West Pomeranian University of Technology in Szczecin, Faculty of Biotechnology and Animal Husbandry, Department of Immunology, Microbiology and Physiological Chemistry, 45 Piastów Avenue, 71-311 Szczecin, Poland.
West Pomeranian University of Technology in Szczecin, Faculty of Chemical Engineering and Technology, 42 Piastów Avenue, 71-065 Szczecin, Poland.
Int J Biol Macromol. 2018 Mar;108:462-470. doi: 10.1016/j.ijbiomac.2017.12.031. Epub 2017 Dec 6.
The usefulness of bacterial cellulose (BC), obtained from the cultures of Komagataeibacter xylinus exposed to rotating magnetic field (RMF), as a carrier for laccase immobilization was investigated in this study. It was found that the highest yield of laccase immobilization (>70%) was achieved in pH of 4.0 and this value was optimal in the case of both types of cellulose carriers applied. The pH equals 4.0 was also the optimal one with regard to immobilized enzymes' activity, while in case of free laccase, optimal pH value was 3.0. Process of immobilization had an impact on enzyme's optimal temperatures: while free laccase and laccase bound to RMF-unexposed cellulose was the most effective at 60°C, optimal activity of enzyme immobilized on RMF-exposed carrier was reached at 70°C. Laccase immobilized on both type of carriers had also better thermal stability at 70°C compared to free laccase. After 8 cycles of use, laccase immobilized on RMF-exposed BC remained more active than laccase immobilized on RMF-unexposed BC (65% vs. 50% of initial activity, respectively). Our results indicate that RMF-modified BC may be successfully used as a carrier for the laccase immobilization.
本研究考察了旋转磁场（RMF）暴露下的木醋杆菌培养物获得的细菌纤维素（BC）作为漆酶固定化载体的用途。结果发现，在 pH 值为 4.0 时，漆酶固定化的产率最高（>70%），并且在应用的两种纤维素载体的情况下，该值都是最佳的。对于固定化酶的活性而言，pH 值 4.0 也是最佳的，而对于游离漆酶而言，最佳 pH 值为 3.0。固定化过程会影响酶的最适温度：游离漆酶和未暴露于 RMF 的纤维素结合的漆酶在 60°C 时效果最佳，而暴露于 RMF 的载体固定化的酶的最佳活性则在 70°C 时达到。与游离漆酶相比，两种载体固定化的漆酶在 70°C 时也具有更好的热稳定性。经过 8 次使用循环后，暴露于 RMF 的 BC 固定化的漆酶比暴露于 RMF 的 BC 固定化的漆酶保持更高的活性（分别为初始活性的 65%和 50%）。我们的结果表明，RMF 改性的 BC 可以成功用作漆酶固定化的载体。
