酶法水解桑叶多糖制备低聚糖及其抑菌活性研究  

Study on Preparation of Oligosaccharide from Mulberry Leaf Poly⁃saccharides by Enzymatic Hydrolysis and Its Antibacterial Activity

作　　者：谭凤翔 余元善[3] 邹宇晓[3] 廖森泰[3] 刘袆帆 王琴[4] 胡腾根 肖更生[1,4] Tan Fengxiang;Yu Yuanshan;Zou Yuxiao;Liao Sentai;Liu Huifan;Wang Qin;Hu Tenggen;Xiao Gengsheng(College of Biological Sciences and Engineering,Jiangxi Agricultural University,Nanchang 330045,China;Chaozhou Branch of Chemistry and Chemical Engineering Guangdong Laboratory,Chaozhou Guangdong 510006,China;Sericul-tural&Agri-Food Research Institute,Guangdong Academy of Agricultural Sciences,Guangzhou 510610,China;Col-lege of Food Science and Technology,Zhongkai University of Agriculture and Engineering,Guangzhou 510631,China)

机构地区：[1]江西农业大学生物科学与工程学院,南昌330045 [2]化学与精细化工广东省实验室潮州分中心,广东潮州510006 [3]广东省农业科学院蚕业与农产品加工研究所,广州510610 [4]仲恺农业工程学院轻工食品学院,广州510631

出　　处：《蚕业科学》2024年第2期127-138,共12页ACTA SERICOLOGICA SINICA

基　　金：广东省科研事业单位(省实验室分中心)重点领域研发计划项目(2021B0707060001);广东省重点研发专项(2022B⁃0202040002,2022B0202050001);“十四五”广东省农业科技创新十大主攻方向“揭榜挂帅”项目(2022SDZG04);灯塔实验室项目(DT20220026);华南理工大学国家大学科技园顺德创新园区教师科技成果转化专项资金项目(KJYS2021KZ05)。

摘　　要：低聚糖被认为可能是多糖具有多种生物活性的关键结构,而酶法水解多糖制备低聚糖由于其反应条件温和、效率高等优点被广泛关注。以桑叶多糖为研究对象,通过生物酶法降解制备功能性桑叶低聚糖。首先,以桑叶低聚糖得率为指标,探究不同种类酶(纤维素酶、半纤维素酶、木聚糖酶以及葡聚糖酶)对低聚糖得率的影响,选出最适合的水解酶(半纤维素酶);再在此基础上,通过单因素优化、Plackett-Burman试验和响应面优化确定酶促水解桑叶多糖制备低聚糖反应的最适酶添加量60 U/mL、底物浓度20 mg/mL、反应温度55℃、pH 47及时间8 h;在此条件下桑叶低聚糖得率为202%,与模型预测值207%接近。最后,桑叶低聚糖的抗菌活性测试结果表明,与桑叶多糖相比,桑叶低聚糖表现出显著的抑制大肠埃希菌(Esch-erichia coli)、沙门氏菌(Salmonella)、痢疾杆菌(Shigella)和普通变形杆菌(Proteus vulgaris)生长的特性,说明桑叶低聚糖是一种优良的抗菌剂。研究结果为功能性桑叶低聚糖的制备及其应用提供了理论参考。Oligosaccharides are considered to be the key structure of polysaccharides with various biological activity.En-zymatic hydrolysis of polysaccharides to prepare oligosaccharides has attracted extensive attention due to its mild reac-tion conditions and high efficiency.In the present study,mulberry leaf polysaccharides were used as the research subject to prepare functional mulberry leaf oligosacchar-ides through enzymatic degradation.First of all,the effect of enzymes(cellulase,hemicellulase,xylanase and glu-canase)on the yield of mulberry leaf oligosaccharide was studied by using the yield of oligosaccharides as an indi-cator to determine the optimum enzyme(hemicellulase).On this basis,the single-factor optimization,Plackett-Bur-man(PB)experiment and response surface optimization were used to determine that in the enzymatic hydrolysis of mulberry leaf polysaccharides for the preparation of oligo-saccharides,the optimal amount of enzyme addition was 60 U/mL,the substrate concentration was 20 mg/mL,the re-action temperature was 55℃,the pH was 47,and the time was 8 h.Under this condition,the yield of mulberry leaf oli-gosaccharide was 202%,which was close to the model prediction value of 207%.Finally,the antibacterial activity of mulberry leaf oligosaccharide was studied.The results showed that compared to polysaccharide,mulberry leaf oligosac-charide could significantly inhibit the growth of Escherichia coli,Salmonella,Shigella dysenteriae and Proteus vulgaris,suggesting that mulberry leaf oligosaccharide was an excellent antibacterial agent.The above results provide theoretical reference for the preparation and application of functional mullberry leaf oligosaccharides.

关 键 词：桑叶多糖 低聚糖 酶法水解 BBD实验 抗菌活性 

分 类 号：S886.9[农业科学—特种经济动物饲养]