[show abstract][hide abstract] ABSTRACT: Desizing of cotton and micropoly fabrics was done using thermostable xylanase from Bacillus pumilus ASH. Micropoly fabric showed better desizing than cotton under same conditions. Violet scale readings from the TEGEWA test after enzymatic desizing for 90 min at pH 7.0 and at 60°C showed the readings falling in the range of 4-5, indicating good desizing efficiency. During bioscouring the weight loss values and liberation of reducing sugars were highest when EDTA was used along with xylanase. The weight loss value of 1.5% was observed for dry cotton fabric after 1 h in case of agitated system at pH 7.0 and at an optimal enzyme dosage of 5 IU/g. The weight loss values and the liberation of reducing sugars were higher in case of cotton fabrics. Wetting time of fabrics was lowered significantly after 60 min of bioscouring using xylanase. Increase in temperature or concentration of surfactant led to further reduction in the wetting time. The whiteness values of fabrics after bioscouring were 0.9% higher than the chemically scoured fabrics indicating good efficacy of xylanase during the scouring process.
Indian Journal of Microbiology 06/2012; 52(2):222-9. · 0.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Molecular Catalysis B Enzymatic 01/2012; · 2.82 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pretreatment of wheat straw pulp using cellulase-free xylanase produced from Bacillus stearothermophilus SDX at 60°C for 120min resulted in 4.75% and 22.31% increase in brightness and whiteness, respectively. Enzyme dose of 10U/g of oven dried pulp at pH 9 decreased the kappa number and permanganate number by 7.14% and 5.31%, respectively. Further chlorine dioxide and alkaline bleaching sequences (CDED(1)D(2)) resulted in 1.76% and 3.63% increase in brightness and whiteness, respectively. Enzymatic prebleaching of pulp decreased 20% of chlorine consumption without any decrease in brightness. Improvement in various pulp properties like viscosity, burst factor, burstness, breaking length, double fold, gurley porosity, tear factor, and tearness were also observed after bleaching of xylanase treated wheat straw pulp.
New Biotechnology 01/2011; 28(1):58-64. · 1.71 Impact Factor
[show abstract][hide abstract] ABSTRACT: Critical factors for xylanase production of Bacillus stearothermophilus under batch fermentation and for clarification of citrus fruit juice using this xylanase were optimized through central composite design of response surface methodology. Statistical approach resulted in an increase of 1.19-fold in xylanase yield over conventional method. Model equation for juice clarification included independent variables viz. temperature, incubation time and enzyme dose to study the dependent variables such as yield, acidic neutrality and filterability etc. Coefficient of determination, R(2) for enzyme production model and for different juice properties were in accordance with the linearity of the model. On the basis of the contour plots the optimum enzyme dose was 12.5 IU/g of xylanase. Enzymatic treatment has resulted in the improvement of twofold in the release of reducing sugars and 52.97% in juice yield, whereas 35.34% reduction in turbidity was observed.
New Biotechnology 11/2010; 28(6):746-55. · 1.71 Impact Factor
[show abstract][hide abstract] ABSTRACT: A new series of complexes of the type [M(C24H16N4)X]X2, where M = Cr(III), Fe(III), and Mn(III), X = Cl-, NO3-, and CH3COO-, has been synthesized by template condensation of 1,8-diaminonaphthalene and glyoxal in the presence of trivalent metal salts in methanolic medium. The complexes have been characterized with the help of elemental analysis, conductance measurements, magnetic measurements, and electronic, NMR, IR, and mass spectral studies. On the basis of these studies, a five-coordinate square pyramidal geometry for all of these complexes has been proposed. All the synthesized metal complexes were also tested for their in vitro antimicrobial activities against some bacterial strains, viz. Bacillus subtilis, Bacillus stearothermophilus (gram-positive bacteria), Escherichia coli, and Pseudomonas putida (gram-negative bacteria), and some fungal strains, viz. Aspergillus flavus and Aspergillus niger. The results obtained were compared with standard antibiotics: chloramphenicol, streptomycin, and the antifungal drug cyclohexamide. Some of the tested complexes showed remarkable antimicrobial activities.
Journal of Enzyme Inhibition and Medicinal Chemistry 02/2010; 25(1):21-8. · 1.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: Ten 2-aryl/hetarylbenzoxazoles (5a, 5b, and 6a–h) were synthesized via oxidative cyclization of Schiff bases (3a, 3b, and 4a–h) with 1.1 equivalent of iodobenzene diacetate (IBD) in methanol. All of these 2-aryl/hetarylbenzoxazoles (5a, 5b, and 6a–h) were tested in vitro for their antibacterial and antifungal activities against Bacillus subtilis, Bacillus stearothermophilus, Escherichia coli, and Pseudomonas putida. These compounds also were screened for their antifungal activity against Aspergillus flavus and Aspergillus niger. Biological activity of these compounds was compared with those of commercially available antibiotics, chloramphenicol and
antifungal agent cycloheximide. Most of these compounds, 5a, 5b, 6a, 6b, 6d, 6e, 6g, 6h, were equipotent or more potent than these commercial drugs at concentration 100 μg/ml.
