Yan Songling, Duan Baiyun, Liu Cuicui, Liu Guiyou, Kang Liqin, Sun Lei, Yi Lin, Zhang Zhenqing, Liu Zhonghua, Yuan Sheng
Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
School of Life Science and Chemical Engineering, Jiangsu Second Normal University, Nanjing 211200, China.
J Fungi (Basel). 2023 Mar 20;9(3):378. doi: 10.3390/jof9030378.
A endo-1,4-β-mannanase (CcMan5C) gene was cloned from and heterologously expressed in , and the recombinant enzyme was purified by Ni-affinity chromatography and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). CcMan5C hydrolyzed only locust bean gum galactomannan (LBG) but not α-mannan from or Avicel cellulose, oat spelt xylan, or laminarin from . CcMan5C exhibited distinctive catalytic features that were different from previously reported β-mannanases. (1) CcMan5C is the first reported fungal β-mannase with an optimal alkalic pH of 8.0-9.0 for hydrolytic activity under assay conditions. (2) CcMan5C is the first reported alkalic fungal β-mannase with an optimal temperature of 70 °C for hydrolytic activity under assay conditions. (3) The organic solvents methanol, ethanol, isopropanol, and acetone at concentrations of 10% or 20% did not inhibit CcMan5C activity, while 10% or 20% isopropanol and acetone even enhanced CcMan5C activity by 9.20-34.98%. Furthermore, CcMan5C tolerated detergents such as Tween 20 and Triton X-100, and its activity was even enhanced to 26.2-45.6% by 1% or 10% Tween 20 and Triton X-100. (4) CcMan5C solution or lyophilized CcMan5C exhibited unchanged activity and even increasing activity after being stored at -20 °C or -80 °C for 12 months and retained above 50% activity after being stored at 4 °C for 12 months. These features make CcMan5C a suitable candidate for the detergent industry and paper and pulp industry.
从[具体来源]克隆了一种内切-1,4-β-甘露聚糖酶（CcMan5C）基因，并在[具体宿主]中进行了异源表达，重组酶通过镍亲和层析进行纯化，并用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF/TOF-MS）进行鉴定。CcMan5C仅水解刺槐豆胶半乳甘露聚糖（LBG），但不水解来自[具体来源]的α-甘露聚糖或微晶纤维素、燕麦麸木聚糖或来自[具体来源]的海带多糖。CcMan5C表现出与先前报道的β-甘露聚糖酶不同的独特催化特性。（1）CcMan5C是首次报道的在测定条件下具有8.0-9.0最佳碱性pH值用于水解活性的真菌β-甘露聚糖酶。（2）CcMan5C是首次报道的在测定条件下具有70℃最佳温度用于水解活性的碱性真菌β-甘露聚糖酶。（3）浓度为10%或20%的有机溶剂甲醇、乙醇、异丙醇和丙酮不抑制CcMan5C活性，而10%或20%的异丙醇和丙酮甚至使CcMan5C活性提高9.20-34.98%。此外，CcMan5C耐受吐温20和曲拉通X-100等洗涤剂，1%或10%的吐温20和曲拉通X-100甚至使其活性提高26.2-45.6%。（4）CcMan5C溶液或冻干的CcMan5C在-20℃或-80℃储存12个月后活性不变甚至增加，在4℃储存12个月后仍保留50%以上的活性。这些特性使CcMan5C成为洗涤剂行业和造纸与纸浆行业的合适候选酶。
