高温漆酶产生菌Bacillus thuringiensis strain Lac-72的筛选、鉴定及其酶学性质研究

Study on the Screening,Identification and Enzymatic Properties of Bacillus thuringiensis strain Lac-72 Produced by Thermostable Laccase

从云南省大理州洱源县牛街镇72℃地热温泉底泥中筛选到1株产漆酶的高温菌。对其进行显微形态及生理生化特征、16 S rRNA基因序列分析,将其初步鉴定为苏云金杆菌(Bacillus thuringiensis)的一株菌,命名为Bacillus thuringiensis strain Lac-72。对其酶学性质及漆酶对染料废水的处理进行了研究。结果表明:Lac-72漆酶最适酶活温度为75℃,最适反应pH值为8.0。在25℃以下,能保持良好的稳定性。Zn^2+、Mn^2+和K^+对该酶有一定的抑制作用,Ca^2+、Mg^2+、Fe^2+、Cu^2+均对该酶活力起到促进作用,其中Cu^2+的促进效果最为明显。在最适酶活条件下,对三苯甲烷类染料孔雀石绿和结晶紫废水进行脱色,脱色率分别可达85%和72%。

A strain of laccase-producing thermophilic bacteria was isolated from the sediment of Niujie town,Eryuan county,Dali,Yunnan province.And its micromorphology,physiological and biochemical characteristics,16 S rRNA gene sequence analysis were carried out.The strain was identified as a strain of Bacillus thuringiensis,and named as B.thuringiensis strain Lac-72.The enzymatic properties and laccase treatment of dye wastewater were studied.The results showed that the optimum temperature of Lac-72 laccase activity was 72℃ and the optimum reaction pH was 8.0.It can keep good stability under 25℃.Zn^2+,Mn^2+ and K^+ inhibited the enzyme to some extent.Ca^2+,Mg^2+,Fe^2+,Cu^2+ all promoted the activity of the enzyme,and Cu^2+ had the most obvious effect.Under the optimum enzymatic conditions,the decolorization of triphenylmethane dye malachite green and crystal violet wastewater can reach 85% and 72%respectively.