Polyextremotolerant Amylase Produced from Novel Enterococcus with Potpourri of Applications

Amylolytic toluene-tolerant Enterococcus faecalis mercadA7 isolated from asbestos contaminated black soil from the Tokat province of Turkey was used for statistically optimized liquid phase fermentation to spawn elevated levels of amylase. Box Behnken technique of Response surface Methodology is followed to optimize three significant factors influencing Amylase production. To purify the amylase, ammonium sulfate fractionation, dialysis and gel filtration on Sephadex G-100 column chromatography were used. Submerged state fermentation at statistically optimized conditions augmented amylase production levels (8467 U ml(-1)) 8.74-fold compared to the conventional optimization. Purified amylase was found to possess specific activity of 1022 U mg(-1), optimal activity at pH 9 and 60 degrees C, 80% stable at 8.0-10.0 pH range and 90% stable at 45-75 degrees C for 1 h; with Km value of 8.06 mg ml(-1) and a V-max of 4.36 mmol h(-1) ml(-1), noteworthy stability up to 43% toluene, and upto 8% NaCl. High titers of Amylase produced from Enterococcus faecalis mercadA7 might find applications in copious industrial processes due to noteworthy stability of the cell-free purified enzyme at elevated temperatures, alkaline, and high toluene or salt concentrated environments.