Characterization of industrially-valuable xylano-pectinolytic enzymes produced concurrently by a novel isolate of Bacillus pumilus.

Xylanase and polygalacturonase were concurrently produced by a novel alkalo-thermotolerant Bacillus pumilus AJK. They were purified and characterized to evaluate their potential for various industrial applications. Xylanase was purified to 19-fold with 67 % recovery and polygalacturonase up to 23-fold with 75 % recovery. Existence of multiple forms of xylanase was indicated by its elution-profile through Sephadex G-100 as two peaks, xylanase-I and xylanase-II, with molecular weights of ~24.5 and ~13 kDa, respectively, and by the presence of two pH optima, one at pH 6.0 and other at pH 8.5. The molecular weight of polygalacturonase was ~40 kDa by gel-filtration chromatography. Zymographic studies confirmed the presence of seven isozymic forms of xylanase. Xylanase and polygalacturonase are stable over a broad range of pH and temperature.