Characterization of a salt-tolerant aminopeptidase from marine Bacillus licheniformis SWJS33 that improves hydrolysis and debittering efficiency for soy protein isolate

卷:214

Lei, Fenfen ; Zhao, Qiangzhong ; Sun-Waterhouse, Dongxiao ; Zhao, Mouming

South China Univ Technol

关键词: Aminopeptidase;    Enzyme characteristics;    Salt-tolerant;    Protein hydrolysis;    Debittering;   

DOI  :  10.1016/j.foodchem.2016.07.028

学科分类：食品科学和技术

【 摘 要 】

An aminopeptidase was isolated from the marine Bacillus licheniformis SWJS33 (BLAP) and purified. According to the tandem mass spectrometry, the enzyme displayed 11% amino acid identity with the aminopeptidase from Bacillus (gi vertical bar 496687392). BLAP exhibited maximum activity at 60 degrees C and pH 8.0-8.5 and had a molecular mass of 100 kDa. The presence of NaCl enabled 50% improvement of enzyme activity with 10-15% NaCl being the best. The observed inactivation by EDTA and bestatin and activation by Co2+ and Ag+ indicated that the obtained enzyme was a metalloaminopeptidase. Such an aminopeptidase could further improve the hydrolysis degree of soy protein isolate hydrolysates catalyzed by papain, Alcalase 2.4 L or Flavourzyme 500MG from 8.5%, 9.5% or 14.4-18.8%, 18.7% or 20.1%, respectively, while decreasing the bitter intensity score of the SPI hydrolysates catalyzed by Alcalase 2.4 L from 3.6 to 0.4. (C) 2016 Elsevier Ltd. All rights reserved.