碩士 / 國立中興大學 / 生物產業機電工程學系所 / 104 / The purpose of this study is to investigate the effect of light factors on biomass composition in Isochrysis galbana. First, the first light source experiment applied stationary light intensity (57.0944 lm) of red, blue and mixed white LEDs to analyze the effect of light quality on the cell density, optical density, chlorophyll fluorescence, lipid content and six fatty acids of Isochrysis galbana. The light wavelengths of red and blue LED are 620~625 and 460~462.5 nm respectively. Wavelength of mixed white light is combined with red LED (620~625nm), blue LED (460~462.5nm) and green LED (522.5~525nm). As a result, the experiment showed the red LED group had the best performance of microalgae reproduction. Blue LED group had the highest chlorophyll fluorescence quenching. On the other hand, there is no significant difference between the three different conditions on the content of lipid and six kinds of fatty acids. Next, the second light source experiment set identical red LED on three light intensity levels in order to investigate the effect of changing the light intensity on biomass composition of Isochrysis galbana. The three levels are 57.0944, 96.1502 and 131.2003 lm respectively. Blue LED which is 57.0944 lm was set to be the compared group in the experiment. The cell density, optical density, chlorophyll fluorescence, carotenoid content, chlorophyll content, lipid content and the concentration of nitrogen source were measured and analyzed. The results from the experiment were compared with each other. Obviously, the consequence of the second experiment proved that the difference of cell density between the four conditions wasn’t significant when the cell density was lower. The self-shading effect increased severely along with the increase of cell density. The red LED 131.2033 lm group had highest cell density (1389.67±97.66×104 cells/mL) because transmittance of optical performed well. The trend of chlorophyll fluorescence was similar to the first tests, and blue LED group had the highest chlorophyll fluorescence quenching. Moreover, the high carotenoid content (1.24±0.01 mg/L) and chlorophyll content (2.50±0.08 mg/L) of Isochrysis galbana were obtained under blue LED group. Similarly, the result showed the conclusion that blue light enhanced pigment accumulation. The red LED 96.1502 and 131.2003 lm groups had higher carotenoid to chlorophyll concentration ratio than that of red LED 57.0944 lm and LED blue groups. Therefore, it revealed the phenomenon that the higher light intensity microalgae was cultivated, the more photo-protective carotenoid content of Isochrysis galbana was generated. Finally, according to the results of the first and second light source experiment, the light change experiment set four experimental conditions. After being cultivated under the red light (57.0944 lm) for four days, the three of experiment conditions were changed into blue light cultivation (25.9855, 41.5386 and 57.0944 lm respectively). The other one was constantly cultivated in red LED 57.0944 lm within the experimental period for the purpose of revolving the impact of two-stage cultivation conditions on the cell density, optical density, chlorophyll fluorescence, carotenoid content, chlorophyll content, and the concentration of nitrogen source. The results demonstrated that the goal of improving the pigment content of Isochrysis galbana could be achieved by turning microalgae original light quality environment into other light quality. Between the four different conditions, the blue LED 25.9825 lm group yielded the most carotenoid and chlorophyll content (1.02±0.06 and 2.30±0.05 mg/L).
| Identifer | oai:union.ndltd.org:TW/104NCHU5415022 |
| Date | January 2016 |
| Creators | Mei-Jia Huang, 黃美嘉 |
| Contributors | 尤瓊琦 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 89 |
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