Zhang Ning, Jiang Yue, Sun Yun-Juan, Jiang Jian-Chun, Tong Ya-Juan
Key Lab of Biomass Energy and Material, Key Lab of Chemical Engineering of Forest Products, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resource, National Forestry and Grassland Administration, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry (CAF), Nanjing, Jiangsu, China.
Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China.
Front Bioeng Biotechnol. 2023 Jan 5;10:1095323. doi: 10.3389/fbioe.2022.1095323. eCollection 2022.
Hemicellulose is an important component in lignocellulose materials, which is second only to cellulose, accounting for 15%-35% of the dry weight of plants. In the current situation of energy shortage, making full use of lignocellulose materials to produce fuel ethanol has become an important way to solve the energy problem. Xylanase plays a crucial role in the utilization of hemicellulose. It is a necessary means to reduce the cost of hemicellulose utilization by improving the activity of xylanase. Moreover, most naturally xylanases are mesophilic enzymes, which limits their industrial application. In this study, was used to produce xylanases and a thermostable mutant 2103 was obtained by atmospheric room temperature plasma (ARTP) mutagenesis. The research work started with exploring the effects of ARTP mutagenesis on the antioxidase system [superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), and antioxidant capacity (AOC)] of , and found that superoxide dismutase activity increased by 221.13%, and polyphenol oxidase activity increased by 486.04% as compared with the original strain when the implantation time was 300 s. So as to determine the conditions for subsequent mutagenesis. For the mutant 2103, the reaction temperature for xylanase production remained stable in the range of 70°C-85°C. Its optimum temperature was 75°C, which was 15°C higher than that of the original strain. And its xylanase activity increased by 21.71% as compared with the original strain. 2103 displayed a significantly higher relative xylanase activity than the original strain in the acidic (pH 4.0-7.0) range, and the xylanase activity was relatively stable in the pH range of 6.0-8.5. These results provide an alternative biocatalyst for the production of xylooligosaccharide, and a potential usage of ARTP in the mutagenesis of thermostable mutant.
半纤维素是木质纤维素材料中的重要成分，仅次于纤维素，占植物干重的15%-35%。在当前能源短缺的形势下，充分利用木质纤维素材料生产燃料乙醇已成为解决能源问题的重要途径。木聚糖酶在半纤维素的利用中起着关键作用。提高木聚糖酶的活性是降低半纤维素利用成本的必要手段。此外，大多数天然木聚糖酶是中温酶，这限制了它们的工业应用。在本研究中，利用[具体菌株未给出]生产木聚糖酶，并通过常压室温等离子体（ARTP）诱变获得了耐热突变体2103。研究工作首先探索了ARTP诱变对[具体菌株未给出]抗氧化酶系统[超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）、多酚氧化酶（PPO）和抗氧化能力（AOC）]的影响，发现当注入时间为300 s时，超氧化物歧化酶活性比原始菌株增加了221.13%，多酚氧化酶活性增加了486.04%。从而确定后续诱变的条件。对于突变体2103，其生产木聚糖酶的反应温度在70°C-85°C范围内保持稳定。其最适温度为75°C，比原始菌株高15°C。并且其木聚糖酶活性比原始菌株增加了21.71%。2103在酸性（pH 4.0-7.0）范围内显示出比原始菌株显著更高的相对木聚糖酶活性，并且木聚糖酶活性在pH 6.0-8.5范围内相对稳定。这些结果为低聚木糖的生产提供了一种替代生物催化剂，以及ARTP在耐热突变体诱变中的潜在用途。
