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T Satyanarayana - One of the best experts on this subject based on the ideXlab platform.
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utility of immobilized recombinant carbonic anhydrase of Bacillus Halodurans tslv1 on the surface of modified iron magnetic nanoparticles in carbon sequestration
Energy & Fuels, 2017Co-Authors: Shazia Faridi, Himadri Bose, T SatyanarayanaAbstract:Carbonic anhydrase (CA) based conversion of CO2 to CaCO3 has been identified as a green and economic strategy to sequester CO2 from flue gas and industrial emissions. The method is, however, cost-intensive as an efficient immobilization method for reusing the enzyme poses a major challenge. In this investigation, the recombinant carbonic anhydrase of polyextremophilic bacterium Bacillus Halodurans TSLV1 (rBhCA) has been immobilized on the surface of modified magnetic (silanized) iron oxide nanoparticles (Si-MNPs). The immobilized rBhCA exhibited improvement in alkalistability and retained significantly high activity at elevated temperatures as compared to the free rBhCA. Furthermore, rBhCA immobilized on Si-MNPs could be easily isolated from the reaction by magnetic separation. After 22 repeated uses, the immobilized rBhCA retained 50% of the initial activity and could be stored for 28 days without any loss in activity. rBhCA-Si-MNPs accelerated the onset of CaCO3 precipitation over that of the free enzym...
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bifunctional recombinant cellulase xylanase rbhcell xyl from the polyextremophilic bacterium Bacillus Halodurans tslv1 and its utility in valorization of renewable agro residues
Extremophiles, 2016Co-Authors: Gurdeep Rattu, Swati Joshi, T SatyanarayanaAbstract:The thermostable bifunctional CMCase and xylanase encoding gene (rBhcell-xyl) from Bacillus Halodurans TSLV1 has been expressed in Escherichia coli. The recombinant E. coli produced rBhcell-xyl (CMCase 2272 and 910 U L−1 xylanase). The rBhcell-xyl is a ~62-kDa monomeric protein with temperature and pH optima of 60 °C and 6.0 with T1/2 of 7.0 and 3.5 h at 80 °C for CMCase and xylanase, respectively. The apparent K m values (CMC and Birchwood xylan) are 3.8 and 3.2 mg mL−1. The catalytic efficiency (k cat/K m ) values of xylanase and CMCase are 657 and 171 mL mg−1 min−1, respectively. End-product analysis confirmed that rBhcell-xyl is a unique endo-acting enzyme with exoglucanase activity. The rBhcell-xyl is a GH5 family enzyme possessing single catalytic module and carbohydrate binding module. The action of rBhcell-xyl on corn cobs and wheat bran liberated reducing sugars, which can be fermented to bioethanol and fine biochemicals.
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characteristics of recombinant α carbonic anhydrase of polyextremophilic bacterium Bacillus Halodurans tslv1
International Journal of Biological Macromolecules, 2016Co-Authors: Shazia Faridi, T SatyanarayanaAbstract:Abstract Carbonic anhydrase (CA) is a biocatalyst that catalyzes the hydration of CO2 to bicarbonate and protons, thus useful in mitigating green house effect by sequestering CO2 from various point sources. An alkalistable and moderately thermostable α- carbonic anhydrase encoding gene (BhCA) from Bacillus Halodurans TSLV1 has been cloned and expressed in Escherichia coli. A 31.4-fold enhancement in CA production was achieved due to cloning and expression in E. coli. About 50% of the CA produced was secreted when recombinant E. coli with BhCA-pET22b was cultivated in a medium with EDTA and lysozyme because of the efficient pelB leader sequence. rBhCA is a ∼75 kDa homodimeric protein with a Tm of 72 °C and T1/2 values of 66 and 24 min at 50 and 60 °C, respectively. SDM analysis revealed that H137, H139, H156 and H110 present in the active site play an important role in catalysis. Mineralization of CO2 using rBhCA led to the accelerated precipitation of CaCO3 in calcite form. rBhCA also functions as an efficient virtual peroxidase when Zn2+ is substituted with Mn2+.
