产β-甘露糖苷酶菌株的筛选、鉴定及酶学性质研究  

Isolation,identification and enzymatic properties of the strain producing β-mannosidase

作　　者：秦玲丽[1] 李雪晴[1] 崔堂兵[1] 

机构地区：[1]华南理工大学生物科学与工程学院,广东广州510006

出　　处：《食品工业科技》2016年第24期249-253,258,共6页Science and Technology of Food Industry

基　　金：国家自然科学基金(31171732);广东省自然科学基金(S2013010013162)

摘　　要：本研究通过初筛（魔芋粉为唯一碳源并结合刚果红染色法）和复筛（利于对硝基苯基-β -D-吡喃甘露糖苷法测定卢一甘露糖苷酶活力），从采集的森林土壤中筛选产β -甘露糖苷酶的菌株，获得1株酶高产菌株B19。通过显微形态、革兰氏染色、生理生化特征、16SrDNA序列及系统发育进化树分析等方法，将其鉴定为肠杆菌属（Enterobacter sp．）。菌株B19所产的β -甘露糖苷酶为胞内酶，在37℃、200r／min条件下培养48h后，测得的酶活力为1．26U／mL。初步酶学性质研究表明：该酶的最适反应pH和最适反应温度分别为7．5和50℃，且在pH6．0～8．0和温度45～50oC稳定性较高，浓度为10mmol／L的Mn2＋和Mg2＋对该β -甘露糖苷酶具有激活作用，但K＋、Fe2＋、ca2＋、cu2＋、CO2＋及Zn2＋抑制酶活力。该菌株可作为产β -甘露糖苷酶的潜在菌株。The strain B19 with high yield of β -mannosidase was isolated from forest soil sample using first screening （Konjac powder as the sole carbon source and Congo red staining method）and secondary screening （determination of β -mannosidase enzyme activity by p-Nitrophenyl-β -D-Mannopyranoside method）.The strain was identified as Enterobacter sp. by electron microscopy, Gram - staining, physiological and biochemical examination, 16S rDNA sequence and phylogenetic tree analysis. The strain B19 could produce intracellular 13-mannosidase,and its activity could be up to 1.26 U/mL when the strain was cultivated 48 h under the condition of 37 ℃,200 r/min.The enzymatic properties analysis showed that the optimal pH and temperature of this enzyme were 7.5 and 50 ℃, respectively.The enzyme exhibited high thermal stability when the temperature ranged from 45 to 50 ℃, or the pH value ranged from 6.0 to 8.0. The enzyme activity was activated by Mg2. and Mn2＋ in concentration of 10 mmol/L, but was inhibited by K＋, candidate strain in studying/3-mannosidase. Fe2＋,ca2＋,Cu2＋,Co2＋ and Zn2＋.It might be a good

关 键 词：β -甘露糖苷酶 筛选 鉴定 肠杆菌属 酶学性质 

分 类 号：TS201.3[轻工技术与工程—食品科学]