strain ZGt-1, an antibacterial peptide producer isolated from the Zara hot spring in Jordan. This study is the first report on genomic data from a thermophilic bacterial strain isolated in Jordan.

  3. Characterization of the newly isolated Geobacillus sp. T1, the efficient cellulase-producer on untreated barley and wheat straws.

    Science.gov (United States)

    Assareh, Reza; Shahbani Zahiri, Hossein; Akbari Noghabi, Kambiz; Aminzadeh, Saeed; Bakhshi Khaniki, Gholamreza

    2012-09-01

    A thermophile cellulase-producing bacterium was isolated and identified as closely related to Geobacillus subterraneus. The strain, named Geobacillus sp. T1, was able to grow and produce cellulase on cellobiose, microcrystalline cellulose, carboxymethylcellulose (CMC), barley straw, wheat straw and Whatman No. 1 filter paper. However, barley and wheat straws were significantly better substrates for cellulase production. When Geobacillus sp. T1 was cultivated in the presence of 0.5% barley straw, 0.1% Tween 80 and pH 6.5 at 50°C, the maximum level of free cellulase up to 143.50 U/mL was produced after 24h. This cellulase (≈ 54 kDa) was most active at pH 6.5 and 70°C. The enzyme in citrate phosphate buffer (10mM) was stable at 60°C for at least 1h. Geobacillus sp. T1 with efficient growth and cellulase production on straws seems a potential candidate for conversion of agricultural biomass to fuels.

  4. Conjugative plasmid transfer from Escherichia coli is a versatile approach for genetic transformation of thermophilic Bacillus and Geobacillus species.

    Science.gov (United States)

    Tominaga, Yurie; Ohshiro, Takashi; Suzuki, Hirokazu

    2016-05-01

    We previously demonstrated efficient transformation of the thermophile Geobacillus kaustophilus HTA426 using conjugative plasmid transfer from Escherichia coli BR408. To evaluate the versatility of this approach to thermophile transformation, this study examined genetic transformation of various thermophilic Bacillus and Geobacillus spp. using conjugative plasmid transfer from E. coli strains. E. coli BR408 successfully transferred the E. coli-Geobacillus shuttle plasmid pUCG18T to 16 of 18 thermophiles with transformation efficiencies between 4.1 × 10(-7) and 3.8 × 10(-2)/recipient. Other E. coli strains that are different from E. coli BR408 in intracellular DNA methylation also generated transformants from 9 to 15 of the 18 thermophiles, including one that E. coli BR408 could not transform, although the transformation efficiencies of these strains were generally lower than those of E. coli BR408. The conjugation was performed by simple incubation of an E. coli donor and a thermophile recipient without optimization of experimental conditions. Moreover, thermophile transformants were distinguished from abundant E. coli donor only by high temperature incubation. These observations suggest that conjugative plasmid transfer, particularly using E. coli BR408, is a facile and versatile approach for plasmid introduction into thermophilic Bacillus and Geobacillus spp., and potentially a variety of other thermophiles.

  5. Purification and Characterization of a Thermostable Lipase from Geobacillus thermodenitrificans IBRL-nra

    Directory of Open Access Journals (Sweden)

    Anuradha Balan

    2012-01-01

    Full Text Available Thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was purified and characterized. The production of thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was carried out in a shake-flask system at 65°C in cultivation medium containing; glucose 1.0% (w/v; yeast extract 1.25% (w/v; NaCl 0.45% (w/v olive oil 0.1% (v/v with agitation of 200 rpm for 24 hours. The extracted extracellular crude thermostable lipase was purified to homogeneity by using ultrafiltration, Heparin-affinity chromatography, and Sephadex G-100 gel-filtration chromatography by 34 times with a final yield of 9%. The molecular weight of the purified enzyme was estimated to be 30 kDa after SDS-PAGE analysis. The optimal temperature for thermostable lipase was 65°C and it retained its initial activity for 3 hours. Thermostable lipase activity was highest at pH 7.0 and stable for 16 hours at this pH at 65°C. Thermostable lipase showed elevated activity when pretreated with BaCl2, CaCl2, and KCl with 112%, 108%, and 106%, respectively. Lipase hydrolyzed tripalmitin (C16 and olive oil with optimal activity (100% compared to other substrates.

  6. Molecular cloning and characterization of a new and highly thermostable esterase from Geobacillus sp. JM6.

    Science.gov (United States)

    Zhu, Yanbing; Zheng, Wenguang; Ni, Hui; Liu, Han; Xiao, Anfeng; Cai, Huinong

    2015-10-01

    A new lipolytic enzyme gene was cloned from a thermophile Geobacillus sp. JM6. The gene contained 750 bp and encoded a 249-amino acid protein. The recombinant enzyme was expressed and purified from Escherichia coli BL21 (DE3) with a molecular mass of 33.6 kDa. Enzyme assays using p-nitrophenyl esters with different acyl chain lengths as the substrates confirmed its esterase activity, yielding the highest activity with p-nitrophenyl butyrate. When p-nitrophenyl butyrate was used as a substrate, the optimum reaction temperature and pH for the enzyme were 60 °C and pH 7.5, respectively. Geobacillus sp. JM6 esterase showed excellent thermostability with 68% residual activity after incubation at 100 °C for 18 h. A theoretical structural model of strain JM6 esterase was developed with a monoacylglycerol lipase from Bacillus sp. H-257 as a template. The predicted core structure exhibits an α/β hydrolase fold, and a putative catalytic triad (Ser97, Asp196, and His226) was identified. Inhibition assays with PMSF indicated that serine residue is involved in the catalytic activity of strain JM6 esterase. The recombinant esterase showed a relatively good tolerance to the detected detergents and denaturants, such as SDS, Chaps, Tween 20, Tween 80, Triton X-100, sodium deoxycholate, urea, and guanidine hydrochloride.

  7. Cloning, Expression, and Characterization of a Novel Thermophilic Monofunctional Catalase from Geobacillus sp. CHB1

    Science.gov (United States)

    2016-01-01

    Catalases are widely used in many scientific areas. A catalase gene (Kat) from Geobacillus sp. CHB1 encoding a monofunctional catalase was cloned and recombinant expressed in Escherichia coli (E. coli), which was the first time to clone and express this type of catalase of genus Geobacillus strains as far as we know. This Kat gene was 1,467 bp in length and encoded a catalase with 488 amino acid residuals, which is only 81% similar to the previously studied Bacillus sp. catalase in terms of amino acid sequence. Recombinant catalase was highly soluble in E. coli and made up 30% of the total E. coli protein. Fermentation broth of the recombinant E. coli showed a high catalase activity level up to 35,831 U/mL which was only lower than recombinant Bacillus sp. WSHDZ-01 among the reported catalase production strains. The purified recombinant catalase had a specific activity of 40,526 U/mg and Km of 51.1 mM. The optimal reaction temperature of this recombinant enzyme was 60°C to 70°C, and it exhibited high activity over a wide range of reaction temperatures, ranging from 10°C to 90°C. The enzyme retained 94.7% of its residual activity after incubation at 60°C for 1 hour. High yield and excellent thermophilic properties are valuable features for this catalase in industrial applications. PMID:27579320

  8. Homologi Gen Seleno Metiltransferase (smt pada Geobacillus sp. 20k dengan smt Astragalus bisulcatus

    Directory of Open Access Journals (Sweden)

    Evi Triana

    2010-09-01

    Full Text Available Methylselenocysteine (MSC is the most effective form of selenium against cancer. The synthesis of MSC is catalyzed by seleno methyltransferase (smt through selenium methylation as its detoxification mechanism. Gene of smt has been characterized in selenium rich plant, Astragalus bisulcatus. This experimental laboratoric study was done on Geobacillus sp. 20k. at Lembaga Ilmu Pengetahuan Indonesia (LIPI, Cibinong, Bogor, November 2008–June 2009.Target gene was detected by polymerase chain reaction and sequencing. DNA sequence was analyzed by the basic local alignment search tool (BLAST. The results showed that smt gene and its homolog were generally found on selenium rich plants, such as A. bisulcatus, C. sinensis, and A. thaliana, with similarity more than 85%. Designed primers for amplification of smt are CAAGCCACCATTCAAGGTTT and CCCTACTGATCCCGCAATTA. Amplification of DNA fragments obtained at approximately 190 base pair. DNA sequence and its protein translation were identified as part of the thermophilic enzyme and smt of A. bisulcatus, with 83% similarity for smt genes and 88–90% for protein. In conclusion, Geobacillus sp. 20k have smt genes similar with that of A. bisulcatus, therefore further development of this isolate as a non toxic selenium source for cancer therapy could be taken into consideration.

  9. Cloning, Expression, and Characterization of a Novel Thermophilic Monofunctional Catalase from Geobacillus sp. CHB1

    Directory of Open Access Journals (Sweden)

    Xianbo Jia

    2016-01-01

    Full Text Available Catalases are widely used in many scientific areas. A catalase gene (Kat from Geobacillus sp. CHB1 encoding a monofunctional catalase was cloned and recombinant expressed in Escherichia coli (E. coli, which was the first time to clone and express this type of catalase of genus Geobacillus strains as far as we know. This Kat gene was 1,467 bp in length and encoded a catalase with 488 amino acid residuals, which is only 81% similar to the previously studied Bacillus sp. catalase in terms of amino acid sequence. Recombinant catalase was highly soluble in E. coli and made up 30% of the total E. coli protein. Fermentation broth of the recombinant E. coli showed a high catalase activity level up to 35,831 U/mL which was only lower than recombinant Bacillus sp. WSHDZ-01 among the reported catalase production strains. The purified recombinant catalase had a specific activity of 40,526 U/mg and Km of 51.1 mM. The optimal reaction temperature of this recombinant enzyme was 60°C to 70°C, and it exhibited high activity over a wide range of reaction temperatures, ranging from 10°C to 90°C. The enzyme retained 94.7% of its residual activity after incubation at 60°C for 1 hour. High yield and excellent thermophilic properties are valuable features for this catalase in industrial applications.

  10. Magnesium-Calcite Crystal Formation Mediated by the Thermophilic Bacterium Geobacillus thermoglucosidasius Requires Calcium and Endospores.

    Science.gov (United States)

    Murai, Rie; Yoshida, Naoto

    2016-11-01

    Fresh Geobacillus thermoglucosidasius cells grown on soybean-casein digest nutrient agar were inoculated as a parent colony 1 cm in diameter on the surface of an agar gel containing acetate and calcium ions (calcite-promoting hydrogel) and incubated at 60 °C for 4 days, after which magnesium-calcite single crystals of 50-130 µm in size formed within the parent colony. Addition of EDTA, polyacrylic acid or N,N-dicyclohexylcarbodiimide to the calcite-forming hydrogel inhibited the parent colony from forming magnesium-calcite crystals. Inoculation of G. thermoglucosidasius on calcite-forming hydrogel containing 5 µM cadmium and 20 µM zinc resulted in a decrease in the sporulation rate from 55 to 7-8 %. Magnesium-calcite synthesis decreased relative to the sporulation rate. G. thermoglucosidasius exhibited higher adsorption/absorbance of calcium than other Geobacillus sp. that do not mediate calcite formation and higher levels of magnesium accumulation. Calcium ions contained in the calcite-promoting hydrogel and magnesium ions concentrated in G. thermoglucosidasius cells serve as the elements for magnesium-calcite synthesis. The observed decreases in sporulation rate and magnesium-calcite formation support the hypothesis that endospores act as nuclei for the synthesis of magnesium-calcite single crystals.

  11. Cloning, Expression, and Characterization of a Novel Thermophilic Monofunctional Catalase from Geobacillus sp. CHB1.

    Science.gov (United States)

    Jia, Xianbo; Chen, Jichen; Lin, Chenqiang; Lin, Xinjian

    2016-01-01

    Catalases are widely used in many scientific areas. A catalase gene (Kat) from Geobacillus sp. CHB1 encoding a monofunctional catalase was cloned and recombinant expressed in Escherichia coli (E. coli), which was the first time to clone and express this type of catalase of genus Geobacillus strains as far as we know. This Kat gene was 1,467 bp in length and encoded a catalase with 488 amino acid residuals, which is only 81% similar to the previously studied Bacillus sp. catalase in terms of amino acid sequence. Recombinant catalase was highly soluble in E. coli and made up 30% of the total E. coli protein. Fermentation broth of the recombinant E. coli showed a high catalase activity level up to 35,831 U/mL which was only lower than recombinant Bacillus sp. WSHDZ-01 among the reported catalase production strains. The purified recombinant catalase had a specific activity of 40,526 U/mg and K m of 51.1 mM. The optimal reaction temperature of this recombinant enzyme was 60°C to 70°C, and it exhibited high activity over a wide range of reaction temperatures, ranging from 10°C to 90°C. The enzyme retained 94.7% of its residual activity after incubation at 60°C for 1 hour. High yield and excellent thermophilic properties are valuable features for this catalase in industrial applications.

  12. Expression and characterization of thermostable glycogen branching enzyme from Geobacillus mahadia Geo-05

    Directory of Open Access Journals (Sweden)

    Nur Syazwani Mohtar

    2016-12-01

    Full Text Available The glycogen branching enzyme (EC 2.4.1.18, which catalyses the formation of α-1,6-glycosidic branch points in glycogen structure, is often used to enhance the nutritional value and quality of food and beverages. In order to be applicable in industries, enzymes that are stable and active at high temperature are much desired. Using genome mining, the nucleotide sequence of the branching enzyme gene (glgB was extracted from the Geobacillus mahadia Geo-05 genome sequence provided by the Malaysia Genome Institute. The size of the gene is 2013 bp, and the theoretical molecular weight of the protein is 78.43 kDa. The gene sequence was then used to predict the thermostability, function and the three dimensional structure of the enzyme. The gene was cloned and overexpressed in E. coli to verify the predicted result experimentally. The purified enzyme was used to study the effect of temperature and pH on enzyme activity and stability, and the inhibitory effect by metal ion on enzyme activity. This thermostable glycogen branching enzyme was found to be most active at 55 °C, and the half-life at 60 °C and 70 °C was 24 h and 5 h, respectively. From this research, a thermostable glycogen branching enzyme was successfully isolated from Geobacillus mahadia Geo-05 by genome mining together with molecular biology technique.

  13. Purification and Characterization of a Thermostable Lipase from Geobacillus thermodenitrificans IBRL-nra.

    Science.gov (United States)

    Balan, Anuradha; Ibrahim, Darah; Abdul Rahim, Rashidah; Ahmad Rashid, Fatimah Azzahra

    2012-01-01

    Thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was purified and characterized. The production of thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was carried out in a shake-flask system at 65°C in cultivation medium containing; glucose 1.0% (w/v); yeast extract 1.25% (w/v); NaCl 0.45% (w/v) olive oil 0.1% (v/v) with agitation of 200 rpm for 24 hours. The extracted extracellular crude thermostable lipase was purified to homogeneity by using ultrafiltration, Heparin-affinity chromatography, and Sephadex G-100 gel-filtration chromatography by 34 times with a final yield of 9%. The molecular weight of the purified enzyme was estimated to be 30 kDa after SDS-PAGE analysis. The optimal temperature for thermostable lipase was 65°C and it retained its initial activity for 3 hours. Thermostable lipase activity was highest at pH 7.0 and stable for 16 hours at this pH at 65°C. Thermostable lipase showed elevated activity when pretreated with BaCl(2), CaCl(2), and KCl with 112%, 108%, and 106%, respectively. Lipase hydrolyzed tripalmitin (C16) and olive oil with optimal activity (100%) compared to other substrates.

  14. EM structure of a helicase-loader complex depicting a 6:2 binding sub-stoichiometry from Geobacillus kaustophilus HTA426.

    Science.gov (United States)

    Lin, Yen-Chen; Naveen, Vankadari; Hsiao, Chwan-Deng

    2016-04-22

    During DNA replication, bacterial helicase is recruited as a complex in association with loader proteins to unwind the parental duplex. Previous structural studies have reported saturated 6:6 helicase-loader complexes with different conformations. However, structural information on the sub-stoichiometric conformations of these previously-documented helicase-loader complexes remains elusive. Here, with the aid of single particle electron-microscopy (EM) image reconstruction, we present the Geobacillus kaustophilus HTA426 helicase-loader (DnaC-DnaI) complex with a 6:2 binding stoichiometry in the presence of ATPγS. In the 19 Å resolution EM map, the undistorted and unopened helicase ring holds a robust loader density above the C-terminal RecA-like domain. Meanwhile, the path of the central DNA binding channel appears to be obstructed by the reconstructed loader density, implying its potential role as a checkpoint conformation to prevent the loading of immature complex onto DNA. Our data also reveals that the bound nucleotides and the consequently induced conformational changes in the helicase hexamer are essential for active association with loader proteins. These observations provide fundamental insights into the formation of the helicase-loader complex in bacteria that regulates the DNA replication process.

  15. Modular system for assessment of glycosyl hydrolase secretion in Geobacillus thermoglucosidasius.

    Science.gov (United States)

    Bartosiak-Jentys, Jeremy; Hussein, Ali H; Lewis, Claire J; Leak, David J

    2013-07-01

    The facultatively anaerobic, thermophilic bacterium Geobacillus thermoglucosidasius is being developed as an industrial micro-organism for cellulosic bioethanol production. Process improvement would be gained by enhanced secretion of glycosyl hydrolases. Here we report the construction of a modular system for combining promoters, signal peptide encoding regions and glycosyl hydrolase genes to facilitate selection of the optimal combination in G. thermoglucosidasius. Initially, a minimal three-part E. coli-Geobacillus sp. shuttle vector pUCG3.8 was constructed using Gibson isothermal DNA assembly. The three PCR amplicons contained the pMB1 E. coli origin of replication and multiple cloning site (MCS) of pUC18, the Geobacillus sp. origin of replication pBST1 and the thermostable kanamycin nucleotidyltransferase gene (knt), respectively. G. thermoglucosidasius could be transformed with pUCG3.8 at an increased efficiency [2.8×10(5) c.f.u. (µg DNA)(-1)] compared to a previously reported shuttle vector, pUCG18. A modular cassette for the inducible expression and secretion of proteins in G. thermoglucosidasius, designed to allow the simple interchange of parts, was demonstrated using the endoglucanase Cel5A from Thermotoga maritima as a secretion target. Expression of cel5A was placed under the control of a cellobiose-inducible promoter (Pβglu) together with a signal peptide encoding sequence from a G. thermoglucosidasius C56-YS93 endo-β-1,4-xylanase. The interchange of parts was demonstrated by exchanging the cel5A gene with the 3' region of a gene with homology to celA from Caldicellulosiruptor saccharolyticus and substituting Pβglu for the synthetic, constitutive promoter PUp2n38, which increased Cel5A activity five-fold. Cel5A and CelA activities were detected in culture supernatants indicating successful expression and secretion. N-terminal protein sequencing of Cel5A carrying a C-terminal FLAG epitope confirmed processing of the signal peptide sequence.

  16. Complete genome sequence, metabolic model construction and phenotypic characterization of Geobacillus LC300, an extremely thermophilic, fast growing, xylose-utilizing bacterium.

    Science.gov (United States)

    Cordova, Lauren T; Long, Christopher P; Venkataramanan, Keerthi P; Antoniewicz, Maciek R

    2015-11-01

    We have isolated a new extremely thermophilic fast-growing Geobacillus strain that can efficiently utilize xylose, glucose, mannose and galactose for cell growth. When grown aerobically at 72 °C, Geobacillus LC300 has a growth rate of 2.15 h(-1) on glucose and 1.52 h(-1) on xylose (doubling time less than 30 min). The corresponding specific glucose and xylose utilization rates are 5.55 g/g/h and 5.24 g/g/h, respectively. As such, Geobacillus LC300 grows 3-times faster than E. coli on glucose and xylose, and has a specific xylose utilization rate that is 3-times higher than the best metabolically engineered organism to date. To gain more insight into the metabolism of Geobacillus LC300 its genome was sequenced using PacBio's RS II single-molecule real-time (SMRT) sequencing platform and annotated using the RAST server. Based on the genome annotation and the measured biomass composition a core metabolic network model was constructed. To further demonstrate the biotechnological potential of this organism, Geobacillus LC300 was grown to high cell-densities in a fed-batch culture, where cells maintained a high xylose utilization rate under low dissolved oxygen concentrations. All of these characteristics make Geobacillus LC300 an attractive host for future metabolic engineering and biotechnology applications.

  17. Higher-order structure in the 3'-terminal domain VI of the 23 S ribosomal RNAs from Escherichia coli and Bacillus stearothermophilus

    DEFF Research Database (Denmark)

    Garrett, R A; Christensen, A; Douthwaite, S

    1984-01-01

    An experimental approach was used to determine, and compare, the higher-order structure within domain VI of the 23 S ribosomal RNAs from Escherichia coli and Bacillus stearothermophilus. This domain, which encompasses approximately 300 nucleotides at the 3' end of the RNAs, consists of two large ...

  18. Crystal structure of the single-stranded RNA binding protein HutP from Geobacillus thermodenitrificans.

    Science.gov (United States)

    Thiruselvam, Viswanathan; Sivaraman, Padavattan; Kumarevel, Thirumananseri; Ponnuswamy, Mondikalipudur Nanjappagounder

    2014-04-18

    RNA binding proteins control gene expression by the attenuation/antitermination mechanism. HutP is an RNA binding antitermination protein. It regulates the expression of hut operon when it binds with RNA by modulating the secondary structure of single-stranded hut mRNA. HutP necessitates the presence of l-histidine and divalent metal ion to bind with RNA. Herein, we report the crystal structures of ternary complex (HutP-l-histidine-Mg(2+)) and EDTA (0.5 M) treated ternary complex (HutP-l-histidine-Mg(2+)), solved at 1.9 Å and 2.5 Å resolutions, respectively, from Geobacillus thermodenitrificans. The addition of 0.5 M EDTA does not affect the overall metal-ion mediated ternary complex structure and however, the metal ions at the non-specific binding sites are chelated, as evidenced from the results of structural features.

  19. Crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus.

    Science.gov (United States)

    Manjula, M; Pampa, K J; Kumar, S M; Mukherjee, S; Kunishima, N; Rangappa, K S; Lokanath, N K

    2015-03-27

    The ATP binding cassette (ABC) transporters, represent one of the largest superfamilies of primary transporters, which are very essential for various biological functions. The crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus has been determined at 1.77 Å resolution. The crystal structure revealed that the protomer has two thick arms, (arm I and II), which resemble 'L' shape. The ATP-binding pocket is located close to the end of arm I. ATP molecule is docked into the active site of the protein. The dimeric crystal structure of ATP-binding subunit of ABC transporter from G. kaustophilus has been compared with the previously reported crystal structure of ATP-binding subunit of ABC transporter from Salmonella typhimurium.

  20. Engineering pyruvate decarboxylase-mediated ethanol production in the thermophilic host Geobacillus thermoglucosidasius.

    Science.gov (United States)

    Van Zyl, L J; Taylor, M P; Eley, K; Tuffin, M; Cowan, D A

    2014-02-01

    This study reports the expression, purification, and kinetic characterization of a pyruvate decarboxylase (PDC) from Gluconobacter oxydans. Kinetic analyses showed the enzyme to have high affinity for pyruvate (120 μM at pH 5), high catalytic efficiency (4.75 × 10(5) M(-1) s(-1) at pH 5), a pHopt of approximately 4.5 and an in vitro temperature optimum at approximately 55 °C. Due to in vitro thermostablity (approximately 40 % enzyme activity retained after 30 min at 65 °C), this PDC was considered to be a suitable candidate for heterologous expression in the thermophile Geobacillus thermoglucosidasius for ethanol production. Initial studies using a variety of methods failed to detect activity at any growth temperature (45-55 °C). However, the application of codon harmonization (i.e., mimicry of the heterogeneous host's transcription and translational rhythm) yielded a protein that was fully functional in the thermophilic strain at 45 °C (as determined by enzyme activity, Western blot, mRNA detection, and ethanol productivity). Here, we describe the first successful expression of PDC in a true thermophile. Yields as high as 0.35 ± 0.04 g/g ethanol per gram of glucose consumed were detected, highly competitive to those reported in ethanologenic thermophilic mutants. Although activities could not be detected at temperatures approaching the growth optimum for the strain, this study highlights the possibility that previously unsuccessful expression of pdcs in Geobacillus spp. may be the result of ineffective transcription/translation coupling.

  1. Highly thermostable xylanase production from a thermophilic Geobacillus sp. strain WSUCF1 utilizing lignocellulosic biomass

    Directory of Open Access Journals (Sweden)

    Aditya eBhalla

    2015-06-01

    Full Text Available AbstractEfficient enzymatic hydrolysis of lignocellulose to fermentable sugars requires a complete repertoire of biomass deconstruction enzymes. Hemicellulases play an important role in hydrolyzing hemicellulose component of lignocellulose to xylo-oligosaccharides and xylose. Thermostable xylanases have been a focus of attention as industrially important enzymes due to their long shelf life at high temperatures. Geobacillus sp. strain WSUCF1 produced thermostable xylanase activity (crude xylanase cocktail when grown on xylan or various inexpensive untreated and pretreated lignocellulosic biomasses such as prairie cord grass and corn stover. The optimum pH and temperature for the crude xylanase cocktail were 6.5 and 70ºC, respectively. The WSUCF1 crude xylanase was found to be highly thermostable with half-lives of 18 and 12 days at 60 and 70ºC, respectively. At 70ºC, rates of xylan hydrolysis were also found to be better with the WSUCF1 secretome than those with commercial enzymes, i.e., for WSUCF1 crude xylanase, CellicHTec2, and AccelleraseXY, the percent xylan conversions were 68.9, 49.4, and 28.92, respectively. To the best of our knowledge, WSUCF1 crude xylanase cocktail is among the most thermostable xylanases produced by thermophilic Geobacillus spp. and other thermophilic microbes (optimum growth temperature ≤70ºC. High thermostability, activity over wide range of temperatures, and better xylan hydrolysis than commercial enzymes make WSUCF1 crude xylanase suitable for thermophilic lignocellulose bioconversion processes.

  2. Arsenate reduction and expression of multiple chromosomal ars operons in Geobacillus kaustophilus A1.

    Science.gov (United States)

    Cuebas, Mariola; Villafane, Aramis; McBride, Michelle; Yee, Nathan; Bini, Elisabetta

    2011-07-01

    Geobacillus kaustophilus strain A1 was previously isolated from a geothermal environment for its ability to grow in the presence of high arsenate levels. In this study, the molecular mechanisms of arsenate resistance of the strain were investigated. As(V) was reduced to As(III), as shown by HPLC analysis. Consistent with the observation that the micro-organism is not capable of anaerobic growth, no respiratory arsenate reductases were identified. Using specific PCR primers based on the genome sequence of G. kaustophilus HTA426, three unlinked genes encoding detoxifying arsenate reductases were detected in strain A1. These genes were designated arsC1, arsC2 and arsC3. While arsC3 is a monocistronic locus, sequencing of the regions flanking arsC1 and arsC2 revealed the presence of additional genes encoding a putative arsenite transporter and an ArsR-like regulator upstream of each arsenate reductase, indicating the presence of sequences with putative roles in As(V) reduction, As(III) export and arsenic-responsive regulation. RT-PCR demonstrated that both sets of genes were co-transcribed. Furthermore, arsC1 and arsC2, monitored by quantitative real-time RT-PCR, were upregulated in response to As(V), while arsC3 was constitutively expressed at a low level. A mechanism for regulation of As(V) detoxification by Geobacillus that is both consistent with our findings and relevant to the biogeochemical cycle of arsenic and its mobility in the environment is proposed.

  3. Purification and characterization of a novel thermo-active amidase from Geobacillus subterraneus RL-2a.

    Science.gov (United States)

    Mehta, Praveen Kumar; Bhatia, Shashi Kant; Bhatia, Ravi Kant; Bhalla, Tek Chand

    2013-07-01

    A thermostable amidase produced by Geobacillus subterraneus RL-2a was purified to homogeneity, with a yield of 9.54 % and a specific activity of 48.66 U mg(-1). The molecular weight of the native enzyme was estimated to be 111 kDa. The amidase of G. subterraneus RL-2a is constitutive in nature, active at a broad range of pH (4.5-11.5) and temperature (40-90 °C) and has a half-life of 5 h and 54 min at 70 °C. Inhibition of enzyme activity was observed in the presence of metal ions, such as Co(2+), Hg(2+), Cu(2+), Ni(2+), and thiol reagents. The presence of mid-chain aliphatic and amino acid amides enhances the enzymatic activity. The acyl transferase activity was detected with propionamide, butyramide and nicotinamide. The enzyme showed moderate stability toward toluene, carbon tetrachloride, benzene, ethylene glycol except acetone, ethanol, butanol, propanol and dimethyl sulfoxide. The K m and V max of the purified amidase with nicotinamide were 6.02 ± 0.56 mM and 132.6 ± 4.4 μmol min(-1) mg(-1) protein by analyzing Michaelis-Menten kinetics. The results of MALDI-TOF analysis indicated that this amidase has homology with the amidase of Geobacillus sp. C56-T3 (gi|297530427). It is the first reported wide-spectrum thermostable amidase from a thermophilic G. subterraneus.

  4. Transglycosylation reactions of Bacillus stearothermophilus maltogenic amylase with acarbose and various acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Hwa Park, K.; Jeong Kim, M.; Seob Lee, H.; Kim, D. [Department of Food Science and Technology and Research Center for New Bio-Materials in Agriculture, Seoul National University, Suwon (Korea, Republic of); Soo Han, N.; Robyt, J.F. [Laboratory for Carbohydrate Chemistry and Enzymology, Department of Biochemistry and Biophysics, Iowa State University, Ames, IA (United States)

    1998-12-15

    It was observed that Bacillus stearothermophilus maltogenic amylase cleaved the first glycosidic bond of acarbose to produce glucose and a pseudotrisaccharide (PTS) that was transferred to C-6 of the glucose to give an {alpha}-(1-6) glycosidic linkage and the formation of isoacarbose. The addition of a number of different carbohydrates to the digest gave transfer products in which PTS was primarily attached {alpha}-(1-6) to d-glucose, d-mannose, d-galactose, and methyl {alpha}-d-glucopyranoside. With d-fructopyranose and d-xylopyranose, PTS was linked {alpha}-(1-5) and {alpha}-(1-4), respectively. PTS was primarily transferred to C-6 of the nonreducing residue of maltose, cellobiose, lactose, and gentiobiose. Lesser amounts of {alpha}-(1-3) and/or {alpha}-(1-4) transfer products were also observed for these carbohydrate acceptors. The major transfer product to sucrose gave PTS linked {alpha}-(1-4) to the glucose residue. {alpha},{alpha}-Trehalose gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4). Maltitol gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4) to the glucopyranose residue. Raffinose gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4) to the d-galactopyranose residue. Maltotriose gave two major products with PTS linked {alpha}-(1-6) and {alpha}-(1-4) to the nonreducing end glucopyranose residue. Xylitol gave PTS linked {alpha}-(1-5) as the major product and d-glucitol gave PTS linked {alpha}-(1-6) as the only product. The structures of the transfer products were determined using thin layer-chromatography, high-performance ion chromatography, enzyme hydrolysis, methylation analysis and {sup 13}C NMR spectroscopy. The best acceptor was gentiobiose, followed closely by maltose and cellobiose, and the weakest acceptor was d-glucitol. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Cloning, expression, purification, crystallization and preliminary X-ray crystallographic study of DHNA synthetase from Geobacillus kaustophilus

    Energy Technology Data Exchange (ETDEWEB)

    Kanaujia, Shankar Prasad; Ranjani, Chellamuthu Vasuki [Bioinformatics Centre (Centre of Excellence in Structural Biology and Biocomputing), Indian Institute of Science, Bangalore 560 012 (India); Jeyakanthan, Jeyaraman [RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Baba, Seiki [RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Kuroishi, Chizu; Ebihara, Akio; Shinkai, Akeo [RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Kuramitsu, Seiki [RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Shiro, Yoshitsugu [RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Sekar, Kanagaraj, E-mail: sekar@serc.iisc.ernet.in [Bioinformatics Centre (Centre of Excellence in Structural Biology and Biocomputing), Indian Institute of Science, Bangalore 560 012 (India); Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore 560 012 (India); Yokoyama, Shigeyuki, E-mail: sekar@serc.iisc.ernet.in [RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045 (Japan); Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Bioinformatics Centre (Centre of Excellence in Structural Biology and Biocomputing), Indian Institute of Science, Bangalore 560 012 (India)

    2007-02-01

    DHNA synthetase from G. kaustophilus has been cloned, expressed, purified and crystallized. The aerobic Gram-positive bacterium Geobacillus kaustophilus is a bacillus species that was isolated from deep-sea sediment from the Mariana Trench. 1,4-Dihydroxy-2-naphthoate (DHNA) synthetase plays a vital role in the biosynthesis of menaquinone (vitamin K{sub 2}) in this bacterium. DHNA synthetase from Geobacillus kaustophilus was crystallized in the orthorhombic space group C222{sub 1}, with unit-cell parameters a = 77.01, b = 130.66, c = 131.69 Å. The crystal diffracted to a resolution of 2.2 Å. Preliminary studies and molecular-replacement calculations reveal the presence of three monomers in the asymmetric unit.

  6. (13)C metabolic flux analysis of the extremely thermophilic, fast growing, xylose-utilizing Geobacillus strain LC300.

    Science.gov (United States)

    Cordova, Lauren T; Antoniewicz, Maciek R

    2016-01-01

    Thermophiles are increasingly used as versatile hosts in the biotechnology industry. One of the key advantages of thermophiles is the potential to achieve high rates of feedstock conversion at elevated temperatures. The recently isolated Geobacillus strain LC300 grows extremely fast on xylose, with a doubling time of less than 30 min. In the accompanying paper, the genome of Geobacillus LC300 was sequenced and annotated. In this work, we have experimentally validated the metabolic network model using parallel (13)C-labeling experiments and applied (13)C-metabolic flux analysis to quantify precise metabolic fluxes. Specifically, the complete set of singly labeled xylose tracers, [1-(13)C], [2-(13)C], [3-(13)C], [4-(13)C], and [5-(13)C]xylose, was used for the first time. Isotopic labeling of biomass amino acids was measured by gas chromatography mass spectrometry (GC-MS). Isotopic labeling of carbon dioxide in the off-gas was also measured by an on-line mass spectrometer. The (13)C-labeling data was then rigorously integrated for flux elucidation using the COMPLETE-MFA approach. The results provided important new insights into the metabolism of Geobacillus LC300, its efficient xylose utilization pathways, and the balance between carbon, redox and energy fluxes. The pentose phosphate pathway, glycolysis and TCA cycle were found to be highly active in Geobacillus LC300. The oxidative pentose phosphate pathway was also active and contributed significantly to NADPH production. No transhydrogenase activity was detected. Results from this work provide a solid foundation for future studies of this strain and its metabolic engineering and biotechnological applications.

  7. Cloning and characterization of a new manganese superoxide dismutase from deep-sea thermophile Geobacillus sp. EPT3.

    Science.gov (United States)

    Zhu, Yanbing; Wang, Guohong; Ni, Hui; Xiao, Anfeng; Cai, Huinong

    2014-04-01

    A new gene encoding a superoxide dismutase (SOD) was identified from a thermophile Geobacillus sp. EPT3 isolated from a deep-sea hydrothermal field in east Pacific. The open reading frame of this gene encoded 437 amino acid residues. It was cloned, overexpressed in Escherichia coli (DE3), and the recombinant protein was purified to homogeneity. Geobacillus sp. EPT3 SOD was of the manganese-containing SOD type, as judged by the insensitivity of the recombinant enzyme to both KCN and H₂O₂, and the activity analysis of Fe or Mn reconstituted SODs by polyacrylamide gel electrophoresis. The recombinant SOD was determined to be a homodimer with monomeric molecular mass of 59.0 kDa. In comparison with other Mn-SODs, the manganese-binding sites are conserved in the sequence (His260, His308, Asp392, His396). The recombinant enzyme had high thermostability at 50 °C. It retained 57 % residual activity after incubation at 90 °C for 1 h, which indicated that this SOD was thermostable. The enzyme also showed striking stability over a wide range of pH 5.0-11.0. At tested conditions, the recombinant SOD from Geobacillus sp. EPT3 showed a relatively good tolerance to some inhibitors, detergents, and denaturants, such as β-mercaptoethanol, dithiothreitol, phenylmethylsulfonyl fluoride, Chaps, Triton X-100, urea, and guanidine hydrochloride.

  8. Geobacillus sp.A27的分离筛选及其淀粉酶酶学性质研究%Isolation of Geobacillus sp.A27 and characterization of its α-amylase

    Institute of Scientific and Technical Information of China (English)

    王晓燕; 高润池; 廖昌珑; 孟艳芬; 唐湘华; 李俊俊; 许波; 黄遵锡

    2011-01-01

    用淀粉平板透明圈法,从分离自腾冲热泉的高温菌中筛选到一株产胞外淀粉酶的菌株,经16sRNA序列比对,在Genbank中与Geobacillus sp.sbs4s有99%同源性,定名为Geobacillus sp.A27.该菌最适生长温度为60-65℃,在LB培养基上不生长,但能在以淀粉为唯一碳源的培养基上生长,并能将来自植物种子、根茎的淀粉质底物水解为以麦芽二糖为主的麦芽寡糖.Geobacillus sp.A27菌株产生的胞外α-淀粉酶最适pH5.6,最适温度70℃.金属离子Fe3+、Cu2+、EDTA对酶活有显著抑制作用,椎测AmyA27可能属于金属酶.粗酶液经饱和硫酸胺沉淀、无水乙醇沉淀、8%分离胶的SDS-PAGE电泳和蛋白质复性,确定该淀粉酶分子量为67kD.%A strain with extracellular amylase was isolated by transparent circle in starch medium from Tengchong hot springs by 16sRNA sequence alignment in Genbank. It has 99% homology with Geobacillus sp. sbs4s, and blongs to Geobacillus sp. lt can grow up in culture medium in which starch was only one carbon source but can not in completely medium LB without starch. The amylase activity on solute starch was optimal at pH5.6 and 70℃.The enzyme efficiently hydrolyzed various types of starch from plant seeds,roots and stems to yield a series of maltooligosaccharides by endo-cleavage mode. The enzyme had different reactions to varity metal ions,it was inhibited significantly by Fe3+, EDTA and Cu2+, it may belong to metal enzymes. The precipitate of the enzymes by ammonium sulfate and ethanol,67kD for amylase molecular weight was determined by 8% separation glue SDSPAGE protein electrophoresis.

