产生物表面活性剂的地衣芽孢杆菌种子培养条件研究

Cultivation conditions of inocula for Bacillus licheniformis producing biosurfactant

本文对产生物表面活性剂的油藏地衣芽孢杆菌种子培养条件进行优化。通过测定种子培养液中菌体浓度和发酵液的菌浓及表面张力,研究温度、通气量、接种龄、接种量对种子生长和发酵产生物表面活性剂的影响。确定了种子适宜培养条件为装液量100 m L/250 m L,12层纱布封口,于50℃、180 r/min摇床培养14 h。以10%接种量接种发酵,发酵24 h的发酵液表面张力降至最低,为22.6 m N/m。在该条件下培养种子,可缩短种子培养时间,实现提前接种发酵并高产生物表面活性剂。

Bacillus licheniformis isolated from crude oil was used to produce biosurfactant. The cultivation condition of inocula was optimized in this research. By measuring the cell density in inoculum culture broth, the cell density and surface tension in fermenting broth, the effects of temperature, ventilation and time of inoculum cultivation and inoculation rate on cell growth and the surfactant production in fermentation were investigated. The results indicated that the inocula should be cultivated at 50℃ , 180 r/min for 14 h in 100 mL/250 mL shaking flasks sealed with 12-layer gauze. And when the fermentation was conducted for 24 h with 10% of inoculation rate, the surface tension of cell-free fermenting broth lowered to the minimum 22.6 mN/m. Inocula cultivation under the optimal conditions could shorten the cultivation time of inocula and result in earlier biosurfactant production and higher yield in the fermentation.