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|Title:||Isolation and characterization of a metal ion-dependent alkaline protease from a halotolerant <i style="">Bacillus aquimaris</i> VITP4|
<i style="">Bacillus aquimaris </i>VITP4
Metal ion binding
|Abstract:||A halotolerant bacterium <i style="">Bacillus acquimaris </i>VITP4 was used for the production of extracellular protease. Fractional precipitation using ammonium chloride was used to obtain the enzyme. The protease exhibited optimum activity at pH 8.0 and 40°C and retained 50% of its optimal proteolytic activity even in the presence of 4 M NaCl, suggesting that it is halotolerant. The molecular mass of protease, as revealed by SDS-PAGE was found to be 34 kDa and the homogeneity of the enzyme was confirmed by gelatin zymography and reverse-phase HPLC. Upon purification, the specific activity of th enzyme increased from 533 U/mg to 1719 U/mg. Protease inhibitors like phenyl methane sulphonyl fluoride and 2-mercaptoethanol did not affect the activity of the enzyme, but EDTA inhibited the activity, indicating the requirement of metal ions for activity. Cu<sup>2+</sup>, Ni<sup>2+</sup> and Mn<sup>2+</sup> enhanced the enzyme activity, but Zn<sup>2+</sup>, Hg<sup>2+</sup> and Fe<sup>2+ </sup>decreased the activity, while Mg<sup>2+</sup>, Ca<sup>2+</sup> and K<sup>+</sup> had no effect on the enzyme activity. The protease was quite stable in the presence of cationic (CTAB), anionic (SDS) and neutral detergents (Triton X-100 and Tween-20) and exhibited antimicrobial activity against selected bacterial and fungal strains. The stability characteristics and broad spectrum antimicrobial activity indicated the potential use of this protease in industrial applications.|
|ISSN:||0975-0959 (Online); 0301-1208 (Print)|
|Appears in Collections:||IJBB Vol.48(2) [April 2011]|
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