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]Guangdong Med Coll, Inst Biochem & Mol Biol, Dongguan 523808, Peoples R China;[2]Guangdong Ocean Univ, Coll Food Sci & Technol, Guangdong Prov Key Lab Aquat Prod Proc & Safety, Key Lab Adv Proc Aquat Prod Guangdong Higher Educ, Zhanjiang 524088, Peoples R China;[3]S China Univ Technol, Sch Light Ind & Food Sci, Guangzhou 510640, Guangdong, Peoples R 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：SCI-EXPANDED(收录号：WOS:000336269200002)、、WOS

基金：The authors gratefully acknowledge the National Natural Science Foundation of China (31201309) for the financial support.

语种：英文

外文关键词：Aspergillus; Acid protease; Production; Purification; Characterization

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 x 10(5) g(-1) dry koji, 31 A degrees 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 % alpha-helix, 64.1 % beta-sheet, and 32 % aperiodic coil. This novel acid protease was active over the temperature range of 35-55 A degrees C with optimum temperature of 40 A degrees 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 (lambda) were 0.96 mg mL(-1), 135.14 mu mol min(-1) mg(-1), 64.11 kJ mol(-1), and 0.59, respectively.