College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, 430023, China.
World J Microbiol Biotechnol. 2019 May 27;35(6):84. doi: 10.1007/s11274-019-2657-2.
Pectin is a type of complex hydrophilic polysaccharide widely distributed in plant resources. Thermal stable pectinase has its advantage in bioapplication in the fields of food processing, brewing, and papermaking, etc. In this study, we enzymatically characterized a putative endo-polygalacturonase TcPG from a Talaromyces cellulolyticus, realized its high-level expression in Pichia pastoris by in vitro constructing of a series of multi-copy expression cassettes and real time quantitative PCR screening. The secretive expression level of TcPG was nonlinear correlated to the gene dosage. Recombinants with five-copy TcPG gene in the host genome showed the highest expression. After cultivation in a bioreactor for about 96 h, the enzyme activity reached 7124.8 U/mL culture. TcPG has its optimal temperature of 70 °C. Under the optimized parameters, the pectin could be efficiently hydrolyzed into oligosaccharides.
果胶是一种广泛存在于植物资源中的复杂亲水性多糖。热稳定的果胶酶在食品加工、酿造和造纸等领域的生物应用中具有优势。在本研究中，我们对来自塔宾曲霉的一种假定内切聚半乳糖醛酸酶 TcPG 进行了酶学表征，通过体外构建一系列多拷贝表达载体和实时定量 PCR 筛选，实现了其在巴斯德毕赤酵母中的高水平表达。TcPG 的分泌表达水平与基因剂量呈非线性相关。在宿主基因组中具有五拷贝 TcPG 基因的重组体表现出最高的表达。在生物反应器中培养约 96 h 后，酶活达到 7124.8 U/mL 培养物。TcPG 的最适温度为 70°C。在优化的参数下，果胶可以有效地水解成寡糖。