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generation of xylooligosaccharides from microwave irradiated agroresidues using recombinant thermo alkali stable endoxylanase of the polyextremophilic bacterium Bacillus Halodurans expressed in pichia pastoris
Bioresource Technology, 2015Co-Authors: Vikash Kumar, T SatyanarayanaAbstract:The recombinant Pichia pastoris harboring the endoxylanase gene (TSEV1xyl) of Bacillus Halodurans TSEV1 yielded a high titer of extracellular xylanase (502±23 U ml(-1)) on induction with methanol. The purified recombinant xylanase (TSEV1xyl) displayed optimal activity at 80°C and pH 9.0. The glycosylated recombinant xylanase exhibited higher thermostability (T1/2 of 45 min at 80°C) than the native enzyme (T1/2 of 35 min at 80°C). The agroresidues subjected to pretreatment (soaking in alkali followed by microwave irradiation) liberated xylooligosaccharides (XOS) upon hydrolysis with the recombinant xylanase. The removal of unhydrolyzed agroresidues, xylanase and xylose from the hydrolysate by two-step ultrafiltration led to the purification of XOS as confirmed by TLC as well as HPLC analysis.
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secretion of recombinant thermo alkali stable endoxylanase of polyextremophilic Bacillus Halodurans tsev1 and its utility in generating xylooligosaccharides from renewable agro residues
Process Biochemistry, 2014Co-Authors: Vikash Kumar, T SatyanarayanaAbstract:Abstract The recombinant thermo-alkali-stable endoxylanase (Bh-xyl) of polyextremophilic bacterium Bacillus Halodurans TSEV1 has been produced extracellularly using a combination of cloning strategies and physico-chemical treatment of recombinant Escherichia coli cells. Sixty percent higher secretion of recombinant xylanase has been achieved by cloning Bh-xyl in pET28a(+) and expression followed by optimization of the cultural variables (EDTA, lysozyme and temperature). The pure recombinant endoxylanase is of 42 kDa, which is active in the broad pH and temperature ranges between 7.0 and 12.0, and 30 and 100 °C, with optima at 9.0 and 70 °C. The K m , V max and k cat values of the Bh-xyl (birchwood xylan) are 2.6 mg ml −1 , 252.3 μmol mg −1 min −1 and 3.36 × 10 3 min −1 , respectively. The enzyme has higher affinity for soft wood xylan than most of the xylanases from extremophilic microbes. The endoxylanase efficiently liberated xylooligosaccharides from the renewable agro-residues, which find application in functional foods as prebiotics.
Vikash Kumar - One of the best experts on this subject based on the ideXlab platform.
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generation of xylooligosaccharides from microwave irradiated agroresidues using recombinant thermo alkali stable endoxylanase of the polyextremophilic bacterium Bacillus Halodurans expressed in pichia pastoris
Bioresource Technology, 2015Co-Authors: Vikash Kumar, T SatyanarayanaAbstract:The recombinant Pichia pastoris harboring the endoxylanase gene (TSEV1xyl) of Bacillus Halodurans TSEV1 yielded a high titer of extracellular xylanase (502±23 U ml(-1)) on induction with methanol. The purified recombinant xylanase (TSEV1xyl) displayed optimal activity at 80°C and pH 9.0. The glycosylated recombinant xylanase exhibited higher thermostability (T1/2 of 45 min at 80°C) than the native enzyme (T1/2 of 35 min at 80°C). The agroresidues subjected to pretreatment (soaking in alkali followed by microwave irradiation) liberated xylooligosaccharides (XOS) upon hydrolysis with the recombinant xylanase. The removal of unhydrolyzed agroresidues, xylanase and xylose from the hydrolysate by two-step ultrafiltration led to the purification of XOS as confirmed by TLC as well as HPLC analysis.