  9. 嗜热菌Geobacillus sp.PZH1产木聚糖酶发酵条件的优化%Optimization of fermentation conditions of xylanase from thermophilic bacterium Geobacillus sp.PZH1

    Institute of Scientific and Technical Information of China (English)

    刘培培; 陈学敏; 王石峰; 张波

    2012-01-01

    The culture conditions for alkali-thermo-stable xylanase production from the thermophilic bacterium Geobacillus sp.PZH1 were optimized.Five factors,such as carbon source,nitrogen source,initial pH,inoculum size and fermentation temperature,were researched in single-factor experiment.C/N ratio,initial pH and inoculum size were researched in orthogonal experiment.The results showed that the xylanase yield reached a highest level for 7d culture,and the best combination of fermentation conditions for alkali-thermo-stable xylanase production from the thermophilic bacterium Geobacillus sp.PZH1 was brichwood xylan as carbon source,beef extract as nitrogen source,C N ratio 2∶3,initial pH 7.0,inoculum size 4%,fermentation temperature 50℃ and fermentation time 7d.Under these optimal conditions,the xylanase production from the thermophilic bacterium Geobacillus sp.PZH1 was 2.56IU/mL,1.44 fold higher than that before the optimization.%对嗜热菌Geobacillus sp.PZH1发酵产嗜热耐碱木聚糖酶的培养条件进行了优化研究。对碳源、氮源、初始pH、接种量以及发酵温度五个因素进行了单因素实验,在此基础上对碳氮比、初始pH以及接种量进行了正交实验。结果表明,该菌株在发酵培养7d时有最大产酶量,Geobacillus sp.PZH1发酵产木聚糖酶最佳发酵条件为:桦木木聚糖为碳源,牛肉膏为氮源,碳氮比2∶3,初始pH7.0,接种量4%,发酵温度50℃,发酵时间7d。在最佳产酶条件下进行发酵,木聚糖酶活力可达2.56IU/mL,是未优化前酶活的1.44倍。

  10. Catalytic properties of maltogenic α-amylase from Bacillus stearothermophilus immobilized onto poly(urethane urea) microparticles.

    Science.gov (United States)

    Straksys, Antanas; Kochane, Tatjana; Budriene, Saulute

    2016-11-15

    The immobilization of maltogenic α-amylase from Bacillus stearothermophilus (BsMa) onto novel porous poly(urethane urea) (PUU) microparticles synthesized from poly(vinyl alcohol) and isophorone diisocyanate was performed by covalent attachment to free isocyanate groups from PUU microparticles, or by physical adsorption of enzyme onto the surface of the carrier. The influence of structure, surface area and porosity of microparticles on the catalytic properties of immobilized BsMa was evaluated. The highest efficiency of immobilization of BsMa was found to be 72%. Optimal activity of immobilized BsMa was found to have increased by 10°C compared with the native enzyme. Influence of concentration of sodium chloride on activity of immobilized BsMa was evaluated. High storage and thermal stability and reusability for starch hydrolysis of immobilized enzyme were obtained. Immobilized BsMa has a great potential for biotechnology.

  11. Combined impact of Bacillus stearothermophilus maltogenic alpha-amylase and surfactants on starch pasting and gelation properties.

    Science.gov (United States)

    Van Steertegem, Bénédicte; Pareyt, Bram; Brijs, Kristof; Delcour, Jan A

    2013-08-15

    In baking applications involving starch gelatinisation, surfactants such as sodium stearoyl lactylate (SSL) and monoacylglycerols (MAG) and Bacillus stearothermophilus maltogenic alpha-amylase (BStA) can be used jointly. We here showed that SSL but not MAG delays wheat starch hydrolysis by BStA. The effects were explained in terms of different degrees of adsorption of the surfactants on the starch granule surface, retarded and/or decreased water uptake and delayed availability of gelatinised starch for hydrolysis by BStA. Additional experiments with waxy maize starch led to the conclusion that SSL impacts swelling power and carbohydrate leaching more by covering the starch granule surface than by forming amylose-lipid complexes. SSL postponed starch hydrolysis by BStA, but this did not influence subsequent starch gelation. Finally, when adding SSL or MAG on top of BStA to starch suspensions, the effect of the surfactants on gel strength predominated over that of BStA.

  12. Complete genome sequences of Geobacillus sp. Y412MC52, a xylan-degrading strain isolated from obsidian hot spring in Yellowstone National Park.

    Science.gov (United States)

    Brumm, Phillip; Land, Miriam L; Hauser, Loren J; Jeffries, Cynthia D; Chang, Yun-Juan; Mead, David A

    2015-01-01

    Geobacillus sp. Y412MC52 was isolated from Obsidian Hot Spring, Yellowstone National Park, Montana, USA under permit from the National Park Service. The genome was sequenced, assembled, and annotated by the DOE Joint Genome Institute and deposited at the NCBI in December 2011 (CP002835). Based on 16S rRNA genes and average nucleotide identity, Geobacillus sp. Y412MC52 and the related Geobacillus sp. Y412MC61 appear to be members of a new species of Geobacillus. The genome of Geobacillus sp. Y412MC52 consists of one circular chromosome of 3,628,883 bp, an average G + C content of 52 % and one circular plasmid of 45,057 bp and an average G + C content of 45 %. Y412MC52 possesses arabinan, arabinoglucuronoxylan, and aromatic acid degradation clusters for degradation of hemicellulose from biomass. Transport and utilization clusters are also present for other carbohydrates including starch, cellobiose, and α- and β-galactooligosaccharides.

  13. Thermophilic fermentation of acetoin and 2,3-butanediol by a novel Geobacillus strain

    Directory of Open Access Journals (Sweden)

    Xiao Zijun

    2012-12-01

    Full Text Available Abstract Background Acetoin and 2,3-butanediol are two important biorefinery platform chemicals. They are currently fermented below 40°C using mesophilic strains, but the processes often suffer from bacterial contamination. Results This work reports the isolation and identification of a novel aerobic Geobacillus strain XT15 capable of producing both of these chemicals under elevated temperatures, thus reducing the risk of bacterial contamination. The optimum growth temperature was found to be between 45 and 55°C and the medium initial pH to be 8.0. In addition to glucose, galactose, mannitol, arabionose, and xylose were all acceptable substrates, enabling the potential use of cellulosic biomass as the feedstock. XT15 preferred organic nitrogen sources including corn steep liquor powder, a cheap by-product from corn wet-milling. At 55°C, 7.7 g/L of acetoin and 14.5 g/L of 2,3-butanediol could be obtained using corn steep liquor powder as a nitrogen source. Thirteen volatile products from the cultivation broth of XT15 were identified by gas chromatography–mass spectrometry. Acetoin, 2,3-butanediol, and their derivatives including a novel metabolite 2,3-dihydroxy-3-methylheptan-4-one, accounted for a total of about 96% of all the volatile products. In contrast, organic acids and other products were minor by-products. α-Acetolactate decarboxylase and acetoin:2,6-dichlorophenolindophenol oxidoreductase in XT15, the two key enzymes in acetoin metabolic pathway, were found to be both moderately thermophilic with the identical optimum temperature of 45°C. Conclusions Geobacillus sp. XT15 is the first naturally occurring thermophile excreting acetoin and/or 2,3-butanediol. This work has demonstrated the attractive prospect of developing it as an industrial strain in the thermophilic fermentation of acetoin and 2,3-butanediol with improved anti-contamination performance. The novel metabolites and enzymes identified in XT15 also indicated its

  14. Thermophilic fermentation of acetoin and 2,3-butanediol by a novel Geobacillus strain.

    Science.gov (United States)

    Xiao, Zijun; Wang, Xiangming; Huang, Yunling; Huo, Fangfang; Zhu, Xiankun; Xi, Lijun; Lu, Jian R

    2012-12-06

    Acetoin and 2,3-butanediol are two important biorefinery platform chemicals. They are currently fermented below 40°C using mesophilic strains, but the processes often suffer from bacterial contamination. This work reports the isolation and identification of a novel aerobic Geobacillus strain XT15 capable of producing both of these chemicals under elevated temperatures, thus reducing the risk of bacterial contamination. The optimum growth temperature was found to be between 45 and 55°C and the medium initial pH to be 8.0. In addition to glucose, galactose, mannitol, arabionose, and xylose were all acceptable substrates, enabling the potential use of cellulosic biomass as the feedstock. XT15 preferred organic nitrogen sources including corn steep liquor powder, a cheap by-product from corn wet-milling. At 55°C, 7.7 g/L of acetoin and 14.5 g/L of 2,3-butanediol could be obtained using corn steep liquor powder as a nitrogen source. Thirteen volatile products from the cultivation broth of XT15 were identified by gas chromatography-mass spectrometry. Acetoin, 2,3-butanediol, and their derivatives including a novel metabolite 2,3-dihydroxy-3-methylheptan-4-one, accounted for a total of about 96% of all the volatile products. In contrast, organic acids and other products were minor by-products. α-Acetolactate decarboxylase and acetoin:2,6-dichlorophenolindophenol oxidoreductase in XT15, the two key enzymes in acetoin metabolic pathway, were found to be both moderately thermophilic with the identical optimum temperature of 45°C. Geobacillus sp. XT15 is the first naturally occurring thermophile excreting acetoin and/or 2,3-butanediol. This work has demonstrated the attractive prospect of developing it as an industrial strain in the thermophilic fermentation of acetoin and 2,3-butanediol with improved anti-contamination performance. The novel metabolites and enzymes identified in XT15 also indicated its strong promise as a precious biological resource. Thermophilic

  15. EM structure of a helicase-loader complex depicting a 6:2 binding sub-stoichiometry from Geobacillus kaustophilus HTA426

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yen-Chen [Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan (China); Naveen, Vankadari [Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan (China); Molecular Cell Biology, Taiwan International Graduate Program, Institute of Molecular Biology, Academia Sinica, and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Hsiao, Chwan-Deng, E-mail: hsiao@gate.sinica.edu.tw [Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan (China); Molecular Cell Biology, Taiwan International Graduate Program, Institute of Molecular Biology, Academia Sinica, and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China)

    2016-04-22

    During DNA replication, bacterial helicase is recruited as a complex in association with loader proteins to unwind the parental duplex. Previous structural studies have reported saturated 6:6 helicase-loader complexes with different conformations. However, structural information on the sub-stoichiometric conformations of these previously-documented helicase-loader complexes remains elusive. Here, with the aid of single particle electron-microscopy (EM) image reconstruction, we present the Geobacillus kaustophilus HTA426 helicase-loader (DnaC-DnaI) complex with a 6:2 binding stoichiometry in the presence of ATPγS. In the 19 Å resolution EM map, the undistorted and unopened helicase ring holds a robust loader density above the C-terminal RecA-like domain. Meanwhile, the path of the central DNA binding channel appears to be obstructed by the reconstructed loader density, implying its potential role as a checkpoint conformation to prevent the loading of immature complex onto DNA. Our data also reveals that the bound nucleotides and the consequently induced conformational changes in the helicase hexamer are essential for active association with loader proteins. These observations provide fundamental insights into the formation of the helicase-loader complex in bacteria that regulates the DNA replication process. - Highlights: • Helicase-loader complex structure with 6:2 sub-stoichiometry is resolved by EM. • Helicase hexamer in 6:2 sub-stoichiometry is constricted and un-opened. • 6:2 binding ratio of helicase-loader complex could act as a DNA loading checkpoint. • Nucleotides stabilize helicase-loader complex at low protein concentrations.

  16. Novel thermostable endo-xylanase cloned and expressed from bacterium Geobacillus sp. WSUCF1.

    Science.gov (United States)

    Bhalla, Aditya; Bischoff, Kenneth M; Uppugundla, Nirmal; Balan, Venkatesh; Sani, Rajesh K

    2014-08-01

    A gene encoding a GH10 endo-xylanase from Geobacillus sp. WSUCF1 was cloned and expressed in Escherichia coli. Recombinant endo-xylanase (37kDa) exhibited high specific activity of 461.0U/mg of protein. Endo-xylanase was optimally active on birchwood xylan at 70°C and pH 6.5. The endo-xylanase was found to be highly thermostable at 50 and 60°C, retaining 82% and 50% of its original activity, respectively, after 60h. High xylan conversions (92%) were obtained with oat-spelt xylan hydrolysis. Higher glucan and xylan conversions were obtained on AFEX-treated corn stover with an enzyme cocktail containing WSUCF1 endo-xylanase (71% and 47%) as compared to enzyme cocktail containing commercial fungal endo-xylanase (64% and 41%). High specific activity, active at high pH's, wide substrate specificity, and higher hydrolytic activity on recalcitrant lignocellulose, make this endo-xylanase a suitable candidate for biofuel and bioprocess industries.

  17. Applicability of recombinant β-xylosidase from the extremely thermophilic bacterium Geobacillus thermodenitrificans in synthesizing alkylxylosides.

    Science.gov (United States)

    Jain, Ira; Kumar, Vikash; Satyanarayana, T

    2014-10-01

    The β-xylosidase encoding gene (XsidB) of the extremely thermophilic bacterium Geobacillus thermodenitrificans has been cloned and expressed in Escherichia coli. The homotrimeric recombinant XsidB is of 204.0kDa, which is optimally active at 60°C and pH 7.0 with T1/2 of 58min at 70°C. The β-xylosidase remains unaffected in the presence of most metal ions and organic solvents. The Km [p-nitrophenyl β-xyloside (pNPX)], Vmax and kcat values of the enzyme are 2×10(-3)M, 1250μmolesmg(-1)min(-1) and 13.20×10(5)min(-1), respectively. The enzyme catalyzes transxylosylation reactions in the presence of alcohols as acceptors. The pharmaceutically important β-methyl-d-xylosides could be produced using pNPX as the donor and methanol as acceptor. The products of transxylosylation were identified by TLC and HPLC, and the structure was confirmed by (1)H NMR analysis. The enzyme is also useful in synthesizing transxylosylation products from the wheat bran hydrolysate.

  18. Characteristics of thermostable amylopullulanase of Geobacillus thermoleovorans and its truncated variants.

    Science.gov (United States)

    Nisha, M; Satyanarayana, T

    2015-05-01

    The far-UV CD spectroscopic analysis of the secondary structure in the temperature range between 30 and 90°C revealed a compact and thermally stable structure of C-terminal truncated amylopullulanase of Geobacillus thermoleovorans NP33 (gt-apuΔC) with a higher melting temperature [58°C] than G. thermoleovorans NP33 amylopullulanase (gt-apu) [50°C] and the N-terminal truncated amylopullulanase from G. thermoleovorans NP33 (gt-apuΔN) [55°C]. A significant decline in random coils in gt-apuΔC and gt-apuΔN suggested an improvement in conformational stability, and thus, an enhancement in their thermal stability. The improvement in the thermostability of gt-apuΔC was corroborated by the thermodynamic parameters for enzyme inactivation. The Trp fluorescence emission (335 nm) and the acrylamide quenching constant (22.69 M(-1)) of gt-apuΔC indicated that the C-terminal truncation increases the conformational stability of the protein with the deeply buried tryptophan residues. The 8-Anilino Naphthalene Sulfonic acid (ANS) fluorescence experiments indicated the unfolding of gt-apu to expose its hydrophobic surface to a greater extent than the gt-apuΔC and gt-apuΔN.

  19. Structure of a bifunctional alcohol dehydrogenase involved in bioethanol generation in Geobacillus thermoglucosidasius.

    Science.gov (United States)

    Extance, Jonathan; Crennell, Susan J; Eley, Kirstin; Cripps, Roger; Hough, David W; Danson, Michael J

    2013-10-01

    Bifunctional alcohol/aldehyde dehydrogenase (ADHE) enzymes are found within many fermentative microorganisms. They catalyse the conversion of an acyl-coenzyme A to an alcohol via an aldehyde intermediate; this is coupled to the oxidation of two NADH molecules to maintain the NAD(+) pool during fermentative metabolism. The structure of the alcohol dehydrogenase (ADH) domain of an ADHE protein from the ethanol-producing thermophile Geobacillus thermoglucosidasius has been determined to 2.5 Å resolution. This is the first structure to be reported for such a domain. In silico modelling has been carried out to generate a homology model of the aldehyde dehydrogenase domain, and this was subsequently docked with the ADH-domain structure to model the structure of the complete ADHE protein. This model suggests, for the first time, a structural mechanism for the formation of the large multimeric assemblies or `spirosomes' that are observed for this ADHE protein and which have previously been reported for ADHEs from other organisms.

  20. Thermostable lipase from Geobacillus sp. Iso5: bioseparation, characterization and native structural studies.

    Science.gov (United States)

    Mahadevan, Gurumurthy D; Neelagund, Shivayogeeswar E

    2014-05-01

    The extracellular thermoalkaline lipase from Geobacillus sp. Iso5 was purified to homogeneity by ultrafiltration, 6% cross-linked agarose and Phenyl spehrose HIC column chromatography. The final purified lipase resulted in 8.7-fold with 6.2% yield. The relative molecular weight of the enzyme was determined to be a monomer of 47 kDa by SDS-PAGE and MALDI-TOF MS/MS spectroscopy. The purified enzyme exhibit optimum activity at 70 °C and pH 8.0. The enzyme retained above 90% activity at temperatures of 70 °C and about 35% activity at 85 °C for 2 h. However, the stability of the enzyme decreased at the temperature over 90 °C. The enzyme activity was promoted in the presence of Ca(2+) and Mg(2+) and strongly inhibited by HgCl2 , PMSF, DTT, K(+) , Co(2+) , and Zn (2+) . EDTA did not affect the enzyme activity. The secondary structure of purified lipase contains 36% α-helix and 64% β-sheet which was determined by Circular dichromism, FTIR, and Raman Spectroscopy.

  1. Purification and characterization of an extremely stable glucose isomerase from Geobacillus thermodenitrificans TH2.

    Science.gov (United States)

    Konak, L; Kolcuoğlu, Y; Ozbek, E; Colak, A; Ergenoglu, B

    2014-01-01

    The D-glucose/D-xylose isomerase was purified from a thermophilic bacterium, Geobacillus thermodenitrificans TH2, by precipitating with heat shock and using Q-Sepharose ion exchange column chromatography, and then characterized. The purified enzyme had a single band having molecular weight of 49 kDa on SDS-PAGE. In the presence of D-glucose as a substrate, the optimum temperature and pH of the enzyme were found to be 80 degrees C and 7.5, respectively. The purified xylose isomerase of G. thermodenitrificans TH2 was extremely stable at pH 7.5 after 96 h incubation at 4 degrees C and 50 degrees C. When the thermal stability profile was analyzed, it was determined that the purified enzyme was extremely stable during incubation periods of 4 months and 4 days at 4 degrees C and 50 degrees C, respectively. The K(m) and V(max) values of the purified xylose isomerase from G. thermodenitrificans TH2 were calculated as 32 mM and 4.68 micromol/min per mg of protein, respectively. Additionally, it was detected that some metal ions affected the enzyme activity at different ratios. The enzyme was active and stable at high temperatures and nearly neutral pHs which are desirable for the usage in the food and ethanol industry.

  2. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.

    Science.gov (United States)

    Zhang, Yu; An, Jiao; Yang, Guang-Yu; Bai, Aixi; Zheng, Baisong; Lou, Zhiyong; Wu, Geng; Ye, Wei; Chen, Hai-Feng; Feng, Yan; Manco, Giuseppe

    2015-01-01

    Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL) from Geobacillus kaustophilus HTA426 (GkaP) exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km) toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.

  3. Production of Thermoalkaliphilic Lipase from Geobacillus thermoleovorans DA2 and Application in Leather Industry

    Directory of Open Access Journals (Sweden)

    Deyaa M. Abol Fotouh

    2016-01-01

    Full Text Available Thermophilic and alkaliphilic lipases are meeting a growing global attention as their increased importance in several industrial fields. Over 23 bacterial strains, novel strain with high lipolytic activity was isolated from Southern Sinai, Egypt, and it was identified as Geobacillus thermoleovorans DA2 using 16S rRNA as well as morphological and biochemical features. The lipase was produced in presence of fatty restaurant wastes as an inducing substrate. The optimized conditions for lipase production were recorded to be temperature 60°C, pH 10, and incubation time for 48 hrs. Enzymatic production increased when the organism was grown in a medium containing galactose as carbon source and ammonium phosphate as nitrogen source at concentrations of 1 and 0.5% (w/v, respectively. Moreover, the optimum conditions for lipase production such as substrate concentration, inoculum size, and agitation rate were found to be 10% (w/v, 4% (v/v, and 120 rpm, respectively. The TA lipase with Triton X-100 had the best degreasing agent by lowering the total lipid content to 2.6% as compared to kerosene (7.5% or the sole crude enzyme (8.9%. It can be concluded that the chemical leather process can be substituted with TA lipase for boosting the quality of leather and reducing the environmental hazards.

  4. Crystal structures and ligand binding of PurM proteins from Thermus thermophilus and Geobacillus kaustophilus.

    Science.gov (United States)

    Kanagawa, Mayumi; Baba, Seiki; Watanabe, Yuzo; Nakagawa, Noriko; Ebihara, Akio; Kuramitsu, Seiki; Yokoyama, Shigeyuki; Sampei, Gen-Ichi; Kawai, Gota

    2016-03-01

    Crystal structures of 5-aminoimidazole ribonucleotide (AIR) synthetase, also known as PurM, from Thermus thermophilus (Tt) and Geobacillus kaustophilus (Gk) were determined. For TtPurM, the maximum resolution was 2.2 Å and the space group was P21212 with four dimers in an asymmetric unit. For GkPurM, the maximum resolution was 2.2 Å and the space group was P21212 with one monomer in asymmetric unit. The biological unit is dimer for both TtPurM and GkPurM and the dimer structures were similar to previously determined structures of PurM in general. For TtPurM, ∼50 residues at the amino terminal were disordered in the crystal structure whereas, for GkPurM, the corresponding region covered the ATP-binding site forming an α helix in part, suggesting that the N-terminal region of PurM changes its conformation upon binding of ligands. FGAM binding site was predicted by the docking simulation followed by the MD simulation based on the SO4 (2-) binding site found in the crystal structure of TtPurM.

  5. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL from Geobacillus kaustophilus HTA426 (GkaP exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.

  6. Production of Thermoalkaliphilic Lipase from Geobacillus thermoleovorans DA2 and Application in Leather Industry.

    Science.gov (United States)

    Abol Fotouh, Deyaa M; Bayoumi, Reda A; Hassan, Mohamed A

    2016-01-01

    Thermophilic and alkaliphilic lipases are meeting a growing global attention as their increased importance in several industrial fields. Over 23 bacterial strains, novel strain with high lipolytic activity was isolated from Southern Sinai, Egypt, and it was identified as Geobacillus thermoleovorans DA2 using 16S rRNA as well as morphological and biochemical features. The lipase was produced in presence of fatty restaurant wastes as an inducing substrate. The optimized conditions for lipase production were recorded to be temperature 60°C, pH 10, and incubation time for 48 hrs. Enzymatic production increased when the organism was grown in a medium containing galactose as carbon source and ammonium phosphate as nitrogen source at concentrations of 1 and 0.5% (w/v), respectively. Moreover, the optimum conditions for lipase production such as substrate concentration, inoculum size, and agitation rate were found to be 10% (w/v), 4% (v/v), and 120 rpm, respectively. The TA lipase with Triton X-100 had the best degreasing agent by lowering the total lipid content to 2.6% as compared to kerosene (7.5%) or the sole crude enzyme (8.9%). It can be concluded that the chemical leather process can be substituted with TA lipase for boosting the quality of leather and reducing the environmental hazards.

  7. Survival and Adaptation of the Thermophilic Species Geobacillus thermantarcticus in Simulated Spatial Conditions

    Science.gov (United States)

    Di Donato, Paola; Romano, Ida; Mastascusa, Vincenza; Poli, Annarita; Orlando, Pierangelo; Pugliese, Mariagabriella; Nicolaus, Barbara

    2017-06-01

    Astrobiology studies the origin and evolution of life on Earth and in the universe. According to the panspermia theory, life on Earth could have emerged from bacterial species transported by meteorites, that were able to adapt and proliferate on our planet. Therefore, the study of extremophiles, i.e. bacterial species able to live in extreme terrestrial environments, can be relevant to Astrobiology studies. In this work we described the ability of the thermophilic species Geobacillus thermantarcticus to survive after exposition to simulated spatial conditions including temperature's variation, desiccation, X-rays and UVC irradiation. The response to the exposition to the space conditions was assessed at a molecular level by studying the changes in the morphology, the lipid and protein patterns, the nucleic acids. G. thermantarcticus survived to the exposition to all the stressing conditions examined, since it was able to restart cellular growth in comparable levels to control experiments carried out in the optimal growth conditions. Survival was elicited by changing proteins and lipids distribution, and by protecting the DNA's integrity.

  8. EFFICACY OF EXTRACTS OF SIX MEDICINAL PLANTS OF INDIA AGAINST SOME PATHOGENIC BACTERIA

    Directory of Open Access Journals (Sweden)

    Indranil Bhattacharjee

    2013-02-01

    Full Text Available The sensitivity of the pathogenic multi-drug resistant bacteria (Aeromonas hydrophila, Bacillus licheniformis, Bacillus mycoides, Bacillus niacini, Bacillus subtilis, Escherichia coli, Geobacillus thermodenitrificans, Klebsiella pneumoniae, Paenibacillus koreensis, Paenibacillus larvae larvae, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas flourescens, Pseudomonas putida and Staphylocccus aureus was tested against aqueous, acetone and ethanol extracts of mature leaves of Mimosa pudica Linn. (Mimosaceae and Moringa oleifera Lam. (Moringaceae, stems of Michelia champaca Linn. (Magnoliaceae and Musa paradisiaca Linn.(Musaceae, roots of Momordica charantia Linn. (Cucurbitaceae and Murraya koenigii Linn. (Rutaceae by agar well diffusion method. Gatifloxacin was the most effective antibiotic against all the reference bacteria. Though all the extracts were found effective, the ethanol extract showed maximum inhibition against the test microorganisms followed by acetone and aqueous extract. Bacillus niacini is the most resistant bacteria and Klebsiella pneumoniae is the most sensitive bacteria against all the extracts used. MIC values of each bacterium were also determined

  9. CLONING, PURIFICATION AND CHARACTERIZATION OF HALOTOLERANT XYLANASE FROM Geobacillus Thermodenitrificans C5

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan

    2016-06-01

    Full Text Available High levels of extracellular xylanase activity (994.50 IU/ml produced by Geobacillus thermodenitrificans C5 originated gene was detected when it was expressed in E. coli BL21 host. Thermostable xylanase (GthC5Xyl was purified to homogeneity and showed a molecular mass of approximately 44 kDa according to SDS-PAGE. The specific activity of the purified GthC5Xyl was up to 1243.125IU/mg with a 9.89-fold purification. The activity of GthC5Xyl was stimulated by CoCl2, MnSO4, CuSO4, MnCl2 but was inhibited by FeSO4, Hg, CaSO4. GthC5Xyl showed resistant to SDS, Tween 20, Triton X-100, β- Mercaptoethanol, PMSF, DTT, NEM and DEPC, SDS, and EDTA. A greater affinity for oat spelt xylan was exhibited by GthC5Xyl with maximum enzymatic activity at 60°C and 6.0 pH. The activity portrayed by GthC5Xyl was found to be acellulytic with stability at high temperature (70°C-80°C and low pH (4.0 to 8.0. Xylobiose and xylopentose were the end products of proficient oat spelt xylanase hydrolysis by GthC5Xyl. High SDS resistance and broader stability of GthC5Xyl proves it to be worthy of impending application in numerous industrial processes especially textile, detergents and animal feed industry.

  10. β-D-xylosidase from Geobacillus thermoleovorans IT-08: biochemical characterization and bioinformatics of the enzyme.

    Science.gov (United States)

    Ratnadewi, Anak Agung Istri; Fanani, Muchzainal; Kurniasih, Sari Dewi; Sakka, Makiko; Wasito, Eddy Bagus; Sakka, Kazuo; Nurachman, Zeily; Puspaningsih, Ni Nyoman Tri

    2013-08-01

    The gene encoding a thermostable β-D-xylosidase (GbtXyl43B) from Geobacillus thermoleovorans IT-08 was cloned in pET30a and expressed in Escherichia coli; additionally, characterization and kinetic analysis of GbtXyl43B were carried out. The gene product was purified to apparent homogeneity showing M r of 72 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme exhibited an optimum temperature and pH of 60 °C and 6.0, respectively. In terms of stability, GbtXyl43B was stable at 60 °C at pH 6.0 for 1 h as well as at pH 6-8 at 4 °C for 24 h. The enzyme had a catalytic efficiency (k cat/K M) of 0.0048 ± 0.0010 s(-1) mM(-1) on p-nitrophenyl-β-D-xylopyranoside substrate. Thin layer chromatography product analysis indicated that GbtXyl43B was exoglycosidase cleaving single xylose units from the nonreducing end of xylan. The activity of GbtXyl43B on insoluble xylan was eightfold higher than on soluble xylan. Bioinformatics analysis showed that GbtXyl43B belonging to glycoside hydrolase family 43 contained carbohydrate-binding module (CBM; residues 15 to 149 forming eight antiparallel β-strands) and catalytic module (residues 157 to 604 forming five-bladed β-propeller fold with predicted catalytic residues to be Asp287 and Glu476). CBM of GbtXyl43B dominated by the Phe residues which grip the carbohydrate is proposed as a novel CBM36 subfamily.

  11. Structural elements of thermostability in the maltogenic amylase of Geobacillus thermoleovorans.

    Science.gov (United States)

    Mehta, Deepika; Satyanarayana, T

    2015-08-01

    Maltogenic amylase of Geobacillus thermoleovorans (Gt-MamyIII), which has the highest thermostability among bacterial maltogenic amylases, has been used as a model enzyme to understand the role of networked salt bridges in thermoadaptation. The role of intra-chain cross-domain salt bridge networks in the thermostabilization of maltogenic amylase of G. thermoleovorans was confirmed by site-directed mutagenesis and CD analysis. The amino acid pairs in seven salt bridges have been mutated singly and pair-wise, and their free energy of thermal inactivation has been calculated. Among seven, single and double mutations in the amino acids corresponding to four salt bridges (lys306.glu336, arg403.asp65, arg497.glu523 and lys524.glu523) decrease T1/2 and Tm of Gt-MamyIII significantly. Moreover, glu523 forms networked salt bridges with arg497 and lys524. OE1 of glu523 forms electrostatic interactions with NH1 of arg497, NH2 of arg497 and NZ of lys524 at a distance of 2.33, 2.02 and 0.33Å, respectively. The mutations in three buried amino acids led to a decline in T1/2 and Tm. The buried as well as networked cross-domain salt bridges thus appear to play a significant role in the thermostabilization of Gt-MamyIII. The salt bridges lys306.glu336 and arg403.asp65, which are isolated and partially accessible, play a minor role in its thermostabilization.

  12. Substrate preference of a Geobacillus maltogenic amylase: a kinetic and thermodynamic analysis.

    Science.gov (United States)

    Nasrollahi, Samira; Golalizadeh, Leila; Sajedi, Reza H; Taghdir, Majid; Asghari, S Mohsen; Rassa, Mehdi

    2013-09-01

    The gene encoding a maltogenic amylase (MAase) from a newly isolated strain of thermophilic Geobacillus has been isolated, cloned and expressed. Following purification, biochemical and structural characterization have been performed. The enzyme exhibited maximal activity at a broad temperature range between 55 and 65 °C, clearly higher than that of other dimeric MAses. The optimum pH was 6.0 and catalytic activity increased by of Li(+) and K(+). A noticeable preference was demonstrated for α-, β- and γ-cyclodextrin (CD) compared to polymeric substrates (amylose, amylopectin, glycogen and starch) possibly due to steric interference. The affinity for CD substrates increased in the order of γ-CD>β-CD>α-CD, but k(cat)/K(m) increased as α-CD>β-CD>γ-CD, implying that increased substrate specificities are mainly attribute to kcat. Thermodynamic analysis of the activation process showed that improved activity (decrease in ΔG(#)) is accompanied by increases in activation entropy (ΔS(#)) for aforementioned substrates. Molecular docking on the binding interactions between substrates and active site residues revealed a considerably higher accessible surface area for the active site residues in the presence of α-CD than β-CD, indicating that interactions in the transition state are stronger in the presence of α-CD. This result explains the increased ΔH(#) of the activation process and increased K(m) of the enzyme in the presence of α-CD, compared to that of β-CD. This study, which presents the first detailed comparative analysis on the substrate preference of dimeric MAases for different substrates, may shed some lights into the molecular mechanism of these enzymes.

  13. Domain C of thermostable α-amylase of Geobacillus thermoleovorans mediates raw starch adsorption.

    Science.gov (United States)

    Mehta, Deepika; Satyanarayana, T

    2014-05-01

    The gene (1,542 bp) encoding thermostable Ca(2+)-independent and raw starch hydrolyzing α-amylase of the extremely thermophilic bacterium Geobacillus thermoleovorans encodes for a protein of 50 kDa (Gt-amyII) with 488 amino acids. The enzyme is optimally active at pH 7.0 and 60 °C with a t 1/2 of 19.4 h at 60 and 4 h at 70 °C. Gt-amyII hydrolyses corn and tapioca raw starches efficiently and therefore finds application in starch saccharification at industrial sub-gelatinisation temperatures. The starch hydrolysis is facilitated following adsorption of the enzyme to starch at the C-terminal domain, as confirmed by the truncation analysis. The adsorption rate constant of Gt-amyII to raw corn starch is 37.6-fold greater than that for the C-terminus truncated enzyme (Gt-amyII-T). Langmuir-Hinshelwood kinetic analysis in terms of equilibrium parameter (K R) suggested that the adsorption of Gt-amyII to corn starch is more favourable than that of Gt-amyII-T. Thermodynamics of temperature inactivation indicated a decrease in thermostabilisation of Gt-amyII upon truncation of its C-terminus. The addition of raw corn starch increased t 1/2 of Gt-amyII, but it has no such effect on Gt-amyII-T. It can, therefore, be stated that Gt-amyII binds to raw corn starch via C-terminal region that contributes to its thermostability. Phylogenetic analysis confirmed that starch binding region of Gt-amyII is, in fact, the non-catalytic domain C, and not the typical SBD of CBM families. The role of domain C in raw starch binding throws light on the evolutionary path of the known SBDs.

  14. Thermostability enhancement and change in starch hydrolysis profile of the maltohexaose-forming amylase of Bacillus stearothermophilus US100 strain.

    Science.gov (United States)

    Ben Ali, Mamdouh; Khemakhem, Bassem; Robert, Xavier; Haser, Richard; Bejar, Samir

    2006-02-15

    The implications of Asn315 and Val450 in the atypical starch hydrolysis profile of Bacillus stearothermophilus Amy (a-amylase) US100 have been suggested previously [Ben Ali, Mhiri, Mezghani and Bejar (2001) Enzyme Microb. Tech. 28, 537-542]. In order to confirm this hypothesis, three mutants were generated. Of these two have a single mutation, N315D or V450G, whereas the third contains both mutations. Analysis of the starch breakdown-profile of these three mutants, as well as of the wild-type, allowed us to conclude that each single mutation induces a small variation in the hydrolysis product. However, the major end product produced by the double mutant shifts from maltopentaose/maltohexaose to maltose/maltotriose, confirming the involvement of these two residues in starch hydrolysis. The superimposition of AmyUS100 model with that of Bacillus licheniformis shows in AmyUS100 an additional loop containing residues Ile214 and Gly215. Remarkably, the deletion of these two residues increases the half-life at 100 degrees C from 15 min to approx. 70 min. Moreover, this engineered amylase requires less calcium, 25 p.p.m. instead of 100 p.p.m., to reach maximal thermostability.

  15. Structural and functional characterization of the Geobacillus copper nitrite reductase: involvement of the unique N-terminal region in the interprotein electron transfer with its redox partner.

    Science.gov (United States)

    Fukuda, Yohta; Koteishi, Hiroyasu; Yoneda, Ryohei; Tamada, Taro; Takami, Hideto; Inoue, Tsuyoshi; Nojiri, Masaki

    2014-03-01

    The crystal structures of copper-containing nitrite reductase (CuNiR) from the thermophilic Gram-positive bacterium Geobacillus kaustophilus HTA426 and the amino (N)-terminal 68 residue-deleted mutant were determined at resolutions of 1.3Å and 1.8Å, respectively. Both structures show a striking resemblance with the overall structure of the well-known CuNiRs composed of two Greek key β-barrel domains; however, a remarkable structural difference was found in the N-terminal region. The unique region has one β-strand and one α-helix extended to the northern surface of the type-1 copper site. The superposition of the Geobacillus CuNiR model on the electron-transfer complex structure of CuNiR with the redox partner cytochrome c551 in other denitrifier system led us to infer that this region contributes to the transient binding with the partner protein during the interprotein electron transfer reaction in the Geobacillus system. Furthermore, electron-transfer kinetics experiments using N-terminal residue-deleted mutant and the redox partner, Geobacillus cytochrome c551, were carried out. These structural and kinetics studies demonstrate that the region is directly involved in the specific partner recognition.

