动态发酵合成球形细菌纤维素条件研究

细菌纤维素(BC)是优良的新型生物材料，尤其以球形BC为代表，在各领域应用广泛。目前，动态发酵产BC多以不规则团块状、星球状、丝状为主，应用范围较局限。故通过控制生产条件，获得均匀度较高的球形BC有着迫切的需要。在动态发酵时，以椰冻驹形杆菌（Komagataeibacter nataicola）Y19作为生产菌株，以中等大小BC的质量及数量百分比为考察指标，研究转速、发酵液液深及发酵容器直径引起的供氧效率及剪切力变化对动态发酵产球形BC合成规律的影响。结果表明，供氧效率提高、剪切力增大时，可使球形颗粒变小，颗粒数量增加。在发酵容器直径为6.0 cm，液深为2.40～2.75 cm，转速为130 r/min时，中球BC质量与数量百分比均＞40%，均匀度最佳。

Culture conditions for the sphere-like bacterial cellulose by dynamic fermentation

Bacterial cellulose(BC), especially sphere-like BC, as an excellent new biological material had been widely applied in various fields. At present, the BC produced by dynamic fermentation was mainly irregular crumb, star shaped and filiform, and the application scope was limited. Therefore, it is urgent to obtain sphere-like BC with high uniformity by controlling the production conditions. During the dynamic fermentation, using Komagataeibacter nataicola Y19 as production strains, quality and quantity percent of sphere-like BC with medium size as the investigation indexes, the effects of the changes of supplying oxygen efficiency and shear force caused by rotate speed, fermented liquid depth and fermentation vessel diameter on the synthesis law of sphere-like BC were discussed. The results showed that the particle size of sphere-like BC was decreased and the quantity of sphere-like BC was increased with increasing the supplying oxygen efficiency and shear force. In the conditions of fermentation vessel diameter 6.0 cm, fermented liquid depth 2.40-2.75 cm and rotation speed 130 r/min, the quality and quantity percent of sphere-like BC with medium size was more than 40%, and the uniformity was up to the high set.