马铃薯淀粉对Komagataeibacter nataicola Y19动态发酵产球形细菌纤维素的影响

Effects of potato starch on sphere-like bacterial cellulose produced by Komagataeibacter nataicola sp.Y9 in agitated culture

球形细菌纤维素（bacterial cellulose,BC）是在动态条件下发酵产生的细菌纤维素,具有机械强度高,结晶度高,持水力强和生物相容性等优良特性。因其比静置发酵产生的膜状纤维素具有更大的比表面积,更多的纳米级孔隙,在生物分离、污水处理、固定化反应、药物缓释载体等领域具有独特的应用前景。该研究通过在Hestrin-Schramm培养基中添加马铃薯淀粉,探讨其对Komagataeibacter nataicola Y19动态发酵产BC的产量、球形均匀度、微观结构的影响。研究发现,添加0.15%的马铃薯淀粉可使产量由2.328 g/L提高至3.660 g/L,形成直径为0.5-0.8 cm的均匀球形BC。通过扫描电镜（SEM）观察可知,与对照相比添加马铃薯淀粉的球形BC呈现出更多的空隙和小洞,傅立叶红外光谱（FT-IR）、X射线衍射（XRD）表征结果显示其具有更小的结晶度和结晶尺寸。因此,Hestrin-Schramm培养基中添加马铃薯淀粉,不仅能够提高球形BC的产量及球形颗粒的均匀度,且对球形BC的微观结构有一定的修饰作用。

Sphere-like bacterial cellulose （BC） is produced in agitated culture, and shows great potentials as an industrial material due to its unique properties. In this study, potato starch of different concentrations was added to Hestrin-Schramm medium and the effects of potato starch on the yield, shape uniformity, and structure of sphere-like BC produced by K. nataicola Y19 in agitated culture were investigated. When 0. 15% potato starch was added, 3. 660g/L BC was obtained as compared with 2. 328 g/L BC produced from the control. And the uniformity of the sphere-like BC was better. By scanning electron microscopy, BC formed through addition of 0. 15% potato starch was looser and showed more gaps and holes in the network structure, and the width of its cellulose fiber was broader. By X-ray diffraction and Fourier transforms infrared spectroscopy, more cellulose I~ formed and the erystalliuity and crys- tal size of the sphere-like BC were decreased through addition of potato starch.