摘要
从腐烂的角叉菜中筛选出卡拉胶酶高产菌株YDK-6,通过形态观察及16S rDNA序列分析对其进行鉴定,采用正交实验对其产酶条件进行了优化,并对其所产卡拉胶酶的酶学性质进行了研究。结果表明,菌株YDK-6为假单胞菌(Pseudomonas sp.);在葡萄糖加量为15 g·L^(-1)、酵母粉加量为10 g·L^(-1)、卡拉胶加量为2 g·L^(-1)、NaNO _(3)加量为2 g·L^(-1)、NaCl加量为15 g·L^(-1)、K _(2)HPO_( 4)加量为1.00 g·L^(-1)、MgSO_(4)加量为0.05 g·L^(-1)、FePO _( 4)加量为0.01 g·L^(-1)、CaCl_( 2)加量为0.01 g·L^(-1)、起始pH值为7.5的条件下,于28℃摇床培养72 h,所产卡拉胶酶的活力达到111.33 U·mL^(-1),是筛选培养条件下酶活的3.56倍;菌株YDK-6所产卡拉胶酶的最适反应pH值为8、最适反应温度为60℃,在30~70℃时,120 min内均能保持60%以上的酶活;Ca^(2+)、Mg^(2+)、Fe^(2+)、Mn^(2+)对菌株YDK-6所产卡拉胶酶活力有一定促进作用,其米氏常数为0.174 mg·mL^(-1)、最大反应速率为0.63 mg·mL^(-1)·min^(-1)。
We screened a high-yield carrageenase-producing strain YDK-6 from the rotting Chondrus ocellatus Aolmes.,identified the strain YDK-6 by morphological observation and 16S rDNA sequence analysis,optimized the enzyme-producing conditions by orthogonal experiments,and studied the enzymatic properties.The results show that the strain YDK-6 is identified as Pseudomonas sp..The activity of carrageenase produced from the strain YDK-6 reaches 111.33 U·mL^(-1)cultured for 72 h at 28℃,under the optimal enzyme-producing conditions as follows:glucose 15 g·L^(-1),yeast powder 10 g·L^(-1),carrageenan 2 g·L^(-1),NaNO_(3)2 g·L^(-1),NaCl 15 g·L^(-1),K 2HPO 41.00 g·L^(-1),MgSO_(4)0.05 g·L^(-1),FePO 40.01 g·L^(-1),CaCl_(2)0.01 g·L^(-1),and the initial pH value of 7.5,which is 3.56 times of the enzyme activity under the screening culture conditions.The optimum reaction pH value of carrageenase produced from the strain YDK-6 is 8,the optimum reaction temperature is 60℃,and the enzyme activity can maintain more than 60%in 120 min at 30-70℃.Ca^(2+),Mg^(2+),Fe^(2+),Mn^(2+)can promote the activity of carrageenase produced from the strain YDK-6,and the Michaelis constant is 0.174 mg·mL^(-1),and the maximum reaction rate is 0.63 mg·mL^(-1)·min^(-1).
作者
翟婧
韩姣
尹海娇
董硕
孙利芹
唐志红
ZHAI Jing;HAN Jiao;YIN Haijiao;DONG Shuo;SUN Liqin;TANG Zhihong(School of Life Sciences,Yantai University,Yantai 264005,China)
出处
《化学与生物工程》
CAS
2023年第4期42-47,共6页
Chemistry & Bioengineering
基金
烟台市校地融合发展专项(SK21H266)。
关键词
卡拉胶酶
假单胞菌
筛选
产酶条件
酶学性质
carrageenase
Pseudomonas sp.
screening
enzyme-producing condition
enzymatic property