  16. Purification, crystallization and preliminary X-ray analysis of a thermostable glycoside hydrolase family 43 beta-xylosidase from Geobacillus thermoleovorans IT-08

    NARCIS (Netherlands)

    Rohman, Ali; van Oosterwijk, Niels; Kralj, Slavko; Dijkhuizen, Lubbert; Dijkstra, Bauke W.; Puspaningsih, Ni Nyoman Tri

    2007-01-01

    The main enzymes involved in xylan-backbone hydrolysis are endo-1,4-beta-xylanase and beta-xylosidase. beta-Xylosidase converts the xylo-oligosaccharides produced by endo-1,4-beta-xylanase into xylose monomers. The beta-xylosidase from the thermophilic Geobacillus thermoleovorans IT-08, a member of

  17. Molecular cloning and characterization of a thermostable lipase from deep-sea thermophile Geobacillus sp. EPT9.

    Science.gov (United States)

    Zhu, Yanbing; Li, Hebin; Ni, Hui; Xiao, Anfeng; Li, Lijun; Cai, Huinong

    2015-02-01

    A gene (1,254 bp) encoding a lipase was identified from a deep-sea hydrothermal field thermophile Geobacillus sp. EPT9. The open reading frame of this gene encoded 417 amino acid residues. The gene was cloned, overexpressed in Escherichia coli, and the target protein was purified to homogeneity. The purified recombinant enzyme presented a molecular mass of 44.8 kDa. When p-nitrophenyl palmitate was used as a substrate, the recombinant lipase was optimally active at 55 °C and pH 8.5. The recombinant enzyme retained 44 % residual activity after incubation at 80 °C for 1 h, which indicated that Geobacillus sp. EPT9 lipase was thermostable. Homology modeling of strain EPT9 lipase was developed with the lipase from Bacillus sp. L2 as a template. The core structure exhibits an α/β-hydrolase fold and the typical catalytic triad might consist of Ser142, Asp346, and His387. The enzymatic activity of EPT9 lipase was inhibited by addition of phenylmethylsulfonyl fluoride, indicating that it contains serine residue, which plays an important role in the catalytic mechanism.

  18. Thermostable hemicellulases of a bacterium, Geobacillus sp. DC3, isolated from the former Homestake gold mine in Lead, South Dakota.

    Science.gov (United States)

    Bergdale, Terran E; Hughes, Stephen R; Bang, Sookie S

    2014-04-01

    A thermophilic strain, Geobacillus sp. DC3, capable of producing hemicellulolytic enzymes was isolated from the 1.5-km depth of the former Homestake gold mine in Lead, South Dakota. The DC3 strain expressed a high level of extracellular endoxylanase at 39.5 U/mg protein with additional hemicellulases including β-xylosidase (0.209 U/mg) and arabinofuranosidase (0.230 U/mg), after the bacterium was grown in xylan for 24 h. Partially purified DC3 endoxylanase exhibited a molecular mass of approximately 43 kDa according to zymography with an optimal pH of 7 and optimal temperature of 70 °C. The kinetic constants, K m and V max, were 13.8 mg/mL and 77.5 μmol xylose/min·mg xylan, respectively. The endoxylanase was highly stable and maintained 70 % of its original activity after 16 h incubation at 70 °C. The thermostable properties and presence of three different hemicellulases of Geobacillus sp. DC3 strain support its potential application for industrial hydrolysis of renewable biomass such as lignocelluloses.

  19. Taguchi's experimental design for optimizing the production of novel thermostable polypeptide antibiotic from Geobacillus pallidus SAT4.

    Science.gov (United States)

    Muhammad, Syed Aun; Ahmed, Safia; Ismail, Tariq; Hameed, Abdul

    2014-01-01

    Polypeptide antimicrobials used against topical infections are reported to obtain from mesophilic bacterial species. A thermophilic Geobacillus pallidus SAT4 was isolated from hot climate of Sindh Dessert, Pakistan and found it active against Micrococcus luteus ATCC 10240, Staphylococcus aureus ATCC 6538, Bacillus subtilis NCTC 10400 and Pseudomonas aeruginosa ATCC 49189. The current experiment was designed to optimize the production of novel thermostable polypeptide by applying the Taguchi statistical approach at various conditions including the time of incubation, temperature, pH, aeration rate, nitrogen, and carbon concentrations. There were two most important factors that affect the production of antibiotic including time of incubation and nitrogen concentration and two interactions including the time of incubation/pH and time of incubation/nitrogen concentration. Activity was evaluated by well diffusion assay. The antimicrobial produced was stable and active even at 55°C. Ammonium sulphate (AS) was used for antibiotic recovery and it was desalted by dialysis techniques. The resulted protein was evaluated through SDS-PAGE. It was concluded that novel thermostable protein produced by Geobacillus pallidus SAT4 is stable at higher temperature and its production level can be improved statistically at optimum values of pH, time of incubation and nitrogen concentration the most important factors for antibiotic production.

  20. Characterization of a thermostable raw-starch hydrolyzing α-amylase from deep-sea thermophile Geobacillus sp.

    Science.gov (United States)

    Jiang, Tao; Cai, Menghao; Huang, Mengmeng; He, Hao; Lu, Jian; Zhou, Xiangshan; Zhang, Yuanxing

    2015-10-01

    A deep-sea thermophile, Geobacillus sp. 4j, was identified to grow on starch and produce thermostable amylase. N-terminally truncated form of Geobacillus sp. 4j α-amylase (Gs4j-amyA) was fused at its N-terminal end with the signal peptide of outer membrane protein A (OmpA) of Escherichia coli. The enzyme was over-expressed in E. coli BL21 with a maximum extracellular production of 130U/ml in shake flask. The yield of the transformant increased 22-fold as compared with that of the wild strain. The recombinant enzyme purified to apparent homogeneity by metal-affinity chromatography, exhibited a molecular mass of 62kDa. It displayed the maximal activity at 60-65°C and pH 5.5. Its half-life (t1/2) at 80°C was 4.25h with a temperature deactivation energy of 166.3kJ/mol. Compared to three commonly used commercial α-amylases, the Gs4j-amyA exhibited similar thermostable performance to BLA but better than BAA and BSA. It also showed a universally efficient raw starch hydrolysis performance superior to commercial α-amylases at an acidic pH approaching nature of starch slurry. As a new acidic-resistant thermostable α-amylase, it has the potential to bypass the industrial gelatinization step in raw starch hydrolysis.

  1. The S-Layer Proteins of Two Bacillus stearothermophilus Wild-Type Strains Are Bound via Their N-Terminal Region to a Secondary Cell Wall Polymer of Identical Chemical Composition

    Science.gov (United States)

    Egelseer, Eva Maria; Leitner, Karl; Jarosch, Marina; Hotzy, Christoph; Zayni, Sonja; Sleytr, Uwe B.; Sára, Margit

    1998-01-01

    Two Bacillus stearothermophilus wild-type strains were investigated regarding a common recognition and binding mechanism between the S-layer protein and the underlying cell envelope layer. The S-layer protein from B. stearothermophilus PV72/p6 has a molecular weight of 130,000 and assembles into a hexagonally ordered lattice. The S-layer from B. stearothermophilus ATCC 12980 shows oblique lattice symmetry and is composed of subunits with a molecular weight of 122,000. Immunoblotting, peptide mapping, N-terminal sequencing of the whole S-layer protein from B. stearothermophilus ATCC 12980 and of proteolytic cleavage fragments, and comparison with the S-layer protein from B. stearothermophilus PV72/p6 revealed that the two S-layer proteins have identical N-terminal regions but no other extended structurally homologous domains. In contrast to the heterogeneity observed for the S-layer proteins, the secondary cell wall polymer isolated from peptidoglycan-containing sacculi of the different strains showed identical chemical compositions and comparable molecular weights. The S-layer proteins could bind and recrystallize into the appropriate lattice type on native peptidoglycan-containing sacculi from both organisms but not on those extracted with hydrofluoric acid, leading to peptidoglycan of the A1γ chemotype. Affinity studies showed that only proteolytic cleavage fragments possessing the complete N terminus of the mature S-layer proteins recognized native peptidoglycan-containing sacculi as binding sites or could associate with the isolated secondary cell wall polymer, while proteolytic cleavage fragments missing the N-terminal region remained unbound. From the results obtained in this study, it can be concluded that S-layer proteins from B. stearothermophilus wild-type strains possess an identical N-terminal region which is responsible for anchoring the S-layer subunits to a secondary cell wall polymer of identical chemical composition. PMID:9515918

  2. Cloning, expression and characterization of the DNA polymerase gene from Geobacillus sp. DYth03%地芽孢杆菌属DYth03 DNA聚合酶基因的克隆、表达及性质分析

    Institute of Scientific and Technical Information of China (English)

    罗淑娅; 李侃; 徐丽美

    2011-01-01

    A strain of thermophilic bacteria (DYth03) that can grow at 65℃ was isolated from the sediment of a hydrothermal vent field on the E53 site of the east Pacific Ocean. The 16S rDNA of DYth03 shared more than 98%sequence homology with related Geobacillus species. The gene encoding the DNA polymerase of DYth03 (DYth-pol)was cloned and sequenced. Analysis indicated that the gene was 2 631 bp in length with a G + C content of 55.5%,encoding an 876-amino-acid peptide, which was most similar to that of Bst DNApolI (98%). The DYth-pol gene was cloned in the expression vetor pTTQ-h and expressed in E. coli DH1. The expressed product was purified and characterized. It showed 5'-3' exonuclease and polymerase activity.%从东太平洋热液区E53站位的深海沉积物样品中分离出1株能在65℃生长的嗜热菌(DYth03).该菌的16S rDNA序列与地芽孢杆菌属(Geobacillus)内各种之间的同源性为98%以上.克隆得到DYth03的DNA聚合酶基因(DYth-pol),序列分析表明该基因全长为2 631 bp,G+C含量为55.5%,推测编码为876个氨基酸,与Bst DNApolI的同源性最高(达98%).将该聚合酶基因克隆到pTTQ-h表达载体上,并在大肠杆菌DH1中进行表达.对纯化到的表达产物进行酶活性测定,结果表明该酶具有聚合酶活性和5'-3'外切酶活性.

  3. Characterization of a Novel Thermostable Oligopeptidase from Geobacillus thermoleovorans DSM 15325.

    Science.gov (United States)

    Jasilionis, Andrius; Kuisiene, Nomeda

    2015-07-01

    A gene (GT-SM3B) encoding a thermostable secreted oligoendopeptidase (GT-SM3B) was cloned from the thermophile Geobacillus thermoleovorans DSM 15325. GT-SM3B is 1,857 bp in length and encodes a single-domain protein of 618 amino acids with a 23-residue signal peptide having a calculated mass of 67.7 kDa after signal cleavage. The deduced amino acid sequence of GT-SM3B contains a conservative zinc metallopeptidase motif (His(400)-Glu(401)-X-XHis (404)). The described oligopeptidase belongs to the M3B subfamily of metallopeptidases and displays the highest amino acid sequence identity (40.3%) to the oligopeptidase PepFBa from mesophilic Bacillus amyloliquefaciens 23-7A among the characterized oligopeptidases. Secretory production of GT-SM3B was used, exploiting successful oligopeptidase signal peptide recognition by Escherichia coli BL21 (DE3). The recombinant enzyme was purified from the culture fluid. Homodimerization of GT-SM3B was determined by SDS-PAGE. Both the homodimer and monomer were catalytically active within a pH range of 5.0-8.0, at pH 7.3 and 40°C, showing the Km, Vmax, and kcat values for carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala-OH peptidolysis to be 2.17 ± 0.04 × 10(-6) M, 2.65 ± 0.03 × 10(-3) micrometer/min, and 5.99 ± 0.07 s(-1), respectively. Peptidase remained stable at a broad pH range of 5.0-8.0. GT-SM3B was thermoactive, demonstrating 84% and 64% of maximum activity at 50°C and 60°C, respectively. The recombinant oligopeptidase is one of the most thermostable M3B peptidase, retaining 71% residual activity after incubation at 60°C for 1 h. GT-SM3B was shown to hydrolyze a collagenous peptide mixture derived from various types of collagen, but less preferentially than synthetic hexapeptide. This study is the first report on an extracellular thermostable metallo-oligopeptidase.

  4. Improving the thermostability and enhancing the Ca(2+) binding of the maltohexaose-forming α-amylase from Bacillus stearothermophilus.

    Science.gov (United States)

    Li, Zhu; Duan, Xuguo; Wu, Jing

    2016-03-20

    The thermostability of the maltohexaose-forming α-amylase from Bacillus stearothermophilus (AmyMH) without added Ca(2+) was improved through structure-based rational design in this study. Through comparison of a homologous model structure of AmyMH with the crystal structure of the thermostable α-amylase from Bacillus licheniformis, Ser242, which located at the beginning of fourth α-helix of the central (β/α)8 barrel was selected for mutation to improve thermostability. In addition, an amide-containing side chain (Asn193) and a loop in domain B (ΔIG mutation), which have been proven to be important for thermostability in corresponding position of other α-amylases, were also investigated. Five mutants carrying the mutations ΔIG, N193F, S242A, ΔIG/N193F, and ΔIG/N193F/S242A were generated and their proteins characterized. The most thermostable mutant protein, ΔIG/N193F/S242A, exhibited a 26-fold improvement in half-life at 95°C compared to the wild-type enzyme without added Ca(2+). Mutant ΔIG/N193F/S242A also exhibited substantially better activity and stability in the presence of the chelator EDTA, demonstrating enhanced Ca(2+) binding. These results suggest that mutant ΔIG/N193F/S242A has potential for use in the industrial liquefaction of starch. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Draft Genome Sequence of Geobacillus icigianus Strain G1w1T Isolated from Hot Springs in the Valley of Geysers, Kamchatka (Russian Federation).

    Science.gov (United States)

    Bryanskaya, Alla V; Rozanov, Aleksey S; Logacheva, Maria D; Kotenko, Anastasia V; Peltek, Sergey E

    2014-10-23

    The Geobacillus icigianus G1w1(T) strain was isolated from sludge samples of unnamed vaporing hydrothermal (97°С) outlets situated in a geyser in the Troinoy region (Valley of Geysers, Kronotsky Nature Reserve, Kamchatka, Russian Federation; 54°25'51.40″N, 160°7'41.40″E). The sequenced and annotated genome is 3,457,810 bp and encodes 3,342 genes.

  6. 嗜热菌Geobacillus sp.HB1的分离鉴定及其α-淀粉酶基因克隆表达

    Institute of Scientific and Technical Information of China (English)

    张光旭; 谢模意; 王凡; 余磊; 梁海秋; 朱萍; 杨辉

    2015-01-01

    淀粉加工和利用是广西的支柱产业,各种优良淀粉酶的开发一直是研究热点。本文从云南腾冲热海温泉分离到一株产嗜热Ⅶ-淀粉酶的菌株Geobacillus sp.HB1,经扩增其16Sr DNA测序比对,表明其与已公布基因组序列的嗜热芽孢菌Geobacillus sp.C56-T3具有99%的相似性。根据Geobacillus sp.C56-T3的AMY2基因设计引物,从Geobacillus sp.HB1中扩增出Ⅶ-淀粉酶基因HBCANH1,其与AMY2基因的核苷酸序列和氨基酸序列的一致性分别为96.7%和98.0%,以p ET-22b(+)为载体构建重组质粒p HBCANH1并在大肠杆菌中获得了外源基因的表达,经破胞后测得表达活力为172.38U/m L。重组酶HBCANH1最适反应温度为70℃,最适反应p H为6.4,具有较好的应用研究前景。

  7. Isolation and complete genome sequence of the thermophilic Geobacillus sp. 12AMOR1 from an Arctic deep-sea hydrothermal vent site.

    Science.gov (United States)

    Wissuwa, Juliane; Stokke, Runar; Fedøy, Anita-Elin; Lian, Kjersti; Smalås, Arne Oskar; Steen, Ida Helene

    2016-01-01

    Members of the genus Geobacillus have been isolated from a wide variety of habitats worldwide and are the subject for targeted enzyme utilization in various industrial applications. Here we report the isolation and complete genome sequence of the thermophilic starch-degrading Geobacillus sp. 12AMOR1. The strain 12AMOR1 was isolated from deep-sea hot sediment at the Jan Mayen hydrothermal Vent Site. Geobacillus sp. 12AMOR1 consists of a 3,410,035 bp circular chromosome and a 32,689 bp plasmid with a G + C content of 52 % and 47 %, respectively. The genome comprises 3323 protein-coding genes, 88 tRNA species and 10 rRNA operons. The isolate grows on a suite of sugars, complex polysaccharides and proteinous carbon sources. Accordingly, a versatility of genes encoding carbohydrate-active enzymes (CAZy) and peptidases were identified in the genome. Expression, purification and characterization of an enzyme of the glycoside hydrolase family 13 revealed a starch-degrading capacity and high thermal stability with a melting temperature of 76.4 °C. Altogether, the data obtained point to a new isolate from a marine hydrothermal vent with a large bioprospecting potential.

  8. Surface plasmon resonance-enabled antibacterial digital versatile discs

    Science.gov (United States)

    Dou, Xuan; Chung, Pei-Yu; Jiang, Peng; Dai, Jianli

    2012-02-01

    We report the achievement of effective sterilization of exemplary bacteria including Escherichia coli and Geobacillus stearothermophilus spores on a digital versatile disc (DVD). The spiral arrangement of aluminum-covered pits generates strong surface plasmon resonance (SPR) absorption of near-infrared light, leading to high surface temperature that could even damage the DVD plastics. Localized protein denaturation and high sterilization efficiency have been demonstrated by using a fluorescence microscope and cell cultures. Numerical simulations have also been conducted to model the SPR properties and the surface temperature distribution of DVDs under laser illumination. The theoretical predictions agree reasonably well with the experimental results.

  9. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

  10. Anaerobic bacteria

    Science.gov (United States)

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  11. Characterization of a thermophilic and halotolerant strain Geobacillus sp.XDF-4%一株耐温耐盐烃降解菌Geobacillus sp. XDF-4性能

    Institute of Scientific and Technical Information of China (English)

    夏文杰; 董汉平; 俞理; 黄立信; 赵婷

    2010-01-01

    从大庆油田龙虎泡区块采油地层水中分离得到一株性能很好的耐盐耐温的兼性烃降解菌XDF-4,经形态观察、生理生化实验和16S rDNA基因序列分析,初步鉴定为地芽孢杆菌Geobacillus sp..该菌在45~75℃、pH 6.5~9.0、盐的质量分数0~10%下生长良好,其最适生长温度为65℃,最适盐的质量分数为 3.0%.研究发现,该菌株能以原油为唯一碳源生长并合成生物表面活性剂, 发酵7 d, 其发酵液表面张力从68.59 mN·m-1降到29.58 mN·m-1.薄层色谱和显色反应表明,XDF-4产出的表面活性剂主要包含:糖类50.26%(质量)、脂类28.47%(质量)、蛋白质15.35%(质量);其临界胶束浓度为22 mg·L-1.GC气相色谱和族组分柱色谱分析表明,烃降解菌Geobacillus sp.XDF-4作用后,原油轻质组分含量明显增加,重质组分含量降低.物理模拟实验表明,该菌可在一次水驱基础上进一步提高采收率5.69%,可有效应用于高温高盐油藏微生物驱现场实验.

  12. Isolation and Characterization of Thermophilic Cellulase-Producing Bacteria from Empty Fruit Bunches-Palm Oil Mill Effluent Compost

    Directory of Open Access Journals (Sweden)

    Azhari S. Baharuddin

    2010-01-01

    Full Text Available Problems statement: Lack of information on locally isolated cellulase-producing bacterium in thermophilic compost using a mixture of Empty Fruit Bunch (EFB and Palm Oil Mill Effluent (POME as composting materials. Approach: The isolation of microbes from compost heap was conducted at day 7 of composting process where the mixture of composting materials consisted of 45.8% cellulose, 17.1% hemicellulose and 28.3% lignin content. The temperature, pH and moisture content of the composting pile at day 7 treatment were 58.3, 8.1 and 65.5°C, respectively. The morphological analysis of the isolated microbes was conducted using Scanning Electron Microscope (SEM and Gram stain method. The congo red test was conducted in order to detect 1% CMC agar degradation activities. Total genomic DNAs were extracted from approximately 1.0 g of mixed compost and amplified by using PCR primers. The PCR product was sequent to identify the nearest relatives of 16S rRNA genes. The localization of bacteria chromosomes was determined by Fluorescence In Situ Hybridization (FISH analysis. Results: Single isolated bacteria species was successfully isolated from Empty Fruit Bunch (EFB-Palm Oil Mill Effluent (POME compost at thermophilic stage. Restriction fragment length polymorphism profiles of the DNAs coding for the 16S rRNAs with the phylogenetic analysis showed that the isolated bacteria from EFB-POME thermophilic compost gave the highest homology (99% with similarity to Geobacillus pallidus. The strain was spore forming bacteria and able to grow at 60°C with pH 7. Conclusion: Thermophilic bacteria strain, Geobacillus pallidus was successfully isolated from Empty Fruit Bunch (EFB and Palm Oil Mil Effluent (POME compost and characterized.

  13. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    , Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  14. Crystallization and preliminary X-ray crystallographic analysis of L-arabinose isomerase from thermophilic Geobacillus kaustophilus.

    Science.gov (United States)

    Cao, Thinh-Phat; Choi, Jin Myung; Lee, Sang-Jae; Lee, Yong-Jik; Lee, Sung-Keun; Jun, Youngsoo; Lee, Dong-Woo; Lee, Sung Haeng

    2014-01-01

    L-arabinose isomerase (AI), which catalyzes the isomerization of L-arabinose to L-ribulose, can also convert D-galactose to D-tagatose, a natural sugar replacer, which is of commercial interest in the food and healthcare industries. Intriguingly, mesophilic and thermophilic AIs showed different substrate preferences and metal requirements in catalysis and different thermostabilities. However, the catalytic mechanism of thermophilic AIs still remains unclear. Therefore, thermophilic Geobacillus kaustophilus AI (GKAI) was overexpressed, purified and crystallized, and a preliminary X-ray diffraction data set was obtained. Diffraction data were collected from a GKAI crystal to 2.70 Å resolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 224.12, b = 152.95, c = 91.28 Å, β = 103.61°. The asymmetric unit contained six molecules, with a calculated Matthews coefficient of 2.25 Å(3) Da(-1) and a solvent content of 45.39%. The three-dimensional structure determination of GKAI is currently in progress by molecular replacement and model building.

  15. Cloning, expression and applicability of thermo-alkali-stable xylanase of Geobacillus thermoleovorans in generating xylooligosaccharides from agro-residues.

    Science.gov (United States)

    Verma, Digvijay; Satyanarayana, T

    2012-03-01

    A xylanase gene (xyl-gt) of 1.224 kbp was cloned from the extremely thermophilic bacterium Geobacillus thermoleovorans that encodes a protein containing 408 amino acid residues. Eight conserved regions (signature sequences) of GH family 10 xylanases have been found in the xylanase. When the xylanase gene was cloned and expressed in Escherichia coli BL21 (DE3), the recombinant strain produced xylanase titer of 270 U mg(-1) which is 27-fold higher than the wild strain. It is optimally active at 80°C and pH 8.5 with a high thermostability over broad range of pH (6-12) and temperature (40-100°C). The end products of the hydrolysis of birch wood xylan and agro-residues included xylobiose, xylotriose, xylotetraose and xylopentaose. The xylanase of G. thermoleovorans is one of the rare xylanases that exhibits thermo-alkali-stability, and thus, it is a suitable candidate for pre-bleaching of paper pulps and generating xylooligosaccharides from agro-residues for use as prebiotics.

  16. Isolation of a thermophilic and halophilic tyrosol-degrading Geobacillus from a Tunisian high-temperature oil field.

    Science.gov (United States)

    Chamkha, Mohamed; Mnif, Sami; Sayadi, Sami

    2008-06-01

    An aerobic, thermophilic, halotolerant and Gram-positive bacterium, designated strain C5, was isolated from a high-temperature oil field, located in Sfax, Tunisia, after enrichment on tyrosol. Strain C5 grew between 25 and 70 degrees C and optimally at 50 degrees C. It grew in the presence of 0-12% (w/v) NaCl, with optimum growth at 3% (w/v) NaCl. Strain C5 was able to degrade tyrosol aerobically, in the presence of 30 g L(-1) NaCl and under warm conditions (55 degrees C). The degradation of tyrosol proceeded via p-hydroxyphenylacetic and 3,4-dihydroxyphenylacetic acids. The products were confirmed by HPLC and GC-MS analyses. Strain C5 was also found to degrde a wide range of other aromatic compounds, including benzoic, p-hydroxybenzoic, protocatechuic, vanillic, p-hydroxyphenylacetic, 3,4-dihydroxyphenylacetic, cinnamic and ferulic acids, phenol and m-cresol. Moreover, strain C5 was grown on diesel and crude oil as sole carbon and energy sources. Strain C5 was also able to utilize several carbohydrates. Phenotypic characteristics and phylogenetic analysis of the 16S rRNA gene sequence of strain C5 revealed that it was related to members of the genus Geobacillus, being most closely related to the type strain of G. pallidus (99% sequence similarity). In addition, we report on growth of the type strain of G. pallidus on different aromatic compounds and hydrocarbons.

  17. 嗜热菌Geobacillus sp.HB1的分离鉴定及其α-淀粉酶基因克隆表达

    Institute of Scientific and Technical Information of China (English)

    张光旭; 谢模意; 王凡; 余磊; 梁海秋; 朱萍; 杨辉

    2015-01-01

    淀粉加工和利用是广西的支柱产业,各种优良淀粉酶的开发一直是研究热点.本文从云南腾冲热海温泉分离到一株产嗜热α-淀粉酶的菌株Geobacillus sp.HB1,经扩增其16SrDNA测序比对,表明其与已公布基因组序列的嗜热芽孢菌Geobacillussp.C56-T3具有99%的相似性.根据Geobacillus sp.C56-T3的AMY2基因设计引物,从Geobacillus sp.HB1中扩增出α-淀粉酶基因HBCANH1,其与AMY2基因的核苷酸序列和氨基酸序列的一致性分别为96.7%和98.0%,以pET-22b(+)为载体构建重组质粒pHB-CANH1并在大肠杆菌中获得了外源基因的表达,经破胞后测得表达活力为172.38U/mL.重组酶HBCANH1最适反应温度为70℃,最造反应pH为6.4,具有较好的应用研究前景.

  18. 嗜热耐盐烃降解菌Geobacillus sp.WJ-2降解原油性能研究%Oil-degrading characterization of thermophilic and halotolerant strain Geobacillus sp.WJ-2

    Institute of Scientific and Technical Information of China (English)

    夏文杰; 董汉平; 俞理

    2012-01-01

    Strain WJ-2 which was identified as Geobacillus sp. By morphology, physiological and biochemical identification and analysis of 16S rDNA sequencing was characterized to degrade crude oil and produce biosurfactant at high temperature and salinity. It could grow at 45-75 °C and 0-10% (mass fraction) of NaCl, and the optimal temperature and NaCl concentration is 65 °C and 3.0%, respectively. Under aerobic or anaerobic condition, the strain could utilize crude oil as sole carbon source to synthesize biosurfactant that the yield is 19.89 g/L and 11.69 g/L, respectively. Based on thin layer chromatography and chromogenic reaction, the purified biosurfactant is extracted from two conditions contain different compounds. Gas chromatography and group composition analysis reveal that the strain WJ-2 has a preference of utilizing light components under aerobic condition, degrading heavy components under anaerobic condition and decreasing the viscosity by 71.57% and 77.45% and freezing point of crude oil by 5 °C and 8 °C, respectively. Sand cores were used to simulate the actual environment in Daqing petroleum reservoirs. The results show that the oil recovery of strain WJ-2 under aerobic and anaerobic condition increases by 6.46% and 5.92%, respectively.%以液蜡为唯一碳源,从大庆油田龙虎泡区块采油污水样中分离到一株高效嗜热耐盐的兼性烃降解菌WJ-2,经形态观察、生理生化实验和16S rRNA基因序列分析,初步鉴定为地芽孢杆菌Geobacillus sp..在有氧或者厌氧条件下,该菌均在45~75℃和0~10% NaCl溶液中生长良好,其最适生长温度为65℃,最适盐的质量分数为3.0%;该菌株能以原油为唯一碳源生长并合成生物表面活性剂,发酵7d,生物表面活性剂产量在好氧条件和厌氧条件下分别为19.89 g/L和11.69 g/L.薄层层析和显色反应表明WJ-2产出的表面活性剂组成在好氧和厌氧条件下不相同.经GC气相色谱和族组分柱层析对菌株WJ-2

  19. Gene Cloning, Expression and Charactrization of the Alapha-amylase Gene from Geobacillus sp GXS1%Geobacillus sp.GXS1α-淀粉酶基因的克隆表达及酶学性质研究

    Institute of Scientific and Technical Information of China (English)

    薛蓓; 裴建新; 刘振东; 罗章; 韦宇拓

    2014-01-01

    以地芽孢杆菌Geobacillus sp.GXS1基因组DNA为模板,PCR扩增获得α-淀粉酶基因,构建重组质粒pSE-amy,转化大肠杆菌诱导表达。SDS-PAGE电泳结果显示,有相对分子质量为58 ku的特异性蛋白得到表达。用金属镍亲和层析将重组蛋白进行分离纯化,并进行酶学性质研究。结果表明:重组酶的最适温度为65℃,最适pH 7.0,Km值为2.93 mg/mL,比活力为353.95 U/mg,Tm为75℃。金属离子Cu2+、Fe3+、Fe2+、Zn2+、Co2+、Hg2+、Ag+及金属鏊合剂EDTA对酶活有显著抑制作用, Mn2+、Ba2+对酶活有微弱的抑制作用, K+、Ca2+、Mg2+、巯基乙醇对酶有微弱的激活作用,而其它一些离子如Na+、Li+对酶活影响不大。经HPLC分析表明,重组α-淀粉酶催化淀粉的水解产物为葡萄糖、麦芽糖和麦芽三糖的混合物。%The gene encoding alpha-amylase from Geobacillus sp.GXS1 was amplified by PCR and expressed in JM109 (DE3). The recombinant protein was purified by nickel affinity chromatography.The purified enzyme presented as one protein band on SDS-PAGE with molecular weight of 58 u.The results showed that the optimum tempreture and pH of purified alpha-amylase were 65℃/7.0 respectively. The Vmax,Km,activity and Tm for soluble-starch were shown to be 2.93 mg/mL,353.95 U/mg,75 ℃. The activity of the enzyme was strongly inhibited by Cu2+, Fe3+,Fe2+,Zn2+,Co2+,Hg2+,Ag+and EDTA, while Na+,Li+had no effect on it. Mn2+,Ba2+had a little inhibition and K+,Ca2+,Mg2+had a little activation on its activity. The results of HPLC of products from starch by the amylase demonstrated that the enzyme can be used to produce maltotriose,maltose and glucose from starch.

  20. Characterization of thermophilic strain Geobacillus sp. SY-9 with capability to lyse bacterial Cells%嗜热溶胞土芽孢杆菌(Geobacillus sp.) SY-9的基本特性

    Institute of Scientific and Technical Information of China (English)

    宋玉栋; 胡洪营; 李鑫

    2007-01-01

    从污泥堆肥中分离得到一株具有溶胞能力的嗜热菌SY-9,经形态及16S rDNA测序初步鉴定为土芽孢杆菌属(Geobacillus sp.).对其生长、产酶及溶胞特性进行了研究.结果表明,SY-9最适生长pH值为7~9,最适生长温度约60℃,60℃的世代时间为34min.SY-9培养上清液具有溶胞能力,上清液经过热处理后溶胞能力明显下降,说明溶胞能力主要来自酶的作用.SY-9间歇培养过程中,培养上清液对大肠杆菌(Escherichia coli)的溶胞活性在SY-9进入稳定生长期后逐渐升高,达到最大值后随着培养时间的延长逐渐下降.SY-9培养上清液对受试的5株革兰氏阴性菌(3株大肠杆菌及2株假单胞菌)及部分革兰氏阳性菌(枯草芽孢杆菌、红球菌、球形节杆菌及溶壁微球菌)都具有溶胞能力.

  1. Inactivation factors of spore-forming bacteria using low-pressure microwave plasmas in an N{sub 2} and O{sub 2} gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M K; Ogino, A; Nagatsu, M [Graduate School of Science and Technology, Shizuoka University, Johoku 3-5-1, Hamamatsu 432-8561 (Japan)], E-mail: tmnagat@ipc.shizuoka.ac.jp

    2009-11-15

    In this study, we investigated the inactivation characteristics of Geobacillus stearothermophilus spores under different plasma exposure conditions using low-pressure microwave plasma in nitrogen, oxygen and an air-simulated (N{sub 2}:O{sub 2}=4:1) gas mixture. The microwave-excited surface-wave plasma discharges were produced at low pressure by a large volume device. The directly plasma-exposed spores, up to 10{sup 6} populations, were successfully inactivated within 15, 10 and 5 min of surface-wave plasma treatment using nitrogen, oxygen and an air-simulated gas mixture, respectively, as working gases within the temperature of 75 deg. C. The contribution of different inactivation factors was evaluated by placing different filters (e.g. a LiF plate, a quartz plate and a Tyvek (registered) sheet) as indirect exposure of spores to the plasma. It was observed that optical emissions (including vacuum UV (VUV)/UV) play an important role in the inactivation process. To further evaluate the effect of VUV/UV photons, we placed an evacuated isolated chamber, inside which spores were set, into the main plasma chamber. The experimental results show that the inactivation time by VUV/UV photons alone, without working gas in the immediate vicinity of the spores, is longer than that with working gas. This suggests that the VUV/UV emission is responsible not only for direct UV inactivation of spores but also for generation of reactive neutral species by photoexcitation. The scanning electron microscopy images revealed significant changes in the morphology of directly plasma-exposed spores but no change in the spores irradiated by VUV/UV photons only.

  2. Inactivation factors of spore-forming bacteria using low-pressure microwave plasmas in an N2 and O2 gas mixture

    Science.gov (United States)

    Singh, M. K.; Ogino, A.; Nagatsu, M.

    2009-11-01

    In this study, we investigated the inactivation characteristics of Geobacillus stearothermophilus spores under different plasma exposure conditions using low-pressure microwave plasma in nitrogen, oxygen and an air-simulated (N2:O2=4:1) gas mixture. The microwave-excited surface-wave plasma discharges were produced at low pressure by a large volume device. The directly plasma-exposed spores, up to 106 populations, were successfully inactivated within 15, 10 and 5 min of surface-wave plasma treatment using nitrogen, oxygen and an air-simulated gas mixture, respectively, as working gases within the temperature of 75 °C. The contribution of different inactivation factors was evaluated by placing different filters (e.g. a LiF plate, a quartz plate and a Tyvek® sheet) as indirect exposure of spores to the plasma. It was observed that optical emissions (including vacuum UV (VUV)/UV) play an important role in the inactivation process. To further evaluate the effect of VUV/UV photons, we placed an evacuated isolated chamber, inside which spores were set, into the main plasma chamber. The experimental results show that the inactivation time by VUV/UV photons alone, without working gas in the immediate vicinity of the spores, is longer than that with working gas. This suggests that the VUV/UV emission is responsible not only for direct UV inactivation of spores but also for generation of reactive neutral species by photoexcitation. The scanning electron microscopy images revealed significant changes in the morphology of directly plasma-exposed spores but no change in the spores irradiated by VUV/UV photons only.

  3. Biophysical and biochemical characterization of a hyperthermostable and Ca2+ -independent alpha-Amylase of an extreme thermophile Geobacillus thermoleovorans.

    Science.gov (United States)

    Uma Maheswar Rao, J L; Satyanarayana, T

    2008-08-01

    alpha-Amylases reported from various microbial sources have been shown to be moderately thermostable and Ca2+ dependent. The bacterial strain used in this investigation is an extremely thermophilic bacterium Geobacillus thermoleovorans that produces a novel alpha-amylase (26 kDa; alpha-amylase gt), which is hyperthermostable (Topt 100 degrees C) and does not require Ca2+ for its activity/stability. These special features of alpha-amylase gt make it applicable in starch saccharification process. The structural aspects of alpha-amylase gt are, therefore, of significant interest to understand its structure-function relationship. The circular dichroism spectroscopic data revealed the native alpha-amylase gt to contain 25% alpha-helix, 21% beta-sheet, and 54% random coils. The addition of urea, at high concentration (8 M), appeared to expose the buried Trp residues of the native alpha-amylase gt to the aqueous environment and thus showed low fluorophore. Fluorescence-quenching experiments using KI, CsCl, N-bromosuccinimide, and acrylamide revealed interesting features of the tryptophan microenvironment. Analysis of Ksv and fa values of KI, CsCl, and acrylamide suggested the overall Trp microenvironment in alpha-amylase to be slightly electropositive. Fluorescence-quenching studies with acrylamide revealed the occurrence of both collisional as well as static quenching processes. There was no change in the alpha-helix content or the enzyme activity with an increase in temperature (60-100 degrees C) that suggested a critical role of the alpha-helix content in maintaining the catalytic activity.