Medicinal Chemistry Research 01/2010; 19(6):541-550. · 1.61 Impact Factor
[show abstract][hide abstract] ABSTRACT: A new series of complexes was synthesized by template condensation of malonyl dihydrazide and glyoxal in methanolic medium in the presence of divalent cobalt, nickel, copper, zinc and cadmium salts, whereby complexes of the type: [M(C5H6N4O2)X2] where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), and X = Cl-, NO3- and OAc-, were formed. The complexes were characterized with the aid of elemental analyses, conductance measurements, magnetic susceptibility measurements, and electronic, NMR and infrared spectral studies. Based on these studies, a six coordinate octahedral geometry is proposed for these complexes. The complexes were tested for their in vitro antibacterial and antifungal activities. The minimum inhibitory concentration shown by complexes was compared with that of standard drugs.
[show abstract][hide abstract] ABSTRACT: Xylanase alone as 'single lay out' (strategy I) and in combination with pectinase as 'mixed lay out' (strategy II) was used to investigate their bio-bleaching potentials. Strategy I was carried at 70 degrees C using 5 U/g of xylanase at pH 9.5 and 12.5 whereas strategy II was carried out at 70 degrees C using 5 U/g of each of the enzyme, respectively at pH 9.5. Bio-bleaching caused 15% and 20% less Cl(2) consumption though strategy I and II, respectively over chemical bleaching. Strategy II was proved to be 35.71% more efficient in ClO(2) saving than conventional method. Significant improvement in various pulp properties viz. tensile strength 25.70%, breaking length 21.80%, burst factor 20.00%, burstness 13.86%, tear factor 6.61% and tearness 18.88%, was also observed through 'mixed lay out' strategy.
[show abstract][hide abstract] ABSTRACT: Synthesis of 12 new 3-aryl/heteroaryl-5,7-dimethyl-1,2,4-triazolo[4,3-c]pyrimidines (3a-l) has been accomplished by the oxidation of pyrimidinylhydrazones (2a-l) of various aryl/heteroaryl aldehydes using 1.1equiv. of iodobenzene diacetate (IBD) in dichloromethane. All the compounds 3a-l tested in vitro for their antibacterial activity against two Gram-positive bacteria namely, Bacillus subtilis, Bacillus stearothermophilus and two Gram-negative bacteria Pseudomonas putida, Escherichia coli. Two compounds, namely 3-(2,4-dichlorophenyl)-5,7-dimethyl-1,2,4-triazolo [4,3-c]pyrimidine (3j) and 3-(4-hydroxy-2-methoxyphenyl)-5,7-dimethyl-1,2,4-triazolo[4,3-c]pyrimidine (3l) were found to be equipotent or more potent than the commercially available antibiotics (chloramphenicol and streptomycin).
European journal of medicinal chemistry 05/2009; 44(5):2260-4. · 3.27 Impact Factor
[show abstract][hide abstract] ABSTRACT: An alkaline and thermostable pectinase production from Bacillus subtilis SS was optimized under submerged fermentation and its application was tested in textile industry for desizing and bioscouring of cotton and micropoly fabrics. Desizing of fabric was the best with 5U/g pectinase treatment for 120min at pH 9.5 and 65°C. Under optimized conditions of bioscouring, desized cotton showed highest reducing sugar liberation and weight loss than desized micropoly. Along with enzyme, addition of chelating (EDTA) and wetting agent markedly enhanced the weight loss compared to single use of enzyme or EDTA alone. Agitation (50±2) enhanced the weight loss values of cotton (1.9%) and micropoly fabric (1.7%) at pH 9.5 after treatment time of 2h. Bioscouring of fabrics with pectinase resulted in enhancement of various physical properties of fabrics viz. whiteness (1.2%), tensile strength (1.6%) and tearness (3.0%) over conventionally alkaline scoured fabrics.
Process Biochemistry - PROCESS BIOCHEM. 01/2009; 44(5):521-526.
[show abstract][hide abstract] ABSTRACT: A novel series of complexes of the type [M(C(24)H(16)N(4))X(2)]; where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II); X = Cl(-1), NO(-1)(3), CH(3)COO(-1) has been synthesized by template condensation of 1,8-diaminonaphthalene and glyoxal in the presence of divalent metal salts in methanolic medium. The complexes have been characterized with the help of elemental analyses, conductance measurements, molecular weight determination, magnetic measurements, electronic, NMR, infrared and far infrared spectral studies. The low value of molar conductance indicates them to be non-electrolytes. On the basis of various studies a distorted octahedral geometry may be proposed for all of these complexes. These metal complexes were also tested for their in vitro antibacterial and antifungal activities to assess their inhibiting potential.
