Study On Conditions Of Mass Sporulation And Fermentation Kinetics Of Blakeslea Trispora

Blakeslea trispora is the only filamentous fungus which is suitable for the industrialproduction of lycopene and other carotenoids at present. In the fermentation process theBlakeslea trispora (+) and (-) strains are inoculated according to a certain ratio as sporesuspension. In terms of the problem that the sporulation amount of (-) strains is very low andthe demand for (-) strains are usually greater than that of (+) strains, the impact of variousconditions on sporulation of Blakeslea trispora (-) strains were systematically studied, andthe culture conditions which could promote mass sporulation of Blakeslea trispora (-) strainswere optimized and established. The optimized culture conditions were as follows. Themedium volume was30ml in each250ml Erlenmeyer flask. Eight layers of gauze wereused for sealing. After inoculation,(-) strains were cultivated at28℃for24h, and thenplaced at4℃for cold storage for7h, and finally placed at20℃for static culture until7d.The treatment of alternating light and dark with interval of12h was used in the entireprocess. When sporulation at the optimized culture conditions, the amount of the spores wasincreased1.57times compared to that before optimization. At the same time, the sporulationmedia of Blakeslea trispora (-) strains was optimized by the respond surface method. Theobtained optimal medium was: based on PDA medium, addition of0.965g/L (NH4)2SO4,0.232mg/L FeCl3·6H2O,250mg/L MnCl·5H2O and225mg/L CuSO4·5H2O, pH7.0. Whensporulation on the optimized medium, the amount of the spores was17.6%higher than thatbefore optimization. Moreover, the fermentation kinetics of lycopene production byBlakeslea trispora was studied. The kinetics models of cell growth, substrate consumptionand product generation were established. These models had been validated, and the resultsshowed that the experimental value matched the model values well. These models can beused to predict the law of cell growth, substrate consumption and product generation in thefermentation process of lycopene production by Blakeslea trispora, and also could providetheoretical basis and scientific guidance for the large scale production of lycopene byindustrial fermentation.