title: Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH.
abstract: A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0-25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca(2+), Mn(2+), and Mg(2+) but strongly inhibited by heavy metals such as Hg(2+), Fe(3+), Ni(2+), and Zn(2+). Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications.
authors.affiliation: Department of Pharmaceutical Sciences, Saurashtra University, Rajkot, Gujarat 360 005, India; Department of Biotechnology, M. & N. Virani Science College, Rajkot, Gujarat 360 005, India.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Sanghvi
authors.affiliation: Department of Biotechnology, M. & N. Virani Science College, Rajkot, Gujarat 360 005, India; Department of Pharmacology and Toxicology, B. V. Patel Pharmaceutical Education and Research Development (PERD) Centre, Sarkhej-Gandhinagar Highway, Thaltej, Ahmedabad, Gujarat 380 054, India.
authors.forename: Mehul
authors.initials: M
authors.lastname: Jivrajani
authors.affiliation: Department of Biotechnology, M. & N. Virani Science College, Rajkot, Gujarat 360 005, India; Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
authors.forename: Nirav
authors.initials: N
authors.lastname: Patel
authors.affiliation: Department of Biochemistry, Saurashtra University, Rajkot, Gujarat 360 005, India.
authors.forename: Heta
authors.initials: H
authors.lastname: Jivrajani
authors.affiliation: Department of Biotechnology, M. & N. Virani Science College, Rajkot, Gujarat 360 005, India.
authors.forename: Govinal Badiger
authors.initials: GB
authors.lastname: Bhaskara
authors.affiliation: Department of Biotechnology, M. & N. Virani Science College, Rajkot, Gujarat 360 005, India.
authors.forename: Shivani
authors.initials: S
authors.lastname: Patel