Wan Juan, Sun Xiaowen, Liu Cheng, Tang Mengjun, Li Lin, Ni Hong
Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Faculty of Life Science, Hubei University, Wuhan, 430062, Hubei, People's Republic of China.
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
World J Microbiol Biotechnol. 2017 Jun;33(6):123. doi: 10.1007/s11274-017-2290-x. Epub 2017 May 22.
A triplicate volcanic rock matrix-Bacillus thuringiensis-laccase WlacD (VRMs-Bt-WlacD) dye decolorization system was developed. WlacD was displayed on the B. thuringiensis MB174 cell surface to prepare a whole-cell laccase biocatalyst by using two repeat N-terminal domains of autolysin Mbg (Mbgn) as the anchoring motif. Immunofluorescence microscopic assays confirmed that the fusion protein (Mbgn)-WlacD was anchored on the surface of the recombinant B. thuringiensis MB174. After optimization by a single factor test, L (3)-orthogonal test, Plackett-Burman test, steepest ascent method, and Box-Behnken response surface methodology, the whole-cell specific laccase activity of B. thuringiensis MB174 was improved to 555.2 U L, which was 2.25 times than that of the primary culture condition. Optimized B. thuringiensis MB174 cells were further adsorbed by VRMs to prepare VRMs-Bt-WlacD, an immobilized whole-cell laccase biocatalyst. Decolorization capacity of as-prepared VRMs-Bt-WlacD toward an initial concentration of 500 mg L of an textile dye reactive blue 19 (RB19) aqueous solution reached 72.36% at a solid-to-liquid ratio of 10 g-100 mL. Repeated decolorization-activation operations showed the high decolorization capacity of VRMs-Bt-WlacD and have the potential for large-scale or continuous operations.
构建了一种三重火山岩基质-苏云金芽孢杆菌-漆酶WlacD（VRMs-Bt-WlacD）染料脱色系统。通过使用自溶素Mbg（Mbgn）的两个重复N端结构域作为锚定基序，将WlacD展示在苏云金芽孢杆菌MB174细胞表面，制备全细胞漆酶生物催化剂。免疫荧光显微镜检测证实融合蛋白（Mbgn）-WlacD锚定在重组苏云金芽孢杆菌MB174的表面。经过单因素试验、L（3）-正交试验、Plackett-Burman试验、最速上升法和Box-Behnken响应面法优化后，苏云金芽孢杆菌MB174的全细胞比漆酶活性提高到555.2 U/L，是原始培养条件下的2.25倍。优化后的苏云金芽孢杆菌MB174细胞进一步被VRMs吸附，制备出固定化全细胞漆酶生物催化剂VRMs-Bt-WlacD。制备的VRMs-Bt-WlacD对初始浓度为500 mg/L的纺织染料活性蓝19（RB19）水溶液的脱色能力在固液比为10 g-100 mL时达到72.36%。重复脱色-活化操作表明VRMs-Bt-WlacD具有较高的脱色能力，具有大规模或连续操作的潜力。
