| Summary: | 碩士 === 大同大學 === 生物工程學系(所) === 99 === Carotenoids of Haloferax mediterranei have anti-oxidant effect and protection against cell damage. The proliferation of H. mediterranei and generation of carotenoids are greatly influenced by different carbon sources and salt concentrations. Increasing the concentrations of glucose, the growth rate didn’t change obviously, but elongated the time for the cell growth and had higher biomass. The cell growth rates were lower by acetate as carbon source than ones by glucose. Lower concentrations of butyrate (≤0.5%) didn’t inhibit the growth, but the cell growth rates and maximum biomass were decreased when the media with butyrate were more than 1%. Additionally, the total production of carotenoids were increased along the culture time. The maximum production was in 0.5% butyrate as carbon source.
The two-stage fed-batch fermentation in the presence of different carbon sources and without NaCl was used for the growth of H. mediterranei and enhancing the production of carotenoids. At first, ATCC1176 medium with 2% glucose was used for first stage of fermentation. After 36 hours, the equal volumes of media with 0.2% different carbon sources and without NaCl were fed, respectively, for second stage of fermentation. The concentrations of NaCl in media were decreasing 50% to induce the productions of carotenoids. The growth rate and the utilization efficiency of residual glucose was inhibited by the addition of 0.1% acetate, but were similar between glucose and butyrate. However, the butyrate boosted the production of carotenoids, and the enhanced production of carotenoids was lowest for glucose.
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