重组角质酶的发酵制备及其对涤纶纤维的表面改性

Preparation of recombinant cutinase and its application in surface modification of poly (ethylene terephthalate)

摘要:

对大肠杆菌表达嗜热子囊菌Thermobifida fusca角质酶的摇瓶诱导条件及3 L发酵罐扩大培养进行了研究，并探讨了角质酶对涤纶纤维的改性作用。结果表明，在摇瓶培养中，采用工业级TB培养基，用2 g/L乳糖诱导，菌体培养至对数生长前期添加0.5％甘氨酸，角质酶产量可达到128 U/mL。在3 L发酵罐扩大培养中，补料培养生物量 (OD600) 最大达到35，角质酶酶活最高达506 U/mL，是迄今国内外报道细菌来源角质酶的最高水平。紫外分光光度法分析初步表明涤纶纤维经角质酶水解产生了对苯二甲酸类物质

Abstract:

Fermentation and induction conditions for recombinant Escherichia coli expressing Thermobifida fusca cutinase were optimized in flasks and 3L fermenter. Surface modification of poly (ethylene terephthalate) fibers with cutinase was also discussed. The results showed that, cutinase yield reached 128 U/mL by adding 2 g/L inducer lactose and 0.5% glycine. In the fed-batch culture in a 3 L fermenter, the maximum biomass cutinase activity was up to 506 U/mL, which is the highest bacterial cutinase activity reported by far. Recombinant cutinase was used to modify polyester fibers and terephthalic acid substance was detected by using UV analysis. The dyeing and wetting properties of cutinase treated fibers were higher than untreated fibers. Combined utilization of cutinase and Triton X-100 can significantly improve the hydrophilicity of polyester. This is the first report of surface modification on polyester fibers by bacterial cutinase.