  4. The quaternary structure of the amidase from Geobacillus pallidus RAPc8 is revealed by its crystal packing

    Energy Technology Data Exchange (ETDEWEB)

    Agarkar, Vinod B. [Advanced Research Centre for Applied Microbiology, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Kimani, Serah W. [Department of Molecular and Cell Biology, University of Cape Town, Rondebosch (South Africa); Cowan, Donald A.; Sayed, Muhammed F.-R. [Advanced Research Centre for Applied Microbiology, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Sewell, B. Trevor, E-mail: sewell@uctvms.uct.ac.za [Electron Microscope Unit, University of Cape Town, Rondebosch (South Africa); Advanced Research Centre for Applied Microbiology, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa)

    2006-12-01

    The amidase from G. pallidus RAPc8, a moderate thermophile, converts amides to the corresponding acids and ammonia and has application as an industrial catalyst. RAPc8 amidase has been cloned, expressed and purified, and then crystallized using the hanging-drop vapour-diffusion method. The amidase from Geobacillus pallidus RAPc8, a moderate thermophile, is a member of the nitrilase enzyme superfamily. It converts amides to the corresponding acids and ammonia and has application as an industrial catalyst. RAPc8 amidase has been cloned and functionally expressed in Escherichia coli and has been purified by heat treatment and a number of chromatographic steps. The enzyme was crystallized using the hanging-drop vapour-diffusion method. Crystals produced in the presence of 1.2 M sodium citrate, 400 mM NaCl, 100 mM sodium acetate pH 5.6 were selected for X-ray diffraction studies. A data set having acceptable statistics to 1.96 Å resolution was collected under cryoconditions using an in-house X-ray source. The space group was determined to be primitive cubic P4{sub 2}32, with unit-cell parameter a = 130.49 (±0.05) Å. The structure was solved by molecular replacement using the backbone of the hypothetical protein PH0642 from Pyrococcus horikoshii (PDB code 1j31) with all non-identical side chains substituted with alanine as a probe. There is one subunit per asymmetric unit. The subunits are packed as trimers of dimers with D3 point-group symmetry around the threefold axis in such a way that the dimer interface seen in the homologues is preserved.

  5. Properties of an alkali-thermo stable xylanase from Geobacillus thermodenitrificans A333 and applicability in xylooligosaccharides generation.

    Science.gov (United States)

    Marcolongo, Loredana; La Cara, Francesco; Morana, Alessandra; Di Salle, Anna; Del Monaco, Giovanni; Paixão, Susana M; Alves, Luis; Ionata, Elena

    2015-04-01

    An extracellular thermo-alkali-stable and cellulase-free xylanase from Geobacillus thermodenitrificans A333 was purified to homogeneity by ion exchange and size exclusion chromatography. Its molecular mass was 44 kDa as estimated in native and denaturing conditions by gel filtration and SDS-PAGE analysis, respectively. The xylanase (GtXyn) exhibited maximum activity at 70 °C and pH 7.5. It was stable over broad ranges of temperature and pH retaining 88 % of activity at 60 °C and up to 97 % in the pH range 7.5-10.0 after 24 h. Moreover, the enzyme was active up to 3.0 M sodium chloride concentration, exhibiting at that value 70 % residual activity after 1 h. The presence of other metal ions did not affect the activity with the sole exceptions of K(+) that showed a stimulating effect, and Fe(2+), Co(2+) and Hg(2+), which inhibited the enzyme. The xylanase was activated by non-ionic surfactants and was stable in organic solvents remaining fully active over 24 h of incubation in 40 % ethanol at 25 °C. Furthermore, the enzyme was resistant to most of the neutral and alkaline proteases tested. The enzyme was active only on xylan, showing no marked preference towards xylans from different origins. The hydrolysis of beechwood xylan and agriculture-based biomass materials yielded xylooligosaccharides with a polymerization degree ranging from 2 to 6 units and xylobiose and xylotriose as main products. These properties indicate G. thermodenitrificans A333 xylanase as a promising candidate for several biotechnological applications, such as xylooligosaccharides preparation.

  6. Thermoadaptation-directed enzyme evolution in an error-prone thermophile derived from Geobacillus kaustophilus HTA426.

    Science.gov (United States)

    Suzuki, Hirokazu; Kobayashi, Jyumpei; Wada, Keisuke; Furukawa, Megumi; Doi, Katsumi

    2015-01-01

    Thermostability is an important property of enzymes utilized for practical applications because it allows long-term storage and use as catalysts. In this study, we constructed an error-prone strain of the thermophile Geobacillus kaustophilus HTA426 and investigated thermoadaptation-directed enzyme evolution using the strain. A mutation frequency assay using the antibiotics rifampin and streptomycin revealed that G. kaustophilus had substantially higher mutability than Escherichia coli and Bacillus subtilis. The predominant mutations in G. kaustophilus were A · T→G · C and C · G→T · A transitions, implying that the high mutability of G. kaustophilus was attributable in part to high-temperature-associated DNA damage during growth. Among the genes that may be involved in DNA repair in G. kaustophilus, deletions of the mutSL, mutY, ung, and mfd genes markedly enhanced mutability. These genes were subsequently deleted to construct an error-prone thermophile that showed much higher (700- to 9,000-fold) mutability than the parent strain. The error-prone strain was auxotrophic for uracil owing to the fact that the strain was deficient in the intrinsic pyrF gene. Although the strain harboring Bacillus subtilis pyrF was also essentially auxotrophic, cells became prototrophic after 2 days of culture under uracil starvation, generating B. subtilis PyrF variants with an enhanced half-denaturation temperature of >10°C. These data suggest that this error-prone strain is a promising host for thermoadaptation-directed evolution to generate thermostable variants from thermolabile enzymes.

  7. Isolation and characterization of a thermotolerant ene reductase from Geobacillus sp. 30 and its heterologous expression in Rhodococcus opacus.

    Science.gov (United States)

    Tsuji, Naoto; Honda, Kohsuke; Wada, Mayumi; Okano, Kenji; Ohtake, Hisao

    2014-07-01

    Rhodococcus opacus B-4 cells are adhesive to and even dispersible in water-immiscible hydrocarbons owing to their highly lipophilic nature. In this study, we focused on the high operational stability of thermophilic enzymes and applied them to a biocatalytic conversion in an organic reaction medium using R. opacus B-4 as a lipophilic capsule of enzymes to deliver them into the organic medium. A novel thermo- and organic-solvent-tolerant ene reductase, which can catalyze the enantioselective reduction of ketoisophorone to (6R)-levodione, was isolated from Geobacillus sp. 30, and the gene encoding the enzyme was heterologously expressed in R. opacus B-4. Another thermophilic enzyme which catalyzes NAD(+)-dependent dehydrogenation of cyclohexanol was identified from the gene-expression library of Thermus thermophilus and the gene was coexpressed in R. opacus B-4 for cofactor regeneration. While the recombinant cells were not viable in the mixture due to high reaction temperature, 634 mM of (6R)-levodione could be produced with an enantiopurity of 89.2 % ee by directly mixing the wet cells of the recombinant R. opacus with a mixture of ketoisophorone and cyclohexanol at 50 °C. The conversion rate observed with the heat-killed recombinant cells was considerably higher than that obtained with a cell-free enzyme solution, demonstrating that the accessibility between the substrates and enzymes could be improved by employing R. opacus cells as a lipophilic enzyme capsule. These results imply that a combination of thermophilic enzymes and lipophilic cells can be a promising approach for the biocatalytic production of water-insoluble chemicals.

  8. Analysis of Metabolic Pathways and Fluxes in a Newly Discovered Thermophilic and Ethanol-Tolerant Geobacillus Strain

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yinjie J.; Sapra, Rajat; Joyner, Dominique; Hazen, Terry C.; Myers, Samuel; Reichmuth, David; Blanch, Harvey; Keasling, Jay D.

    2009-01-20

    A recently discovered thermophilic bacterium, Geobacillus thermoglucosidasius M10EXG, ferments a range of C5 (e.g., xylose) and C6 sugars (e.g., glucose) and istolerant to high ethanol concentrations (10percent, v/v). We have investigated the central metabolism of this bacterium using both in vitro enzyme assays and 13C-based flux analysis to provide insights into the physiological properties of this extremophile and explore its metabolism for bio-ethanol or other bioprocess applications. Our findings show that glucose metabolism in G. thermoglucosidasius M10EXG proceeds via glycolysis, the pentose phosphate pathway, and the TCA cycle; the Entner?Doudoroff pathway and transhydrogenase activity were not detected. Anaplerotic reactions (including the glyoxylate shunt, pyruvate carboxylase, and phosphoenolpyruvate carboxykinase) were active, but fluxes through those pathways could not be accuratelydetermined using amino acid labeling. When growth conditions were switched from aerobic to micro-aerobic conditions, fluxes (based on a normalized glucose uptake rate of 100 units (g DCW)-1 h-1) through the TCA cycle and oxidative pentose phosphate pathway were reduced from 64+-3 to 25+-2 and from 30+-2 to 19+-2, respectively. The carbon flux under micro-aerobic growth was directed formate. Under fully anerobic conditions, G. thermoglucosidasius M10EXG used a mixed acid fermentation process and exhibited a maximum ethanol yield of 0.38+-0.07 mol mol-1 glucose. In silico flux balance modeling demonstrates that lactate and acetate production from G. thermoglucosidasius M10EXG reduces the maximum ethanol yieldby approximately threefold, thus indicating that both pathways should be modified to maximize ethanol production.

  9. Decontamination effects of low-temperature plasma generated by corona discharge. Part II: new insights.

    Science.gov (United States)

    Scholtz, V; Julák, J; Kríha, V; Mosinger, J; Kopecká, S

    2007-01-01

    The second part of our paper presents the results of experiments with the decontamination of surfaces by low-temperature plasma generated by corona discharge in air at atmospheric pressure. A simple device is described and the effects of the corona discharge on model microorganisms, viz. the yeast Candida albicans, Gram-negative bacteria Escherichia coli, Enterobacter aerogenes, Neisseria sicca, Stenotrophomonas maltophilia, Gram-positive bacteria Deinococcus radiodurans, Enterococcus faecium, Staphylococcus epidermidis, Streptococcus sanguinis, and vegetative and spore forms of Geobacillus stearothermophilus are discussed. A similar microbicidal effect after about one-minute exposure was observed in all vegetative forms of the microorganisms. Measurement in growth inhibition zones on a semisolid medium was used to determine the dependence of the microbicidal effect on exposure time and the distance between electrodes. Counting of colonies served to assess the microbicidal effect of the discharge on contaminated inert surfaces observable after more than 1 min exposure. Geobacillus stearothermophilus spores were found to have several times lower susceptibility to the action of the discharge and the microbicidal effect was observed only after an 8 min exposure. Reaction with the iodide reagent did not unambiguously demonstrate the difference between ozone and singlet oxygen as presumed active components of the corona. The area distribution of reactive oxygen species was determined; it was found to differ from the Wartburg law depending on exposure time. Qualitative evidence was obtained on the penetration of the reactive oxygen species into the semisolid medium.

  10. Purification and Characterization of a New Thermostable, Haloalkaline, Solvent Stable, and Detergent Compatible Serine Protease from Geobacillus toebii Strain LBT 77

    Directory of Open Access Journals (Sweden)

    Wajdi Thebti

    2016-01-01

    Full Text Available A new thermostable, haloalkaline, solvent stable SDS-induced serine protease was purified and characterized from a thermophilic Geobacillus toebii LBT 77 newly isolated from a Tunisian hot spring. This study reveals the potential of the protease from Geobacillus toebii LBT 77 as an additive to detergent with spectacular proprieties described for the first time. The protease was purified to homogeneity by ammonium sulfate precipitation followed by Sephadex G-75 and DEAE-Cellulose chromatography. It was a monomeric enzyme with molecular weight of 30 kDa. The optimum pH, temperature, and NaCl for maximum protease activity were 13.0, 95°C, and 30%, respectively. Activity was stimulated by Ca2+, Mg2+, DTNB, β-mercaptoethanol, and SDS. The protease was extremely stable even at pH 13.25, 90°C, and 30% NaCl and in the presence of hydrophilic, hydrophobic solvents at high concentrations. The high compatibility with ionic, nonionic, and commercial detergents confirms the utility as an additive to cleaning products. Kinetic and thermodynamic characterization of protease revealed Km=1 mg mL−1,  Vmax=217.5 U mL−1, Kcat/Km=99 mg mL−1 S−1, Ea=51.5 kJ mol−1, and ΔG⁎=56.5 kJ mol−1.

  11. Enzymatic synthesis of fructose 1,6-diphosphate with ATP regeneration in a batch reactor and a semibatch reactor using purified enzymes of Bacillus stearothermophilus.

    Science.gov (United States)

    Widjaja, A; Shiroshima, M; Yasuda, M; Ogino, H; Nakajima, H; Ishikawa, H

    1999-01-01

    The enzymatic synthesis of fructose 1,6-diphosphate (FDP), an important glycolytic intermediate whose applications in the field of medicine have generated a great deal of interest, was performed in a batch reactor and a semibatch reactor. Using the batch reactor, FDP was first synthesized from glucose by three enzymatic reactions and the ATP consumed was regenerated simultaneously using conjugated enzymes, all of which were purified from crude cell extract of thermophilic Bacillus stearothermophilus. The results of the experiments performed using several enzyme concentrations suggest the existence of an optimum concentration for each enzyme at which the maximum FDP yield can be attained. Since the thermal decomposition of acetyl phosphate reduced the yield of FDP in the batch reactor, the use of a semibatch reactor in which acetyl phosphate was fed continuously was examined. The yield of FDP was improved but the time required to complete the reaction was longer, resulting in a lower productivity of FDP. The yields observed in the two reactors using various enzyme and substrate concentrations were in good agreement with the theoretical predictions calculated based on differential equations derived for the system using the rate equations and the kinetic parameters determined previously. This means that these equations can be used for the analysis of the experimental results as well as for determining the optimum experimental conditions.

  12. Secretory expression of thermostable alkaline protease from Bacillus stearothermophilus FI by using native signal peptide and α-factor secretion signal in Pichia pastoris.

    Science.gov (United States)

    Latiffi, Amaliawati Ahmad; Salleh, Abu Bakar; Rahman, Raja Noor Zaliha Raja Abd; Oslan, Siti Nurbaya; Basri, Mahiran

    2013-01-01

    The thermostable alkaline protease from Bacillus stearothermophilus F1 has high potential for industrial applications, and attempt to produce the enzyme in yeast for higher yield was undertaken. Secretory expression of F1 protease through yeast system could improve enzyme's capability, thus simplifying the purification steps. Mature and full genes of F1 protease were cloned into Pichia pastoris expression vectors (pGAPZαB and pPICZαB) and transformed into P. pastoris strains (GS115 and SMD1168H) via electroporation method. Recombinant F1 protease under regulation constitutive GAP promoter revealed that the highest expression was achieved after 72 h cultivation. While inducible AOX promoter showed that 0.5% (v/v) methanol was the best to induce expression. It was proven that constitutive expression strategy was better than inducible system. The α-secretion signal from the plasmid demonstrated higher secretory expression level of F1 protease as compared to native Open Reading Frame (ORF) in GS115 strain (GE6GS). Production medium YPTD was found to be the best for F1 protease expression with the highest yield of 4.13 U/mL. The protein was expressed as His-tagged fusion protein with a size about 34 kDa.

  13. Application of artificial neural networks to describe the combined effect of pH and NaCl on the heat resistance of Bacillus stearothermophilus.

    Science.gov (United States)

    Esnoz, A; Periago, P M; Conesa, R; Palop, A

    2006-02-01

    A model for prediction of bacterial spore inactivation was developed. The influence of temperature, pH and NaCl on the heat resistance of Bacillus stearothermophilus spores was described using low-complexity, black box models based on artificial neural networks. Literature data were used to build and train the neural network, and new experimental data were used to evaluate it. The neural network models gave better predictions than the classical quadratic response surface model in all the experiments tried. When the neural networks were evaluated using new experimental data, also good predictions were obtained, providing fail-safe predictions of D values in all cases. The weights and biases values of neurons of the neural network that gave the best results are presented, so the reader can use the model for their own purposes. The use of this non-linear modelling technique makes it possible to describe more accurately interacting effects of environmental factors when compared with classical predictive microbial models.

  14. Rhizosphere Bacteria

    Directory of Open Access Journals (Sweden)

    N.V. Feoktistova

    2016-06-01

    Full Text Available The review deals with the analysis of modern literature data on rhizosphere bacteria and their role in plant life. The structure of rhizosphere has been characterized. The role of plants as the centers of formation of microbial communities has been shown. Data on the main groups of microorganisms inhabiting the rhizosphere have been provided. The associative relationship between rhizobacteria and partner plants has been investigated. The modern concept of holobiont defined as the whole host plant organism and microorganisms associated with it has been reviewed. The role of rhizobacteria in the processes of nitrogen fixation has been discussed in detail. The mechanisms of direct stimulation of plant growth by biosynthesis of phytohormones, improvement of phosphorus and nitrogen nutrition, increase in resistance to stress, and stimulation mediated by antagonism against pathogenic microorganisms have been analyzed. The criteria for selection of rhizobacteria for practical purposes have been discussed.

  15. Dimerization mediates thermo-adaptation, substrate affinity and transglycosylation in a highly thermostable maltogenic amylase of Geobacillus thermoleovorans.

    Directory of Open Access Journals (Sweden)

    Deepika Mehta

    Full Text Available BACKGROUND: Maltogenic amylases belong to a subclass of cyclodextrin-hydrolyzing enzymes and hydrolyze cyclodextrins more efficiently than starch unlike typical α-amylases. Several bacterial malto-genic amylases with temperature optima of 40-60°C have been previously characterized. The thermo-adaption, substrate preferences and transglycosylation aspects of extremely thermostable bacterial maltogenic amylases have not yet been reported. METHODOLOGY/PRINCIPAL FINDINGS: The recombinant monomeric and dimeric forms of maltogenic α-amylase (Gt-Mamy of the extremely thermophilic bacterium Geobacillus thermoleovorans are of 72.5 and 145 kDa, which are active optimally at 80°C. Extreme thermostability of this enzyme has been explained by analyzing far-UV CD spectra. Dimerization increases T1/2 of Gt-Mamy from 8.2 h to 12.63 h at 90°C and mediates its enthalpy-driven conformational thermostabilization. Furthermore, dime-rization regulates preferential substrate binding of the enzyme. The substrate preference switching of Gt-Mamy upon dimerization has been confirmed from the substrate-binding affinities of the enzyme for various high and low molecular weight substrates. There is an alteration in Km and substrate hydrolysis efficiency (Vmax/Km of the enzyme (for cyclodex-trins/starch upon dimerization. N-terminal truncation indicated the role of N-terminal 128 amino acids in the thermostabilization and modulation of substrate-binding affinity. This has been confirmed by molecular docking of β-cyclodextrin to Gt-Mamy that indicated the requirement of homodimer formation by the interaction of a few N-terminal residues of chain A with the catalytic residues of (α/β8 barrel of chain B and vice-versa for stable cyclodextrin binding. Site directed mutagenesis provided evidence for the role of N-terminal D109 at the dimeric interface in substrate affinity modulation and thermostabilization. The dimeric Gt-Mamy transglycosylates hydrolytic products of G4/G

  16. Identification of Two Binding Domains, One for Peptidoglycan and Another for a Secondary Cell Wall Polymer, on the N-Terminal Part of the S-Layer Protein SbsB from Bacillus stearothermophilus PV72/p2

    Science.gov (United States)

    Sára, Margit; Egelseer, Eva M.; Dekitsch, Christine; Sleytr, Uwe B.

    1998-01-01

    First studies on the structure-function relationship of the S-layer protein from B. stearothermophilus PV72/p2 revealed the coexistence of two binding domains on its N-terminal part, one for peptidoglycan and another for a secondary cell wall polymer (SCWP). The peptidoglycan binding domain is located between amino acids 1 to 138 of the mature S-layer protein comprising a typical S-layer homologous domain. The SCWP binding domain lies between amino acids 240 to 331 and possesses a high serine plus glycine content. PMID:9852032

  17. Crystallization and preliminary crystallographic analysis of the catechol 2,3-dioxygenase PheB from Bacillus stearothermophilus BR219

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Keisuke; Matsufuzi, Kazuki; Ohnuma, Hiroaki [Department of Material Chemistry, Asahikawa National College of Technology, 2-2-1-6 Shunko-dai, Asahikawa, Hokkaido 071-8142 (Japan); Senda, Miki [Japan Biological Information Research Center (JBIRC), Japan Biological Informatics Consortium (JBIC), 2-42 Aomi, Koto-ku, Tokyo 135-0064 (Japan); Fukuda, Masao [Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188 (Japan); Senda, Toshiya, E-mail: tsenda@jbirc.aist.go.jp [Biological Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-42 Aomi, Koto-ku, Tokyo (Japan); Department of Material Chemistry, Asahikawa National College of Technology, 2-2-1-6 Shunko-dai, Asahikawa, Hokkaido 071-8142 (Japan)

    2006-02-01

    PheB, an extradiol-cleaving catecholic dioxygenase, was crystallized by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The crystal belongs to the orthorhombic system, space group P2{sub 1}2{sub 1}2{sub 1}, and diffracts to 2.3 Å resolution. Class II extradiol-cleaving catecholic dioxygenase, a key enzyme of aromatic compound degradation in bacteria, cleaves the aromatic ring of catechol by adding two O atoms. PheB is one of the class II extradiol-cleaving catecholic dioxygenases and shows a high substrate specificity for catechol derivatives, which have one aromatic ring. In order to reveal the mechanism of the substrate specificity of PheB, PheB has been crystallized by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The space group of the obtained crystal was P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 65.5, b = 119.2, c = 158.7 Å. The crystal diffracted to 2.3 Å resolution.

  18. Influence of the Secondary Cell Wall Polymer on the Reassembly, Recrystallization, and Stability Properties of the S-Layer Protein from Bacillus stearothermophilus PV72/p2

    Science.gov (United States)

    Sára, Margit; Dekitsch, Christine; Mayer, Harald F.; Egelseer, Eva M.; Sleytr, Uwe B.

    1998-01-01

    The high-molecular-weight secondary cell wall polymer (SCWP) from Bacillus stearothermophilus PV72/p2 is mainly composed of N-acetylglucosamine (GlcNAc) and N-acetylmannosamine (ManNAc) and is involved in anchoring the S-layer protein via its N-terminal region to the rigid cell wall layer. In addition to this binding function, the SCWP was found to inhibit the formation of self-assembly products during dialysis of the guanidine hydrochloride (GHCl)-extracted S-layer protein. The degree of assembly (DA; percent assembled from total S-layer protein) that could be achieved strongly depended on the amount of SCWP added to the GHCl-extracted S-layer protein and decreased from 90 to 10% when the concentration of the SCWP was increased from 10 to 120 μg/mg of S-layer protein. The SCWP kept the S-layer protein in the water-soluble state and favored its recrystallization on solid supports such as poly-l-lysine-coated electron microscopy grids. Derived from the orientation of the base vectors of the oblique S-layer lattice, the subunits had bound with their charge-neutral outer face, leaving the N-terminal region with the polymer binding domain exposed to the ambient environment. From cell wall fragments about half of the S-layer protein could be extracted with 1 M GlcNAc, indicating that the linkage type between the S-layer protein and the SCWP could be related to that of the lectin-polysaccharide type. Interestingly, GlcNAc had an effect on the in vitro self-assembly and recrystallization properties of the S-layer protein that was similar to that of the isolated SCWP. The SCWP generally enhanced the stability of the S-layer protein against endoproteinase Glu-C attack and specifically protected a potential cleavage site in position 138 of the mature S-layer protein. PMID:9696762

  19. Bacteria isolated from amoebae/bacteria consortium

    Science.gov (United States)

    Tyndall, Richard L.

    1995-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  20. The prevalence and control of Bacillus and related spore-forming bacteria in the dairy industry

    Directory of Open Access Journals (Sweden)

    Nidhi eGopal

    2015-12-01

    Full Text Available Milk produced in udder cells is sterile but due to its high nutrient content, it can be a good growth substrate for contaminating bacteria. The quality of milk is monitored via somatic cell counts and total bacterial counts, with prescribed regulatory limits to ensure quality and safety. Bacterial contaminants can cause disease, or spoilage of milk and its secondary products. Aerobic spore-forming bacteria, such as those from the genera Sporosarcina, Paenisporosarcina, Brevibacillus, Paenibacillus, Geobacillus and Bacillus, are a particular concern in this regard as they are able to survive industrial pasteurisation and form biofilms within pipes and stainless steel equipment. These single or multiple-species biofilms become a reservoir of spoilage microorganisms and a cycle of contamination can be initiated. Indeed, previous studies have highlighted that these microorganisms are highly prevalent in dead ends, corners, cracks, crevices, gaskets, valves and the joints of stainless steel equipment used in the dairy manufacturing plants. Hence, adequate monitoring and control measures are essential to prevent spoilage and ensure consumer safety. Common controlling approaches include specific cleaning-in-place processes, chemical and biological biocides and other novel methods. In this review, we highlight the problems caused by these microorganisms, and discuss issues relating to their prevalence, monitoring thereof and control with respect to the dairy industry.

  1. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  2. Study on the application of Bacillus stearothermophilus in the detection of antibiotics residues in milk%嗜热脂肪芽孢杆菌检测牛乳中抗生素残留的研究

    Institute of Scientific and Technical Information of China (English)

    赵新淮; 潘琳琳

    2009-01-01

    基于嗜热脂肪芽孢杆菌繁殖分解乳糖产酸,将其应用于原料乳的抗生素残留检测.以嗜热脂肪芽孢杆茵为指示菌株.通过改变指示剂组成、添加增效剂乳糖酶以及对分析条件进行筛选,得到适宜的检测条件参数.具体条件参数为:茵液活茵数5×10~6,茵液添加量0.1 mL,30 g·L~(-1)的乳糖酶溶液0.1 mL,混合指示剂0.1mL,乳样0.1 mL,发酵温度64℃,检测时间2.5 h.与国家标准法(TTC法)相比较,所研究的方法对5种抗生素的检出限更低.结果更易于肉眼判断.%Based on the fact that Bacillus stearothermophilus can degrade lactose to produce acid, Bacillus stearothermophilus was used as indicator strain to detect antibiotics residues in the raw milk. The composition of mixed indicators was modified and lactase was added to milk sample to enhance detection rate. Other detection parameters were also studied. The optimal parameters for detection were as follows: the viable cells of Bacillus stearothermophilus 5×10~6 in 0.1 mL solution, addition of 30 g·L~(-1) lactase solution 0.1 mL, addition volume of indicator 0.1 mL, detection volume of milk 0.1 mL, fermentation temperature 64°C and detection time 2.5 h. Compared with national standard method (TTC method), this new method has lower detection limits for five antibiotics, and is easy to judge result by nude eyes.

  3. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  4. 嗜热菌Geobacillus Kaustophilus HTA426磷酸三酯酶在毕赤酵母GS115中的表达%Overexpression of Phosphotriesterase(PTE) Gene from thermophilic Geobacillus Kaustophilus HTA426 in Pichia pastoris GS115

    Institute of Scientific and Technical Information of China (English)

    詹冬玲; 林禹欣; 任玉雪; 刘洋

    2013-01-01

    将嗜热菌Geobacillus Kaustophilus HTA426中的磷酸三酯酶基因转入毕赤酵母GS115中,整合到染色体DNA基因组上,并进行诱导表达.SDS-PAGE和Western-blot试验结果显示,重组蛋白是一个分子量约为50KD的磷酸三酯酶二聚体.酶活检测证明重组蛋白具有较高的磷酸三酯酶活性,其最适温度为70℃,最适pH为10.0.

  5. Indigenous cellulolytic and hemicellulolytic bacteria enhanced rapid co-composting of lignocellulose oil palm empty fruit bunch with palm oil mill effluent anaerobic sludge.

    Science.gov (United States)

    Zainudin, Mohd Huzairi Mohd; Hassan, Mohd Ali; Tokura, Mitsunori; Shirai, Yoshihito

    2013-11-01

    The composting of lignocellulosic oil palm empty fruit bunch (OPEFB) with continuous addition of palm oil mill (POME) anaerobic sludge which contained nutrients and indigenous microbes was studied. In comparison to the conventional OPEFB composting which took 60-90 days, the rapid composting in this study can be completed in 40 days with final C/N ratio of 12.4 and nitrogen (2.5%), phosphorus (1.4%), and potassium (2.8%), respectively. Twenty-seven cellulolytic bacterial strains of which 23 strains were closely related to Bacillus subtilis, Bacillus firmus, Thermobifida fusca, Thermomonospora spp., Cellulomonas sp., Ureibacillus thermosphaericus, Paenibacillus barengoltzii, Paenibacillus campinasensis, Geobacillus thermodenitrificans, Pseudoxanthomonas byssovorax which were known as lignocellulose degrading bacteria and commonly involved in lignocellulose degradation. Four isolated strains related to Exiguobacterium acetylicum and Rhizobium sp., with cellulolytic and hemicellulolytic activities. The rapid composting period achieved in this study can thus be attributed to the naturally occurring cellulolytic and hemicellulolytic strains identified.

  6. Intracellular Bacteria in Protozoa

    Science.gov (United States)

    Görtz, Hans-Dieter; Brigge, Theo

    Intracellular bacteria in humans are typically detrimental, and such infections are regarded by the patients as accidental and abnormal. In protozoa it seems obvious that many bacteria have coevolved with their hosts and are well adapted to the intracellular way of life. Manifold interactions between hosts and intracellular bacteria are found, and examples of antibacterial resistance of unknown mechanisms are observed. The wide diversity of intracellular bacteria in protozoa has become particularly obvious since they have begun to be classified by molecular techniques. Some of the bacteria are closely related to pathogens; others are responsible for the production of toxins.

  7. Identification and characterisation of oil sludge degrading bacteria isolated from compost

    Directory of Open Access Journals (Sweden)

    Ubani Onyedikachi

    2016-06-01

    Full Text Available Compounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR. The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the genera Bacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus. The results showed that Bacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.

  8. A putative Type IIS restriction endonuclease GeoICI from Geobacillus sp. – A robust, thermostable alternative to mezophilic prototype BbvI

    Indian Academy of Sciences (India)

    Joanna Zebrowska; Olga Zołnierkiewicz; Marta A Skowron; Agnieszka Zylicz-Stachula; Joanna Jezewska-Frackowiak; Piotr M Skowron

    2016-03-01

    Screening of extreme environments in search for novel microorganisms may lead to the discovery of robust enzymes with either new substrate specificities or thermostable equivalents of those already found in mesophiles, better suited for biotechnology applications. Isolates from Iceland geysers’ biofilms, exposed to a broad range of temperatures, from ambient to close to water boiling point, were analysed for the presence of DNA-interacting proteins, including restriction endonucleases (REases). GeoICI, a member of atypical Type IIS REases, is the most thermostable isoschizomer of the prototype BbvI, recognizing/cleaving 5′-GCAGC(N8/12)-3′ DNA sequences. As opposed to the unstable prototype, which cleaves DNA at 30°C, GeoICI is highly active at elevated temperatures, up to 73°C and over a very wide salt concentration range. Recognition/cleavage sites were determined by: (i) digestion of plasmid and bacteriophage lambda DNA (λ); (ii) cleavage of custom PCR substrates, (iii) run-off sequencing of GeoICI cleavage products and (iv) shotgun cloning and sequencing of λ DNA fragmented with GeoICI. Geobacillus sp. genomic DNA was PCR-screened for the presence of other specialized REases-MTases and as a result, another putative REase-MTase, GeoICII, related to the Thermus sp. family of bifunctional REases-methyltransferases (MTases) was detected.

  9. Characterization of recombinant amylopullulanase (gt-apu) and truncated amylopullulanase (gt-apuT) of the extreme thermophile Geobacillus thermoleovorans NP33 and their action in starch saccharification.

    Science.gov (United States)

    Nisha, M; Satyanarayana, T

    2013-07-01

    A gene encoding amylopullulanase (gt-apu) of the extremely thermophilic Geobacillus thermoleovorans NP33 was cloned and expressed in Escherichia coli. The gene has an open reading frame of 4,965 bp that encodes a protein of 1,655 amino acids with molecular mass of 182 kDa. The six conserved regions, characteristic of GH13 family, have been detected in gt-apu. The recombinant enzyme has only one active site for α-amylase and pullulanase activities based on the enzyme kinetic analyses in a system that contains starch as well as pullulan as competing substrates and response to inhibitors. The end-product analysis confirmed that this is an endoacting enzyme. The specific enzyme activities for α-amylase and pullulanase of the truncated amylopullulanase (gt-apuT) are higher than gt-apu. Both enzymes exhibited similar temperature (60 °C) and pH (7.0) optima, although gt-apuT possessed a higher thermostability than gt-apu. The overall catalytic efficiency (K(cat)/K(m)) of gt-apuT is greater than that of gt-apu, with almost similar substrate specificities. The C-terminal region of gt-apu appeared to be non-essential, and furthermore, it negatively affects the substrate binding and stability of the enzyme.

  10. The role of N1 domain on the activity, stability, substrate specificity and raw starch binding of amylopullulanase of the extreme thermophile Geobacillus thermoleovorans.

    Science.gov (United States)

    Nisha, M; Satyanarayana, T

    2015-07-01

    In order to understand the role of N1 domain (1-257 aa) in the amylopullulanase (gt-apu) of the extremely thermophilic bacterium Geobacillus thermoleovorans NP33, N1 deletion construct (gt-apuΔN) has been generated and expressed in Escherichia coli. The truncated amylopullulanase (gt-apuΔN) exhibits similar pH and temperature optima like gt-apu, but enhanced thermostability. The gt-apuΔN has greater hydrolytic action and specific activity on pullulan than gt-apu. The k cat (starch and pullulan) and K m (starch) values of gt-apuΔN increased, while K m (pullulan) decreased. The enzyme upon N1 deletion hydrolyzed maltotetraose as the smallest substrate in contrast to maltopentaose of gt-apu. The role of N1 domain of gt-apu in raw starch binding has been confirmed, for the first time, based on deletion and Langmuir-Hinshelwood kinetics. Furthermore, N1 domain appears to exert a negative influence on the thermostability of gt-apu because N1 truncation significantly improves thermostability.

  11. Characterization and multiple applications of a highly thermostable and Ca²⁺-independent amylopullulanase of the extreme thermophile Geobacillus thermoleovorans.

    Science.gov (United States)

    Nisha, M; Satyanarayana, T

    2014-12-01

    The amylopullulanase of Geobacillus thermoleovorans NP33 (apu105) is Ca(2+)-independent with a molecular mass of 105 kDa and optimum activity at 80 °C and pH 7.0. The apu105 is extremely thermostable with T 1/2 of 7.8 h at 90 °C and hydrolyzes starch, pullulan, and malto-oligosaccharides, but not panose and cyclodextrins. The low K m values of apu105 (starch, pullulan, amylose, and amylopectin) indicates higher affinity of apu105 than others. The action of the enzyme on mixed substrates (starch and pullulan) confirmed the presence of only one active site for cleaving both α-1,4- and α-1,6- glycosidic linkages. The raw starches are efficiently hydrolyzed into glucose, maltose, and malto-oligosaccharides. Two-step starch saccharification involving pretreatment with apu105 followed by glucoamylase enhanced glucose yield. The supplementation of whole wheat dough with apu105 markedly enhanced the loaf volume, shelf-life, and the texture of bread. The enzyme is compatible with detergents and useful in desizing of cotton fabrics.

  12. Purification, crystallization and preliminary X-ray analysis of a thermostable glycoside hydrolase family 43 β-xylosidase from Geobacillus thermoleovorans IT-08

    Energy Technology Data Exchange (ETDEWEB)

    Rohman, Ali [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Airlangga University, Kampus C Unair, Jl. Mulyorejo, Surabaya 60115 (Indonesia); Oosterwijk, Niels van [Laboratory of Biophysical Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Kralj, Slavko; Dijkhuizen, Lubbert [Laboratory of Microbial Physiology, University of Groningen, Kerklaan 30, 9750 NN Haren (Netherlands); Dijkstra, Bauke W. [Laboratory of Biophysical Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Puspaningsih, Ni Nyoman Tri, E-mail: nyomantri@unair.ac.id [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Airlangga University, Kampus C Unair, Jl. Mulyorejo, Surabaya 60115 (Indonesia)

    2007-11-01

    The β-xylosidase was crystallized using PEG 6000 as precipitant. 5% PEG 6000 yielded bipyramid-shaped tetragonal crystals diffracting to 1.55 Å resolution, and 13% PEG 6000 gave rectangular monoclinic crystals diffracting to 1.80 Å resolution. The main enzymes involved in xylan-backbone hydrolysis are endo-1,4-β-xylanase and β-xylosidase. β-Xylosidase converts the xylo-oligosaccharides produced by endo-1,4-β-xylanase into xylose monomers. The β-xylosidase from the thermophilic Geobacillus thermoleovorans IT-08, a member of glycoside hydrolase family 43, was crystallized at room temperature using the hanging-drop vapour-diffusion method. Two crystal forms were observed. Bipyramid-shaped crystals belonging to space group P4{sub 3}2{sub 1}2, with unit-cell parameters a = b = 62.53, c = 277.4 Å diffracted to 1.55 Å resolution. The rectangular crystals belonged to space group P2{sub 1}, with unit-cell parameters a = 57.94, b = 142.1, c = 153.9 Å, β = 90.5°, and diffracted to 1.80 Å resolution.

  13. Thermostable and alkalistable endoxylanase of the extremely thermophilic bacterium Geobacillus thermodenitrificans TSAA1: cloning, expression, characteristics and its applicability in generating xylooligosaccharides and fermentable sugars.

