生淀粉酶产生菌的筛选和研究

Isolation of amylase-producing strain and its enzymatic properties

利用透明圈法再经单菌分离纯化从土壤中筛到一株产酶为158U/mL的生淀粉酶产生菌TCCC451031,经16S rDNA鉴定为Paenibacillus属。最适发酵培养基:碳源为2%的玉米粉,最佳氮源为酵母粉与玉米浆混用比例为1∶2,用量为1%。最适发酵条件:35℃、pH值为7.0、转速160r/min,发酵5d酶活达312U/mL。该酶最适作用温度40℃,最适作用pH值为4.2,Ca2+、Mg2+、Zn2+对酶有一定的激活作用,Cu2+、Mn2+、K+、Fe2+、Ba2+对酶活有抑制作用。

TCCC451031 producing amylase was isolated from soil with the methods of transparent circles and single separation and purification.The amylase activity of the strain was 158U/ml.The strain was identified as Paenibacillus sp.by amplification,sequencing and alignment analysis of 16S rDNA sequence.The optimal fermentation conditions were as followed： carbon source 2% cornmeal,nitrogen sources 1% corn steep liquor and yeast powder,the ratio of corn steep liquor and yeast powder 1∶ 2,temperature 35℃,pH value 7.0 and rotation speed of shaking flask 160r/min.Under these conditions,the enzyme activity reached 312U/ml after 5d.The optimum catalysis temperature and pH value were 40℃ and 4.2,respectively.The enzyme activity was stimulated by Ca2＋,Mg2＋ and Zn2＋,while was inhibited by Cu2＋,Mn2＋,K＋,Fe2＋ and Ba2＋.