关键词: 三孢布拉氏霉菌, 番茄红素, 发酵, 响应面分析, 代谢控制

Abstract: Lycopene is a kind of carotene, which exists in many fruits and vegetables. It has good antioxidant, anti-aging and immunity enhancing functions. It is widely used in medicine, food, cosmetics and other fields. However, the traditional extraction method of lycopene has the disadvantages of low yield and high cost, and it is limited by the source of raw materials. Chemical synthesis method has potential safety hazards. Microbial fermentation has attracted increasing attention due to its advantages of simple process, high production efficiency, and the same biological activity as natural plant extracts. Based on this, taking lycopene yield as response value, response surface methodology was used to optimize metabolic control conditions on the basis of single factor experiments, and the effects of positive and negative strain inoculation ratio, metabolic flow inhibitor and exogenous vegetable oil on lycopene yield were investigated. The results showed that the optimal conditions were as follows: the inoculation ratio of the negative and positive strain of Braxella trisporus was 6∶1, the addition of lycopene cyclase inhibitor 2,6-dimethylpyridine was 0.09 g·L-1, and 3.57 g·L-1 soybean oil was used as exogenous vegetable oil. Under the optimal conditions, the lycopene yield in the fermentation broth reached 1.51 g·L-1, and the bacterial biomass was 51 g·L-1. The research significantly increased the biomass of fermented bacteria, promoted the conversion rate of lycopene biosynthesis, and provided a theoretical basis for the industrial production of lycopene.

Key words: Braxella trisporus, lycopene, fermentation, response surface analysis, metabolic control