    Science.gov (United States)

    Verma, Digvijay; Anand, Ashima; Satyanarayana, T

    2013-05-01

    Xylanase encoding gene (1,224 bp) from Geobacillus thermodenitrificans was cloned in pET28a (+) vector and successfully expressed in Escherichia coli BL21 (DE3). The deduced amino acid sequence analysis revealed homology with that of glycosyl hydrolase (GH) 10 family with a high molecular mass (50 kDa). The purified recombinant xylanase is optimally active at pH 9.0 and 70 °C with T(1/2) of 10 min at 80 °C, and retains greater than 85 % activity after exposure to 70 °C for 180 min. The enzyme liberates xylose as well as xylooligosaccharides from birchwood xylan and agro-residues, and therefore, this is an endoxylanase. The xylan hydrolytic products (xylooligosaccharides, xylose, and xylobiose) find application as prebiotics and in the production of bioethanol. The xylanase being thermostable and alkalistable, it has released chromophores and phenolics from the residual lignin of pulps, suggesting its utility in mitigating chlorine requirement in pulp bleaching.

  14. Gene Cloning and Characterization of the Geobacillus thermoleovorans CCR11 Carboxylesterase CaesCCR11, a New Member of Family XV.

    Science.gov (United States)

    Espinosa-Luna, Graciela; Sánchez-Otero, María Guadalupe; Quintana-Castro, Rodolfo; Matus-Toledo, Rodrigo Eloir; Oliart-Ros, Rosa María

    2016-01-01

    A gene encoding a carboxylesterase produced by Geobacillus thermoleovoras CCR11 was cloned in the pET-3b cloning vector, sequenced and expressed in Escherichia coli BL21(DE3). Gene sequence analysis revealed an open reading frame of 750 bp that encodes a polypeptide of 250 amino acid residues (27.3 kDa) named CaesCCR11. The enzyme showed its maximum activity at 50 °C and pH 5-8, with preference for C4 substrates, confirming its esterase nature. It displayed good resistance to temperature, pH, and the presence of organic solvents and detergents, that makes this enzyme biotechnologically applicable in the industries such as fine and oleo-chemicals, cosmetics, pharmaceuticals, organic synthesis, biodiesel production, detergents, and food industries. A 3D model of CaesCCR11 was predicted using the Bacillus sp. monoacyl glycerol lipase bMGL H-257 structure as template (PBD code 3RM3, 99 % residue identity with CaesCCR11). Based on its canonical α/β hydrolase fold composed of 7 β-strands and 6 α-helices, the α/β architecture of the cap domain, the GLSTG pentapeptide, and the formation of distinctive salt bridges, we are proposing CaesCCR11 as a new member of family XV of lipolytic enzymes.

  15. A putative Type IIS restriction endonuclease GeoICI from Geobacillus sp.--A robust, thermostable alternative to mezophilic prototype BbvI.

    Science.gov (United States)

    Zebrowska, Joanna; Zolnierkiewicz, Olga; Skowron, Marta A; Zylicz-Stachula, Agnieszka; Jezewska-Frackowiak, Joanna; Skowron, Piotr M

    2016-03-01

    Screening of extreme environments in search for novel microorganisms may lead to the discovery of robust enzymes with either new substrate specificities or thermostable equivalents of those already found in mesophiles, better suited for biotechnology applications. Isolates from Iceland geysers' biofilms, exposed to a broad range of temperatures, from ambient to close to water boiling point, were analysed for the presence of DNA-interacting proteins, including restriction endonucleases (REases). GeoICI, a member of atypical Type IIS REases, is the most thermostable isoschizomer of the prototype BbvI, recognizing/cleaving 5'-GCAGC(N8/12)-3'DNA sequences. As opposed to the unstable prototype, which cleaves DNA at 30°C, GeoICI is highly active at elevated temperatures, up to 73°C and over a very wide salt concentration range. Recognition/cleavage sites were determined by: (i) digestion of plasmid and bacteriophage lambda DNA (Λ); (ii) cleavage of custom PCR substrates, (iii) run-off sequencing of GeoICI cleavage products and (iv) shotgun cloning and sequencing of Λ DNA fragmented with GeoICI. Geobacillus sp. genomic DNA was PCR-screened for the presence of other specialized REases-MTases and as a result, another putative REase- MTase, GeoICII, related to the Thermus sp. family of bifunctional REases-methyltransferases (MTases) was detected.

  16. Bioprocess exploration for thermostable α-amylase production of a deep-sea thermophile Geobacillus sp. in high-temperature bioreactor.

    Science.gov (United States)

    Jiang, Tao; Huang, Mengmeng; He, Hao; Lu, Jian; Zhou, Xiangshan; Cai, Menghao; Zhang, Yuanxing

    2016-08-17

    Geobacillus sp. 4j, a deep-sea high-salt thermophile, was found to produce thermostable α-amylase. In this work, culture medium and conditions were first optimized to enhance the production of thermostable α-amylase by statistical methodologies. The resulting extracellular production was increased by five times and reached 6.40 U/ml. Then, a high-temperature batch culture of the thermophile in a 15 l in-house-designed bioreactor was studied. The results showed that a relatively high dissolved oxygen (600 rpm and 15 l/min) and culture temperature of 60°C facilitated both cell growth and α-amylase production. Thus, an efficient fermentation process was established with initial medium of pH 6.0, culture temperature of 60°C, and dissolved oxygen above 20%. It gave an α-amylase production of 79 U/ml and productivity of 19804 U/l·hr, which were 10.8 and 208 times higher than those in shake flask, respectively. This work is useful for deep-sea high-salt thermophile culture, where efforts are lacking presently.

  17. Studies of nitrile oxide cycloadditions, and the phenolic oxidative coupling of vanillin aldoxime by Geobacillus sp. DDS012 from Italian rye grass silage.

    Science.gov (United States)

    Kelly, David R; Baker, Simon C; King, David S; de Silva, Deepa S; Lord, Gwyn; Taylor, Jason P

    2008-02-21

    During studies directed towards the discovery of nitrile hydrolysing enzymes from thermophiles, vanillin aldoxime was incubated with the thermophilic organism, Geobacillus sp. DDS012 isolated from Italian rye grass (Lolium multiflorum) silage. The predominant product was a dihydro-dimer, which could only be characterised by LC-MS. This was initially imagined to be the product of cycloaddition of vanillin aldoxime with the corresponding nitrile oxide, but preparation of the supposed adduct and model studies excluded this possibility. The rate constant for the second order dimerisation of 4-O-acetyl vanillin nitrile oxide was measured (1.21 x 10(-4) M(-1) s(-1), 0.413 M, 25 degrees C) and the (13)C-NMR signal for the nitrile oxide carbon was observed (delta(C) 34.4, br. t (1)J(13)C,(14)N circa 50 Hz). Treatment of vanillin aldoxime with potassium persulfate and iron sulfate gave material with the same LC-MS properties as the natural product, which is therefore identified as 5,5'-dehydro-di-(vanillin aldoxime) 1d formed by phenolic oxidative coupling.

  18. Cellular viability of Saccharomyces cerevisiae cultivated in association with contaminates bacteria of alcoholic fermentation;Viabilidade celular de Saccharomyces cerevisiae cultivada em associacao com bacterias contaminantes da fermentacao alcoolica

    Energy Technology Data Exchange (ETDEWEB)

    Nobre, Thais de Paula

    2005-07-01

    The aim of this work was to study the influence of the bacteria Bacillus and Lactobacillus, as well as their metabolic products, in reduction of cellular viability of Saccharomyces cerevisiae, when in mixed culture of yeast and active and treated bacteria. Also was to evaluated an alternative medium (MCC) for the cultivation of bacteria and yeast, constituted of sugarcane juice diluted to 5 deg Brix and supplemented with yeast extract and peptone. The bacteria Bacillus subtilis, Bacillus coagulans, Bacillus stearothermophilus, Lactobacillus fermentum and Lactobacillus plantarum were cultivated in association with yeast Saccharomyces cerevisiae (strain Y-904) for 72 h on 32 deg C, under agitation. The cellular viability, budding rate and population of S. cerevisiae, the total acidity, volatile acidity and pH of culture were determined from 0, 24, 48 e 72 h of mixed culture. Also were determined the initial and final of microorganism population across the pour plate method, in traditional culture medium (PCA for Bacillus, MRS-agar for Lactobacillus and YEPD-agar for yeast S. cerevisiae) and in medium constituted of sugarcane juice. The bacteria cultures were treated by heat sterilization (120 deg C for 20 minutes), antibacterial agent (Kamoran HJ in concentration 3,0 ppm) or irradiation (radiation gamma, with doses of 5,0 kGy for Lactobacillus and 15,0 kGy for Bacillus). The results of the present research showed that just the culture mediums more acids (with higher concentrations of total and volatile acidity, and smaller values of pH), contaminated with active bacteria L. fermentum and B. subtilis, caused reduction on yeast cellular viability. Except the bacteria B. subtilis treated with radiation, the others bacteria treated by different procedures (heat, radiation e antibacterial) did not cause reduction on yeast cellular viability and population, indicating that the isolated presence of the cellular metabolic of theses bacteria was not enough to reduce the

  19. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  20. Isolation and identification of bacteria for producing thermophilic β-glucosidase%产耐热β-葡萄糖苷酶细菌的筛选与鉴定

    Institute of Scientific and Technical Information of China (English)

    廖德芳; 陈献忠; 张梁; 王正祥; 石贵阳

    2011-01-01

    From 1323 bacteria strains collected by the Culture Collection Center of Industrial Microorganism sin Jiangnan Uninversity (CIC IM-CU ), 20 strains with relatively high capability of producing therm ophilic β-glucosidase were isolated . 5 strains were identified as Geobacillus sp . and the others were identified as B acillus licheniform is by 16s rDN A sequencing analysis . C rude enzym es was characterized from Geobacillus sp . (170-28-2 ) and B acinus licheniform is (F157043A ) . The Geobacillussp . with a specific activity of 0.36 U/m g showed optimal activity at pH 8 .0 and 53℃ and the B acillus licheniform is with a specific activity of 0.66 U /m g show ed optim alactivity at pH 9 .0 and 55℃ . Based on morpholoigcal, physiological and biochem ical properties , the strain of F157043A was further identfied as Bacillus lichen iform is .%从中国高校工业微生物资源和信息中心(CICIM-CU)菌种库的1323株细菌保藏物中筛选出20株产β-葡萄糖苷酶能力较高的细菌.通过16S rDNA序列鉴定,初步确定其中有5株为嗜热溶胞土芽孢杆菌 (Geobacillus sp.),其余为地衣芽孢杆菌 (Bacillus licheniformis).对其中编号为F157043A的地衣芽孢杆菌和编号为170-28-2的嗜热溶胞土芽孢杆菌进行了粗酶液酶学性质分析,发现地衣芽孢杆菌最适反应温度为55 ℃,最适反应pH值为9.0,该条件下测得粗酶液比酶活为0.66 U/mg;嗜热溶胞土芽孢杆菌最适反应温度为53 ℃,最适反应pH值为8.0,该条件下测得粗酶液比酶活为0.36 U/mg.通过菌体和菌落形态观察以及生理生化特征分析,进一步鉴定编号为F157043A的菌株为地衣芽孢杆菌.

  1. How honey kills bacteria

    NARCIS (Netherlands)

    P.H.S. Kwakman; A.A. te Velde; L. de Boer; D. Speijer; C.M.J.E. Vandenbroucke-Grauls; S.A.J. Zaat

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria t

  2. Unique plasmids generated via pUC replicon mutagenesis in an error-prone thermophile derived from Geobacillus kaustophilus HTA426.

    Science.gov (United States)

    Kobayashi, Jyumpei; Tanabiki, Misaki; Doi, Shohei; Kondo, Akihiko; Ohshiro, Takashi; Suzuki, Hirokazu

    2015-11-01

    The plasmid pGKE75-catA138T, which comprises pUC18 and the catA138T gene encoding thermostable chloramphenicol acetyltransferase with an A138T amino acid replacement (CATA138T), serves as an Escherichia coli-Geobacillus kaustophilus shuttle plasmid that confers moderate chloramphenicol resistance on G. kaustophilus HTA426. The present study examined the thermoadaptation-directed mutagenesis of pGKE75-catA138T in an error-prone thermophile, generating the mutant plasmid pGKE75(αβ)-catA138T responsible for substantial chloramphenicol resistance at 65°C. pGKE75(αβ)-catA138T contained no mutation in the catA138T gene but had two mutations in the pUC replicon, even though the replicon has no apparent role in G. kaustophilus. Biochemical characterization suggested that the efficient chloramphenicol resistance conferred by pGKE75(αβ)-catA138T is attributable to increases in intracellular CATA138T and acetyl-coenzyme A following a decrease in incomplete forms of pGKE75(αβ)-catA138T. The decrease in incomplete plasmids may be due to optimization of plasmid replication by RNA species transcribed from the mutant pUC replicon, which were actually produced in G. kaustophilus. It is noteworthy that G. kaustophilus was transformed with pGKE75(αβ)-catA138T using chloramphenicol selection at 60°C. In addition, a pUC18 derivative with the two mutations propagated in E. coli at a high copy number independently of the culture temperature and high plasmid stability. Since these properties have not been observed in known plasmids, the outcomes extend the genetic toolboxes for G. kaustophilus and E. coli.

  3. Characterization of a F280N variant of L-arabinose isomerase from Geobacillus thermodenitrificans identified as a D-galactose isomerase.

    Science.gov (United States)

    Kim, Baek-Joong; Hong, Seung-Hye; Shin, Kyung-Chul; Jo, Ye-Seul; Oh, Deok-Kun

    2014-11-01

    The double-site variant (C450S-N475K) L-arabinose isomerase (L-AI) from Geobacillus thermodenitrificans catalyzes the isomerization of D-galactose to D-tagatose, a functional sweetener. Using a substrate-docking homology model, the residues near to D-galactose O6 were identified as Met186, Phe280, and Ile371. Several variants obtained by site-directed mutagenesis of these three residues were analyzed, and a triple-site (F280N) variant enzyme exhibited the highest activity for D-galactose isomerization. The k cat/K m of the triple-site variant enzyme for D-galactose was 2.1-fold higher than for L-arabinose, whereas the k cat/K m of the double-site variant enzyme for L-arabinose was 43.9-fold higher than for D-galactose. These results suggest that the triple-site variant enzyme is a D-galactose isomerase. The conversion rate of D-galactose to D-tagatose by the triple-site variant enzyme was approximately 3-fold higher than that of the double-site variant enzyme for 30 min. However, the conversion yields of L-arabinose to L-ribulose by the triple-site and double-site variant enzymes were 10.6 and 16.0 % after 20 min, respectively. The triple-site variant enzyme exhibited increased specific activity, turnover number, catalytic efficiency, and conversion rate for D-galactose isomerization compared to the double-site variant enzyme. Therefore, the amino acid at position 280 determines the substrate specificity for D-galactose and L-arabinose, and the triple-site variant enzyme has the potential to produce D-tagatose on an industrial scale.

  4. Characteristic features in the structure and collagen-binding ability of a thermophilic collagenolytic protease from the thermophile Geobacillus collagenovorans MO-1.

    Science.gov (United States)

    Itoi, Yuichi; Horinaka, Mano; Tsujimoto, Yoshiyuki; Matsui, Hiroshi; Watanabe, Kunihiko

    2006-09-01

    A collagen-degrading thermophile, Geobacillus collagenovorans MO-1, extracellularly produces a collagenolytic protease with a large molecular mass. Complete nucleotide sequencing of this gene after gene cloning revealed that the collagenolytic protease is a member of the subtilisin family of serine proteases and consists of a signal sequence for secretion, a prosequence for maturation, a catalytic region, 14 direct repeats of 20 amino acids at the C terminus, and a region with unknown function intervening between the catalytic region and the numerous repeats. Since the unusual repeats are most likely to be cleaved in the secreted form of the enzyme, the intervening region was investigated to determine whether it participates in collagen binding to facilitate collagen degradation. It was found that the mature collagenolytic protease containing the intervening region at the C terminus bound collagen but not the other insoluble proteins, elastin and keratin. Furthermore, the intervening region fused with glutathione S-transferase showed a collagen-binding ability comparable to that of the mature collagenolytic protease. The collagen-binding ability was finally attributed to two-thirds of the intervening region which is rich in beta-strands and is approximately 35 kDa in molecular mass. In the collagenolytic protease from strain MO-1, hydrogen bonds most likely predominate over the hydrophobic interaction for collagen binding, since a higher concentration of NaCl released collagen from the enzyme surface but a nonionic detergent could not. To the best of our knowledge, this is the first report of a thermophilic collagenolytic protease containing the collagen-binding segment.

  5. Improvement of Thermal Stability via Outer-Loop Ion Pair Interaction of Mutated T1 Lipase from Geobacillus zalihae Strain T1

    Directory of Open Access Journals (Sweden)

    Mahiran Basri

    2012-01-01

    Full Text Available Mutant D311E and K344R were constructed using site-directed mutagenesis to introduce an additional ion pair at the inter-loop and the intra-loop, respectively, to determine the effect of ion pairs on the stability of T1 lipase isolated from Geobacillus zalihae. A series of purification steps was applied, and the pure lipases of T1, D311E and K344R were obtained. The wild-type and mutant lipases were analyzed using circular dichroism. The Tm for T1 lipase, D311E lipase and K344R lipase were approximately 68.52 °C, 70.59 °C and 68.54 °C, respectively. Mutation at D311 increases the stability of T1 lipase and exhibited higher Tm as compared to the wild-type and K344R. Based on the above, D311E lipase was chosen for further study. D311E lipase was successfully crystallized using the sitting drop vapor diffusion method. The crystal was diffracted at 2.1 Å using an in-house X-ray beam and belonged to the monoclinic space group C2 with the unit cell parameters a = 117.32 Å, b = 81.16 Å and c = 100.14 Å. Structural analysis showed the existence of an additional ion pair around E311 in the structure of D311E. The additional ion pair in D311E may regulate the stability of this mutant lipase at high temperatures as predicted in silico and spectroscopically.

  6. Metallization of bacteria cells

    Institute of Scientific and Technical Information of China (English)

    黎向锋; 李雅芹; 蔡军; 张德远

    2003-01-01

    Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.

  7. Presence and potential role of thermophilic bacteria in temperate terrestrial environments

    Science.gov (United States)

    Portillo, M. C.; Santana, M.; Gonzalez, J. M.

    2012-01-01

    Organic sulfur and nitrogen are major reservoirs of these elements in terrestrial systems, although their cycling remains to be fully understood. Both sulfur and nitrogen mineralization are directly related to microbial metabolism. Mesophiles and thermophiles were isolated from temperate environments. Thermophilic isolates were classified within the Firmicutes, belonging to the Geobacillus, Brevibacillus, and Ureibacillus genera, and showed optimum growth temperatures between 50°C and 60°C. Sulfate and ammonium produced were higher during growth of thermophiles both for isolated strains and natural bacterial assemblages. They were positively related to organic nutrient load. Temperature also affected the release of sulfate and ammonium by thermophiles. Quantitative, real-time reverse-transcription polymerase chain reaction on environmental samples indicated that the examined thermophilic Firmicutes represented up to 3.4% of the total bacterial community RNA. Temperature measurements during summer days showed values above 40°C for more than 10 h a day in soils from southern Spain. These results support a potential role of thermophilic bacteria in temperate terrestrial environments by mineralizing organic sulfur and nitrogen ruled by the existence and length of warm periods.

  8. 近海温泉中嗜热菌Geobacillus sp.ZH1锰超氧化物歧化酶的克隆与表达%Cloning and expression of manganese-containing superoxide dismutase from offshore hot spring Geobacillus sp.ZH1

    Institute of Scientific and Technical Information of China (English)

    李鹤宾; 洪璇; 黄秀梅

    2012-01-01

    将嗜热菌Geobacillus sp.ZH1的超氧化物歧化酶(supseroxide dismutase,SOD)基因插入表达载体pET-32α(+),在Escherichia coli BL21( DE3)中进行表达,并利用亲和层析纯化重组超氧化物歧化酶.将制备的脱辅SOD进行Mn2+和Fe2+金属重构后,得到的Mn2+重构SOD的比活力达668U/mg,Fe2+重构Fe-SOD没有活性,说明ZH1菌株的超氧化物歧化酶为Mn-SOD.凝胶过滤及SDS-PAGE分析显示,Mn2+重构SOD为同聚二聚体,亚基分子量为71.7 kDa.这些研究结果为进一步研究该酶的生化特性及酶的定向进化研究奠定了良好的基础.%The gene encoding a putative superoxide dismutase from thermophilic Geobacillus sp. ZH1 was cloned into the expression vector pET-32a ( + ) and overexpressed in Escherichia coli BL21 (DE3). Recombinant superoxide dismutase was purified using affinity chromatography. The prepared apo-SOD was reconstituted with either Mn or Fe by means of incubation with appropriate metal salts. The molecular mass of Mn2+ -reconstituted SOD was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and size exclusion chromatography. Mn2 +-reconstituted SOD exhibited the specific activity of 668 U/mg and Fe2 +-reconstituted SOD had no specific activity which showed that SOD from strain ZH1 was Mn-SOD. The Mn2 +-reconstituted SOD was determined as homodimer with a monomeric molecular mass of 71. 7 kDa. These results laid a foundation for further research of biochemical characteristics and directed evolution of this enzyme.

  9. Identification and Characterization of a Novel Thermophilic Geobacillus Degrading Phenol%一株嗜热菌的分离鉴定及其苯酚降解特性

    Institute of Scientific and Technical Information of China (English)

    唐赟; 刘沐之; 梁凤来; 冯露; 刘如林

    2006-01-01

    从油田地层水中分离到一株嗜热并高效降解苯酚的BF80菌株,其最适生长和降解苯酚的温度为60℃~65℃.利用API 50 CHB/E系统和16S rDNA序列分析对菌株BF80进行了分类鉴定,该菌株的形态和生理生化特性与Geobacillus thermoglucosidasius基本相同,其16S rDNA序列与Geobacillus thermoglucosidasius BGSC W95A1(=ATCC 43742)的相似性为99.22%.在接种量为1%的条件下,该菌在20 h内能完全降解3 mmol/L的苯酚;在pH值5.5~9.0范围内能保持对苯酚良好的降解能力,并在12 mmol/L苯酚的无机盐培养基中也能生长和降解苯酚,表明该菌能耐受高浓度苯酚并可用于高温含酚废水的生物处理.

  10. Cloning and Bioinformatics Analysis of the Sulfatase Gene from Thermophilic Geobacillus sp.EPT3%嗜热菌EPT3硫酸酯酶基因的克隆及生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    朱艳冰; 倪辉; 蔡慧农

    2013-01-01

    利用筛选培养基筛选到一株产硫酸酯酶的深海嗜热菌EPT3,通过16S rDNA分析,将该菌株归属为Geobacillus sp.EPT3.以菌株EPT3的基因组DNA为模板,使用硫酸酯酶引物进行PCR扩增,将目的基因克隆至pUCm-T载体后进行测序.测序结果表明,克隆基因的大小为1956 bp,预测编码651个氨基酸残基.对该基因编码蛋白质进行了生物信息学分析,结果表明,该蛋白质序列与其他菌株来源的硫酸酯酶具有很高的相似性,提示本研究克隆的基因编码硫酸酯酶.该硫酸酯酶的理论分子质量为75.1 ku,理论等电点为6.90.采用同源建模法建立了Geobacillus sp.EPT3硫酸酯酶的三维结构模型,为球状结构.

  11. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  12. [Darwin and bacteria].

    Science.gov (United States)

    Ledermann D, Walter

    2009-02-01

    As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

  13. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.

    2005-01-01

    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  14. Lipopolysaccharides in diazotrophic bacteria

    Directory of Open Access Journals (Sweden)

    Rodrigo Vassoler Serrato

    2014-09-01

    Full Text Available Biological nitrogen fixation is a process in which the atmospheric nitrogen (N2 is transformed into ammonia (NH3 by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS and lipochitooligosaccharides (LCO produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS, anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  15. Lipopolysaccharides in diazotrophic bacteria.

    Science.gov (United States)

    Serrato, Rodrigo V

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  16. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  17. A modeling study by response surface methodology and artificial neural network on culture parameters optimization for thermostable lipase production from a newly isolated thermophilic Geobacillus sp. strain ARM

    Directory of Open Access Journals (Sweden)

    Basri Mahiran

    2008-12-01

    Full Text Available Abstract Background Thermostable bacterial lipases occupy a place of prominence among biocatalysts owing to their novel, multifold applications and resistance to high temperature and other operational conditions. The capability of lipases to catalyze a variety of novel reactions in both aqueous and nonaqueous media presents a fascinating field for research, creating interest to isolate novel lipase producers and optimize lipase production. The most important stages in a biological process are modeling and optimization to improve a system and increase the efficiency of the process without increasing the cost. Results Different production media were tested for lipase production by a newly isolated thermophilic Geobacillus sp. strain ARM (DSM 21496 = NCIMB 41583. The maximum production was obtained in the presence of peptone and yeast extract as organic nitrogen sources, olive oil as carbon source and lipase production inducer, sodium and calcium as metal ions, and gum arabic as emulsifier and lipase production inducer. The best models for optimization of culture parameters were achieved by multilayer full feedforward incremental back propagation network and modified response surface model using backward elimination, where the optimum condition was: growth temperature (52.3°C, medium volume (50 ml, inoculum size (1%, agitation rate (static condition, incubation period (24 h and initial pH (5.8. The experimental lipase activity was 0.47 Uml-1 at optimum condition (4.7-fold increase, which compared well to the maximum predicted values by ANN (0.47 Uml-1 and RSM (0.476 Uml-1, whereas R2 and AAD were determined as 0.989 and 0.059% for ANN, and 0.95 and 0.078% for RSM respectively. Conclusion Lipase production is the result of a synergistic combination of effective parameters interactions. These parameters are in equilibrium and the change of one parameter can be compensated by changes of other parameters to give the same results. Though both RSM and

  18. Isolation of Lignin Degraded Thermophilic Geobacillus Caldoxylosilyticus Strain J16 and Characteristics of its Enzymes and Fermentation%高温木质素降解菌Geobacillus caldoxylosilyticus J16的筛选及其产酶发酵性质研究

    Institute of Scientific and Technical Information of China (English)

    晋果果; 翁海波; 李萍萍; 孙武举; 覃勉

    2011-01-01

    从张家界、白云山采集到的朽木及落叶中,经分离、纯化后,获得了一株高温木质素降解菌,命名为地芽孢杆菌(Geobacillus caldoxylosilyticus J16),此菌嗜热,耐高温,只降解木质素且不降解纤维素,对造纸业和可再生能源产业具有重要意义.笔者通过对木质素中2种酶木质素过氧化物酶、锰过氧化物酶活性的研究,确定了木质素过氧化物酶的最适温度为65℃.最适pH为4,在55℃至70℃之间时酶活力较其他温度高且较稳定;锰过氧化物酶最是温度为60℃,最适pH为3在温度为55℃至65℃之间时,活力较其他温度高.作者发酵了黄豆杆、玉米杆、芝麻杆、油菜杆、锯末、小麦杆这6种农业废弃物,通过发酵前后的比较,说明了J16菌株对木质素降解的最大减少量为7.5%.上述数据显示此菌可以应用于废弃秸秆的处理和造纸厂污水的处理,对环保有重要意义.%The thermophilic Geobacillus caldoxylosilyticus strain J16 was isolated after screening many microorganisms.Its factors was thermophilic, but could not degrade cellulose.It was significance for paper industry and renewable energy industry.The factors were studied, which effected on lignin peroxidase and manganese peroxidase.The strain could grow very well at 65℃ and pH 4.0.When fermented with the agriculture wastes about soybean stem, maize stem, rape stem, sawdust, wheat stem and sesame stem, it could efficiently degrade lignin up to 7.5%, but not degrade cellulose.All of above showed that it was significant for paper industry and renewable energy industry.All the data showed that this strain could be applied to agriculture wastes and sewage, and it was very important for environmental protection.

  19. Optizing cultivation condition of thermophilic protease from Geobacillus sp. YMTC1049 strain%泥土芽孢杆菌YMTC1049菌株高温蛋白酶产酶条件的优化

    Institute of Scientific and Technical Information of China (English)

    祝伟; 彭谦; 李勇; 郭春雷; 杨红亚

    2003-01-01

    报道高温蛋白酶产生菌YMTC1049(Geobacillus sp.)产酶条件的优化过程.在基础培养基中分别添加葡萄糖、麦芽糖、酵母提取物、蛋白胨、胰蛋白胨、酪蛋白、聚胨等7种营养成分,获得对酶活影响较大的碳、氮源.用多因素正交试验设计考察了pH、酪蛋白、葡萄糖和温度对酶活的影响水平,菌株在优化发酵条件下培养24 h时,上清液蛋白酶活力达312U/(mL·min).

  20. Study on Physico-chemical Properties of the Biosurfactant Produced by Geobacillus thermoleovorans%喜热噬油芽胞杆菌代谢产生表面活性剂的研究

    Institute of Scientific and Technical Information of China (English)

    王凤兰; 王晓东

    2007-01-01

    采用丙酮抽提、高压液相分离纯化等技术从嗜热菌Geobacillus thermoleovorans以正十六烷为碳源培养的发酵液中分离获得性能突出的表面活性物质.利用甲脂化、乙酰化衍生技术结合GC-MS,MS(ESI)等鉴定该表面活性剂为单脂肪酸甘油脂.实验条件下,该表面活性剂使水的表面张力降低到 32.7 mN/m,测定其临界胶束浓度为 41 mg/L.

  1. Bacteria-surface interactions.

    Science.gov (United States)

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  2. Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

    A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

  3. Mycophagous soil bacteria

    NARCIS (Netherlands)

    Rudnick, M.B.

    2015-01-01

    Abstract

    Soil microorganisms evolved several strategies to compete for limited nutrients in soil. Bacteria of the genus Collimonas developed a way to exploit fungi as a source of organic nutrients. This strategy has been termed “mycophagy&r

  4. Sterilization of single-use helical stone baskets: an experimental study

    Directory of Open Access Journals (Sweden)

    Cely Barreto da Silva

    2011-03-01

    Full Text Available Objectives: To experimentally evaluate the efficacy of a standard sterilization protocol employed during reuse of disposable helical stone baskets. Methods: Study performed on 20 helical stone baskets: 10 were used in the initial validation process, contaminated with Escherichia coli ATCC 25922 and imprinted on Müeller-Hinton media; 10 catheters were contaminated with Geobacillus stearothermophilus ATCC 7953, processed, inoculated in TSB and incubated in a water bath at a temperature of 55ºC. Bacterial growth was evaluated after 1, 3, 5 and 7 days. After sterilization, stone baskets were also opened and closed 40 times to check for functional problems. All plastic and basket parts were carefully checked for damages. Results: After the 72-hour incubation period, there was growth of E. coli ATCC 25922 in 100% of imprints. After the sterilization process and up to 7 days incubation period on a blood agar plate, there was no growth of G. stearothermophilus ATCC 7953 or any other bacteria. There were no functional problems or damage to baskets after the sterilization process. Conclusion: The ethylene oxide system is efficacious and safe for sterilization of disposable helical stone baskets. However, further clinical studies are required and should provide more safety information.

  5. Expression and cytosolic assembly of the S-layer fusion protein mSbsC-EGFP in eukaryotic cells

    NARCIS (Netherlands)

    Blecha, Andreas; Zarschler, Kristof; Sjollema, Klaas A.; Veenhuis, Marten; Rödel, Gerhard; Rodel, G.

    2005-01-01

    Background: Native as well as recombinant bacterial cell surface layer (S-layer) protein of Geobacillus (G.) stearothermophilus ATCC 12980 assembles to supramolecular structures with an oblique symmetry. Upon expression in E. coli, S-layer self assembly products are formed in the cytosol. We tested

  6. 一株嗜热菌产耐热木聚糖酶对馒头品质和保质期的影响%Effect of Thermo-tolerant Xylanase from Thermophilic Geobacillus sp.PZH1 on the Quality and Shelf-life of Steamed Bread

    Institute of Scientific and Technical Information of China (English)

    王石峰; 林孔亮; 秦晓培; 陈学敏; 刘培培; 郭小虎; 张波

    2011-01-01

    研究嗜热细菌Geobacillus sp.PZH1产耐热木聚糖酶对馒头品质及保质期的影响作用.从嗜热细菌Geobacillus sp.的PZH1制备木聚糖酶,添加到面粉中制作馒头,观察其对馒头品质和保质期的影响.结果表明:在馒头中添加适量的耐热木聚糖酶,能明显降低馒头的持水性,提高面筋网络的弹性,改变面团的加工及稳定性能,增大馒头体积,并能有效抑制馒头中细菌的生长,延长馒头的保质期.

  7. Is Your ATM Dispensing Bacteria?

    Science.gov (United States)

    ... news/fullstory_162067.html Is Your ATM Dispensing Bacteria? Study in New York City found most of ... keypads in New York City were covered in bacteria, researchers reported, with most of the microbes coming ...

  8. Exopolysaccharides from Marine Bacteria

    Institute of Scientific and Technical Information of China (English)

    CHI Zhenming; FANG Yan

    2005-01-01

    Microbial polysaccharides represent a class of important products of growing interest for many sectors of industry. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-producing bacteria from marine environments, particularly from various extreme marine environments. Many new marine microbial EPSs with novel chemical compositions, properties and structures have been found to have potential applications in fields such as adhesives,textiles, pharmaceuticals and medicine for anti-cancer, food additives, oil recovery and metal removal in mining and industrial waste treatments, etc This paper gives a brief summary of the information about the EPSs produced by marine bacteria,including their chemical compositions, properties and structures, together with their potential applications in industry.

  9. Genomics of oral bacteria.

    Science.gov (United States)

    Duncan, Margaret J

    2003-01-01

    Advances in bacterial genetics came with the discovery of the genetic code, followed by the development of recombinant DNA technologies. Now the field is undergoing a new revolution because of investigators' ability to sequence and assemble complete bacterial genomes. Over 200 genome projects have been completed or are in progress, and the oral microbiology research community has benefited through projects for oral bacteria and their non-oral-pathogen relatives. This review describes features of several oral bacterial genomes, and emphasizes the themes of species relationships, comparative genomics, and lateral gene transfer. Genomics is having a broad impact on basic research in microbial pathogenesis, and will lead to new approaches in clinical research and therapeutics. The oral microbiota is a unique community especially suited for new challenges to sequence the metagenomes of microbial consortia, and the genomes of uncultivable bacteria.

  10. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  11. South-Seeking Magnetic Bacteria

    OpenAIRE

    Kirschvink, J.L.

    1980-01-01

    Magnetotactic bacteria, originally discovered by Blakemore (1975), are by far the most convincing and abundant example of magnetically sensitive organisms in existence. Their magnetite crystals passively align the bacteria with the earth's magnetic field like a 3-dimensional compass (Frankel et al. 1979). These microaerophilic bacteria normally live in the soupy, oxygen-poor mud/water transition zone in many freshwater and marine environments. If the mud is disturbed so that the bacteria are ...

  12. Cable Bacteria in Freshwater Sediments

    OpenAIRE

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the fre...

  13. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  14. Genetic diversity of root nodule bacteria nodulating Lotus corniculatus and Anthyllis vulneraria in Sweden.

    Science.gov (United States)

    Ampomah, Osei Yaw; Huss-Danell, Kerstin

    2011-06-01

    Very little is known about the genetic diversity and phylogeny of rhizobia nodulating Lotus species in northern temperate regions. We have therefore studied the genetic diversity among a total of 61 root nodule bacteria isolated from Lotus corniculatus and Anthyllis vulneraria from different geographic sites and habitats in Sweden by restriction fragment length polymorphism (RFLP) of the internal transcribed spacer between their 16S rRNA and 23S rRNA (IGS) region. A high diversity consisting of 26 IGS types from 54 L. corniculatus isolates and five IGS types from seven A. vulneraria isolates was found. The 16S rRNA sequences and phylogeny of representatives of the different IGS types showed four interesting exceptions from the majority of the isolates belonging to the genus Mesorhizobium: Two isolates were both found to be closely related to Rhodococcus spp., and two other isolates showed close relationship with Geobacillus spp. and Paenibacillus spp., respectively. The nodA sequences and phylogeny showed that all the isolates, including those not belonging to the traditional rhizobia genera, harbored nodA sequences which were typical of Mesorhizobium loti. Generally, the 16S rRNA and nodA phylogenetic trees were not congruent in that isolates with similar 16S rRNA sequences were associated with isolates harboring different nodA sequences. All the isolates were confirmed to nodulate L. corniculatus in an inoculation test. This is the first report of members of these non-rhizobia genera being able to nodulate legumes, and we suggest that they may have acquired their nodulating properties through lateral gene transfer.

  15. Bacteria counting method based on polyaniline/bacteria thin film.

    Science.gov (United States)

    Zhihua, Li; Xuetao, Hu; Jiyong, Shi; Xiaobo, Zou; Xiaowei, Huang; Xucheng, Zhou; Tahir, Haroon Elrasheid; Holmes, Mel; Povey, Malcolm

    2016-07-15

    A simple and rapid bacteria counting method based on polyaniline (PANI)/bacteria thin film was proposed. Since the negative effects of immobilized bacteria on the deposition of PANI on glass carbon electrode (GCE), PANI/bacteria thin films containing decreased amount of PANI would be obtained when increasing the bacteria concentration. The prepared PANI/bacteria film was characterized with cyclic voltammetry (CV) technique to provide quantitative index for the determination of the bacteria count, and electrochemical impedance spectroscopy (EIS) was also performed to further investigate the difference in the PANI/bacteria films. Good linear relationship of the peak currents of the CVs and the log total count of bacteria (Bacillus subtilis) could be established using the equation Y=-30.413X+272.560 (R(2)=0.982) over the range of 5.3×10(4) to 5.3×10(8)CFUmL(-1), which also showed acceptable stability, reproducibility and switchable ability. The proposed method was feasible for simple and rapid counting of bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Brotes germinados y bacterias

    OpenAIRE

    García Olmedo, Francisco

    2011-01-01

    Ante la confusión y el revuelo asociados al último incidente causado por una cepa de la bacteria Escherichia coli (E. coli) en Alemania, tal vez no esté de más esta carta para recordar y actualizar escritos míos anteriores aparecidos en Revista de Libros sobre los riesgos alimentarios en general y sobre los peligros de dicho microorganismo en particular. 1 . Aunque es cierto que la proporción de cepas peligrosas de E. coli es quizás inferior a la de delincuentes entre los humanos, exi...