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secretion of recombinant thermo alkali stable endoxylanase of polyextremophilic Bacillus Halodurans tsev1 and its utility in generating xylooligosaccharides from renewable agro residues
Process Biochemistry, 2014Co-Authors: Vikash Kumar, T SatyanarayanaAbstract:Abstract The recombinant thermo-alkali-stable endoxylanase (Bh-xyl) of polyextremophilic bacterium Bacillus Halodurans TSEV1 has been produced extracellularly using a combination of cloning strategies and physico-chemical treatment of recombinant Escherichia coli cells. Sixty percent higher secretion of recombinant xylanase has been achieved by cloning Bh-xyl in pET28a(+) and expression followed by optimization of the cultural variables (EDTA, lysozyme and temperature). The pure recombinant endoxylanase is of 42 kDa, which is active in the broad pH and temperature ranges between 7.0 and 12.0, and 30 and 100 °C, with optima at 9.0 and 70 °C. The K m , V max and k cat values of the Bh-xyl (birchwood xylan) are 2.6 mg ml −1 , 252.3 μmol mg −1 min −1 and 3.36 × 10 3 min −1 , respectively. The enzyme has higher affinity for soft wood xylan than most of the xylanases from extremophilic microbes. The endoxylanase efficiently liberated xylooligosaccharides from the renewable agro-residues, which find application in functional foods as prebiotics.
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highly thermo halo alkali stable β 1 4 endoxylanase from a novel polyextremophilic strain of Bacillus Halodurans
Bioprocess and Biosystems Engineering, 2013Co-Authors: Vikash Kumar, Poonam Syal, T SatyanarayanaAbstract:A novel bacterial isolate, capable of producing extracellular highly thermostable, halo-alkali-stable and cellulase-free xylanase, was isolated from soil and identified as Bacillus Halodurans TSPV1 by polyphasic approach. The Plackett–Burman design identified wheat bran, lactose, tryptone and NaCl as the factors that significantly affect xylanase production, and thus, these were optimized by response surface methodology. The data analysis suggested that optimum levels of wheat bran (15–20 g L−1), lactose (1.0–1.5 g L−1), tryptone (2–2.5 g L−1) and NaCl (7.0–8.0 g L−1) support 6.75-fold higher xylanase production than that in the un-optimized medium. The xylanase is optimally active at 90 °C and pH 10, and stable for 4 h at 90 °C (T 1/2 60 h) over a broad range of NaCl concentrations (0–29 %). This is the first report on the isolation of polyextremophilic B. Halodurans strain that produces thermo-halo-alkali-stable xylanase in submerged fermentation. This enzyme efficiently saccharifies agro residues like wheat bran and corncobs. Fifty-six percent of hemicellulose of wheat bran could be hydrolyzed by xylanase (100 U g−1 substrate) along with cellulase (22 U FPase and 50 U CMCase g−1). The xylanase, being thermo-alkali stable and cellulase free, can find applications in pre-bleaching of paper pulps and hydrolysis of xylan in agricultural residues.
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thermo alkali stable xylanase of a novel polyextremophilic Bacillus Halodurans tsev1 and its application in biobleaching
International Biodeterioration & Biodegradation, 2012Co-Authors: Vikash Kumar, T SatyanarayanaAbstract:Abstract The production of thermo-alkali-stable and cellulase-free xylanase of polyextremophilic novel Bacillus Halodurans TSEV1 (MTCC 10962) was optimized in batch fermentation using statistical approaches. Plackett–Burman (PB) design identified temperature, inoculum size, KH2PO4 and wheat bran (WB) as the significant variables that affect xylanase production, and therefore, these variables have been optimized by Central composite design (CCD) matrix of response surface methodology (RSM). A 7.35-fold enhancement in xylanase production was attained due to optimization. The UV absorption spectrum of the compounds released by the enzyme action on unbleached pulp showed a characteristic peak at 280 nm indicating the presence of lignin related compounds in the filtrate. The materials released after biobleaching also displayed strong absorption at 237 and 465 nm. The enzyme dose 40 Ug−1, pH 10.0, and treatment time of 3 h are optimal for enzymatic pre-bleaching of wheat pulp that caused 14.6% reduction in kappa number and 5.6% enhancement in brightness of hand sheets without noticeable change in viscosity. This is the first report on xylanase production by a wild type polyextremophilic B. Halodurans in submerged fermentation and its application in pre-bleaching of paper pulps.