Journal of Enzyme Inhibition and Medicinal Chemistry 11/2008; 24(3):795-803. · 1.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pectinase production from Bacillus subtilis SS was optimized under solid-state fermentation (5,943 U/g of dry bacterial bran). The pectinase produced was stable in neutral to alkaline pH range at 70 degrees C; therefore, the suitability of this pectinase in pulp and paper industry was investigated. The enzyme pretreatment process was optimized, and a pectinase dose of 5 IU/g of oven-dried pulp (10% consistency) at pH 9.5 temperature 70 degrees C after 150 min of treatment gave the best pretreatment to the pulp. An increase of 4.3% in brightness along with an increase of 14.8 and 65.3% in whiteness and fluorescence, respectively, whereas a 15% decrease in the yellowness of the pretreated pulp were observed. There was a 5.85% reduction in kappa number and 6.1% reduction in permanganate number along with a reduction in the chemical oxygen demand value. Significant characteristics showed by pectinase open new possibilities of application of this cellulase-free enzyme in the pulp and paper industry by reducing the negative environmental impact of chemicals apart from improving the properties of paper.
Applied Biochemistry and Biotechnology 07/2008; 149(3):287-93. · 1.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: A highly active alkalothermophilic cellulase free xylanase (3446 U/g of dry substrate) has been produced from newly isolated strain of Bacillus stearothermophilus under solid-state fermentation using wheat bran (2.5%, w/v) pH 7.0 and at 37 °C. The xylanase was stable over broad range of pH (6.0–12.5) and temperature (37–85 °C) and hence was used in the bioprocessing of fabrics as an alternative to conventional chemical method. The desizing and bioscouring treatments were most efficient at 70 °C after 90 and 180 min of incubation respectively using 5 g/l of xylanase dose in the medium of pH 9.5. Enzymatically desized fabrics when subjected to bioscouring resulted in 0.91%, 0.88% weight loss for micropoly and 0.83%, 0.80% for cotton respectively under agitated (50 ± 2 rpm) and non-agitated conditions. Consequently Whiteness index for cotton (11.81%) and micropoly (52.15%) fabrics was increased. Induction in the release of reducing sugars was also observed for cotton (8.37%) and micropoly (16.79%) fabric over conventional method. Enzymatically processed fabric samples possessed 1.12% and 1.95% more tensile strength than reference. Tearness value also increased for bio-treated cotton (1.57%) and micropoly (2.37%) fabric samples as compared to control.
[show abstract][hide abstract] ABSTRACT: A very high level of alkalophilic and thermostable pectinase and xylanase has been produced from newly isolated strains of Bacillus subtilis and Bacillus pumilus respectively. Enzyme production for pectinase was carried out under SSF using combinations of cheap agricultural residues while xylanase was produced under submerged fermentation using wheat bran as substrate to minimize the cost of production of these enzymes Among the various substrates tested, the highest yield of pectinase production was observed by using combination of WB + CW (6592 U/g of dry substrate) supplemented with 4% yeast extract when incubated at 37 degrees C for 72 h using deionized water of pH 7.0 as moistening agent. The biobleaching effect of these cellulase free enzymes on kraft pulp was determined. Both xylanase and pectinase showed stability over a broad range of pH from 6 to 10 and temperature from 55 to 70 degrees C. The bleaching efficiency of the pectinase and xylanase on kraft pulp was maximum after 150 min at 60 degrees C using enzyme dosage of 5 IU/ml of each enzyme at 10% pulp consistency with about 16% reduction in kappa number and 84% reduction in permanganate number. Enzyme treated pulp when subjected to CDED(1)D(2) steps, 25% reduction in chlorine consumption and upto 19% reduction in consumption of chlorine dioxide was observed for obtaining the same %ISO brightness. Also an increase of 22 and 84% in whiteness and fluorescence respectively and a decrease of approximately 19% in the yellowness of the biotreated pulp were observed by pretreatment of the pulp with our enzymatic mixture.
Journal of Industrial Microbiology and Biotechnology 01/2008; 34(12):763-70. · 2.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: A very high level of cellulase-free, thermostable xylanase has been produced from newly isolated strain of Bacillus pumilus under submerged fermentation in a basal medium supplemented with wheat bran (2%, w/v) pH 8.0 and at 37 °C. After optimization of various production parameters, an increase of nearly 13-fold in xylanase production (5407 IU/ml) was achieved. The produced xylanase is stable in neutral to alkaline pH region at 70 °C. The suitability of this xylanase for use in the bioleaching of eucalyptus Kraft pulp was investigated. A xylanase dose of 5 IU/g of oven dried pulp of 10% consistency exhibited the optimum bleach boosting of the pulp at pH 7.0 and 60 °C after 180 min of treatment. An increase of 5% in brightness along with an increase of 21% and 28% in whiteness and fluorescence respectively, whereas 18% decrease in the yellowness of the biotreated pulp was observed. Enzyme treated pulp when subjected to chemical bleaching, resulted in 20% reduction in chlorine consumption and up to 10% reduction in consumption of chlorine dioxide. Also a reduction of about 16% in kappa number and 83% in permanganate number, along with a reduction in COD value and significant improvement in various pulp properties, viz. viscosity, tensile strength, breaking length, burst factor, burstness, tear factor and tearness were observed in comparison to the conventional chemical bleaching.