Production Techniques Optimization Of Lycopene-producing Strains

Lycopene was one of the most important carotenoids, and it had many physiological functions such as anti-cancer, anti-aging, enhancing immune ability and so on. Microbial fermentation by Blakeslea trispora was a leading approach to produce lycopene industrially. It was more important to optimize culture condition and breed excellent strains.By natural selection with Blakeslea trispora plus （+） and minus （-） strains, which were conserved in our laboratory, and with HPLC measure method, we acquired seven strains with lycopene output between 1000～1500mg/L. In normal conditions, the output stability experiment showed that when the strains were subcultured one generation, the max drop rate of lycopene output was up to 50%, because the culture condition was unfit.Through freezing the strain P_3-8（+） and strain M2-4（-）, and studying the culture medium、freezing time、molds inhibitor、temperature and so on. The result showed that after freezed with 1h at-20℃, and cultured on PDA plate with 0.1% sodium desoxycholate at 25℃for 4～5d, the strains took on excellent characteristics.Through studying the fermentation temperature and fermentation period, we learned that when cultured the seed at 25℃, and fermented at 27℃in 120h, compared with primitive output, the lycopene average output improved 30%, and the maximum was 1542.74mg/L.The output stability experiment showed that rejuvenated strains had excellent characteristics of lycopene high-yielding and excellent output stability. Also, we studied the conservation method of Blakeslea trispora, and the result indicated that by conserved with PDA plate at 4℃, the strains could maintain primitive activity in 30d.