  17. Beneficial bacteria inhibit cachexia.

    Science.gov (United States)

    Varian, Bernard J; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M; Mirabal, Sheyla; Erdman, Susan E

    2016-03-15

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny.

  18. Chemical communication in bacteria

    Science.gov (United States)

    Suravajhala, Srinivasa Sandeep; Saini, Deepak; Nott, Prabhu

    Luminescence in Vibrio fischeri is a model for quorum-sensing-gene-regulation in bacteria. We study luminescence response of V. fischeri to both internal and external cues at the single cell and population level. Experiments with ES114, a wild-type strain, and ainS mutant show that luminescence induction in cultures is not always proportional to cell-density and there is always a basal level of luminescence. At any given concentration of the exogenously added signals, C6-HSL and C8-HSL, luminescence per cell reaches a maximum during the exponential phase and decreases thereafter. We hypothesize that (1) C6-HSL production and LuxR activity are not proportional to cell-density, and (2) there is a shift in equilibrium from C6-HSL to C8-HSL during the later stages of growth of the culture. RT-PCR analysis of luxI and luxR shows that the expression of these genes is maximum corresponding to the highest level of luminescence. The shift in equilibrium is shown by studying competitive binding of C6-HSL and C8-HSL to LuxR. We argue that luminescence is a unicellular behaviour, and an intensive property like per cell luminescence is more important than gross luminescence of the population in understanding response of bacteria to chemical signalling. Funding from the Department of Science and Technology, India is acknowledged.

  19. Replication Restart in Bacteria.

    Science.gov (United States)

    Michel, Bénédicte; Sandler, Steven J

    2017-07-01

    In bacteria, replication forks assembled at a replication origin travel to the terminus, often a few megabases away. They may encounter obstacles that trigger replisome disassembly, rendering replication restart from abandoned forks crucial for cell viability. During the past 25 years, the genes that encode replication restart proteins have been identified and genetically characterized. In parallel, the enzymes were purified and analyzed in vitro, where they can catalyze replication initiation in a sequence-independent manner from fork-like DNA structures. This work also revealed a close link between replication and homologous recombination, as replication restart from recombination intermediates is an essential step of DNA double-strand break repair in bacteria and, conversely, arrested replication forks can be acted upon by recombination proteins and converted into various recombination substrates. In this review, we summarize this intense period of research that led to the characterization of the ubiquitous replication restart protein PriA and its partners, to the definition of several replication restart pathways in vivo, and to the description of tight links between replication and homologous recombination, responsible for the importance of replication restart in the maintenance of genome stability. Copyright © 2017 American Society for Microbiology.

  20. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

  1. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...

  2. 易错PCR法提高土芽孢杆菌ZH1羧酸酯酶的热稳定性%Improving thermal stability of Geobacillus sp.ZH1 carboxylesterase by error-prone PCR

    Institute of Scientific and Technical Information of China (English)

    刘韩; 吴丽云; 高贺; 倪辉; 蔡慧农; 朱艳冰

    2015-01-01

    [目的]对土芽孢杆菌(Geobacillus sp.)ZH1的羧酸酯酶基因进行定向进化,筛选得到酶热稳定性提高的突变酶.[方法]利用易错PCR技术向羧酸酯酶基因中随机引入突变,建立酶基因突变文库,筛选获得热稳定性提高的突变体,并对突变酶进行诱导表达、纯化及部分酶学性质研究.[结果]通过筛选,获得羧酸酯酶热稳定性提高的突变菌株65.序列分析表明,突变酯酶65有2个氨基酸发生了改变,包括T113S和M160K.突变酶的三维结构模拟显示,突变T113S位于酶分子的第5个β-折叠上;突变M160K处在酶分子第5个和第6个α-螺旋之间的环结构上,位于酶分子表面,突变后的Lys160与邻近的Thr162形成一个额外氢键.在90℃下,突变酶65和亲本酶的半衰期分别为3.1h和1.9h,表明筛选到的突变酶65比亲本酶的热稳定性好.[结论]基于易错PCR技术对Geobacillus sp.ZH1羧酸酯酶的热稳定性进行了定向进化,对改善酶的性质、扩大酯酶的应用范围,以及研究酯酶的结构与功能的关系具有重要意义.

  3. Bacteria transport under unsaturated conditions

    OpenAIRE

    Gargiulo, Grazia

    2007-01-01

    The aim of this work was to study the bacteria transport behaviour in different conditions using an unsaturated porous media. A column based system able to keep the unsaturated conditions was designed and developed to perform the experiments. Two bacteria strains Deinococcus radiodurans and Rhodococcus rhodochrous strongly different in hydrophobicity were employed. During the experiments the bacteria concentration in the outflow was continuously on-line measured and after the experiment the c...

  4. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Science.gov (United States)

    Grande Burgos, María José; Pérez Pulido, Rubén; López Aguayo, María del Carmen; Gálvez, Antonio; Lucas, Rosario

    2014-01-01

    Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica) and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria). The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure. PMID:25493478

  5. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Directory of Open Access Journals (Sweden)

    María José Grande Burgos

    2014-12-01

    Full Text Available Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria. The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure.

  6. Bacteriophages of methanotrophic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tyutikow, F.M. (All-Union Research Inst. for Genetics and Selection of Industrial Microorganisms, Moscow, USSR); Bespalova, I.A.; Rebentish, B.A.; Aleksandrushkina, N.N.; Krivisky, A.S.

    1980-10-01

    Bacteriophages of methanotrophic bacteria have been found in 16 out of 88 studied samples (underground waters, pond water, soil, gas and oil installation waters, fermentor cultural fluids, bacterial paste, and rumen of cattle) taken in different geographic zones of the Soviet Union. Altogether, 23 phage strains were isolated. By fine structure, the phages were divided into two types (with very short or long noncontractile tails); by host range and serological properties, they fell into three types. All phages had guanine- and cytosine-rich double-stranded deoxyribonucleic acid consisting of common nitrogen bases. By all of the above-mentioned properties, all phages within each of the groups were completely identical to one another, but differed from phages of other groups.

  7. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  8. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  9. 普洱茶渥堆发酵过程中嗜热细菌的分离和鉴定%Isolation and identification of thermophilic bacteria during the pile-fermentation of Pu'er tea

    Institute of Scientific and Technical Information of China (English)

    李晨晨; 吕杰; 杨瑞娟; 严亮; 季爱兵; 赵远艳; 李艳华; 盛军

    2012-01-01

    pH values of Pu'er tea samples were measured during the pile-fermentation process. The study found that during the fermentation, pH decreased to 4. 5 at the beginning, stabilized in the mid-term and finally increased. According to the characteristics of high temperature and acidity, combining culture-independent with molecular biology methods allowed bacteria to be isolated and identified from all the tea samples at high temperatures. The results showed the presence of a large number of thermophilic bacteria including Bacillus coagulans, Bacillus subtilis, Bacillus licheniformis, Bacillus thermoamylovorans, Bacillus shackletonii, Geobacillus thermoleovorans, Pediococcus acidilactici and Lactobacillus plantarum. These thermophilic bacteria and thermophilic fungi play a key role in the fermentation of Pu'er tea.%对普洱茶发酵全过程的茶样进行了pH检测,发现在渥堆过程中pH在前期有所下降达到4.5,中期基本趋于稳定,后期又有所回升.根据渥堆过程中高温和偏酸性的特征,采用传统培养与分子生物学方法相结合,对全过程的茶样在高温条件下进行细菌的分离、纯化及鉴定.结果发现有大量嗜热细菌的存在,包括凝结芽孢杆菌Bacillus coagulans,枯草芽孢杆菌Bacillus subtilis,地衣芽孢杆菌Bacillus licheniformis,热嗜淀粉芽孢杆菌Bacillus thermoamylovorans,Bacillus shackletonii,喜热噬油芽胞杆菌Geobacillus thermoleovorans,乳酸片球菌Pediococcus acidilactici,植物乳杆菌Lactobacillus plantarum,等.这些嗜热细菌和嗜热真菌一起在普洱茶的发酵中起到了关键作用.

  10. Swimming bacteria in liquid crystal

    Science.gov (United States)

    Sokolov, Andrey; Zhou, Shuang; Aranson, Igor; Lavrentovich, Oleg

    2014-03-01

    Dynamics of swimming bacteria can be very complex due to the interaction between the bacteria and the fluid, especially when the suspending fluid is non-Newtonian. Placement of swimming bacteria in lyotropic liquid crystal produces a new class of active materials by combining features of two seemingly incompatible constituents: self-propelled live bacteria and ordered liquid crystals. Here we present fundamentally new phenomena caused by the coupling between direction of bacterial swimming, bacteria-triggered flows and director orientations. Locomotion of bacteria may locally reduce the degree of order in liquid crystal or even trigger nematic-isotropic phase transition. Microscopic flows generated by bacterial flagella disturb director orientation. Emerged birefringence patterns allow direct optical observation and quantitative characterization of flagella dynamics. At high concentration of bacteria we observed the emergence of self-organized periodic texture caused by bacteria swimming. Our work sheds new light on self-organization in hybrid bio-mechanical systems and can lead to valuable biomedical applications. Was supported by the US DOE, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under the Contract No. DE AC02-06CH11357.

  11. Ecophysiology of the anammox bacteria

    NARCIS (Netherlands)

    Kartal, Mustafa Boran

    2008-01-01

    Anaerobic ammonium oxidizing (anammox) bacteria oxidize ammonium to dinitrogen gas with nitrite as the electron acceptor. These bacteria are the key players in the global nitrogen cycle, responsible for the most of nitrogen production in natural ecosystems. The anammox process is also a cost-effecti

  12. Money and transmission of bacteria

    NARCIS (Netherlands)

    Gedik, H.; Voss, T.A.; Voss, A.

    2013-01-01

    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria

  13. A novel β-xylosidase structure from Geobacillus thermoglucosidasius: the first crystal structure of a glycoside hydrolase family GH52 enzyme reveals unpredicted similarity to other glycoside hydrolase folds.

    Science.gov (United States)

    Espina, Giannina; Eley, Kirstin; Pompidor, Guillaume; Schneider, Thomas R; Crennell, Susan J; Danson, Michael J

    2014-05-01

    Geobacillus thermoglucosidasius is a thermophilic bacterium that is able to ferment both C6 and C5 sugars to produce ethanol. During growth on hemicellulose biomass, an intracellular β-xylosidase catalyses the hydrolysis of xylo-oligosaccharides to the monosaccharide xylose, which can then enter the pathways of central metabolism. The gene encoding a G. thermoglucosidasius β-xylosidase belonging to CAZy glycoside hydrolase family GH52 has been cloned and expressed in Escherichia coli. The recombinant enzyme has been characterized and a high-resolution (1.7 Å) crystal structure has been determined, resulting in the first reported structure of a GH52 family member. A lower resolution (2.6 Å) structure of the enzyme-substrate complex shows the positioning of the xylobiose substrate to be consistent with the proposed retaining mechanism of the family; additionally, the deep cleft of the active-site pocket, plus the proximity of the neighbouring subunit, afford an explanation for the lack of catalytic activity towards the polymer xylan. Whilst the fold of the G. thermoglucosidasius β-xylosidase is completely different from xylosidases in other CAZy families, the enzyme surprisingly shares structural similarities with other glycoside hydrolases, despite having no more than 13% sequence identity.

  14. Components and Properties of a Bioemulsifier from Geobacillus thermoleovorans%喜热噬油芽胞杆菌产生的生物乳化剂的组成与性质

    Institute of Scientific and Technical Information of China (English)

    薛峰; 刘瑾

    2009-01-01

    由喜热噬油芽胞杆菌(Geobacillus thermoleovorans str 5366T)以正十六烷为碳源 55 ℃培养的发酵液中分离获得了一种生物乳化剂,经鉴定为糖-肽-脂复合物.该乳化剂中糖、肽、脂和烃的含量分别为29.4%、15.8%和35.8%.利用肽水解结合氨基酸分析、糖醇乙酰化结合GC-MS、脂肪酸甲脂化结合GC-MS等技术手段鉴定乳化剂中糖主要为D-甘露糖;主要氨基酸为谷氨酸、天冬氨酸、丙氨酸;构成脂的主要脂肪酸为十六烷酸、十八烯酸和十八烷酸.该菌及其代谢产生的乳化剂乳化性能良好,具有高温条件下应用的潜力.

  15. 嗜热土芽孢杆菌GSEY01及其高温蛋白酶的初步研究%Study on A Thermophilic Geobacillus sp.GSEY01 and Its Thermophilic Protease

    Institute of Scientific and Technical Information of China (English)

    廖艳江; 季秀玲; 魏云林; 林连兵

    2010-01-01

    从云南腾冲热海热泉中分离出一株产高温蛋白酶的菌株GSEY01.该菌株最适生长温度为60℃,16S rRNA基因序列分析表明,该菌株为土芽孢杆菌属(Geobacillus)的耐热菌株.该菌株所产高温蛋白酶可以通过超滤浓缩,硫酸铵分级沉淀和强阴离子交换层析获得纯酶.此高温蛋白酶分子量约为42 kD,最适催化温度为80℃,最适催化pH7.5,Mg2+能增强该酶活力,Fe3+,Cd2+和Ni2+对其活性则有抑制作用.PMSF对该酶影响较小,乙二胺四乙酸(EDTA) 和十二烷基磺酸钠(SDS) 则对其有强烈的抑制作用,此高温蛋白酶和其他土芽孢杆菌所产蛋白酶有较大差异,可以应用于相关的高温催化环境.

  16. Study on the activation Geobacillus species in Zhan 3 blocks of Shengli Oilfield%胜利油田沾3区块油藏中Geobacillus菌的激活研究

    Institute of Scientific and Technical Information of China (English)

    李彩风; 李阳; 吴昕宇; 曹嫣镔; 汪卫东; 包木太

    2016-01-01

    利用16S rRNA克隆文库技术分析胜利油田沾3区块油藏样品的微生物群落结构,使用不同激活剂对沾3区块油藏样品进行内源微生物激活,对激活后样品进行乳化能力、产生表面活性物质能力评价及微生物群落结构分析,并开展物理模拟驱油实验.结果表明:沾3区块油藏样品中含有2%的Geobacillus,该菌是沾3区块油藏内源微生物中产生表面活性物质、发挥乳化功能的关键菌群;加入适宜的激活剂体系可以选择性激活该类细菌,使其成为优势菌;利用选择性激活Geobacillus的配方激活沾3区块油藏内源微生物,可以在水驱基础上提高原油采收率10.8%.

  17. L-Ribose production from L-arabinose by immobilized recombinant Escherichia coli co-expressing the L-arabinose isomerase and mannose-6-phosphate isomerase genes from Geobacillus thermodenitrificans.

    Science.gov (United States)

    Kim, Kyoung-Rok; Seo, Eun-Sun; Oh, Deok-Kun

    2014-01-01

    L-Ribose is an important precursor for antiviral agents, and thus its high-level production is urgently demanded. For this aim, immobilized recombinant Escherichia coli cells expressing the L-arabinose isomerase and variant mannose-6-phosphate isomerase genes from Geobacillus thermodenitrificans were developed. The immobilized cells produced 99 g/l L-ribose from 300 g/l L-arabinose in 3 h at pH 7.5 and 60 °C in the presence of 1 mM Co(2+), with a conversion yield of 33 % (w/w) and a productivity of 33 g/l/h. The immobilized cells in the packed-bed bioreactor at a dilution rate of 0.2 h(-1) produced an average of 100 g/l L-ribose with a conversion yield of 33 % and a productivity of 5.0 g/l/h for the first 12 days, and the operational half-life in the bioreactor was 28 days. Our study is first verification for L-ribose production by long-term operation and feasible for cost-effective commercialization. The immobilized cells in the present study also showed the highest conversion yield among processes from L-arabinose as the substrate.

  18. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

  19. Commensal ocular bacteria degrade mucins.

    Science.gov (United States)

    Berry, M; Harris, A; Lumb, R; Powell, K

    2002-12-01

    Antimicrobial activity in tears prevents infection while maintaining a commensal bacterial population. The relation between mucin and commensal bacteria was assessed to determine whether commensals possess mucinolytic activity, how degradation depends on mucin integrity, and whether mucins affect bacterial replication. Bacteria were sampled from healthy eyes and contact lenses from asymptomatic wearers. Intracellular mucins were extracted and purified from cadaver conjunctivas, and surface mucins from extended wear contact lenses. After exposure to bacteria, changes in mucin hydrodynamic volume (proteolytic cleavage) and subunit charge (oligosaccharide degradation) were assayed by size exclusion and ion exchange chromatography. The effect of mucin on bacterial replication was followed for up to 24 hours from the end of incubation with purified ocular mucins. Ocular bacteria decreased the hydrodynamic volume of intracellular and contact lens adherent mucins, irrespective of glycosylation density. A decrease in mucin sialylation was observed after exposure to commensal bacteria. Subunit charge distributions were generally shifted to lesser negative charge, consistent with loss of charged epitopes. Subunits with high negative charge, observed after digesting lightly adhering contact lens mucins with bacteria, suggest preferential cleavage sites in the mucin molecule. The presence of purified ocular mucin in the medium inhibited bacterial growth. Bacteria in the healthy ocular surface possess mucinolytic activity on both intact and surface processed mucins, targeted to discrete sites in the mucin molecule. Inhibition of bacterial growth by ocular mucins can be seen as part of the mucosal control of microbiota.

  20. Sampling bacteria with a laser

    Science.gov (United States)

    Schwarzwälder, Kordula; Rutschmann, Peter

    2014-05-01

    Water quality is a topic of high interest and it's getting more and more important due to climate change and the implementation of European Water Framework Directive (WFD). One point of interest here is the inflow of bacteria into a river caused by combined sewer overflows which lead untreated wastewater including bacteria directly into a river. These bacteria remain in the river for a certain time, they settle down and can be remobilised again. In our study we want to investigate these processes of sedimentation and resuspension and use the results for the development of a software module coupled with the software Flow3D. Thereby we should be able to simulate and therefore predict the water quality influenced by combined sewer overflows. Hence we need to get information about the bacteria transport and fate. We need to know about the size of the bacteria or of the bacteria clumps and the size of the particles the bacteria are attached to. The agglomerates lead to different characteristics and velocities of settlement. The timespan during this bacteria can be detected in the bulk phase depends on many factors like the intensity of UV light, turbidity of the water, the temperature of the water, if there are grazers and a lot more. The size, density and composition of the agglomerates is just a part of all these influencing factors, but it is extremely difficult to differ between the other effects if we have no information about the simple sedimentation in default of these basic information. However we have a big problem getting the data. The chaining between bacteria or bacteria and particles is not too strong, so filtering the water to get a sieving curve may destroy these connections. We did some experiments similar to PIV (particle image velocimetry) measurements and evaluated the pictures with a macro written for the software ImageJ. Doing so we were able to get the concentration of bacteria in the water and collect information about the size of the bacteria. We

  1. Motility of Electric Cable Bacteria

    OpenAIRE

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner; Schramm, Andreas; Nielsen, Lars Peter

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces with a highly variable speed of 0.5 ± 0.3 μm s−1 (mean ± standard deviation) and time between reversals of 155 ± 108 s. They frequently moved forward in loops, and formation of twisted loops revealed ...

  2. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

  3. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Mega

  4. Sewage-pollution indicator bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Rodrigues, V.; Alwares, E.; Rodrigues, C.; Baksh, R.; Jayan, S.; Mohandass, C.

    Spatial distribution and annual cycle of sewage pollution indicator (total coliforms and total fecal coliforms) and human pathogenic bacteria (Escherichia coli and Streptococcus faecalis) in water and sediment samples in the Mandovi and Zuari...

  5. 洗涤厂排污口可培养中度嗜热菌的多样性%Diversity of Culturable Mesophilic Bacteria from Outfall Soil of Laundry Factory

    Institute of Scientific and Technical Information of China (English)

    叶学军; 邱宏端; 林新坚; 贾宪波; 陈济琛

    2014-01-01

    To investigate the diversity of mesophilic bacteria resulting from constant thermal conditions , the soil sample was collected at outfall of thermal wastewater from laundry factory .The culturable mesophilic bacteria were isolated with different medium to obtain pure culture , identified by 16S rDNA and the data were analyzed in phylogenetic tree .The results showed that the 29 strains in pure culture were obtained from the thermal wastewater outfall soil with different phenotype .The strains were classified into Bacilli ,attributed to 5 genus and 11 species , including three species of Geobacillus ,three species of Bacillus ,three species of Anoxybacillus ,one species of Ureibacillus ,and one species of Thermoactinomyces .The diversity of species was rich ,and the resources of species would have potential in practical application .%为考查洗涤厂热废水排放口土壤在常年人为热环境下的可培养嗜热菌的多样性,采集洗涤厂热废水排放口附近的湿热泥土,应用不同培养基分离纯化泥土中的可培养嗜热菌,并对获得的纯培养细菌进行16S rDNA鉴定和系统发育相关分析。结果表明:分离纯化得到的29株不同表型的纯培养菌株均属于坚壁菌门芽孢杆菌纲,归属于5个属11个种,分别是地芽孢杆菌属 Geobacillus 3个种,芽孢杆菌属 Bacillus 3个种,无氧芽孢杆菌属 Anoxybacillus 3个种,解脲芽孢杆菌属Ureibacillus 1个种和高温放线菌属 Thermoactinomyces 1个种,属种多样性丰富,菌株资源具有潜在开发应用价值。

  6. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  7. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  8. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  9. Geobiology of Marine Magnetotactic Bacteria

    Science.gov (United States)

    2006-06-01

    Coast. Shelf Sci., 45:769-788. [38] Overmann, J. and H. van Gemerden. 2000. Microbial interactions involving sulfur bacteria: implications for the...1998) Organic acids in the rhizosphere : a critical review. Plant and Soil 205: 25-44. J0rgensen BB, Kuenen JG, Cohen Y (1979) Microbial ...my advisor Katrina Edwards for taking a chance on someone who initially knew nothing about magnetotactic bacteria, microbial ecology, or microbiology

  10. A comparative effect of 3 disinfectants on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The disinfection effect of chlorine dioxide, chlorine and their mixture on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria in circulating cooling water was studied. The results of the test indicated that high purity chlorine dioxide was the most effective biocide in the 3 disinfectants, and with a dosage of 0.5mg/L, chlorine dioxide could obtain perfect effect. High purity chloride dioxide could have the excellent effect with the pH value of 6 to 10, and could keep it within 72 h. Chlorine and their mixture couldn't reach the effect of chlorine dioxide.

  11. Bioreporter bacteria for landmine detection

    Energy Technology Data Exchange (ETDEWEB)

    Burlage, R.S. [Oak Ridge National Lab., TN (United States); Youngblood, T. [Frisby Technologies, Aiken, SC (United States); Lamothe, D. [American Technologies, Inc., Huntsville, AL (United States). Ordnance/Explosives Environmental Services Div.

    1998-04-01

    Landmines (and other UXO) gradually leak explosive chemicals into the soil at significant concentrations. Bacteria, which have adapted to scavenge low concentrations of nutrients, can detect these explosive chemicals. Uptake of these chemicals results in the triggering of specific bacterial genes. The authors have created genetically recombinant bioreporter bacteria that detect small concentrations of energetic chemicals. These bacteria are genetically engineered to produce a bioluminescent signal when they contact specific explosives. A gene for a brightly fluorescent compound can be substituted for increased sensitivity. By finding the fluorescent bacteria, you find the landmine. Detection might be accomplished using stand-off illumination of the minefield and GPS technology, which would result in greatly reduced risk to the deminers. Bioreporter technology has been proven at the laboratory scale, and will be tested under field conditions in the near future. They have created a bacterial strain that detects sub-micromolar concentrations of o- and p-nitrotoluene. Related bacterial strains were produced using standard laboratory protocols, and bioreporters of dinitrotoluene and trinitrotoluene were produced, screening for activity with the explosive compounds. Response time is dependent on the growth rate of the bacteria. Although frill signal production may require several hours, the bacteria can be applied over vast areas and scanned quickly, producing an equivalent detection speed that is very fast. This technology may be applicable to other needs, such as locating buried explosives at military and ordnance/explosive manufacturing facilities.

  12. Filtrating forms of soil bacteria

    Science.gov (United States)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  13. Cable Bacteria in Freshwater Sediments.

    Science.gov (United States)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage.

  14. Isolation and Identification of Concrete Environment Bacteria

    Science.gov (United States)

    Irwan, J. M.; Anneza, L. H.; Othman, N.; Husnul, T.; Alshalif, A. F.

    2016-07-01

    This paper presents the isolation and molecular method for bacteria identification through PCR and DNA sequencing. Identification of the bacteria species is required in order to fully utilize the bacterium capability for precipitation of calcium carbonate in concrete. This process is to enable the addition of suitable catalyst according to the bacterium enzymatic pathway that is known through the bacteria species used. The objective of this study is to isolate, enriched and identify the bacteria species. The bacteria in this study was isolated from fresh urine and acid mine drainage water, Kota Tinggi, Johor. Enrichment of the isolated bacteria was conducted to ensure the bacteria survivability in concrete. The identification of bacteria species was done through polymerase chain reaction (PCR) and rRDNA sequencing. The isolation and enrichment of the bacteria was done successfully. Whereas, the results for bacteria identification showed that the isolated bacteria strains are Bacillus sp and Enterococus faecalis.

  15. [Genetic resources of nodule bacteria].

    Science.gov (United States)

    Rumiantseva, M L

    2009-09-01

    Nodule bacteria (rhizobia) form highly specific symbiosis with leguminous plants. The efficiency of accumulation of biological nitrogen depends on molecular-genetic interaction between the host plant and rhizobia. Genetic characteristics of microsymbiotic strains are crucial in developing highly productive and stress-resistant symbiotic pairs: rhizobium strain-host plant cultivar (species). The present review considers the issue of studying genetic resources of nodule bacteria to identify genes and their blocks, responsible for the ability of rhizobia to form highly effective symbiosis in various agroecological conditions. The main approaches to investigation of intraspecific and interspecific genetic and genomic diversity of nodule bacteria are considered, from MLEE analysis to the recent methods of genomic DNA analysis using biochips. The data are presented showing that gene centers of host plants are centers of genetic diversification of nodule bacteria, because the intraspecific polymorphism of genetic markers of the core and the accessory rhizobial genomes is extremely high in them. Genotypic features of trapped and nodule subpopulations of alfalfa nodule bacteria are discussed. A survey of literature showed that the genomes of natural strains in alfalfa gene centers exhibit significant differences in genes involved in control of metabolism, replication, recombination, and the formation of defense response (hsd genes). Natural populations of rhizobia are regarded as a huge gene pool serving as a source of evolutionary innovations.

  16. Challenges to validation of a complex nonsterile medical device tray.

    Science.gov (United States)

    Prince, Daniel; Mastej, Jozef; Hoverman, Isabel; Chatterjee, Raja; Easton, Diana; Behzad, Daniela

    2014-01-01

    Validation by steam sterilization of reusable medical devices requires careful attention to many parameters that directly influence whether or not complete sterilization occurs. Complex implant/instrument tray systems have a variety of configurations and components. Geobacillus stearothermophilus biological indicators (BIs) are used in overkill cycles to to simulate worst case conditions and are intended to provide substantial sterilization assurance. Survival of G. stearothermophilus spores was linked to steam access and size of load in the chamber. By a small and reproducible margin, it was determined that placement of the trays in a rigid container into minimally loaded chambers were more difficult to completely sterilize than maximally loaded chambers.

  17. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  18. Methylotrophic bacteria in sustainable agriculture.

    Science.gov (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices.

  19. IDENTIFICATION OF BACTERIA IN LATEX PAINTS

    Directory of Open Access Journals (Sweden)

    Rojas, J.

    2008-01-01

    Full Text Available The bacteria are prokaryote organisms with a high capacity to colonize many types of habits. This research was developed with the object to identify extremophiles bacteria presents in latex paint. The bacteria were cultivated in culture mediums TSA, Blood Agar, Mc Conkey and finally the biochemical proof API-NF® for bacteria's isolation and identification, respectively. Characterization showed bacterial profile of Pasteurella sp. Hypothesis that could be found extremophiles bacteria in latex paint were demonstrated.

  20. Adaptation, Bacteria and Maxwell's Demons

    Science.gov (United States)

    Galajda, Peter; Keymer, Juan E.; Austin, Robert H.

    2007-03-01

    We propose a method to study the adaptation of bacterial populations with an asymmetric wall of Maxwell Demon openings. A Maxwell Demon opening is a funnel which is easier to enter than to leave. The interaction of swimming cells with such a Maxwell Demon Wall results in a population density separation, in apparent (but not real) violation of the Second Law of Thermodynamics, as we will show. Bacteria can be exposed to spatial challenges in order to move to e. g. higher food levels. The question we address in these experiments is: do the bacteria adapt and overcome the Maxwell Demon Wall?

  1. Study on the Optimization of Bio-emulsifier Production by Geobacillus sp.XS2 by Means of Response Surface Methodology%响应面法优化土芽孢杆菌XS2产生物乳化剂的研究

    Institute of Scientific and Technical Information of China (English)

    徐爽; 黄志勇; 路福平; 王永莉

    2011-01-01

    [目的]采用响应面法对土芽孢杆茵XS2产生物乳化剂的发酵培养基进行优化研究.[方法]利用单因素试验确定影响土芽孢杆菌XS2产生物乳化剂的主要培养基成分,再采用响应面分析法和Design-Expert 7.0软件建立响应曲面模型,来优化土芽孢杆菌XS2产生物乳化剂的发酵培养基.[结果]葡萄糖、磷酸氢二钾、磷酸二氢钾为影响土芽孢杆茵XS2产生物乳化荆的主要因素,土芽孢杆菌XS2产生物乳化剂的最佳发酵培养基为:葡萄糖68 g/L,硝酸钠2 g/L,磷酸二氢钾5.03 g/L,磷酸氢二钾1.36 g/L,硫酸镬结晶0.2 g/L,硫酸亚铁0.02 g/L,氯化钙0.01 g/L,微量元素液2 ml.在此条件下,生物乳化剂乳化活性的实测值(67.0%)与预测值(66.7%)较为接近,比优化前提高了27%.[结论]响应面法适用于土芽孢杆茵XS2产生物乳化剂发酵培养基的优化,优化结果与实际情况吻合较好.%[Objective] The aim was to study the optimization of fermentation medium for bio-emulsifier production by Geobacillus sp. XS2 by means of response surface methodology. [Method] Firstly, single-factor experiment was conducted to determine the main medium components influencing bio-emulsifier production by Geobacillus sp. XS2, and then response surface model was established by using response surface methodology and Design-Expert 7.0.2, so as to optimize the fermentation medium for bio-emulsifier production by Geobacillus sp. XS2. [Result] Glucose, KH2PO4 and K2HPO4 were the main factors influencing bio-emulsifier production by Geobacillus sp. XS2, and its optimal fermentation medium was as follows; glucose 68 g/L, NaNO3 2 g/L, KH2PO4 5.03 g/L, K2HPO4 1. 36 g/L, MgSO4 · 7H2O 0. 2 g/L, FeSO4 · 7H2O 0.02 g/L, CaCl2 · 2H2O 0.01 g/L, element solution 2 ml. Under the optimal condition, the measured value (67.0% ) of bio-emulsifier of e-mulsifying activity was close to predictive value (66.7% ) and increased by 27% compared with previous value

  2. Manipulating Genetic Material in Bacteria

    Science.gov (United States)

    1998-01-01

    Lisa Crawford, a graduate research assistant from the University of Toledo, works with Laurel Karr of Marshall Space Flight Center (MSFC) in the molecular biology laboratory. They are donducting genetic manipulation of bacteria and yeast for the production of large amount of desired protein. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  3. Programmed survival of soil bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Molin, Søren; Sternberg, Claus

    Biological containment systems have been developed for Pseudomonas putida and related soil bacteria. The systems are based on combinations of lethal genes and regulated gene expression. Two types of killing function have been employed: 1) A membrane protein interfering with the membrane potential...

  4. ENDOSPORES OF THERMOPHILIC FERMENTATIVE BACTERIA

    DEFF Research Database (Denmark)

    Volpi, Marta

    2016-01-01

    solely based on endospores of sulphate-reducing bacteria (SRB), which presumably constitute only a small fraction of the total thermophilic endospore community reaching cold environments. My PhD project developed an experimental framework for using thermophilic fermentative endospores (TFEs) to trace...

  5. Functional genomics of intracellular bacteria.

    Science.gov (United States)

    de Barsy, Marie; Greub, Gilbert

    2013-07-01

    During the genomic era, a large amount of whole-genome sequences accumulated, which identified many hypothetical proteins of unknown function. Rapidly, functional genomics, which is the research domain that assign a function to a given gene product, has thus been developed. Functional genomics of intracellular pathogenic bacteria exhibit specific peculiarities due to the fastidious growth of most of these intracellular micro-organisms, due to the close interaction with the host cell, due to the risk of contamination of experiments with host cell proteins and, for some strict intracellular bacteria such as Chlamydia, due to the absence of simple genetic system to manipulate the bacterial genome. To identify virulence factors of intracellular pathogenic bacteria, functional genomics often rely on bioinformatic analyses compared with model organisms such as Escherichia coli and Bacillus subtilis. The use of heterologous expression is another common approach. Given the intracellular lifestyle and the many effectors that are used by the intracellular bacteria to corrupt host cell functions, functional genomics is also often targeting the identification of new effectors such as those of the T4SS of Brucella and Legionella.

  6. Hydrocarbon degradation by antarctic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.A.E.; Nichols, P.D.; McMeekin, T.A.; Franzmann, P.D. [Univ. of Tasmania (Australia)] [and others

    1996-12-31

    Bacterial cultures obtained from sediment samples collected during a trial oil spill experiment conducted at Airport beach, Eastern Antarctica were selectively enriched for n-alkane-degrading and phenanthrenedegrading bacteria. Samples were collected from a control site and sites treated with different hydrocarbon mixtures - Special Antarctic blend (SAB), BP-Visco and orange roughy oils. One set of replicate sites was also treated with water from Organic Lake which had previously been shown to contain hydrocarbon-degrading bacteria. No viable bacteria were obtained from samples collected from sites treated with orange roughy oil. Extensive degradation of n-alkanes by enrichment cultures obtained from sites treated with SAB and BP-Visco occurred at both 25{degrees}C and 10{degrees}C. Extensive degradation of phenanthrene also occurred in enrichment cultures from these sites grown at 25{degrees}C. Concurrent increases of polar lipid in these cultures were also observed. The presence of 1,4-naphthaquinone and 1-naphthol during the growth of the cultures on phenanthrene is unusual and warrants further investigation of the mechanism of phenanthrene-degradation by these Antarctic bacteria.

  7. Deodorant bacteria; Des bacteries desodorisantes

    Energy Technology Data Exchange (ETDEWEB)

    Fanlo, J.L. [Ecole Nationale Superieure des Mines, 30 - Ales (France)

    1998-02-01

    Purifying bacteria: if this concept is not new, its application to gases cleansing has only been developed recently. This method allows to eliminate the volatile organic compounds and the gaseous effluents odors which come from industrial sites. Three bioreactors types exist at the present time. Their principles are explained. (O.M.) 6 refs.

  8. Engineering robust lactic acid bacteria

    NARCIS (Netherlands)

    Bron, P.A.; Bokhorst-van de Veen, van H.; Wels, M.; Kleerebezem, M.

    2011-01-01

    For centuries, lactic acid bacteria (LAB) have been industrially exploited as starter cultures in the fermentation of foods and feeds for their spoilage-preventing and flavor-enhancing characteristics. More recently, the health-promoting effects of LAB on the consumer have been widely acknowledged,

  9. Photoreceptor proteins from purple bacteria

    NARCIS (Netherlands)

    Hendriks, J.; van der Horst, M.A.; Chua, T.K.; Ávila Pérez, M.; van Wilderen, L.J.; Alexandre, M.T.A.; Groot, M.-L.; Kennis, J.T.M.; Hellingwerf, K.J.; Hunter, C.N.; Daldal, F.; Thurnauer, M.C.; Beatty, J.T.

    2009-01-01

    Purple bacteria contain representatives of four of the six main families of photoreceptor proteins: phytochromes, BLUF domain containing proteins, xanthopsins (i.e., photoactive yellow proteins), and phototropins (containing one or more light, oxygen, or voltage (LOV) domains). Most of them have a

  10. Synthetic Biology in Streptomyces Bacteria

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko

    2011-01-01

    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer . Genome sequencing has revealed that

  11. SYNTHETIC BIOLOGY IN STREPTOMYCES BACTERIA

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko; Voigt, C

    2011-01-01

    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer. Genome sequencing has revealed that t

  12. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  13. Pesticide Exposures May Alter Mouth Bacteria

    Science.gov (United States)

    ... fullstory_162249.html Pesticide Exposures May Alter Mouth Bacteria Study of Washington farm workers finds alterations persist ... News) -- Pesticide exposure may change the makeup of bacteria in the mouths of farm workers, a new ...

