An alkali-halotolerant cellulase from Bacillus flexus Isolated from green seaweed Ulva lactuca

An extracellular alkali-halotolerant cellulase from the strain Bacillus flexus NT isolated from Ulva lactuca was purified to homogeneity with a recovery of 25 03% and purity fold of 22 31 The molecular weight of the enzyme was about 97 kDa and the V-max and K-m was 370 17 U/ml/min and 6 18 mg/ml respectively The optimum pH and temperature for enzyme activity was 10 and 45 C respectively The enzymatic hydrolysis of the CMC was confirmed with GPC and GC-MS analysis The stabilized activity of the enzyme even at high pH of 9 0-12 0 and residual activity of about 70% at salt concentration (NaCl 15%) revealed for its alkali-halotolerance nature The metal ions Cd2+ and Li1+ were found as inducers while Cr2+ Co2+ Zn2+ and metal chelator EDTA have significantly inhibited the enzyme activity Enzyme activity was insensitive to ethanol and isopropanol while partially inhibited by acetone cyclohexane and benzene (C) 2010 Elsevier Ltd All rights reserved