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applicability of thermo alkali stable and cellulase free xylanase from a novel thermo halo alkaliphilic Bacillus Halodurans in producing xylooligosaccharides
Biotechnology Letters, 2011Co-Authors: Vikash Kumar, T SatyanarayanaAbstract:An alkaliphilic, moderately thermophilic and halophilic bacterial isolate capable of producing a high titer of extracellular thermo-alkali-stable, cellulase-free endoxylanase was isolated from the paper mill effluents. It was identified as Bacillus Halodurans. The purified xylanase was active from pH 7 to 12 and 30 to 100°C with optimal activity at pH 9.0 and 80°C. It had T1/2 values of 40 and 15 min at 70 and 80°C, respectively. Activity was stimulated by dithiothreitol but strongly inhibited by N-bromosuccinimide. Its action on birchwood xylan and agro-residues liberated xylooligosaccharides of 2–7 degree of polymerization, and thus, the mode of action is similar to endoxylanases of the family 10 glucoside hydrolases.
Sergey Shleev - One of the best experts on this subject based on the ideXlab platform.
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direct heterogeneous electron transfer reactions of Bacillus Halodurans bacterial blue multicopper oxidase
Electroanalysis, 2008Co-Authors: Yan Wang, Sergey Shleev, M.a. Gorbacheva, Andreas Christenson, Dietmar Haltrich, Roland Ludwig, Tautgirdas Ruzgas, Lo GortonAbstract:Direct electron transfer reactions of Bacillus Halodurans bacterial multicopper oxidase on bare spectrographic graphite, as well as bare and thiol-modified gold electrodes were studied using cyclic voltammetry, potentiometry, amperometry, and spectroelectrochemistry. The redox potential of the T1 site of the enzyme was measured using mediatorless redox titration and found to be 325 mV +/- 10 mV vs. NHE. From measurements with a mercaptopropionic acid-modified gold electrode under aerobic conditions a midpoint potential of 360 mV vs. NHE for the T2/T3 copper cluster is deduced. Differing from most other characterized laccases of fungal and plant origins this bacterial enzyme exhibits bioelectrocatalytic activity at neutral pH and tolerates high chloride concentrations (200 mM), conditions that usually strongly inhibit catalysis. Moreover, it has the very high affinity towards molecular oxygen both in solution and in the adsorbed state (K-M <= 50 mu M). (Less)
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Direct Heterogeneous Electron Transfer Reactions of Bacillus Halodurans Bacterial Blue Multicopper Oxidase
Electroanalysis, 2008Co-Authors: Sergey Shleev, Yan Wang, M.a. Gorbacheva, Andreas Christenson, Dietmar Haltrich, Roland Ludwig, Tautgirdas Ruzgas, Lo GortonAbstract:Direct electron transfer reactions of Bacillus Halodurans bacterial multicopper oxidase on bare spectrographic graphite, as well as bare and thiol-modified gold electrodes were studied using cyclic voltammetry, potentiometry, amperometry, and spectroelectrochemistry. The redox potential of the T1 site of the enzyme was measured using mediatorless redox titration and found to be 325 mV +/- 10 mV vs. NHE. From measurements with a mercaptopropionic acid-modified gold electrode under aerobic conditions a midpoint potential of 360 mV vs. NHE for the T2/T3 copper cluster is deduced. Differing from most other characterized laccases of fungal and plant origins this bacterial enzyme exhibits bioelectrocatalytic activity at neutral pH and tolerates high chloride concentrations (200 mM), conditions that usually strongly inhibit catalysis. Moreover, it has the very high affinity towards molecular oxygen both in solution and in the adsorbed state (K-M
Lo Gorton - One of the best experts on this subject based on the ideXlab platform.
