Production, purification, characterization and usage of a detergent additive of endoglucanase from isolated halotolerant Amycolatopsis cihanbeyliensis mutated strain Mut43

The Amycolatopsis cihanbeyliensis Mut43, which is obtained by UV radiation, exhibited endoglucanase activity of 5.21U/mL, which was approximate to 2.3-fold higher than that of the wild strain (2.04U/mL). The highest enzyme activity was obtained after 3days of incubation at 32 degrees C, pH 7.0, 150rpm, and 6% NaCl in a liquid medium containing 1.5% (w/v) wheat straw (0.25mm of particle size) and 0.6% (w/v) yeast extract. Enzyme activity was eluted as a single peak (gel filtration chromatography), and Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the corresponding peak revealed a molar mass of 30kDa. Zymogram analysis confirmed the presence of a single active endoglucanase component. The enzyme was purified to approximate to 21-fold, and the mean overall yield was approximate to 6%. The purified endoglucanase was active up to 80 degrees C and showed a half-life of 214min at 60 degrees C in the absence of substrate at pH 8.0. The apparent K-m value for the purified endoglucanase was 0.70mg/mL, while the V-max value was 6.20Units/g. Endoglucanase activity was reduced (25%) by treatment with 30U of proteinase K/mg. The addition of Mg+2 and Ca+2 (5mM) enhanced endoglucanase activity. Additionally, endoglucanase activity in the presence of 5mM SDS or organic solvents was 75 and 50% of maximum activity, respectively. The high levels of enzyme production from A. cihanbeyliensis Mut43 achieved under batch conditions, coupled with the temperature stability, activity over a broad pH range, relatively high stability (70-80%) in the presence of industrial laundry detergents and storage half-lives of 45days at +4 degrees C and 75days at -20 degrees C signify the suitability of this enzyme for industrial applications as detergent additive.