Optimization Of Lycopene Fermentation Based On The Multi Parameters Correlation Analysis And Lycopene Extraction Of Blakeslea Trispora

Lycopene, one of intermediates in the biosynthesis of carotene has many excellent physiological functions, just like anti-oxygenation, anticancer and cancer prevention, resistance enhancement. With the rapid increasing demand in medicine and health care industry and of pressure in market competition, it is the key to improve lycopene productivity and reduce the cost by fermentation optimization and fermentation control.At present, fermentation of Blakeslea trispora is the main lycopene production process with the advantages of low production cost, simple process and safety. In this paper, the fermentation process control and extraction of lycopene were studied, including fermentation condition optimization and supplementary addition strategy creation to enhance lycopene synthesis, setting up feeding strategy of sugar and oil based on online RQ feedback control, as well as the optimization of lycopene extraction process.(1) The influence of different factors including carbon source, condition of seed(the ratio of (+) and (-) type, inoculation quantity), environment condition(pH, oxygen level), the adding condition of additive that influence metabolism (?-ionone, imidazole) and the shear force are discussed in the paper. It showed that the optimum condition are using corn starch as the initial carbon source,7.5 as the initial pH, inoculating 10% with 1:10 ratio of (+) and (-) in 50 mL/500 mL, using ?-ionone 0.15% as promoter at 24 h and imidazole 0.1%as inhibitor at 48 h with a fermentation period of 120 h.(2) A new glucose feeding strategy based on RQ feedback control was established in lycopene fermentation. Different ratios of starch and oil have obviously influence on lycopene synthesis in shake flask, and reasonable control of the consumption of sugar can effectively promote the synthesis rate of lycopene. Process research results showed that the RQ values had a good corresponding relationship with the proportion of sugar and oil consumption in fermentation process. Therefore, we set up the strategy to feedback control of the tiny glucose feeding rate according to RQ value. It showed that the glucose feeding rate control based on the RQ can effectively enhance the respiratory metabolism of bacteria and provide enough energy to promote lycopene synthesis. However, high glucose feeding rate significantly inhibited the product synthesis. The experiment of glucose feeding control based on RQ feedback showed that with controlling RQ at 0.80±0.2 can promote the growth of Blakeslea trispora and the synthesis of lycopene with maximum limit, and improve the production by above 10% when compared with all the oil process.(3) The facors of different mycelium state, saponification conditions, dehydrating agent and dehydrating time, extraction solvents, the ratio of mycelium biomass and extraction solvent (g/mL), extraction time and temperature were tested by the combination of organic solvents extraction and ultrasonication in this study. It suggests that it is feasible to extract lycopene directly from wet mycelium. The best conditions with wet mycelium are listed below: saponification agents and concentration of 0.6 mol/L NaOH, the ratio of mycelium biomass and extraction solvent of 1:75, ultrasonic processing time of 20min at 45? with ethyl acetate as extraction agent give maximum extraction.