文献类型：期刊文献

英文题名：Production optimization, purification, and characterization of a novel acid protease from a fusant by Aspergillus oryzae and Aspergillus niger

作者：Li, Caihong[1]; Xu, Defeng[2]; Zhao, Mouming[3]; Sun, Lijun[2]; Wang, Yaling[2]

机构：[1] Institute of Biochemistry and Molecular Biology, Guangdong Medical College, Dongguan, 523808, China; [2] Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang, 524088, China; [3] School of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510640, China

年份：2014

卷号：238

期号：6

起止页码：905

外文期刊名：European Food Research and Technology

收录：EI(收录号：20142217761773)、Scopus(收录号：2-s2.0-84901234848)

语种：英文

外文关键词：Aspergillus - Activation energy

外文摘要：The production of a novel acid protease was enhanced by 44 % through statistical optimization. The cultural parameters, such as inoculum size, temperature, moisture content, and incubation time, were 8.59 × 105 g-1 dry koji, 31 °C, 57 %, and 86 h, respectively. This novel acid protease was purified by 17 folds with a recovery yield of 33.56 % and a specific activity of 4,105.49 U mg-1. Far-UV circular dichroic spectra revealed that this purified protease contained 7.1 % α-helix, 64.1 % β-sheet, and 32 % aperiodic coil. This novel acid protease was active over the temperature range of 35-55 °C with optimum temperature of 40 °C and was stable in the pH range of 2.5-6.5 with optimum pH of 3.5. Mn2+ enhanced its activity while Co2+ showed inhibitory effect. With casein as substrate, the kinetic parameters of K m, V max, energy of activation (E a), and attenuation index of inactivation velocity by heat inducing (λ) were 0.96 mg mL-1, 135.14 μmol min-1 mg-1, 64.11 kJ mol-1, and 0.59, respectively. ? 2014 Springer-Verlag Berlin Heidelberg.