Purification and Characterization of the Extracellular Alginase Produced by Bacillus licheniformis AL-577

摘要

The extracellular enzyme alginase produced by Bacillus licheniformis AL-577 was purified by ion chro-matography on CM-Cellulose column, DEAE-Sepharose column, and followed by gel filtration on Sephadx G-100 column. The optimum pH and temperature for the activity of the purified enzyme were 6.0 and 35°C, respectively. The enzyme was stable at the pH range of 6.0 approx 9.0 and at 20°C. The molecular weight of the enzyme was estimated to be about 25,500 daltons by SDS-polyacrylamide gel electrophoresis. NaCl was required for high activity of the enzyme. The enzyme was inhibited by Ba~(2+), Co~(2+), Cu~(2+), Fe~(2+), Mg~(2+), Zn~(2+), NH~+_4, EDTA, L-cysteine, and 2-mercaptoethanol, while stimulated by DTT, O-phenanthroline, K~+ and Li~+. This enzymewas proposed to be an alginase specifically degrading alginic acid.