碩士 / 元智大學 / 化學工程與材料科學學系 / 100 / Development and promotion of biodiesel, a substitute fuel for fossil energy, has resulted in an environmental issue of overproducing crude glycerol. The microalgae can be applied for producing polyunsaturated fatty acid, such as EPA and DHA, from glycerol.
Schizochytrium limacinum SR21 is one of the indigenous marine heterotrophic microalgae and it can utilize glycerol to produce DHA. From the results of shake flask study, we found that maximum specific growth rates was 0.71 day-1 and biomass reached 7.8 g L-1 by feeding 30 g L-1 crude glycerol in medium 2. However, 50 g L-1 crude glycerol had optimal DHA content and its productivity was 157.81 mg-1. The effects of temperature and light supply depicted a significant impact on synthesis of fatty acids. When cell was cultured at 25 ℃ and in mixotrophy, the cell growth was suitable and the biomass reached 9.03 g L-1. Besides, culturing the cell at 20℃ and 30℃ promoted DHA accumulation by mixo/heterotrophic, the productivity of DHA were 233.73 mg g-1 and 222.87 mg g-1, respectively. When culturing at 20 ℃, the cell can accumulate DHA about 189.80 ~ 200.16 mg g-1.
The DO was controlled at 50% and under pH non-control showed a better result of cell growth and DHA accumulation than pH control. When cell was cultured at 30℃, the biomass reached 8.74 g L-1, total lipid had 82.77% and DHA content had 192.83 mg g-1. When cell was cultured at 25℃, the maximum biomass reached 10.16 g L-1 and the biomass yield had 0.43g g-1 in 120 hr. However, culturing the cell in 132 hr can get the best DHA accumulation about 208.20 mg g-1.
| Identifer | oai:union.ndltd.org:TW/100YZU05063112 |
| Creators | Yun-Tsun Lung, 龍韻存 |
| Contributors | 藍祺偉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 87 |
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