【摘要】 【目的】岩藻多糖是一种有免疫调节、抗肿瘤等多种生理功能的天然生物活性物质，在食品领域应用前景广泛。但这些生理活性大多基于低分子量岩藻多糖，所以将其降解为低分子量岩藻多糖尤为重要。岩藻多糖降解酶能够将岩藻多糖降解为低分子量岩藻多糖。【方法】克隆了蜡样芽胞杆菌(Bacillus cereus)来源的岩藻多糖降解酶基因BcFucA,并通过优化诱导表达条件提高可溶性重组酶的表达水平。【结果】试验表明重组酶在诱导温度为16℃、IPTG浓度为0.8 mol/L、诱导时间为22 h时，在大肠杆菌BL21(DE3)中可溶性表达量达到最大。利用DNS法检测酶活，表明重组酶能够降解岩藻多糖。【结论】研究结果为后续可溶性重组酶固定化应用降解岩藻多糖奠定良好基础，也为产生价值更高的低分子量岩藻多糖提供数据支持。更多还原

【Abstract】 [Objective] Fucoidan is a natural bioactive substance with a variety of physiological functions, including immunomodulatory, antitumor effects, which make fucoidan have a wide range of application prospects in many food fields.However, almost all of the above physiological activities are based on low molecular weight fucoidans, so how to degrade fucoidans to oligocoidans is particularly important.The fucoidan degrading enzyme can degrade fucoidan to oligogocoidan.[Methods]The fucoidan-degrading enzyme gene BcFucA derived from Bacillus cereus was cloned, and the expression level of soluble recombinase was increased by optimizing the induction conditions.[Result]The results showed that the soluble expression of recombinase in E.coli BL21(DE3) reached the maximum when the induction temperature was 16 ℃,the IPTG concentration was 0.8 mol/L,and the induction time was 22 h.The enzyme activity was detected by DNS method, and the recombinant enzyme could degrade fucoidans.[Conclusions]The results of this study lay a good foundation for the subsequent application of soluble recombinase immobilization to degrade fucoidans, and also provided data support for the generation of low-molecular-weight fucoidans with higher value.更多还原