组合酶水解羽绒加工副产物工艺参数的优化

Optimization of Process Parameters of Hydrolyzed By-product of Combined Enzyme Down Processing

本研究旨在对来源于地衣芽孢杆菌CP-16的重组角蛋白酶和二硫键还原酶协同酶解羽绒加工副产品最佳工艺条件进行探讨。试验探讨角蛋白酶与二硫键还原酶组合水解羽毛角蛋白的适宜比例,并研究蒸汽压力处理时间、酶解时间、组合酶添加水平和水分含量等单一因素对酶解效率的影响,再利用L9(34)正交试验进一步优化处理工艺条件。结果显示,当角蛋白酶与二硫键还原酶的酶活比例为80∶1,角蛋白酶终浓度为90 U/mL时,组合酶酶解羽绒加工副产品效率最佳;经压力处理2 h更有利于提高酶解效率;水解60 h酶解率最高,但与48 h差异不显著(P>0.05);总反应体系中缓冲液为5.5 mL时酶解效率显著高于对照组(P<0.05),但与4.5 mL组差异不显著(P>0.05)。正交试验优化酶解羽绒加工副产品条件发现,影响组合酶酶解效率的因素由大到小依次为压力处理时间、酶解时间、酶剂量;酶解羽绒加工副产品最适条件为:角蛋白酶与二硫键还原酶活性比例为80∶1,121℃高压处理2 h,角蛋白酶终浓度为90 U/mL,50℃酶解48 h,此时1 g羽绒加工副产品产生的上清液可溶性蛋白含量为352.72 mg,比对照组提高640.26%。综上,利用多种处理工艺相结合更有利于提高组合酶水解羽绒加工副产品的效率。本试验结果可为羽绒加工副产品资源开发利用提供理论指导。

The aim of this study was to explore the optimal technological conditions for the synergistic enzymatic hydrolysis of feather processing by-products by recombinant keratinase and disulfide bond reductase from Bacillus licheniformis CP-16.Firstly,the appropriate proportion of keratinase and disulfide bond reductase was explored in this experiment.Secondly,the factors affecting the treatment of combined enzymes were studied,including steam pressure treatment time,enzymatic hydrolysis time,combined enzyme addition level and water content.Finally,L9(34)orthogonal test was used to further optimize the processing conditions.The results were as follows:When the enzyme activity ratio of keratinase and disulfide bond reductase was 80∶1 and the final concentration of keratinase was 90 U/mL,the combined enzyme had the best efficiency in feather hydrolysis.Pressure treatment of feather keratin for 2 h was more conducive to hydrolysis of feathers processing by-products by combined enzymes.Feather hydrolysis rate was the highest at 60 h hydrolysis,but it was not significantly different from that at 48 h(P>0.05).The efficiency of feather enzymatic hydrolysis in the total reaction system with 5.5 mL buffer was significantly higher than control group(P<0.05),but the difference was not significant compare to the group with 4.5 mL buffer(P>0.05).The results of orthogonal test showed that,the factors affecting the hydrolysis efficiency were pressure treatment time,enzymolysis time and enzyme dosage from large to small.The optimal conditions for feather enzymatic hydrolysis were:The ratio of keratinase to disulphide bond reductase was 80∶1,121℃for 2 h,the final concentration of keratinase was 90 U/mL,and the enzymatic hydrolysis was conducted at 50℃for 48 h.At this condition,the soluble protein content of supernatant produced of each gram feather was 352.72 mg,which was 640.26%higher than that of the control group.In conclusion,the combination of multiple treatment processes was more conducive to improving the efficiency of hydrolysis of feathers processing by-products by combined enzymes.The study could provide guidance for the development and utilization of feather resources.