Metabolic Regulation Of Lycopene Production By Blakeslea Trisopora

Lycopene, a red carotenoid, has received great attention in recent years due to its antioxidant activity and superior physiological function of dispelling the human free radical, resisting cancers, alleviating cardiovascular diseases, etc. The production of lycopene from microbial sources has been the focus of extensive research. The dissertation focused on the metabolic regulation of production of lycopene by Blakeslea trisopora.The concepts of enhancing precursors and minimizing metabolic flow to related products were applied here. The main research items and results as follows:(1) The influence of trisporic acid (TA), a well known sex hormone of Blakeslea trisopora, on biomass, lycopene and ergosterol biosynthesis were investigated. The results indicated that biomass of mated strains of Blakeslea trisopora was greater than unmated strain because TA was biosynthesized by mated strains. With the addition of1.775mg·L-1TA at72h, the lycopene content of (-) strain reached1.3mg·g-1, which was128%higher than that of the control. TA enhanced lycopene production when added into mated starins fermentation. With4.42mg·L-1TA added in the medium at72h, lycopene content was5.79mg·g-1, which was37.2%higher than that of the control. TA improved ergosterol biosynthesis. Over the period studied (24-120h), ergosterol content in mated strains was1.5times greater than unmated strain.(2) Effects of some ergosterol biosynthesis inhibitors on the production of lycopene by Blakeslea trisopora have been discussed. Effect of imidazole on lycopene production was not very obvious. With the addition of0.5mg·L-1imdazole at48h of fermentation, lycopene content was only15..3%higher than that of the control. With0.7mg·L-1TH or30mg·L-1ketoconazole added in the medium of fermentation, lycopene content was23%or277%higher than that of the control. The joint addition of0.352mM P-inone and10mg·L-1ketoconazole accelerated lycopene contne at60.7%compared to that of the control.(3)Influence of archidonic acid (AA) on the production of lycopene was investigated. When700mgL-1was added at24h of fermentation, lycopene content reached2.55mg·g-1, which was22%higher than that of the control.