纤维素降解菌N32产酶条件优化及其酶学性质

Optimization of Enzyme Production Condition for Cellulose-degrading Strain N32 and Enzymatic Characterization

本试验筛选出一株高纤维素酶活性菌株—弗村假单胞菌N32。通过单因素及正交设计试验优化发酵条件,再利用发酵罐扩大培养,最后对N32酶学性质进行研究。结果表明,单因素试验显示最佳产酶条件为:培养时间3 d,碳源淀粉,氮源酵母粉,初始p H 5.0,装液量100 mL,培养温度30℃,接种量2.0%,摇床速度160 r/min;最佳组合为A_(3)B_(2)C_(2)D_(2)E_(1)F_(3)G_(3),与单因素不同条件pH 6.0,摇床速度140 r/min,培养温度35℃,装液量125 mL;酶学性质研究表明最适温度为30℃,最适pH为4.0,Na^(+)、Cl^(-)、NO_(3)^(-)、CH_(3)COO^(-)对CMC酶活均有一定的激活作用,而K^(+)、Mg^(2+)对CMC酶活均产生抑制作用,尿素、EDTA、SDS对CMC酶活均产生抑制作用,其中EDTA的抑制作用最强。

In this study,a high cellulase activity strain,Pseudomonas fuchunensis N32,was screened.The fermentation conditions were optimized by single factor and orthogonal design,and then the fermentation tank was used to expand the culture.Finally,the enzymatic properties of N32 were studied.Finally,the enzymatic properties of N32 were obtained.The results showed that the optimum conditions of enzyme production were as follows:culture time was 3 days,carbon source was starch,nitrogen source was yeast powder,initial p H was 5.0,liquid volume was 100mL,the culture temperature was 30℃,inoculum amount was of 2.0%,the speed of shaking table was 160 r/min.The optimal combination was A_(3)B_(2)C_(2)D_(2)E_(1)F_(3)G_(3),i.e.,initial pH was 6.0,the speed of shaking table was 140 r/min,the culture temperature was 35℃,liquid volume was 125 mL.The study of enzymatic properties showed that the opti-mum temperature was 30℃,and the optimum pH was 4.0%,Na^(+)、Cl^(-)、NO_(3)^(-)、CH_(3)COO^(-)had a activation effect on CMC,while K^(+),Mg^(2+)had inhibition effect on CMC activity.Urea,EDTA,SDS had inhibition effect on CMC activity,and EDTA had the strongest inhibition effect.