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In the present investigation, xylooligosaccharides were produced from wheat bran and wheat bran extracted xylan through enzymatic hydrolysis using xylanase from novel Enterobacter hormaechei KS1. Xylooligosaccharides/reducing sugars production from wheat bran was found maximum (374 mg/g) when 4.0% of wheat bran was treated with 375 units (IU/mL) of Enterobacter hormaechei KS1 xylanase at pH 6.0 and incubated at 50 °C for 24 h of incubation. In case of wheat bran extracted xylan 419 mg/g of xylooligosaccharides were produced when 3% of extracted xylan was incubate for 8 h. Analysis of the enzymatic hydrolysate through high performance liquid chromatography equipped with refractive index detector showed the presence of xylose, xylopentose and xylohexose. The decrease in pH with 1.0% dose of xylooligosacchaides produced from extracted xylan hydrolysis using E. hormaechei KS1 xylanase showed more decrease with L. rhamnosus (6.72 to 5.94) followed by L. brevis (6.71 to 6.15) and L. plantarum (6.71 to 6.41). In case of increase in optical density both wheat bran and wheat bran extracted xylan generated xylooligosaccharides exhibited similar pattern i.e., L. rhamnosus > L. plantarum > L. brevis. [ABSTRACT FROM AUTHOR]

The study has been designed to isolate xylanase-producing bacteria and parametric optimization for maximum production. The xylanase was utilized for enzymatic hydrolysis of wheat bran (WB) and wheat bran extracted xylan (WBEx) to obtain xylooligosaccharides. The research was planned for value addition in the agriculture sector with low-cost enzyme production and its utilization in prebiotic production from agro-residue. The xylanase obtained from the new isolate Bacillus australimaris KS2 was optimized with 2.0% of 24 h inoculum supplemented with 2.0% wheat bran at pH 7, 35 °C for 48 h with an agitation rate of 150 rpm. There was a 2.96-fold increase in xylanase activity from its initial (2997.07 IU/mL) activity to the optimized condition (8873.07 IU/mL). The maximum reducing sugar production over enzymatically hydrolyzed WB was found after 8 h of reaction time at pH 5, 55 °C with 375 units of enzyme. In the case of enzymatically hydrolyzed WBEx, the maximum production of 588 mg/g was achieved after 16 h at pH 6 and 55 °C of reaction temperature at the same amount of enzyme dose. The results demonstrated that the new isolate Bacillus australimaris KS2 was an efficient xylanase producer. Xylooligosaccharides produced through enzymatic hydrolysis of WBEx showed good prebiotic potential over Lactobacillus plantarum , Lactobacillus brevis, and Lactobacillus rhamnosus. • A high xylanase titer of 8873 IU/mL from wheat bran using B. australimaris KS2. • A yield of 588 mg/g of xylooligosaccharides from alkali-extracted wheat bran xylan. • Stimulated growth of gut microbiota with the prepared xylooligosaccharides. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate ( PMMA) nanofiber membrane ( NFM) was synthesized by an electrospinning technique. These membranes were utilized as a support for immobilization of xylanase enzyme to study its p H stability, thermal stability, and reusability. The morphology of aligned NFM was studied by optical microscopy and scanning electron microscopy. The PMMA NFM was functionalized with phenylenediamine and activated with glutaraldehyde to yield an aldehyde group on its surface for covalent immobilization of xylanase. The Fourier transform infrared analysis of the covalently immobilized xylanase confirmed that the enzyme was immobilized on PMMA NFM via amide linkages. The immobilization efficiency of covalently bound xylanase was found experimentally to be 90%. A forward shift in p H optima from 6.0-7.0 (soluble enzyme) to 7.0-9.0 (immobilized enzyme) was observed after xylanase immobilization. The p H and temperature stability of xylanase were enhanced upon its covalent immobilization. The immobilized enzyme was active on repeated use and retained ∼80% of its initial activity after 11 reaction cycles. The improved thermal and operational stability of the covalently immobilized enzyme on PMMA NFM might be advantageous for industrial applications. [ABSTRACT FROM AUTHOR]