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direct heterogeneous electron transfer reactions of Bacillus Halodurans bacterial blue multicopper oxidase
Electroanalysis, 2008Co-Authors: Yan Wang, Sergey Shleev, M.a. Gorbacheva, Andreas Christenson, Dietmar Haltrich, Roland Ludwig, Tautgirdas Ruzgas, Lo GortonAbstract:Direct electron transfer reactions of Bacillus Halodurans bacterial multicopper oxidase on bare spectrographic graphite, as well as bare and thiol-modified gold electrodes were studied using cyclic voltammetry, potentiometry, amperometry, and spectroelectrochemistry. The redox potential of the T1 site of the enzyme was measured using mediatorless redox titration and found to be 325 mV +/- 10 mV vs. NHE. From measurements with a mercaptopropionic acid-modified gold electrode under aerobic conditions a midpoint potential of 360 mV vs. NHE for the T2/T3 copper cluster is deduced. Differing from most other characterized laccases of fungal and plant origins this bacterial enzyme exhibits bioelectrocatalytic activity at neutral pH and tolerates high chloride concentrations (200 mM), conditions that usually strongly inhibit catalysis. Moreover, it has the very high affinity towards molecular oxygen both in solution and in the adsorbed state (K-M <= 50 mu M). (Less)
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Direct Heterogeneous Electron Transfer Reactions of Bacillus Halodurans Bacterial Blue Multicopper Oxidase
Electroanalysis, 2008Co-Authors: Sergey Shleev, Yan Wang, M.a. Gorbacheva, Andreas Christenson, Dietmar Haltrich, Roland Ludwig, Tautgirdas Ruzgas, Lo GortonAbstract:Direct electron transfer reactions of Bacillus Halodurans bacterial multicopper oxidase on bare spectrographic graphite, as well as bare and thiol-modified gold electrodes were studied using cyclic voltammetry, potentiometry, amperometry, and spectroelectrochemistry. The redox potential of the T1 site of the enzyme was measured using mediatorless redox titration and found to be 325 mV +/- 10 mV vs. NHE. From measurements with a mercaptopropionic acid-modified gold electrode under aerobic conditions a midpoint potential of 360 mV vs. NHE for the T2/T3 copper cluster is deduced. Differing from most other characterized laccases of fungal and plant origins this bacterial enzyme exhibits bioelectrocatalytic activity at neutral pH and tolerates high chloride concentrations (200 mM), conditions that usually strongly inhibit catalysis. Moreover, it has the very high affinity towards molecular oxygen both in solution and in the adsorbed state (K-M
Bo Mattiasson - One of the best experts on this subject based on the ideXlab platform.
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production of haloduracin by Bacillus Halodurans using solid state fermentation
Biotechnology Letters, 2011Co-Authors: Abolghasem Danesh, Gashaw Mamo, Bo MattiassonAbstract:Bacillus Halodurans was cultivated on wheat bran as a solid-state substrate and produced haloduracin, a bacteriocin, at about 245 AU per wheat bran. Supplementation of the bran with Lauria-Bertani broth decreased haloduracin production. However, production was stimulated by addition of Mg2SO4 and K2HPO4. The highest production was achieved at a wheat bran/moisture ratio of 1:1.8 and in the presence of 10% (w/w) Na2CO3. Under optimum conditions, the organism produced about 3,000 AU per gram dry bran.
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Fusion of carbohydrate binding modules from Thermotoga neapolitana with a family 10 xylanase from Bacillus Halodurans S7
Extremophiles, 2007Co-Authors: Gashaw Mamo, Rajni Hatti-kaul, Bo MattiassonAbstract:Xylanase A of Thermotoga neapolitana contains binding domains both at the N- and C-terminal ends of the catalytic domain. In the N-terminal position it contains two carbohydrate-binding modules (CBM) which belong to family 22. These CBMs bind xylan but not to cellulose. The gene encoding the mature peptide of these CBMs was fused with an alkaline active GH10 xylanase from Bacillus Halodurans S7 and expressed in Escherichia coli . The (His)_6 tagged hybrid protein was purified by immobilized metal affinity chromatography and characterized. Xylan binding by the chimeric protein was influenced by NaCl concentration and pH of the binding medium. Binding increased with increasing salt concentration up to 200 mM. Higher extent of binding was observed under acidic conditions. The fusion of the CBM structures enhanced the hydrolytic efficiency of the xylanase against insoluble xylan, but decreased the stability of the enzyme. The optimum temperature and pH for the activity of the xylanase did not change.
