纳豆芽孢杆菌生产维生素K2的连续发酵工艺优化

Optimization on the continuous fermentation process of Vitamin K2 from Bacillus subtilis natto

为优化维生素K2的高密度连续发酵生产工艺,通过对纳豆芽孢杆菌发酵培养,研究了培养基组成、转速、p H、溶氧量、后处理技术等因素对维生素K2产量的影响。实验结果表明以香菇菌渣复配蛋白胨为氮源(5%),甘油为碳源(5%),pH为7,通气比大于1.5 vvm,转速为600 r/min时,采用高密度连续发酵技术,5 L罐发酵产量最高达35.58 mg/L。发酵液萃取后,废液再通过纳滤膜截流,提高维生素K2回收率,并制成富含维生素K2的菌菇粉。维生素K2的结构经高效液相及质谱确证。大鼠急性毒性实验证明该菌菇粉产品安全无毒。

To optimize the high density continuous fermentation process of Vitamin K2,the effects of raw materials concentration,rotation rate,p H,dissolved oxygen( DO) and post- processing techniques were investigated by the fermentation of Bacillus subtilis natto.It was found that the optimal condition was of Glycerol 5%,soybean protein2%,mushroom compost 3%,p H7 and DO of 20% at 600 r / min. The highest yield reached 35.58 mg / L in 5 L fermentation tank.Mushroom compost,as a supplementary nitrogen source,can promote the biosynthesis of VK2,and its effective concentration was 3%. The fermentation broth was extracted by extract liquor and filtered by nanofiltration membrane.As a result,Vitamin K2 can be well isolated and the VK2 mixed mushroom powder was obtained through spray drying. The structure of Vitamin K2 was characterized by HPLC and MS. The quality of product was safe and qualified.