摘要
以海藻酸钠为唯一碳源,从中国南北潮间带的单齿螺肠道中筛选得到1株高产褐藻胶裂解酶菌株ML17,经菌株形态特征分析和16S rRNA初步鉴定为Vibrio sp.ML17(菌种保藏编号:CGMCC No.20377)。通过我妻氏血琼脂平板分析,该菌株没有溶血性,表明其安全性较好。通过单因素试验确定该菌株在海藻酸钠(5 g/L)、胰蛋白胨(5 g/L)、NaCl(30 g/L)、pH 7~8、30℃的条件生长最快,同时相比于其他已报道的产褐藻胶裂解酶菌株,Vibrio sp.ML17在最适生长条件下10 h即可达到生长平台期,14 h达到最高产酶量,生长速度快、周期短的特点有利于其后续工业应用。此外,酶学性质分析结果证明,其所产褐藻胶裂解酶酶活力为26.31 U/mL;该粗酶的最适温度为40℃,在40和45℃具有一定的热稳定性;最适pH值为7.5;在5 mmol/L Na^(+)和Ca^(^(2+))的条件下,对酶活力有明显促进作用,Fe^(2+)、Cu^(2+)、Zn^(2+)则有明显抑制作用。进一步的应用实验发现,Vibrio sp.ML17能够有效降解褐藻,在对海带和马尾藻处理72 h后,其降解率可分别达到44.0%和38.9%。鉴于Vibrio sp.ML17生长速度快且产酶性能好的特点,该菌株可望在褐藻寡糖的制备和水产养殖中的褐藻防治去除等领域发挥潜力。
High-yield alginate lyase producing strain ML17 was screened from the intestinal tract of Monodonta labio in the North-South intertidal zone of China by sodium alginate as the sole carbon source.The strain was identified as Vibrio sp.ML17(CGMCC NO.20377)by morphological analysis and 16S rRNA.The results of Wagstsuma blood agar plate analysis showed that ML17 was non-hemolytic.Single factor results showed that ML17 optimal conditions as follows:sodium alginate of 5 g/L,tryptone of 5 g/L,NaCl of 30 g/L,pH 7-8 and 30℃.Vibrio sp.ML17 reached the growth plateau after 10 h under the optimal conditions,and the highest enzyme production was achieved after 14 h.In addition,the activity of alginate lyase was 26.31 U/mL.The optimal temperature pH was 40℃and 7.5,respectively.It had certain thermal-stability at 40℃and 45℃.Under the condition of 5 mmol/L Na^(+) and Ca^(2+),the activity was significantly promoted,while Fe^(2+),Cu^(2+)and Zn^(2+)inhibited.Further application results showed that Vibrio sp.ML17 could effectively degrade brown algae,and the degradation rates of kelp and sargassum reached 44.0%and 38.9%after 72 h,respectively.Vibrio sp.ML17 could have good application potential in the preparation of alginate oligo-saccharides and the control and removal of alginate in aquaculture.
作者
刘耀天
席茂盛
赵阳
李月婵
罗学刚
LIU Yaotian;XI Maosheng;ZHAO Yang;LI Yuechan;LUO Xuegang(College of Bioengineering,Tianjin University of Science and Technology,Tianjin 300457,China;Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education,Tianjin University of Science and Technology,Tianjin 300457,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2021年第15期29-35,共7页
Food and Fermentation Industries
基金
国家重点研发计划项目“益生菌健康功能与基于肠道微生物组学的食品营养代谢机理研究”(2017YFD0400303)
国家863计划项目“天然多糖的制备与功能多糖的研制”(2012AA021505)。
关键词
单齿螺
肠道
弧菌属
海藻酸钠
褐藻胶裂解酶
Monodonta labio
intestinal tract
Vibrio sp.
sodium alginate
alginate lyase