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a thermostable alkaline active endo β 1 4 xylanase from Bacillus Halodurans s7 purification and characterization
Enzyme and Microbial Technology, 2006Co-Authors: Gashaw Mamo, Rajni Hattikaul, Bo MattiassonAbstract:A thermostable, alkaline active xylanase was purified to homogeneity from the culture supernatant of an alkaliphilic Bacillus Halodurans S7, which was isolated from a soda lake in the Ethiopian Rift Valley. The molecular weight and the pI of this enzyme were estimated to be around 43 kDa and 4.5, respectively. When assayed at 70 degrees C, it was optimally active at pH 9.0-9.5. The optimum temperature for the activity was 75 degrees C at pH 9 and 70 degrees C at pH 10. The enzyme was stable over a broad pH range and showed good thermal stability when incubated at 65 degrees C in pH 9 buffer. The enzyme activity was strongly inhibited by Mn2+. Partial inhibition was also observed in the presence of 5 mM Cu2+ Co2+ and EDTA. Inhibition by Hg2+ and dithiothreitol was insignificant. The enzyme was free from cellulase activity and degraded xylan in an endo-fashion. (c) 2006 Elsevier Inc. All rights reserved. (Less)
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cloning sequence analysis and expression of a gene encoding an endoxylanase from Bacillus Halodurans s7
Molecular Biotechnology, 2006Co-Authors: Gashaw Mamo, Osvaldo Delgado, Bo Mattiasson, Alejandra Martinez, Rajni HattikaulAbstract:The gene encoding an alkaline active xylanase of Bacillus Halodurans S7, containing an open reading frame of 1188 nucleotides encoding 396 amino acids, was cloned and expressed in Escherchia coli. On the basis of sequence similarity, possible −10 and −35, ribosome binding, and transcription terminator regions were identified. Analysis of the deduced amino acid sequence revealed that the protein was a single domain enzyme belonging to family 10 and designated as xyn 10A. The calculated molecular mass and isoelectric point (pI) of the mature peptide were 42.6 and 4.5 kDa, respectively. Xylanase activity expressed by the recombinant organism was detected in the cytoplasm, periplasm and the extracellular medium. In an 18-h old culture, about 39% of the xylanase was detected in the medium. The stability and activity profile of the recombinant xylanase was similar to the properties of the enzyme produced by the wild-type organism.
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hydrogen peroxide degradation by immobilized cells of alkaliphilic Bacillus Halodurans
Biocatalysis and Biotransformation, 2006Co-Authors: Kevin Raymond Oluoch, Francis Mulaa, Bo Mattiasson, Ulrika Welander, Maria M Andersson, Rajni HattikaulAbstract:Whole cells of Bacillus Halodurans LBK 261 were used as a source of catalase for degradation of hydrogen peroxide. The organism, B. Halodurans grown at 55°C and pH 10, yielded a maximum catalase activity of 275 U g−1 (wet wt.) cells. The catalase in the whole cells was active over a broad range of pH with a maximum at pH 8–9. The enzyme was optimally active at 55°C, but had low stability above 40°C. The whole cell biocatalyst exhibited a Km of 6.6 mM for H2O2 and Vmax of 707 mM H2O2 min−1 g−1 wet wt. cells, and showed saturation kinetics at 50 mM H2O2. The cells were entrapped in calcium alginate and used for H2O2 degradation at pH 9 in batch and continuous mode. In the batch process, the immobilized preparation containing 1.5 g (wet wt.) cells could be recycled at least four times for complete degradation of the peroxide in 50 mL solution at 25°C. An excess of immobilized biocatalyst could be used in a continuous stirred tank reactor for an average of 9 days at temperatures upto 55°C, and in a packed bed...
