Mycobiology.  2004 Jun;32(2):74-78. 10.4489/MYCO.2004.32.2.074.

Purification and Characterization of an Extracellular Alkaline Protease from Aspergillus niger C-15

• Kim JD

• KMID: 1516938
• DOI: http://doi.org/10.4489/MYCO.2004.32.2.074

Abstract

An alkaline protease produced by Aspergillus niger C-15 was purified and characterized. The enzyme was purified 19.41-fold with a specific activity of 74150 U/mg and a recovery of 34.4% by gel filtration and ion exchange chromatography. The molecular weight of the enzyme was estimated to be 34 kDa. The optimum pH and temperature for the protease activity were pH 8.0 and 60degrees C, respectively. The enzyme activity inhibited by EDTA suggests that the preparation contains a metalloprotease. The enzyme activity of the metalloprotease was completely inhibited by 5 mM HgCl2 and FeCl3, while partially inhibited by CuSO4, and MnCl2. When polyols such as glycerol, mannitol, sorbitol and xylitol, were added to the reaction medium, most polyols tested enhanced protease activity. Especially, glycerol showed the highest effect. The alkaline metalloprotease was stable at high temperature and retained more than 90% of the initial activity at 60degrees C and 86.4% under addition of glycerol.

Keyword

Alkaline protease; Aspergillus niger; Metalloprotease; Protease

MeSH Terms

Aspergillus niger*
Aspergillus*
Chromatography, Gel
Chromatography, Ion Exchange
Edetic Acid
Glycerol
Hydrogen-Ion Concentration
Mannitol
Mercuric Chloride
Molecular Weight
Sorbitol
Xylitol
Edetic Acid
Glycerol
Mannitol
Mercuric Chloride
Sorbitol
Xylitol