Screening And Optimizing Of Blakeslea Trispora Strains For Producing Lycopene

Lycopene is a unique caroteniod with non-ring structure. It demonstrates strong antioxdative reactivity and multi-physiological effects. It has great potential in food industry, drug production and medical care. Producing lycopene with fermentation method of microbion, the quality and physiological activityof products are identical with the natural products. It would be to reduce the cost and pollution by applying fermentation method. Accordingly the rather ideal way of implementing industrialized production is to ensure highly producing strain, optimize fermentation condition and get higher extraction ratio.In this paper, the production of lycopene by Blakeslea trispora was investigated in four parts.1. Using 192 sand soil test tubes and 6 freeze dried test tubes, Blakeslea trispora strains 6⁺, 80⁺, 83⁺, 75^-, 94^-, G₃⁺and F₂^- were obtained by separating, purifying and screening. After fermentation, the content of lipid in dry mycelia was 45.1～62.5%,β-carotene and lycopene were 453.4～821.2 mg/L and 29.2～65.4 mg/L respectively. According to growth state and experimental result of fermentation, 83⁺,94^-,G₃⁺and F₂^-strains were chosen as original strains for mutagenesis breeding.2. Blakeslea trispora that had been isolated was treated twice with ⁶⁰Co-γirradiation. According to the research of thalli figure,living in culture utensil,fermentation culture and pigment test, we bred two strains with MG₃⁺ and MF₂^- for fermentability production. Its genetic characteristic was stable and its yield of lycopene reached 661.8mg/L.3. In order to raise the mutant strain production, we designed an orthogonal experiment according to L₉(3⁴) table for screening the optimization medium. The experiment took the following four factors for each at three different levels. And the four factors were corn flour, bean cake flour, vegetable oil and glucose of main medium. The targets of experiment was mycel weight and lycopene yield. Result was analyzed by SPSS. According to the analysis of direct-viewing and variance, we concluded that in the optimization medium the content of four factors was A3B1C2D2. The lycopene yield raised more than 30%, was 968.2 mg/L.4. At the base of mutagenesis selection and shake flask fermentation experiment of Blakeslea trispora, in order to try to find out technology flow-sheet and specification, we completed the experiment by 30 L fermentor. The highest lycopene yield is 1295.6 mg/L through continuously fermenting 5 times.