Mon Maria Laura, Marrero Díaz de Villegas Rubén, Campos Eleonora, Soria Marcelo A, Talia Paola M
Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina.
Facultad de Agronomía, Cátedra de Microbiología Agrícola, Universidad de Buenos Aires, INBA UBA-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.
Bioresour Bioprocess. 2022 Aug 17;9(1):84. doi: 10.1186/s40643-022-00572-w.
The aim of the present study was to assess the biochemical and molecular structural characteristics of a novel alkali-thermostable GH10 xylanase (Xyl10B) identified in a termite gut microbiome by a shotgun metagenomic approach. This endoxylanase candidate was amplified, cloned, heterologously expressed in Escherichia coli and purified. The recombinant enzyme was active at a broad range of temperatures (37-60 ºC) and pH values (4-10), with optimal activity at 50 ºC and pH 9. Moreover, its activity remained at more than 80% of its maximum at 50 °C for 8 h. In addition, Xyl10B was found to be stable in the presence of salt and several ions and chemical reagents frequently used in the industry. These characteristics make this enzyme an interesting candidate for pulp and paper bleaching industries, since this process requires enzymes without cellulase activity and resistant to high temperatures and alkaline pH (thermo-alkaliphilic enzymes). The products of xylan hydrolysis by Xyl10B (short xylooligosaccharides, xylose and xylobiose) could be suitable for application as prebiotics and in the production of bioethanol.
本研究的目的是通过鸟枪法宏基因组学方法评估在白蚁肠道微生物群中鉴定出的一种新型碱热稳定GH10木聚糖酶（Xyl10B）的生化和分子结构特征。该内切木聚糖酶候选物被扩增、克隆，在大肠杆菌中进行异源表达并纯化。重组酶在广泛的温度（37-60℃）和pH值（4-10）范围内具有活性，在50℃和pH 9时活性最佳。此外，其在50℃下8小时的活性仍保持在最大值的80%以上。此外，发现Xyl10B在盐以及工业中常用的几种离子和化学试剂存在下是稳定的。这些特性使这种酶成为制浆造纸漂白工业中一个有趣的候选物，因为该过程需要没有纤维素酶活性且耐高温和碱性pH的酶（热嗜碱酶）。Xyl10B水解木聚糖的产物（短木寡糖、木糖和木二糖）可适合用作益生元以及用于生物乙醇的生产。