The xylanase obtained from a hyper-producer Bacillus pumilus SV-85S was purified and characterized to evaluate its potential in industrial applications. Xylanase was purified to homogeneity 25.3-fold with 63.2% recovery using cation-exchange chromatography through CMSephadex C-50. The purified xylanase showed a single band on Native-PAGE and a single peak in RP-HPLC confirming its homogeneity. The purified enzyme revealed a single band on SDS-PAGE with a molecular mass of 23.6 kDa, which was confirmed with gel filtration chromatography through Sepharose 6B. The K and V of the purified xylanase was 1.0 mg/mL and 333.3 IU/mL, respectively. The temperature and pH profiles of the purified xylanase revealed that it was thermo and alkali stable. In recent years due to the overall increase in natural fruit juice consumption, juices have become important from a consumption point of view. However, raw juice is turbid and viscous which tends to settle during storage. Therefore, it must be clarified before commercialization. The efficacy of absolutely purified xylanase was studied on juice enrichment of apples ( Malus domestica), pineapples ( Ananas comosus L.) and tomatos ( Lycopersicum esculentum). The treatment with xylanase lead to an increased juice yield by 23.53% (apple), 10.78% (pineapple), and 20.78% (tomato) as well as having a significant effect on juice clarity by an increase of % transmittance of 22.20, 19.80, and 14.30, respectively. The turbidity and viscosity was also decreased without affecting acid neutrality significantly. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports covalent immobilization of xylanase by response surface methodology on glutaraldehyde-activated aluminum oxide pellets. The optimization of process parameters gave an immobilization yield of 83.65%. The bound enzyme displayed increase in optimum temperature (from 50 to 60°C) and V max (from 3333.33 to 5000IU/mL) in comparison with free enzyme. The pH and temperature stability were also enhanced. An observed increase in half-lives and D-values resulted in improved thermostability. Thermodynamically, increase in enthalpy and free energy change after covalent immobilization could be credited to the enhanced stability. Immobilized xylanase could be reused for 10 consecutive cycles retaining 60% of its initial activity. It was found to be effective in releasing reducing sugar from poultry feed. Immobilization on aluminum oxide pellets is important due to their mechanical resistance at high pH and temperature. So, considerable stability and reusability of bound enzyme may be advantageous for its industrial application. [Copyright &y& Elsevier]

Abstract: The fermentation conditions were optimized for hyper production of xylanase from Bacillus pumilus SV-205. The bacterium secretes high levels (7382.7±1200IU/mL) of cellulase-free xylanase using wheat bran led to 21.63 fold increase in activity. A combination of yeast extract and peptone stimulated highest xylanase production (2448.0IU/mL) as compared to other combinations. The most important characteristic of the enzyme is its high pH stability (100%) over a broad pH range of 6–11 for 24h. Thermostability studies revealed that enzyme retained 65% activity after an incubation of 2h at 60°C. The level of production is remarkable as compared to earlier reports. [Copyright &y& Elsevier]

High level production of an extracellular cellulase-poor alkali stable xylanase has been conceded from newly isolated Bacillus pumilus SV-85S under solid state fermentation using wheat bran as a substrate. Optimization of the fermentation conditions enhanced the enzyme production to 73,000±1000IU/g dry substrate, which was 13.8-fold higher than unoptimized conditions (5300IU/g). The enzyme titre was highest after 48h of incubation at 30°C with 1:3 ratios of substrate to moistening agent using wheat bran as a carbon source. The enzyme could be produced in significant levels by using either tap water or distilled water alone as a moistening agent. An elevated production of xylanase by B. pumilus SV-85S in the presence of wheat bran, a cheap and easily available agro-residue, in shorter duration would apparently reduce the enzyme cost substantially. The enzyme was completely stable over a broad pH (5–11) range and retained 52% of its activity at a temperature of 70°C for 30min. The desired characteristics of this enzyme together with economic production would be important for its application in paper and pulp industry. [Copyright &y& Elsevier]

This paper reports the production of a cellulase-free and alkali-stable xylanase in high titre from a newly isolated Bacillus pumilus SV-85S using cheap and easily available agro-residue wheat bran. Optimization of fermentation conditions enhanced the enzyme production to 2995.20 ± 200.00 IU/ml, which was 9.91-fold higher than the activity under unoptimized basal medium (302.2 IU/ml). Statistical optimization using response-surface methodology was employed to obtain a cumulative effect of peptone, yeast extract, and potassium nitrate (KNO3) on enzyme production. A 23 central composite design best optimized the nitrogen source at the 0 level for peptone and yeast extract and at the −α level for KNO3, along with 5.38-fold increase in xylanase activity. Addition of 0.1% tween 80 to the medium increased production by 1.5-fold. Optimum pH for xylanase was 6.0. The enzyme was 100% stable over the pH range from 5 to 11 for 1 h at 37°C and it lost no activity, even after 3 h of incubation at pH 7, 8, and 9. Optimum temperature for the enzyme was 50°C, but the enzyme displayed 78% residual activity even at 65°C. The enzyme retained 50% activity after an incubation of 1 h at 60°C. Characteristics of B. pumilus SV-85S xylanase, including its cellulase-free nature, stability in alkali over a long duration, along with high-level production, are particularly suited to the paper and pulp industry. [ABSTRACT FROM AUTHOR]