  14. Smokeless Tobacco May Contain Potentially Harmful Bacteria

    Science.gov (United States)

    ... 160769.html Smokeless Tobacco May Contain Potentially Harmful Bacteria Infections, diarrhea and vomiting are possible consequences, FDA ... products can harbor several species of potentially harmful bacteria, researchers warn. Two types in particular -- Bacillus licheniformis ...

  15. Certain Bacteria May Affect Preterm Birth Risk

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163401.html Certain Bacteria May Affect Preterm Birth Risk Bad 'bugs' tied ... Feb. 3, 2017 (HealthDay News) -- Certain types of bacteria in a pregnant woman's cervix and vagina can ...

  16. A RAPD based study revealing a previously unreported wide range of mesophilic and thermophilic spore formers associated with milk powders in China.

    Science.gov (United States)

    Sadiq, Faizan A; Li, Yun; Liu, TongJie; Flint, Steve; Zhang, Guohua; He, GuoQing

    2016-01-18

    Aerobic spore forming bacteria are potential milk powder contaminants and are viewed as indicators of poor quality. A total of 738 bacteria, including both mesophilic and thermophilic, isolated from twenty-five powdered milk samples representative of three types of milk powders in China were analyzed based on the random amplified polymorphic DNA (RAPD) protocol to provide insight into species diversity. Bacillus licheniformis was found to be the most prevalent bacterium with greatest diversity (~43% of the total isolates) followed by Geobacillus stearothermophilus (~21% of the total isolates). Anoxybacillus flavithermus represented only 8.5% of the total profiles. Interestingly, actinomycetes represented a major group of the isolates with the predominance of Laceyella sacchari followed by Thermoactinomyces vulgaris, altogether comprising of 7.3% of the total isolates. Out of the nineteen separate bacterial species (except five unidentified groups) recovered and identified from milk powders, twelve proved to belong to novel or previously unreported species in milk powders. Assessment and characterization of the harmful effects caused by this particular micro-flora on the quality and safety of milk powders will be worth doing in the future.

  17. Aggregation Patterns in Stressed Bacteria

    CERN Document Server

    Tsimring, L S; Aranson, I S; Ben-Jacob, E; Cohen, I; Shochet, O; Tsimring, Lev; Levine, Herbert; Aranson, Igor; Ben-Jacob, Eshel; Cohen, Inon; Shochet, Ofer

    1995-01-01

    We study the formation of spot patterns seen in a variety of bacterial species when the bacteria are subjected to oxidative stress due to hazardous byproducts of respiration. Our approach consists of coupling the cell density field to a chemoattractant concentration as well as to nutrient and waste fields. The latter serves as a triggering field for emission of chemoattractant. Important elements in the proposed model include the propagation of a front of motile bacteria radially outward form an initial site, a Turing instability of the uniformly dense state and a reduction of motility for cells sufficiently far behind the front. The wide variety of patterns seen in the experiments is explained as being due the variation of the details of the initiation of the chemoattractant emission as well as the transition to a non-motile phase.

  18. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

  19. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    Directory of Open Access Journals (Sweden)

    NEENA GARG

    2015-10-01

    Full Text Available Lactic acid bacteria (LAB is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LAB are used as starter culture, consortium members and bioprotective agents in food industry that improve food quality, safety and shelf life. A variety of probiotic LAB species are available including Lactobacillus acidophilus, L. bulgaricus, L. lactis, L. plantarum, L. rhamnosus, L. reuteri, L. fermentum, Bifidobacterium longum, B. breve, B. bifidum, B. esselnsis, B. lactis, B. infantis that are currently recommended for development of functional food products with health-promoting capacities.

  20. Dissipative Shocks behind Bacteria Gliding

    CERN Document Server

    Virga, Epifanio G

    2014-01-01

    Gliding is a means of locomotion on rigid substrates utilized by a number of bacteria includingmyxobacteria and cyanobacteria. One of the hypotheses advanced to explain this motility mechanism hinges on the role played by the slime filaments continuously extruded from gliding bacteria. This paper solves in full a non-linear mechanical theory that treats as dissipative shocks both the point where the extruded slime filament comes in contact with the substrate, called the filament's foot, and the pore on the bacterium outer surface from where the filament is ejected. We prove that kinematic compatibility for shock propagation requires that the bacterium uniform gliding velocity (relative to the substrate) and the slime ejecting velocity (relative to the bacterium) must be equal, a coincidence that seems to have already been observed.

  1. Re-engineering bacteria for ethanol production

    Science.gov (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  2. Compartmentalization of bacteria in microcapsules.

    Science.gov (United States)

    van Wijk, Judith; Heunis, Tiaan; Harmzen, Elrika; Dicks, Leon M T; Meuldijk, Jan; Klumperman, Bert

    2014-12-18

    Lactobacillus plantarum strain 423 was encapsulated in hollow poly(organosiloxane) microcapsules by templating water-in-oil Pickering emulsion droplets via the interfacial reaction of alkylchlorosilanes. The bacteria were suspended in growth medium or buffer to protect the cells against pH changes during the interfacial reactions with alkylchlorosilanes. The results of this work open up novel avenues for the encapsulation of microbial cells.

  3. Endocytosis of Viruses and Bacteria

    Science.gov (United States)

    Cossart, Pascale; Helenius, Ari

    2014-01-01

    Of the many pathogens that infect humans and animals, a large number use cells of the host organism as protected sites for replication. To reach the relevant intracellular compartments, they take advantage of the endocytosis machinery and exploit the network of endocytic organelles for penetration into the cytosol or as sites of replication. In this review, we discuss the endocytic entry processes used by viruses and bacteria and compare the strategies used by these dissimilar classes of pathogens. PMID:25085912

  4. Characterization of Mediterranean Magnetotactic Bacteria

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Magnetotactic bacteria are a diverse group of motile prokaryotes that are ubiquitous in aquatic habitats and cosmopolitan in distribution. In this study, we collected magnetotactic bacteria from the Mediterranean Sea. A remarkable diversity of morphotypes was observed, including muiticellular types that seemed to differ from those previously found in North and South America. Another interesting organism was one with magnetosomes arranged in a six-stranded bundle which occupied one third of the cell width. The magnetosome bundle was evident even under optic microscopy. These cells were connected together and swam as a linear entire unit. Magnetosomes did not always align up to form a straight linear chain. A chain composed of rectangle magnetosomes bent at a position with an oval crystal. High resolution transmission electron microscopy analysis of the crystal at the pivotal position suggested uncompleted formation of the crystal. This is the first report of Mediterranean magnetotactic bacteria, which should be useful for studies of biogeochemical cycling and geohistory of the Mediterranean Sea.

  5. 地芽孢杆菌Y565-5分离鉴定及其木糖异构酶基因xylA的克隆表达和酶学性质%Cloning, expression and characterization of xylose isomerase, XylA from Geobacillus sp.Y565-5

    Institute of Scientific and Technical Information of China (English)

    张洁; 黄志勇; 王钦宏; 王永莉; 王硕

    2011-01-01

    从甘肃玉门油田地表土中分离到一株嗜热木糖利用菌,地芽孢杆菌Y565-5.利用PCR方法从该菌株中克隆得到一个木糖异构酶基因,xylA.该基因开放阅读框长1 182 bp,编码394个氨基酸,XylA氨基酸序列与Geobacillus sp.Y412MC52相似性达到99%.将xylA基因克隆到原核表达载体pET-28a(+)上,得到重组质粒pET-28a(+)-xylA,然后将此重组质粒转化至BL21(DE3)中,经IPTG诱导后,通过SDS-PAGE电泳检测出明显的45 kD(相对分子质量)特异性蛋白质条带,并且通过半胱氨酸咔唑法检测出表达产物具有木糖异构酶的活性.对其酶学性质的研究发现,XylA最适温度为90℃,最适pH值为8.0.%Xylose-utilizing and thermophilic Geobacillus sp. Y565-5 was isolated from surface soil of an oilfield in Yumen Town, Gansu Province, China. A xylose isomerase (XylA) gene was cloned from the strain by PCR. The open reading frame of xylA (1 182 bp) encoded a protein of 394 amino acids,which showed high sequence homology (99% identity) with that of Geobacillus sp. Y412MC52. The intact coding region was subcloned into pET28a(+) vector and expressed in Escherichia coli BL21(DE3).The molecular weight of the recombinant protein was 45 kD based on SDS-PAGE and its xylose isomerase activity was detected through cysteine welts thiazole method after the induction of isopropyl β-D-1-thiogalactopyranoside (IPTG). The optimum temperature and pH for the partially purified recombinant XylA activity were 90 ℃ and pH 8.0, respectively.

  6. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in common that

  7. Laser-Based Identification of Pathogenic Bacteria

    Science.gov (United States)

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  8. Ecology of mycophagous collimonas bacteria in soil

    NARCIS (Netherlands)

    Höppener-Ogawa, Sachie

    2008-01-01

    Bacteria belonging to the genus Collimonas consist of soil bacteria that can grow at expense of living fungal hyphae i.e. they are mycophagous. This PhD studies deals with the ecology of mycophagous bacteria in soil using collimonads as model organisms. Collimonads were found to be widely distribut

  9. Laser-Based Identification of Pathogenic Bacteria

    Science.gov (United States)

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  10. Current strategies for improving food bacteria

    NARCIS (Netherlands)

    Kuipers, O P; Buist, Girbe; Kok, Jan

    2000-01-01

    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in micro

  11. Electron transport chains of lactic acid bacteria

    NARCIS (Netherlands)

    Brooijmans, R.J.W.

    2008-01-01

    Lactic acid bacteria are generally considered facultative anaerobic obligate fermentative bacteria. They are unable to synthesize heme. Some lactic acid bacteria are unable to form menaquinone as well. Both these components are cofactors of respiratory (electron transport) chains of prokaryotic bact

  12. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in

  13. Concentric-flow electrokinetic injector enables serial crystallography of ribosome and photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, Raymond G.; Gati, Cornelius; Laksmono, Hartawan; Dao, E. Han; Gul, Sheraz; Fuller, Franklin; Kern, Jan; Chatterjee, Ruchira; Ibrahim, Mohamed; Brewster, Aaron S.; Young, Iris D.; Michels-Clark, Tara; Aquila, Andrew; Liang, Mengning; Hunter, Mark S.; Koglin, Jason E.; Boutet, Sébastien; Junco, Elia A.; Hayes, Brandon; Bogan, Michael J.; Hampton, Christina Y.; Puglisi, Elisabetta V.; Sauter, Nicholas K.; Stan, Claudiu A.; Zouni, Athina; Yano, Junko; Yachandra, Vittal K.; Soltis, S. Michael; Puglisi, Joseph D.; DeMirci, Hasan

    2015-11-30

    We describe a concentric-flow electrokinetic injector for efficiently delivering microcrystals for serial femtosecond X-ray crystallography analysis that enables studies of challenging biological systems in their unadulterated mother liquor. We used the injector to analyze microcrystals of Geobacillus stearothermophilus thermolysin (2.2-Å structure), Thermosynechococcus elongatus photosystem II (<3-Å diffraction) and Thermus thermophilus small ribosomal subunit bound to the antibiotic paromomycin at ambient temperature (3.4-Å structure).

  14. Concentric-flow electrokinetic injector enables serial crystallography of ribosome and photosystem II.

    Science.gov (United States)

    Sierra, Raymond G; Gati, Cornelius; Laksmono, Hartawan; Dao, E Han; Gul, Sheraz; Fuller, Franklin; Kern, Jan; Chatterjee, Ruchira; Ibrahim, Mohamed; Brewster, Aaron S; Young, Iris D; Michels-Clark, Tara; Aquila, Andrew; Liang, Mengning; Hunter, Mark S; Koglin, Jason E; Boutet, Sébastien; Junco, Elia A; Hayes, Brandon; Bogan, Michael J; Hampton, Christina Y; Puglisi, Elisabetta V; Sauter, Nicholas K; Stan, Claudiu A; Zouni, Athina; Yano, Junko; Yachandra, Vittal K; Soltis, S Michael; Puglisi, Joseph D; DeMirci, Hasan

    2016-01-01

    We describe a concentric-flow electrokinetic injector for efficiently delivering microcrystals for serial femtosecond X-ray crystallography analysis that enables studies of challenging biological systems in their unadulterated mother liquor. We used the injector to analyze microcrystals of Geobacillus stearothermophilus thermolysin (2.2-Å structure), Thermosynechococcus elongatus photosystem II (<3-Å diffraction) and Thermus thermophilus small ribosomal subunit bound to the antibiotic paromomycin at ambient temperature (3.4-Å structure).

  15. Probabilistic exposure assessment model to estimate aseptic-UHT product failure rate.

    Science.gov (United States)

    Pujol, Laure; Albert, Isabelle; Magras, Catherine; Johnson, Nicholas Brian; Membré, Jeanne-Marie

    2015-01-02

    Aseptic-Ultra-High-Temperature (UHT) products are manufactured to be free of microorganisms capable of growing in the food at normal non-refrigerated conditions at which the food is likely to be held during manufacture, distribution and storage. Two important phases within the process are widely recognised as critical in controlling microbial contamination: the sterilisation steps and the following aseptic steps. Of the microbial hazards, the pathogen spore formers Clostridium botulinum and Bacillus cereus are deemed the most pertinent to be controlled. In addition, due to a relatively high thermal resistance, Geobacillus stearothermophilus spores are considered a concern for spoilage of low acid aseptic-UHT products. A probabilistic exposure assessment model has been developed in order to assess the aseptic-UHT product failure rate associated with these three bacteria. It was a Modular Process Risk Model, based on nine modules. They described: i) the microbial contamination introduced by the raw materials, either from the product (i.e. milk, cocoa and dextrose powders and water) or the packaging (i.e. bottle and sealing component), ii) the sterilisation processes, of either the product or the packaging material, iii) the possible recontamination during subsequent processing of both product and packaging. The Sterility Failure Rate (SFR) was defined as the sum of bottles contaminated for each batch, divided by the total number of bottles produced per process line run (10(6) batches simulated per process line). The SFR associated with the three bacteria was estimated at the last step of the process (i.e. after Module 9) but also after each module, allowing for the identification of modules, and responsible contamination pathways, with higher or lower intermediate SFR. The model contained 42 controlled settings associated with factory environment, process line or product formulation, and more than 55 probabilistic inputs corresponding to inputs with variability

  16. [Bacteria ecology in planting-culturing system].

    Science.gov (United States)

    Huang, Fenglian; Xia, Beicheng; Dai, Xin; Chen, Guizhu

    2004-06-01

    Planting-culturing system in inter-tidal zone is a new type eco-culturing model. The survey on bacteria biomass and water quality in the designed planting-culturing system in inter-tidal zone showed that the mangrove planted in the system improved water quality and made water quality to II-III type, better than the IV and V type in the control pond. Designed ponds made heterotrophic bacteria, vibrio, phosphorus bacteria and enzyme-producing bacteria populations 1-2 order lower than the control pond without mongrove planting. Correlation analyses with CORREL software showed that the biomass of these bacteria was positively related with the nitrogen and phosphorus contents in water of the system, and the correlation coefficient for heterogeneous bacteria and vibrio was up to 0.9205. Heterotrophic bacteria and vibrio could be used as the water-quality monitoring organisms.

  17. Bacteria and vampirism in cinema.

    Science.gov (United States)

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C

    2013-09-01

    A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  18. DMTB: the magnetotactic bacteria database

    Science.gov (United States)

    Pan, Y.; Lin, W.

    2012-12-01

    Magnetotactic bacteria (MTB) are of interest in biogeomagnetism, rock magnetism, microbiology, biomineralization, and advanced magnetic materials because of their ability to synthesize highly ordered intracellular nano-sized magnetic minerals, magnetite or greigite. Great strides for MTB studies have been made in the past few decades. More than 600 articles concerning MTB have been published. These rapidly growing data are stimulating cross disciplinary studies in such field as biogeomagnetism. We have compiled the first online database for MTB, i.e., Database of Magnestotactic Bacteria (DMTB, http://database.biomnsl.com). It contains useful information of 16S rRNA gene sequences, oligonucleotides, and magnetic properties of MTB, and corresponding ecological metadata of sampling sites. The 16S rRNA gene sequences are collected from the GenBank database, while all other data are collected from the scientific literature. Rock magnetic properties for both uncultivated and cultivated MTB species are also included. In the DMTB database, data are accessible through four main interfaces: Site Sort, Phylo Sort, Oligonucleotides, and Magnetic Properties. References in each entry serve as links to specific pages within public databases. The online comprehensive DMTB will provide a very useful data resource for researchers from various disciplines, e.g., microbiology, rock magnetism and paleomagnetism, biogeomagnetism, magnetic material sciences and others.

  19. Mitochondria are not captive bacteria.

    Science.gov (United States)

    Harish, Ajith; Kurland, Charles G

    2017-12-07

    Lynn Sagan's conjecture (1967) that three of the fundamental organelles observed in eukaryote cells, specifically mitochondria, plastids and flagella were once free-living primitive (prokaryotic) cells was accepted after considerable opposition. Even though the idea was swiftly refuted for the specific case of origins of flagella in eukaryotes, the symbiosis model in general was accepted for decades as a realistic hypothesis to describe the endosymbiotic origins of eukaryotes. However, a systematic analysis of the origins of the mitochondrial proteome based on empirical genome evolution models now indicates that 97% of modern mitochondrial protein domains as well their homologues in bacteria and archaea were present in the universal common ancestor (UCA) of the modern tree of life (ToL). These protein domains are universal modular building blocks of modern genes and genomes, each of which is identified by a unique tertiary structure and a specific biochemical function as well as a characteristic sequence profile. Further, phylogeny reconstructed from genome-scale evolution models reveals that Eukaryotes and Akaryotes (archaea and bacteria) descend independently from UCA. That is to say, Eukaryotes and Akaryotes are both primordial lineages that evolved in parallel. Finally, there is no indication of massive inter-lineage exchange of coding sequences during the descent of the two lineages. Accordingly, we suggest that the evolution of the mitochondrial proteome was autogenic (endogenic) and not endosymbiotic (exogenic). Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The mycorrhiza helper bacteria revisited.

    Science.gov (United States)

    Frey-Klett, P; Garbaye, J; Tarkka, M

    2007-01-01

    In natural conditions, mycorrhizal fungi are surrounded by complex microbial communities, which modulate the mycorrhizal symbiosis. Here, the focus is on the so-called mycorrhiza helper bacteria (MHB). This concept is revisited, and the distinction is made between the helper bacteria, which assist mycorrhiza formation, and those that interact positively with the functioning of the symbiosis. After considering some examples of MHB from the literature, the ecological and evolutionary implications of the relationships of MHB with mycorrhizal fungi are discussed. The question of the specificity of the MHB effect is addressed, and an assessment is made of progress in understanding the mechanisms of the MHB effect, which has been made possible through the development of genomics. Finally, clear evidence is presented suggesting that some MHB promote the functioning of the mycorrhizal symbiosis. This is illustrated for three critical functions of practical significance: nutrient mobilization from soil minerals, fixation of atmospheric nitrogen, and protection of plants against root pathogens. The review concludes with discussion of future research priorities regarding the potentially very fruitful concept of MHB.

  1. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

  2. Serological studies on chloridazon-degrading bacteria.

    Science.gov (United States)

    Layh, G; Böhm, R; Eberspächer, J; Lingens, F

    1983-01-01

    Agglutination tests and immunofluorescence tests with antisera against four strains of chloridazon-degrading bacteria revealed the serological uniformity of a group of 22 chloridazon-degrading bacterial strains. No serological relationship could be found between chloridazon-degrading bacteria and representatives of other Gram-negative bacteria. This was demonstrated by agglutination tests, including testing of the antiserum against Acinetobacter calcoaceticus, and by immunofluorescence tests, including testing of the sera against Pseudomonas and Acinetobacter strains. The tests were performed with 31 representatives of different Gram-negative bacteria, and with 22 strains of chloridazon-degrading bacteria as antigens. Differences in the extent of agglutination reactions and antibody titres among chloridazon-degrading bacterial strains together with cross-adsorption xperiments, suggest a rough classification of chloridazon-degrading bacteria into two subgroups. On the basis of immunofluorescence data, a linkage-map was worked out to represent serological relationships in the group of chloridazon-degrading strains.

  3. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette

    2010-01-01

    of coryneform bacteria was 16% among 55 cases of canine otitis externa examined at the Danish hospital during 2007. In contrast, detectable levels of coryneform bacteria were not demonstrated in samples from the acustic meatus of 35 dogs with apparently healthy ears, attending the hospital during the same year......This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...

  4. Endophytic bacteria in Coffea arabica L.

    Science.gov (United States)

    Vega, Fernando E; Pava-Ripoll, Monica; Posada, Francisco; Buyer, Jeffrey S

    2005-01-01

    Eighty-seven culturable endophytic bacterial isolates in 19 genera were obtained from coffee plants collected in Colombia (n = 67), Hawaii (n = 17), and Mexico (n = 3). Both Gram positive and Gram negative bacteria were isolated, with a greater percentage (68%) being Gram negative. Tissues yielding bacterial endophytes included adult plant leaves, various parts of the berry (e.g., crown, pulp, peduncle and seed), and leaves, stems, and roots of seedlings. Some of the bacteria also occurred as epiphytes. The highest number of bacteria among the berry tissues sampled was isolated from the seed, and includes Bacillus , Burkholderia , Clavibacter , Curtobacterium , Escherichia , Micrococcus , Pantoea , Pseudomonas , Serratia , and Stenotrophomonas . This is the first survey of the endophytic bacteria diversity in various coffee tissues, and the first study reporting endophytic bacteria in coffee seeds. The possible role for these bacteria in the biology of the coffee plant remains unknown.

  5. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  6. Survival of soil bacteria during prolonged desiccation.

    Science.gov (United States)

    Chen, M.; Alexander, M.

    1973-01-01

    A determination was made of the kinds and numbers of bacteria surviving when two soils were maintained in the laboratory under dry conditions for more than half a year. Certain non-spore-forming bacteria were found to survive in the dry condition for long periods. A higher percentage of drought-tolerant than drought-sensitive bacteria was able to grow at low water activities. When they were grown in media with high salt concentrations, bacteria generally became more tolerant of prolonged drought and they persisted longer. The percent of cells in a bacterial population that remained viable when exposed to drought stress varied with the stage of growth.

  7. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...

  8. Coryneform bacteria associated with canine otitis externa.

    Science.gov (United States)

    Aalbæk, Bent; Bemis, David A; Schjærff, Mette; Kania, Stephen A; Frank, Linda A; Guardabassi, Luca

    2010-10-26

    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10 cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other bacteria, mainly Staphylococcus pseudintermedius alone (n=5) or in combination with Malassezia pachydermatis (n=5). Some coryneform isolates displayed resistance to fusidic acid or enrofloxacin, two antimicrobial agents commonly used for the treatment of otitis externa in dogs. The frequency of isolation of coryneform bacteria was 16% among 55 cases of canine otitis externa examined at the Danish hospital during 2007. In contrast, detectable levels of coryneform bacteria were not demonstrated in samples from the acustic meatus of 35 dogs with apparently healthy ears, attending the hospital during the same year. On basis of the current knowledge, these coryneform bacteria should be regarded as potential secondary pathogens able to proliferate in the environment of an inflamed ear canal.

  9. Single Bacteria as Turing Machines

    Science.gov (United States)

    Bos, Julia; Zang, Qiucen; Vyawahare, Saurabh; Austin, Robert

    2014-03-01

    In Allan Turing's famous 1950 paper on Computing Machinery and Intelligence, he started with the provocative statement: ``I propose to consider the question, `Can machines think?' This should begin with definitions of the meaning of the terms `machine' and `think'.'' In our own work on exploring the way that organisms respond to stress and evolve, it seems at times as if they come to remarkably fast solutions to problems, indicating some sort of very clever computational machinery. I'll discuss how it would appear that bacteria can indeed create a form of a Turing Machine, the first example of a computer, and how they might use this algorithm to do rapid evolution to solve a genomics problem.

  10. Cell Size Regulation in Bacteria

    Science.gov (United States)

    Amir, Ariel

    2014-05-01

    Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

  11. Sterol Synthesis in Diverse Bacteria.

    Science.gov (United States)

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  12. Mitochondria: a target for bacteria.

    Science.gov (United States)

    Lobet, Elodie; Letesson, Jean-Jacques; Arnould, Thierry

    2015-04-01

    Eukaryotic cells developed strategies to detect and eradicate infections. The innate immune system, which is the first line of defence against invading pathogens, relies on the recognition of molecular patterns conserved among pathogens. Pathogen associated molecular pattern binding to pattern recognition receptor triggers the activation of several signalling pathways leading to the establishment of a pro-inflammatory state required to control the infection. In addition, pathogens evolved to subvert those responses (with passive and active strategies) allowing their entry and persistence in the host cells and tissues. Indeed, several bacteria actively manipulate immune system or interfere with the cell fate for their own benefit. One can imagine that bacterial effectors can potentially manipulate every single organelle in the cell. However, the multiple functions fulfilled by mitochondria especially their involvement in the regulation of innate immune response, make mitochondria a target of choice for bacterial pathogens as they are not only a key component of the central metabolism through ATP production and synthesis of various biomolecules but they also take part to cell signalling through ROS production and control of calcium homeostasis as well as the control of cell survival/programmed cell death. Furthermore, considering that mitochondria derived from an ancestral bacterial endosymbiosis, it is not surprising that a special connection does exist between this organelle and bacteria. In this review, we will discuss different mitochondrial functions that are affected during bacterial infection as well as different strategies developed by bacterial pathogens to subvert functions related to calcium homeostasis, maintenance of redox status and mitochondrial morphology.

  13. Added value of experts' knowledge to improve a quantitative microbial exposure assessment model--Application to aseptic-UHT food products.

    Science.gov (United States)

    Pujol, Laure; Johnson, Nicholas Brian; Magras, Catherine; Albert, Isabelle; Membré, Jeanne-Marie

    2015-10-15

    In a previous study, a quantitative microbial exposure assessment (QMEA) model applied to an aseptic-UHT food process was developed [Pujol, L., Albert, I., Magras, C., Johnson, N. B., Membré, J. M. Probabilistic exposure assessment model to estimate aseptic UHT product failure rate. 2015 International Journal of Food Microbiology. 192, 124-141]. It quantified Sterility Failure Rate (SFR) associated with Bacillus cereus and Geobacillus stearothermophilus per process module (nine modules in total from raw material reception to end-product storage). Previously, the probabilistic model inputs were set by experts (using knowledge and in-house data). However, only the variability dimension was taken into account. The model was then improved using expert elicitation knowledge in two ways. First, the model was refined by adding the uncertainty dimension to the probabilistic inputs, enabling to set a second order Monte Carlo analysis. The eight following inputs, and their impact on SFR, are presented in detail in this present study: D-value for each bacteria of interest (B. cereus and G. stearothermophilus) associated with the inactivation model for the UHT treatment step, i.e., two inputs; log reduction (decimal reduction) number associated with the inactivation model for the packaging sterilization step for each bacterium and each part of the packaging (product container and sealing component), i.e., four inputs; and bacterial spore air load of the aseptic tank and the filler cabinet rooms, i.e., two inputs. Second, the model was improved by leveraging expert knowledge to develop further the existing model. The proportion of bacteria in the product which settled on surface of pipes (between the UHT treatment and the aseptic tank on one hand, and between the aseptic tank and the filler cabinet on the other hand) leading to a possible biofilm formation for each bacterium, was better characterized. It was modeled as a function of the hygienic design level of the aseptic

  14. Receptor-transporter interactions of canonical ATP-binding cassette import systems in prokaryotes.

    Science.gov (United States)

    Schneider, Erwin; Eckey, Viola; Weidlich, Daniela; Wiesemann, Nicole; Vahedi-Faridi, Ardeshir; Thaben, Paul; Saenger, Wolfram

    2012-04-01

    ATP-binding cassette (ABC) transport systems mediate the translocation of solutes across biological membranes at the expense of ATP. They share a common modular architecture comprising two pore-forming transmembrane domains and two nucleotide binding domains. In prokaryotes, ABC transporters are involved in the uptake of a large variety of chemicals, including nutrients, osmoprotectants and signal molecules. In pathogenic bacteria, some ABC importers are virulence factors. Canonical ABC import systems require an additional component, a substrate-specific receptor or binding protein for function. Interaction of the liganded receptor with extracytoplasmic loop regions of the transmembrane domains initiate the transport cycle. In this review we summarize the current knowledge on receptor-transporter interplay provided by crystal structures as well as by biochemical and biophysical means. In particular, we focus on the maltose/maltodextrin transporter of enterobacteria and the transporters for positively charged amino acids from the thermophile Geobacillus stearothermophilus and Salmonella enterica serovar Typhimurium. Copyright © 2011 Elsevier GmbH. All rights reserved.

  15. Cold Atmospheric Air Plasma Sterilization against Spores and Other Microorganisms of Clinical Interest

    Science.gov (United States)

    Isbary, Georg; Shimizu, Tetsuji; Li, Yang-Fang; Zimmermann, Julia L.; Stolz, Wilhelm; Schlegel, Jürgen; Morfill, Gregor E.; Schmidt, Hans-Ulrich

    2012-01-01

    Physical cold atmospheric surface microdischarge (SMD) plasma operating in ambient air has promising properties for the sterilization of sensitive medical devices where conventional methods are not applicable. Furthermore, SMD plasma could revolutionize the field of disinfection at health care facilities. The antimicrobial effects on Gram-negative and Gram-positive bacteria of clinical relevance, as well as the fungus Candida albicans, were tested. Thirty seconds of plasma treatment led to a 4 to 6 log10 CFU reduction on agar plates. C. albicans was the hardest to inactivate. The sterilizing effect on standard bioindicators (bacterial endospores) was evaluated on dry test specimens that were wrapped in Tyvek coupons. The experimental D23°C values for Bacillus subtilis, Bacillus pumilus, Bacillus atrophaeus, and Geobacillus stearothermophilus were determined as 0.3 min, 0.5 min, 0.6 min, and 0.9 min, respectively. These decimal reduction times (D values) are distinctly lower than D values obtained with other reference methods. Importantly, the high inactivation rate was independent of the material of the test specimen. Possible inactivation mechanisms for relevant microorganisms are briefly discussed, emphasizing the important role of neutral reactive plasma species and pointing to recent diagnostic methods that will contribute to a better understanding of the strong biocidal effect of SMD air plasma. PMID:22582068

  16. Prevalence of Clostridium botulinum and thermophilic heat-resistant spores in raw carrots and green beans used in French canning industry.

    Science.gov (United States)

    Sevenier, V; Delannoy, S; André, S; Fach, P; Remize, F

    2012-04-16

    Two categories of vegetables (carrots and green beans) that are widely used in the manufacture of canned food were surveyed for their spore contamination. Samples were recovered from 10 manufactures spread over all producing areas in France. Two samples over 316 raw vegetables collected were found positive for botulinum neurotoxin producing Clostridia spores as tested by PCR-based GeneDisc assay. Both positive samplestested positive for the type B neurotoxin gene (bont/B). In parallel, heat-resistant spores of thermophilic bacteria that are likely to be associated with canned food spoilage after prolonged incubation at 55 °C were surveyed after specific enrichment. Prevalence varied between 1.6% for Moorella thermoacetica/thermoautotrophica in green bean samples and 8.6% for either Geobacillus stearothermophilus or Thermoanaerobacterium spp. in carrot samples. Vegetable preparation, e.g. washing and edge cutting, considerably reduced spore contamination levels. These data constitute the first wide examination of vegetables specifically cultivated for industrialpurposes for their contamination by spores of thermophilic bacterial species.

  17. Cyclic lipodepsipeptides produced by Pseudomonas spp. naturally present in raw milk induce inhibitory effects on microbiological inhibitor assays for antibiotic residue screening.

    Directory of Open Access Journals (Sweden)

    Wim Reybroeck

    Full Text Available Two Pseudomonas strains, identified as closely related to Pseudomonas tolaasii, were isolated from milk of a farm with frequent false-positive Delvotest results for screening putative antibiotic residues in raw milk executed as part of the regulatory quality programme. Growth at 5 to 7°C of these isolates in milk resulted in high lipolysis and the production of bacterial inhibitors. The two main bacterial inhibitors have a molecular weight of 1168.7 and 1140.7 Da respectively, are heat-tolerant and inhibit Geobacillus stearothermophilus var. calidolactis, the test strain of most of the commercially available microbiological inhibitor tests for screening of antibiotic residues in milk. Furthermore, these bacterial inhibitors show antimicrobial activity against Staphylococcus aureus, Bacillus cereus and B. subtilis and also interfere negatively with yoghurt production. Following their isolation and purification with RP-HPLC, the inhibitors were identified by NMR analysis as cyclic lipodepsipeptides of the viscosin group. Our findings bring to light a new challenge for quality control in the dairy industry. By prolonging the refrigerated storage of raw milk, the keeping quality of milk is influenced by growth and metabolic activities of psychrotrophic bacteria such as pseudomonads. Besides an increased risk of possible spoilage of long shelf-life milk, the production at low temperature of natural bacterial inhibitors may also result in false-positive results for antibiotic residue screening tests based on microbial inhibitor assays thus leading to undue production loss.

  18. Progress in Research of Bacteria Fertilizer Strengthening Resistance of Plants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).

  19. Characterization of (per)chlorate-reducing bacteria

    NARCIS (Netherlands)

    Wolterink, A.F.W.M.

    2004-01-01

    Some bacteria can use (per)chlorateas terminal electron acceptor for growth. These bacteria convert perchlorate via chlorate and chlorite into chloride and molecular oxygen. Oxygen formation in microbial respiration is unique. In this study two chlorate-reducing strains belo

  20. Lactic Acid Bacteria in the Gut

    NARCIS (Netherlands)

    Stolaki, M.; Vos, de W.M.; Kleerebezem, M.; Zoetendal, E.G.

    2012-01-01

    From all bacterial groups, the lactic acid bacteria (LAB) are probably the group of bacteria that is most associated with human lifestyle. The term LAB mainly refers to the ability of these organisms to convert sugars to lactic acid. The LAB comprise non-sporing, aerotolerant, coccus or rod-shaped,

  1. Rock-degrading endophytic bacteria in cacti

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  2. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...... weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment....

  3. Rapid methods for detection of bacteria

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Andersen, B.Ø.; Miller, M.

    2006-01-01

    Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods...

  4. Symbiosis: Gut Bacteria Manipulate Host Behaviour.

    Science.gov (United States)

    Yuval, Boaz

    2017-08-07

    Bacteria resident in the gut of Drosophila modify the fly's innate chemosensory responses to nutritional stimuli. In effect, the gut microbiome compels the host to forage on food patches that favour particular assemblages of bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Why do bacteria engage in homologous recombination?

    NARCIS (Netherlands)

    Vos, M.

    2009-01-01

    Microbiologists have long recognized that the uptake and incorporation of homologous DNA from outside the cell is a common feature of bacteria, with important implications for their evolution. However, the exact reasons why bacteria engage in homologous recombination remain elusive. This Opinion

  6. Lactic Acid Bacteria in the Gut

    NARCIS (Netherlands)

    Stolaki, M.; Vos, de W.M.; Kleerebezem, M.; Zoetendal, E.G.

    2012-01-01

    From all bacterial groups, the lactic acid bacteria (LAB) are probably the group of bacteria that is most associated with human lifestyle. The term LAB mainly refers to the ability of these organisms to convert sugars to lactic acid. The LAB comprise non-sporing, aerotolerant, coccus or rod-shaped,

  7. Energy transduction in lactic acid bacteria

    NARCIS (Netherlands)

    Poolman, Bert

    In the discovery of some general principles of energy transduction, lactic acid bacteria have played an important role. In this review, the energy transducing processes of lactic acid bacteria are discussed with the emphasis on the major developments of the past 5 years. This work not only includes

  8. Method of dispersing a hydrocarbon using bacteria

    Science.gov (United States)

    Tyndall, Richard L.

    1996-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  9. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B. T.; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  10. Rapid methods for detection of bacteria

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Andersen, B.Ø.; Miller, M.

    2006-01-01

    Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods...

  11. Why do bacteria engage in homologous recombination?

    NARCIS (Netherlands)

    Vos, M.

    2009-01-01

    Microbiologists have long recognized that the uptake and incorporation of homologous DNA from outside the cell is a common feature of bacteria, with important implications for their evolution. However, the exact reasons why bacteria engage in homologous recombination remain elusive. This Opinion art

  12. Bacteria dispersal by hitchhiking on zooplankton

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Dziallas, Claudia; Leunert, Franziska;

    2010-01-01

    and nonpathogenic bacteria has shown that direct association with zooplankton has significant influences on the bacteria's physiology and ecology. We used stratified migration columns to study vertical dispersal of hitchhiking bacteria through migrating zooplankton across a density gradient that was otherwise...... impenetrable for bacteria in both upward and downward directions (conveyor-belt hypothesis). The strength of our experiments is to permit quantitative estimation of transport and release of associated bacteria: vertical migration of Daphnia magna yielded an average dispersal rate of 1.3 x 10(5) x cells x...... Daphnia(-1) x migration cycle(-1) for the lake bacterium Brevundimonas sp. Bidirectional vertical dispersal by migrating D. magna was also shown for two other bacterial species, albeit at lower rates. The prediction that diurnally migrating zooplankton acquire different attached bacterial communities from...

