糠醛渣复合材料固定果胶酶的制备

本文以糠醛渣为原始材料进行磺化预处理,利用静自电组装技术将壳聚糖包覆表面,得到糠醛渣-壳聚糖和磺化糠醛渣-壳聚糖复合材料。以FT-IR、SEM等技术对以上制备的复合材料的进行分析表征;然后将两种复合材料利用戊二醛交联后进行果胶酶的固定化。采用单因素变量法研究新型固定化酶的最佳催化性能和稳定性。未磺化糠醛渣复合材料固定酶的最佳催化条件:pH 3.5,果胶酶浓度50 mg/mL,果胶浓度15 mg/mL,反应时间120 min,反应温度45℃;磺化糠醛渣复合材料固定酶的最佳催化条件:pH 3.5,果胶酶浓度20 mg/mL,果胶浓度10 mg/mL,反应时间60 min,反应温度50℃。其中糠醛渣复合材料的固定化果胶酶的最大载酶量为197.20 mg/g,在重复循环使用8次后剩余相对酶活可达81.78%,磺化糠醛渣复合材料的固定化果胶酶在4℃下储存32 d后仍剩余88.98%的相对酶活。两种固定酶都表现出较好的操载酶量和储存稳定性,有较好的经济价值和应用前景。

Synthesis of the Furfural Residue Composite for Immobilized Pectinase

In this paper,furfural residue was used as raw material for the sulfonated pretreatment.The furfural residue-chitosan-glutaraldehyde composite material and the sulfonated furfural residue-chitosan-glutaraldehyde composite material were obtained by wrapping chitosan and crosslinking with glutaraldehyde,using electrostatic self-assembly;the appearance and properties of the two new kinds of materials were characterized by FT-IR and SEM.Then,they were used for immobilizing pectinase,and the catalytic performance and stability of the novel immobilized enzyme were optimized by single factor variable method.The optimum catalytic conditions for the immobilized enzyme of uncarbonized furfural residue composite material were determined as:pH=3.5,pectinase concentration=50 mg/mL,pectin concentration=15 mg/mL,reaction time=120 min,reaction temperature=45℃.The optimum catalytic conditions for the immobilized enzyme of carbonized furfural residue composite material were as below:pH=3.5,pectinase concentration=20 mg/mL,pectin concentration=10 mg/mL,reaction time=60 min,reaction temperature=50℃.The relative enzyme activities of the two immobilized enzymes were 95.52%and 95.03%,respectively.Under the optimal reaction conditions,the maximum enzyme loading of the two immobilized enzymes were 197.20 mg/g and 60.40 mg/g,respectively.The residual relative activity of immobilized pectinase in furfural residue composite was 81.78%after 8 times of recycling,and the immobilized pectinase activity of sulfonated furfural residue composite was still 88.98%after 32 days of storage at 4℃.The two kinds of immobilized enzymes show better loading enzyme capacity and storage stability,and have better economic value and application prospects.