College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China.
Laboratory for Marine Drugs and Bioproducts , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266237 , China.
J Agric Food Chem. 2018 Jul 11;66(27):7087-7095. doi: 10.1021/acs.jafc.8b01974. Epub 2018 Jun 27.
Here we report a simple and efficient method to produce 3,6-anhydro-l-galactose (l-AHG) and agarotriose (AO3) in one step by a multienzyme system with the coimmobilized β-agarase AgWH50B and α-neoagarobiose hydrolase K134D. K134D was obtained by AgaWH117 mutagenesis and showed improved thermal stability when immobilized via covalent bonds on functionalized magnetic nanoparticles. The obtained multienzyme biocatalyst was characterized by Fourier transform infrared spectroscopy (FTIR). Compared with free agarases, the coimmobilized agarases exhibited a relatively higher agarose-to-l-AHG conversion efficiency. The yield of l-AHG obtained with the coimmobilized agarases was 40.6%, which was 6.5% higher than that obtained with free agarases. After eight cycles, the multienzyme biocatalyst still preserved 46.4% of the initial activity. To the best of our knowledge, this is the first report where two different agarases were coimmobilized. These results demonstrated the feasibility of the new method to fabricate a new multienzyme system onto magnetic nanoparticles via covalent bonds to produce l-AHG.
在这里，我们报告了一种简单而有效的方法，通过共固定化β-琼脂酶 AgWH50B 和α-新琼寡糖水解酶 K134D 的多酶系统一步法生产 3,6-脱水-l-半乳糖（l-AHG）和琼脂三糖（AO3）。K134D 通过 AgaWH117 突变获得，并通过共价键固定在功能化磁性纳米粒子上时表现出更好的热稳定性。所得多酶生物催化剂通过傅里叶变换红外光谱（FTIR）进行了表征。与游离琼脂酶相比，共固定化琼脂酶表现出相对更高的琼脂糖到 l-AHG 的转化效率。用共固定化琼脂酶获得的 l-AHG 的产率为 40.6%，比用游离琼脂酶获得的产率高 6.5%。经过 8 个循环后，多酶生物催化剂仍保留 46.4%的初始活性。据我们所知，这是首次报道两种不同的琼脂酶共固定化。这些结果证明了通过共价键将新的多酶系统制备到磁性纳米粒子上以生产 l-AHG 的新方法的可行性。