  13. Hydrocarbon Degrading Bacteria: Isolation and Identification

    Directory of Open Access Journals (Sweden)

    Lies Indah Sutiknowati

    2007-11-01

    Full Text Available There is little information how to identify hydrocarbon degrading bacteria for bioremediation of marine oil spills. We have used gravel which contaminated oil mousse from Beach Simulator Tank, in Marine Biotechnology Institute, Kamaishi, Japan, and grown on enrichment culture. Biostimulation with nutrients (N and P was done to analyze biodegradation of hydrocarbon compounds: Naphthalene, Phenanthrene, Trichlorodibenzofuran and Benzo[a]pyrene. Community of bacteria from enrichment culture was determined by DGGE. Isolating and screening the bacteria on inorganic medium contain hydrocarbon compounds and determination of bacteria by DAPI (number of cells and CFU. DNA was extracted from colonies of bacteria and sequence determination of the 16S rDNA was amplified by primers U515f and U1492r. Twenty nine strains had been sequence and have similarity about 90-99% to their closest taxa by homology Blast search and few of them have suspected as new species.

  14. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  15. Chryseobacterium indologenes, novel mannanase-producing bacteria

    Directory of Open Access Journals (Sweden)

    Surachai Rattanasuk

    2009-10-01

    Full Text Available Mannanase is a mannan degrading enzyme which is produced by microorganisms, including bacteria. This enzyme can be used in many industrial processes as well as for improving the quality of animal feeds. The aim of the present study was toscreen and characterize the mannanase-producing bacteria. Two genera of bacteria were isolated from Thai soil samples,fermented coconut, and fertilizer. Screening was carried out on agar plates containing mannan stained with iodine solution.The bacteria were identified by partial 16S rRNA gene sequence, biochemical test and morphology, respectively. The mannanase activity was determined by zymogram and DNS method. Two strains of bacteria with mannanase activity were identified as Bacillus and Chryseobacterium. This is the first report of mannanase-producing Chryseobacterium.

  16. Hyphae colonizing bacteria associated with Penicillium bilaii

    DEFF Research Database (Denmark)

    Ghodsalavi, Behnoushsadat

    shown that mycorrhizal helper bacteria presenting in mycorrhizal fungi could stimulate fungal growth, promote establishment of root-fungus symbiosis and enhance plant production. But it is unknown if the comparable relationship exist between the non-mycorrhizal fungus P. bilaii and its hyphae associated...... bacteria. In the current PhD thesis, we assumed that hyphae-associated microbiome of P. bilaii might harbor helper bacteria with ability to improve fungal growth and P solubilization performance. Therefore, we aimed to isolate bacteria associated with the P. bilaii hyphae and identify the fungal growth...... stimulating bacteria with the perspective of promoting efficiency of Jumpstart in soil – plant system. For this purpose, most of the work within the current project was carried out by development of suitable model systems by mimicking the natural soil habitat to reach to the reliable performance in soil...

  17. Antibiotic resistance in probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Miguel eGueimonde

    2013-07-01

    Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue.

  18. Comparative cytotoxicity of periodontal bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, R.H.; Hammond, B.F.

    1988-11-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species.

  19. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  20. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria.

    Science.gov (United States)

    Denoncourt, Alix M; Paquet, Valérie E; Charette, Steve J

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  1. 嗜热脱氮土壤芽孢杆菌β-葡萄糖苷酶的克隆与重组表达及其酶学性质研究%Cloning, expression and characterization of a beta-glucosidase from Geobacillus thermodenitrificans

    Institute of Scientific and Technical Information of China (English)

    胡开蕾; 韩剑; 刘伟丰; 王艳萍; 陶勇

    2012-01-01

    [Objective] Cloning of P-glucosidase gene bglB from Geobacillus thermodenitrifl-cans, heterologous expression in E.coli, purification and characterization of its enzymatic properties.[Methods] Molecular cloning of the β-glucosidase encoding gene (bglB) from Geobacillus thermodenitrificans was performed by using a PCR technique.The gene was expressed in BL21(DE3) of Escherichia coli.After purification, the enzymatic properties and the protein aggregation of β-glucosidase was investigated.[Results] The optimum temperature and optimum pH of the recombinant β-glucosidase are 65 ℃ and 7.0 respectively, the enzyme is stable for 4 h under the conditions of pH 5-10, 60 ℃, and it maintains its high enzymatic activity at the high salt concentration (up to 880 mmol/L K+).The recombinant β-glucosidase is strongly activated by Al3+, while slightly inhibited by Co2+.Under the optimal reaction condition, the enzyme specific activity of recombinant β-glucosidase is 0.043 IU/mg.The β-glucosidase GST fusion protein exists in different oligomers by a Superdex G-200 gel filtration analysis, and the different oligomers of enzymes all have hydrolase activity.[Conclusion] We successfully obtained a heat- and salt- resistant neutral recombinant β-glucosidase from Geobacillus thermodenitrificans, and paved a way for further study of its catalytic mechanism and improvement its thermal stability of beta-glucosidase.%[目的]克隆嗜热脱氮土壤芽孢杆菌中的β-葡萄糖苷酶基因bglB,在E.coli中异源表达,纯化并研究其酶学性质.[方法]利用PCR技术从嗜热脱氮土壤芽孢杆菌的基因组DNA中克隆得到bglB基因,将该基因克隆到表达载体pGEX-2TL上并在大肠杆菌BL21(DE3)中表达,对纯化后的β-葡萄糖苷酶的酶学性质及寡聚状态进行分析.[结果]重组表达的β-葡萄糖苷酶最适温度为65℃,最适pH为7.0,能在pH 5-10、60℃下稳定存在4h,并能在较高的离子强度(880 mmol/L K+)下发挥其功能.A13+

  2. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi

    2011-01-01

    Full Text Available Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  3. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  4. Light scattering by marine heterotrophic bacteria

    Science.gov (United States)

    Ulloa, Osvaldo; Sathyendranath, Shubha; Platt, Trevor; Quinones, Renato A.

    1992-01-01

    Mie theory is applied to estimate scattering by polydispersions of marine heterotrophic bacteria, and a simple expression is derived for the bacterial scattering coefficient. The error incurred in deriving bacterial optical properties by use of the van de Hulst approximations is computed. The scattering properties of natural bacterial assemblages in three marine environments, Georges Bank, Northeast Channel, and Sargasso Sea, are assessed by applying Mie theory to field data on bacterial size and abundance. Results are used to examine the potential contribution of bacteria to the scattering properties of seawater. The utility of using pigment data to predict the magnitude of scattering by bacteria is discussed.

  5. Do symbiotic bacteria subvert host immunity?

    Science.gov (United States)

    Hooper, Lora V

    2009-05-01

    The mammalian intestine is home to dense and complex indigenous bacterial communities. Most of these bacteria establish beneficial symbiotic relationships with their hosts, making important contributions to host metabolism and digestive efficiency. The vast numbers of intestinal bacteria and their proximity to host tissues raise the question of how symbiotic host-bacterial relationships are established without eliciting potentially harmful immune responses. In light of the varied ways in which pathogenic bacteria manipulate host immunity, this Opinion article explores the role of immune suppression, subversion and evasion in the establishment of symbiotic host-bacterial associations.

  6. The Microworld of Marine-Bacteria

    DEFF Research Database (Denmark)

    JØRGENSEN, BB

    1995-01-01

    Microsensor studies show that the marine environment in the size scale of bacteria is physically and chemically very different from the macroenvironment. The microbial world of the sediment-water interface is thus dominated by water viscosity and steep diffusion gradients. Because of the diverse...... metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples....

  7. Anaerobic bacteria, the colon and colitis.

    Science.gov (United States)

    Roediger, W E

    1980-02-01

    Anaerobic bacteria constitute more than 90% of the bacteria in the colon. An anaerobic environment is needed to maintain their growth and the production of short-chain fatty acids by these bacteria from carbohydrates. Short-chain fatty acids are rapidly absorbed and essential for metabolic as well as functional welfare of the colonic mucosa. The importance of these acids in water absorption and in the patogenesis of colitis is discussed in relation to the concept of "energy deficiency diseases" of the colonic mucosa.

  8. The Microworld of Marine-Bacteria

    DEFF Research Database (Denmark)

    JØRGENSEN, BB

    1995-01-01

    Microsensor studies show that the marine environment in the size scale of bacteria is physically and chemically very different from the macroenvironment. The microbial world of the sediment-water interface is thus dominated by water viscosity and steep diffusion gradients. Because of the diverse...... metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples....

  9. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean, carn

  10. Bacteria-mediated bisphenol A degradation.

    Science.gov (United States)

    Zhang, Weiwei; Yin, Kun; Chen, Lingxin

    2013-07-01

    Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

  11. Bioluminescent hydrocarbonclastic bacteria of the Niger Delta

    African Journals Online (AJOL)

    Administrator

    2007-02-19

    Feb 19, 2007 ... Bioluminescence is the chemical emission of light by organisms (Lang and Lange, ... (TNT) – contaminated soils by two different erated comp- .... Effect of phosphate levels on growth of bioluminescent bacteria. Phosphate ...

  12. ISOLATION AND CHARACTERIZATION OF BACTERIA FROM THE ...

    African Journals Online (AJOL)

    xx

    Key words: Drosophila melanogaster, gut-bacteria, larval development, Lysinibacillus sp. P-011 .... each test, 50 1st instar larvae and three replications were used. All the tests ..... molecules are produced by the blood-sucking insect Stomoxys.

  13. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

    2006-06-01

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

  14. Discovering lactic acid bacteria by genomics

    NARCIS (Netherlands)

    Klaenhammer, T.; Altermann, E.; Arigoni, F.; Bolotin, A.; Breidt, F.; Broadbent, J.; Cano, R.; Chaillou, S.; Deutscher, J.; Gasson, M.; Guchte, van de M.; Guzzo, J.; Hartke, A.; Hawkins, T.; Hols, P.; Hutkins, R.; Kleerebezem, M.; Kok, J.; Kuipers, O.; Lubbers, M.; Maguin, E.; McKay, L.; Mills, D.; Nauta, A.; Overbeek, R.; Pel, H.; Pridmore, D.; Saier, M.; Sinderen, van D.; Sorokin, A.; Steele, J.; O'Sullivan, D.; Vos, de W.; Weimer, B.; Zagorec, M.; Siezen, R.

    2002-01-01

    This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, nvironmental habitat, and its role in

  15. Discovering lactic acid bacteria by genomics

    NARCIS (Netherlands)

    Klaenhammer, T; Altermann, E; Arigoni, F; Bolotin, A; Breidt, F; Broadbent, J; Cano, R; Chaillou, S; Deutscher, J; Gasson, M; van de Guchte, M; Guzzo, J; Hartke, A; Hawkins, T; Hols, P; Hutkins, R; Kleerebezem, M; Kok, J; Kuipers, O; Maguin, E; McKay, L; Mills, D; Nauta, A; Overbeek, R; Pel, H; Pridmore, D; Saier, M; van Sinderen, D; Sorokin, A; Steele, J; O'Sullivan, D; de Vos, W; Weimer, B; Zagorec, M; Siezen, R

    This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in

  16. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  17. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...... and particularly higher organisms, covering a variety of functions ranging from pathogenic to symbiotic interactions. The detailed knowledge of these bacterial communication systems has opened completely new perspectives for controlling undesired microbial activities....

  18. Protection of probiotic bacteria in synbiotic matrices

    Science.gov (United States)

    Probiotics, like Lactobacillus acidophilus, Lactobacillus reuteri, Bifidobacterium breve, Bifidobacterium longum, when encapsulated with prebiotic fibers such as fructo-oligosaccharides (FOS), inulin (I) and pectic-oligosaccharides (POS), formed a synbiotic matrix system that protected the bacteria ...

  19. Distribution of phytopathogenic bacteria in infested seeds

    Science.gov (United States)

    Populations of phytopathogenic bacteria representing five host-pathogen combinations were assessed to determine if there was a mathematical relationship common across seedborne bacterial diseases. Bacterial populations were estimated from naturally-infested seeds of cowpea (Vigna unguiculata), peppe...

  20. Preparation of genomic DNA from bacteria.

    Science.gov (United States)

    Andreou, Lefkothea-Vasiliki

    2013-01-01

    The purpose of this protocol is the isolation of bulk cellular DNA from bacteria (alternatively see Preparation of genomic DNA from Saccharomyces cerevisiae or Isolation of Genomic DNA from Mammalian Cells protocols). Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Do bacteria, not fish, produce 'fish kairomone'?

    NARCIS (Netherlands)

    Ringelberg, J.; Van Gool, E.

    1998-01-01

    Fish-associated chemicals enhance phototactic downward swimming in Daphnia. If perch were treated with the antibiotic ampicillin, this enhancement was significantly decreased. Therefore, not fish, but bacteria associated with fish, seem to produce this kairomone. [KEYWORDS: Diel vertical migration;

  2. Lactic acid bacteria: microbiological and functional aspects

    National Research Council Canada - National Science Library

    Lahtinen, Sampo

    2012-01-01

    "Updated with the substantial progress made in lactic acid and bacteria research since the third edition, this fourth volume discusses improved insights in genetics and new molecular biological techniques...

  3. Quorum sensing in Gram-negative bacteria

    Institute of Scientific and Technical Information of China (English)

    WU Hong; SONG Zhijun; Niels HФIBY; Michael GIVSKOV

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community,and the mechanism is referred to as quorum sensing (QS).Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal molecules.Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread.These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment and particularly higher organisms,covering a variety of functions ranging from pathogenic to symbiotic interactions.The detailed knowledge of these bacterial communication systems has opened completely new perspectives for controlling undesired microbial activities.

  4. T cell polarizing properties of probiotic bacteria.

    Science.gov (United States)

    Barberi, Chiara; Campana, Stefania; De Pasquale, Claudia; Rabbani Khorasgani, Mohammad; Ferlazzo, Guido; Bonaccorsi, Irene

    2015-12-01

    Different commensal bacteria employed as probiotics have been shown to be endowed with immunomodulatory properties and to actively interact with antigen presenting cells, such as dendritic cells and macrophages. In particular, different strains of probiotic bacteria may induce the secretion of a discrete cytokine profile able to induce divergent T cell polarization. Here, we briefly review current knowledge regarding the effects of different species and strains of probiotic bacteria on T cell polarization. Given that the loss of intestinal homeostasis is frequently associated with an aberrant T cell polarization profile, a comprehensive knowledge of the immunomodulatory potential of these bacteria is crucial for their employment in the management of human immune-mediated pathologies, such as allergies or inflammatory bowel diseases.

  5. Distribution of urease producing bacteria in the

    African Journals Online (AJOL)

    higher proportion of bacteria associated with the caecal wall. (63%) were facultative .... Of even more importance is the role that the domestic rabbit can and ... Until more is known about digestion of plant foods in the monogastric herbivore ...

  6. Lactic Acid Bacteria in Health and Disease

    African Journals Online (AJOL)

    reports demonstrating the health promoting effects of ... therapy. In 1908, élie Metchinkoff, proposed that the acid-producing organisms (lactic acid bacteria) ... Phage resistance aids in .... In a study conducted [29] in children aged 3 it was found.

  7. Ecology: Electrical Cable Bacteria Save Marine Life.

    Science.gov (United States)

    Nielsen, Lars Peter

    2016-01-11

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.

  8. Draft genome sequences of four thermophilic spore formers isolated from a dairy-processing environment

    NARCIS (Netherlands)

    Caspers, M.P.M.; Boekhorst, J.; Jong, de A.; Kort, R.; Nierop Groot, M.N.; Abee, T.

    2016-01-01

    Spores of thermophilic spore-forming bacteria are a common cause of contamination in dairy products. Here, we report draft genome sequences of four thermophilic strains from a milk-processing plant or standard milk, namely, a Geobacillus thermoglucosidans isolate (TNO-09.023), Geobacillus stearother

  9. The antibiotics relo in bacteria resistance

    OpenAIRE

    Santana, Vinicius Canato; CESUMAR

    2007-01-01

    The paper explains how antibiotics help us to combat bacteriosis, and also presents a brief historical report about the emergence of the antibiotic era with the discovery of penicillin. It introduces the problem of bacteria resistance, and brings the concept of antibiotics and its that produce these substance, and brings the concept of antibiotics and its main function. It questions about the self-defense of the organisms that produce these substances. relates the bacteria structures attacked...

  10. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  11. How do bacteria tune translation efficiency?

    OpenAIRE

    Li, Gene-Wei

    2015-01-01

    Bacterial proteins are translated with precisely determined rates to meet cellular demand. In contrast, efforts to express recombinant proteins in bacteria are often met with large unpredictability in their levels of translation. The disconnect between translation of natural and synthetic mRNA stems from the lack of understanding of the strategy used by bacteria to tune translation efficiency. The development of array-based oligonucleotide synthesis and ribosome profiling provides new approac...

  12. ORAL BACTERIA AND SYSTEMS DISEASES: A REVIEW

    OpenAIRE

    Moromi Nakata, Hilda; Profesor Principal de Microbiología, jefe de la sección de C. Dinámicas. D.A. Ciencia Básicas. Miembro permanente del Instituto de Investigaciones Estomatológicas de la Facultad de Odontología de la Universidad Nacional Mayor de San Marcos. Lima. Perú.

    2014-01-01

    In order to show a global vision of oral bacteria in systemic diseases, it is important to analyze the presence and consequences of these microorganisms in relation with: bacteremia, endocarditis, cardiovascular disease, cerebrovascular disease, bacterial pneumonia, neonatal weight, nefritis, arthritis, dermatitis and diabetes mellitus, reaching conclusions for each one of them. Con el objeto de presentar una visión general de la bacterias orales en los procesos sistémicos, se analiza la p...

  13. Quorum sensing mechanism in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hatice Yılmaz - Yıldıran

    2015-04-01

    and detection occurs as a consecution it is hard to understand their QS mechanism. In this review, connection between QS mechanism and some characteristics of lactic acid bacteria are evaluated such as concordance with its host, inhibition of pathogen development and colonization in gastrointestinal system, bacteriocin production, acid and bile resistance, adhesion to epithelium cells. Understanding QS mechanism of lactic acid bacteria will be useful to design metabiotics which is defined as novel probiotics.

  14. Study of Lactobacillus as Probiotic Bacteria

    OpenAIRE

    J Nowroozi; M Mirzaii; M. Norouzi

    2004-01-01

    Because of inhibitory effect, selected probiotic lactobacilli may be used as biological preservative, so, the aim of this study was to present some data on lactobacillus as probiotic bacteria. Lactic acid bacteria were isolated from sausage. Each isolate of lactobacillus species was identified by biochemical tests and comparing their sugar fermentation pattern. Antibacterial activities were done by an agar spot, well diffusion and blank disk method. Enzyme sensitivity of supernatant fluid and...

  15. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  16. Study of Lactobacillus as Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    J Nowroozi

    2004-07-01

    Full Text Available Because of inhibitory effect, selected probiotic lactobacilli may be used as biological preservative, so, the aim of this study was to present some data on lactobacillus as probiotic bacteria. Lactic acid bacteria were isolated from sausage. Each isolate of lactobacillus species was identified by biochemical tests and comparing their sugar fermentation pattern. Antibacterial activities were done by an agar spot, well diffusion and blank disk method. Enzyme sensitivity of supernatant fluid and concentrated cell free culture after treatment with α-amylase, lysozyme and trypsin was determined. The isolated bacteria were Lacto. plantarum, Lacto delbruekii, Lacto. acidophilus, Lacto. brevis. The isolated bacteria had strong activity against indicator strains. The antibacterial activity was stable at 100ºC for 10 min and at 56ºC for 30 min, but activity was lost after autoclaving. The maximum production of plantaricin was obtained at 25 - 30ºC at pH 6.5. Because, lactobacilli that used to process sausage fermentation are producing antimicrobial activity with heat stability bacteriocin, so, these bacteria may be considered to be a healthy probiotic diet. Lactobacilli originally isolated from meat products are the best condidates as probiotic bacteria to improve the microbiological safety of these foods.

  17. Tyramine and phenylethylamine biosynthesis by food bacteria.

    Science.gov (United States)

    Marcobal, Angela; De las Rivas, Blanca; Landete, José María; Tabera, Laura; Muñoz, Rosario

    2012-01-01

    Tyramine poisoning is caused by the ingestion of food containing high levels of tyramine, a biogenic amine. Any foods containing free tyrosine are subject to tyramine formation if poor sanitation and low quality foods are used or if the food is subject to temperature abuse or extended storage time. Tyramine is generated by decarboxylation of the tyrosine through tyrosine decarboxylase (TDC) enzymes derived from the bacteria present in the food. Bacterial TDC have been only unequivocally identified and characterized in Gram-positive bacteria, especially in lactic acid bacteria. Pyridoxal phosphate (PLP)-dependent TDC encoding genes (tyrDC) appeared flanked by a similar genetic organization in several species of lactic acid bacteria, suggesting a common origin by a single mobile genetic element. Bacterial TDC are also able to decarboxylate phenylalanine to produce phenylethylamine (PEA), another biogenic amine. The molecular knowledge of the genes involved in tyramine production has led to the development of molecular methods for the detection of bacteria able to produce tyramine and PEA. These rapid and simple methods could be used for the analysis of the ability to form tyramine by bacteria in order to evaluate the potential risk of tyramine biosynthesis in food products.

  18. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone

    2015-01-01

    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum as solidif......Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum...... as solidifying agents, and enumerated bacteria from seawater and algal exudates. We tested if culturability could be influenced by addition of quorum sensing signals (AHLs). All plates were incubated at 15°C. Bacterial counts (CFU/g) from algal exudates from brown algae were highest on media containing algal...... polymers. In general, bacteria isolated from algal exudates preferred more rich media than bacteria isolated from seawater. Overall, culturability ranged from 0.01 to 0.8% as compared to total cell count. Substitution of agar with gellan gum increased the culturability of seawater bacteria approximately...

  19. Antioxidant activity of Sphaerococcus coronopifolius associated bacteria

    Directory of Open Access Journals (Sweden)

    Nádia Fino

    2014-06-01

    Full Text Available Associated bacteria living on macroalgae surfaces are an interesting source of new secondary metabolites with biological activities. The aim of this study was the isolation and identification of epiphytic bacteria from the marine algae Sphaerococcus coronopifolius and the evaluation of the antioxidant activity of the bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1 extraction. Antioxidant activity was evaluated by quantification of total phenolic content (TPC, 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging activity and oxygen radical absorbent capacity (ORAC. The extracts with higher antioxidant activity were tested on MCF-7 and HepG-2 cell lines in oxidative stress conditions induced by H2O2 at 0.2 mM and 0.5 mM, respectively. In total were isolated 21 Sphaerococcus coronopifolius associated bacteria and identified as Vibrio sp. (28.57%, Shewanella sp. (23.81%, Pseudoalteromonas sp. (19.05%, Bacillus sp. (9.52% and Halomonas sp. (9.52%. Two (9.52% of them presented less than 90% Basic Local Alignment Search Tool (BLAST match. The epiphytic bacteria with the most antioxidant potential evaluated by ORAC and DPPH methods were Sp2, Sp12, Sp23, Sp25 and Sp27. The strain Sp4 show high antioxidant activity in all antioxidant methods (ORAC, DPPH and TPC. In oxidative stress conditions on MCF-7 cell line, the extracts of bacteria (1mg.ml-1: 24hours Sp4 (16.15%, Sp25 (17.95% and Sp27 (10.65% prevented the cell death induced by H2O2. In the HepG-2 cell line was the extracts of Sp2 (9.01%, Sp4 (11.21%, Sp12 (7.20% and Sp23 (8.81% bacteria that high prevented the oxidative stress condition induced by H2O2. In conclusion, the Sphaerococcus coronopifolius associated bacteria can be an interesting and excellent source of marine natural compounds with antioxidant activity.

  20. Nanotextile membranes for bacteria Escherichia coli capturing

    Directory of Open Access Journals (Sweden)

    Jaroslav Lev

    2010-01-01

    Full Text Available The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP. As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

  1. [Spectrum and susceptibility of preoperative conjunctival bacteria].

    Science.gov (United States)

    Fernández-Rubio, M E; Cuesta-Rodríguez, T; Urcelay-Segura, J L; Cortés-Valdés, C

    2013-12-01

    To describe the conjunctival bacterial spectrum of our patients undergoing intraocular surgery and their antibiotic sensitivity during the study period. A retrospective study of preoperative conjunctival culture of patients consecutively scheduled for intraocular surgery from 21 February 2011 to 1 April 2013. Specimens were directly seeded onto blood-agar and MacConkey-agar (aerobiosis incubation, 2 days), and on chocolate-agar (6% CO2 incubation, 7 days). The identified bacteria were divided into 3 groups according to their origin; the bacteria susceptibility tests were performed on those more pathogenic and on some of the less pathogenic when more than 5 colonies were isolated. The sensitivity of the exigent growing bacteria was obtained with disk diffusion technique, and for of the non-exigent bacteria by determining their minimum inhibitory concentration. The Epidat 3.1 program was used for statistical calculations. A total of 13,203 bacteria were identified in 6,051 cultures, with 88.7% being typical colonizers of conjunctiva (group 1), 8.8% typical of airways (group 2), and the remaining 2.5% of undetermined origin (group 3). 530 cultures (8.8%) were sterile. The sensitivity of group 1 was: 99% vancomycin, 95% rifampicin, 87% chloramphenicol, 76% tetracycline. Levels of co-trimoxazole, aminoglycosides, quinolones, β-lactams and macrolides decreased since 2007. The group 2 was very sensitive to chloramphenicol, cefuroxime, rifampicin, ciprofloxacin and amoxicillin/clavulanate. In group 3, to levofloxacin 93%, ciprofloxacin 89%, tobramycin 76%, but ceftazidime 53% and cefuroxime 29% decreased. None of the tested antibiotics could eradicate all possible conjunctival bacteria. Bacteria living permanently on the conjunctiva (group 1) have achieved higher resistance than the eventual colonizers. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  2. Flagellated ectosymbiotic bacteria propel a eucaryotic cell.

    Science.gov (United States)

    Tamm, S L

    1982-09-01

    A devescovinid flagellate from termites exhibits rapid gliding movements only when in close contact with other cells or with a substrate. Locomotion is powered not by the cell's own flagella nor by its remarkable rotary axostyle, but by the flagella of thousands of rod bacteria which live on its surface. That the ectosymbiotic bacteria actually propel the protozoan was shown by the following: (a) the bacteria, which lie in specialized pockets of the host membrane, bear typical procaryotic flagella on their exposed surface; (b) gliding continues when the devescovinid's own flagella and rotary axostyle are inactivated; (c) agents which inhibit bacterial flagellar motility, but not the protozoan's motile systems, stop gliding movements; (d) isolated vesicles derived from the surface of the devescovinid rotate at speeds dependent on the number of rod bacteria still attached; (e) individual rod bacteria can move independently over the surface of compressed cells; and (f) wave propagation by the flagellar bundles of the ectosymbiotic bacteria is visualized directly by video-enhanced polarization microscopy. Proximity to solid boundaries may be required to align the flagellar bundles of adjacent bacteria in the same direction, and/or to increase their propulsive efficiency (wall effect). This motility-linked symbiosis resembles the association of locomotory spirochetes with the Australian termite flagellate Mixotricha (Cleveland, L. R., and A. V. Grimstone, 1964, Proc. R. Soc. Lond. B Biol. Sci., 159:668-686), except that in our case propulsion is provided by bacterial flagella themselves. Since bacterial flagella rotate, an additional novelty of this system is that the surface bearing the procaryotic rotary motors is turned by the eucaryotic rotary motor within.

  3. Learning from bacteria about natural information processing.

    Science.gov (United States)

    Ben-Jacob, Eshel

    2009-10-01

    Under natural growth conditions, bacteria live in complex hierarchical communities. To conduct complex cooperative behaviors, bacteria utilize sophisticated communication to the extent that their chemical language includes semantic and even pragmatic aspects. I describe how complex colony forms (patterns) emerge through the communication-based interplay between individual bacteria and the colony. Individual cells assume newly co-generated traits and abilities that are not prestored in the genetic information of the cells, that is, not all the information required for efficient responses to all environmental conditions is stored. To solve newly encountered problems, they assess the problem via collective sensing, recall stored information of past experience, and then execute distributed information processing of the 10(9)-10(12) bacteria in the colony--transforming the colony into a "super-brain." I show illuminating examples of swarming intelligence of live bacteria in which they solve optimization problems that are beyond what human beings can solve. This will lead to a discussion about the special nature of bacterial computational principles compared to Turing algorithm computational principles, in particular about the role of distributed information processing.

  4. Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light

    Science.gov (United States)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  5. COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

    NARCIS (Netherlands)

    VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

    1992-01-01

    The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for th

  6. COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

    NARCIS (Netherlands)

    VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

    The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for

  7. Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

    Institute of Scientific and Technical Information of China (English)

    DAI Yongding; SONG Haiming; SHEN Jiying

    2004-01-01

    Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium, sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and constrictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two categories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky,bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae combined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipitation of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

  8. Studies on ultrasmall bacteria in relation to the presence of bacteria in the stratosphere

    Science.gov (United States)

    Alshammari, Fawaz; Wainwright, Milton; Alabri, Khalid; Alharbi, Sulamain A.

    2011-04-01

    Recent studies confirm that bacteria exist in the stratosphere. It is generally assumed that these bacteria are exiting from Earth, although it is possible that some are incoming from space. Most stratospheric bacterial isolates belong to the spore-forming genus Bacillus, although non-spore formers have also been isolated. Theoretically, the smaller a bacterium is, the more likely it is to be carried from Earth to the stratosphere. Ultrasmall bacteria have been frequently isolated from Earth environments, but not yet from the stratosphere. This is an anomalous situation, since we would expect such small bacteria to be over represented in the stratosphere-microflora. Here, we show that ultrasmall bacteria are present in the environment on Earth (i.e. in seawater and rainwater) and discuss the paradox of why they have not been isolated from the stratosphere.

  9. High Life Expectancy of Bacteria on Lichens.

    Science.gov (United States)

    Cernava, Tomislav; Berg, Gabriele; Grube, Martin

    2016-10-01

    Self-sustaining lichen symbioses potentially can become very old, sometimes even thousands of years in nature. In the joint structures, algal partners are sheltered between fungal structures that are externally colonized by bacterial communities. With this arrangement lichens survive long periods of drought, and lichen thalli can be revitalized even after decades of dry storage in a herbarium. To study the effects of long-term ex situ storage on viability of indigenous bacterial communities we comparatively studied herbarium-stored material of the lung lichen, Lobaria pulmonaria. We discovered that a significant fraction of the lichen-associated bacterial community survives herbarium storage of nearly 80 years, and living bacteria can still be found in even older material. As the bacteria reside in the upper surface layers of the lichen material, we argue that the extracellular polysaccharides of lichens contribute to superior life expectancy of bacteria. Deeper understanding of underlying mechanisms could provide novel possibilities for biotechnological applications.

  10. Encapsulation of probiotic bacteria in biopolymeric system.

    Science.gov (United States)

    Huq, Tanzina; Khan, Avik; Khan, Ruhul A; Riedl, Bernard; Lacroix, Monique

    2013-01-01

    Encapsulation of probiotic bacteria is generally used to enhance the viability during processing, and also for the target delivery in gastrointestinal tract. Probiotics are used with the fermented dairy products, pharmaceutical products, and health supplements. They play a great role in maintaining human health. The survival of these bacteria in the human gastrointestinal system is questionable. In order to protect the viability of the probiotic bacteria, several types of biopolymers such as alginate, chitosan, gelatin, whey protein isolate, cellulose derivatives are used for encapsulation and several methods of encapsulation such as spray drying, extrusion, emulsion have been reported. This review focuses on the method of encapsulation and the use of different biopolymeric system for encapsulation of probiotics.

  11. [Bacteriocins produced by lactic acid bacteria].

    Science.gov (United States)

    Bilková, Andrea; Sepova, Hana Kinová; Bilka, Frantisek; Balázová, Andrea

    2011-04-01

    Lactic acid bacteria comprise several genera of gram-positive bacteria that are known for the production of structurally different antimicrobial substances. Among them, bacteriocins are nowadays in the centre of scientific interest. Bacteriocins, proteinaceous antimicrobial substances, are produced ribosomally and have usually a narrow spectrum of bacterial growth inhibition. According to their structure and the target of their activity, they are divided into four classes, although there are some suggestions for a renewed classification. The most interesting and usable class are lantibiotics. They comprise the most widely commercially used and well examined bacteriocin, nisin. The non-pathogenic character of lactic acid bacteria is advantageous for using their bacteriocins in food preservation as well as in feed supplements or in veterinary medicine.

  12. Inorganic nanoparticles engineered to attack bacteria.

    Science.gov (United States)

    Miller, Kristen P; Wang, Lei; Benicewicz, Brian C; Decho, Alan W

    2015-11-01

    Antibiotics were once the golden bullet to constrain infectious bacteria. However, the rapid and continuing emergence of antibiotic resistance (AR) among infectious microbial pathogens has questioned the future utility of antibiotics. This dilemma has recently fueled the marriage of the disparate fields of nanochemistry and antibiotics. Nanoparticles and other types of nanomaterials have been extensively developed for drug delivery to eukaryotic cells. However, bacteria have very different cellular architectures than eukaryotic cells. This review addresses the chemistry of nanoparticle-based antibiotic carriers, and how their technical capabilities are now being re-engineered to attack, kill, but also non-lethally manipulate the physiologies of bacteria. This review also discusses the surface functionalization of inorganic nanoparticles with small ligand molecules, polymers, and charged moieties to achieve drug loading and controllable release.

  13. Microgravity effects on pathogenicity of bacteria

    Directory of Open Access Journals (Sweden)

    Ya-juan WANG

    2013-01-01

    Full Text Available Microgravity is one of the important environmental conditions during spaceflight. A series of studies have shown that many kinds of bacteria could be detected in space station and space shuttle. Space environment or simulated microgravity may throw a certain influence on those opportunistic pathogens and lead to some changes on their virulence, biofilm formation and drug tolerance. The mechanism of bacteria response to space environment or simulated microgravity has not been defined. However, the conserved RNA-binding protein Hfq has been identified as a likely global regulator involved in the bacteria response to this environment. In addition, microgravity effects on bacterial pathogenicity may threaten astronauts' health. The present paper will focus on microgravity-induced alterations of pathogenicity and relative mechanism in various opportunistic pathogens.

  14. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  15. Monitoring of environmental pollutants by bioluminescent bacteria.

    Science.gov (United States)

    Girotti, Stefano; Ferri, Elida Nora; Fumo, Maria Grazia; Maiolini, Elisabetta

    2008-02-04

    This review deals with the applications of bioluminescent bacteria to the environmental analyses, published during the years 2000-2007. The ecotoxicological assessment, by bioassays, of the environmental risks and the luminescent approaches are reported. The review includes a brief introduction to the characteristics and applications of bioassays, a description of the characteristics and applications of natural bioluminescent bacteria (BLB), and a collection of the main applications to organic and inorganic pollutants. The light-emitting genetically modified bacteria applications, as well as the bioluminescent immobilized systems and biosensors are outlined. Considerations about commercially available BLB and BLB catalogues are also reported. Most of the environmental applications, here mentioned, of luminescent organisms are on wastewater, seawater, surface and ground water, tap water, soil and sediments, air. Comparison to other bioindicators and bioassay has been also made. Various tables have been inserted, to make easier to take a rapid glance at all possible references concerning the topic of specific interest.

  16. Lethal photosensitization of biofilm-grown bacteria

    Science.gov (United States)

    Wilson, Michael

    1997-12-01

    Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

  17. Threats and opportunities of plant pathogenic bacteria.

    Science.gov (United States)

    Tarkowski, Petr; Vereecke, Danny

    2014-01-01

    Plant pathogenic bacteria can have devastating effects on plant productivity and yield. Nevertheless, because these often soil-dwelling bacteria have evolved to interact with eukaryotes, they generally exhibit a strong adaptivity, a versatile metabolism, and ingenious mechanisms tailored to modify the development of their hosts. Consequently, besides being a threat for agricultural practices, phytopathogens may also represent opportunities for plant production or be useful for specific biotechnological applications. Here, we illustrate this idea by reviewing the pathogenic strategies and the (potential) uses of five very different (hemi)biotrophic plant pathogenic bacteria: Agrobacterium tumefaciens, A. rhizogenes, Rhodococcus fascians, scab-inducing Streptomyces spp., and Pseudomonas syringae. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Ancient bacteria show evidence of DNA repair

    DEFF Research Database (Denmark)

    Johnson, Sarah Stewart; Hebsgaard, Martin B; Christensen, Torben R

    2007-01-01

    Recent claims of cultivable ancient bacteria within sealed environments highlight our limited understanding of the mechanisms behind long-term cell survival. It remains unclear how dormancy, a favored explanation for extended cellular persistence, can cope with spontaneous genomic decay over......-term survival of bacteria sealed in frozen conditions for up to one million years. Our results show evidence of bacterial survival in samples up to half a million years in age, making this the oldest independently authenticated DNA to date obtained from viable cells. Additionally, we find strong evidence...... that this long-term survival is closely tied to cellular metabolic activity and DNA repair that over time proves to be superior to dormancy as a mechanism in sustaining bacteria viability....

  19. Using Fluorescent Viruses for Detecting Bacteria in Water

    Science.gov (United States)

    Tabacco, Mary Beth; Qian, Xiaohua; Russo, Jaimie A.

    2009-01-01

    A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by fluorescence spectroscopy. The novelty of the present method lies in the use of bacteriophages (viruses that infect bacteria) to deliver the fluorescent reporter molecules to the bacteria of the species of interest.

  20. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    OpenAIRE

    Wessel, Stefan W.; van der Mei, Henny C.; David Morando; Slomp, Anje M.; Betsy van de Belt-Gritter; Amarnath Maitra; Busscher, Henk J.

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-...