摘要
采用Plackett-Burman法对影响假单胞菌(Pseudomonas sp.)W7产低温蛋白酶的因素进行显著性分析,筛选出对产酶影响显著的3个因素:葡萄糖、蛋白胨和MgSO_4;然后用最陡爬坡试验逼近最大产酶区域;应用Box-Behnken原理设计和响应面分析确定产酶培养基的最佳组合为:葡萄糖4.25 g/L、蛋白胨7.00 g/L、干酪素4.00 g/L、K2HPO_4 5.00 g/L、KH_2PO_4 1.00 g/L、CaCl_2 0.26 g/L、MgSO_4 0.14 g/L,低温蛋白酶的酶活力达到了183.9 U/mL,比优化前提高了21%。另外,对Pseudomonas sp.W7的产酶条件进行了优化,在单因素的基础上,利用正交试验设计,最终确定产酶的最优培养条件为:培养温度为20℃、初始pH值为7.0、接种量为3%、装液量为20%、摇床转速为100r/min,在最佳条件时测得的酶活力为193.2 U/mL。通过生长曲线和产酶曲线的测定,确定产酶的培养时间为48 h。
Cold-adapted proteases have great superiority in the food,cosmetic,pharmaceutical and detergent industries due to high catalytic activity at low temperature and thermal instability.In the present study,the Plackett-Burman design was used to identify glucose,peptone and MgSO_4 as the most significant medium components affecting the production of cold-adapted protease by Pseudomonas sp.W7.Then the steepest ascent experiment was used to approach the optimal region of the three medium components.Box-Behnken design and response surface analysis were used to determine the best culture medium containing 4.25 g/L glucose,7.00 g/L peptone,4.00 g/L casein,5.00 g/L K_2HPO_4,1.00 g/L KH_2PO_4,0.26 g/L CaCl_2 and 0.14 g/L MgSO_4.After the optimization,the yield of the protease was increased by 21%to 183.9 U/mL.In addition,the optimal culture conditions for producing cold-adapted protease using the optimized medium were determined using combination of single factor experiments and orthogonal array design experiments as culture temperature of 20 ℃,initial medium pH of 7.0,inoculum amount of 3%,medium loading volume of 20%and rotation speed of 100 r/min.Under these conditions,the enzyme activity was 193.2 U/mL.Based on the growth curve and enzyme production curve,the optimal culture period was determined to be 48 h.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2015年第19期163-169,共7页
Food Science
基金
黑龙江省自然科学基金项目(C201035)
关键词
低温蛋白酶
假单胞菌W7
培养条件优化
响应面分析
cold-adapted protease
Pseudomonas sp.W7
optimization of fermentation conditions
response surface analysis
