碩士 / 國立臺灣大學 / 漁業科學研究所 / 95 / 英文摘要
Lab cultures of Hincksia mitchelliae were studied for the effects of light intensity and nitrate concentration on their growth. Field-collected specimens were also cultured to compare the morphological changes during lab condition. It was observed that the long filaments of field specimen turned short and become aster-clusters. The length/width ratio of the cells changed from 3.6 to 3. In this study, twelve pigments were identified in the acetone extracts. Other than chl a, chl c1, and three chl a congeners, there were seven carotenoids among which fucoxanthin was the most abundant one. It was observed that the growth of H. mitchelliae were not affected by the different nitrate concentrations(0~2.4 mM) in the medium within 18 days, nor the relative pigment content to chlorophyll a.
However, it was found that the growth were significantly affected by the light illumination, stronger the light intensity higher the average weight gain. Both fucoxanthin and chlorophyll a declined under stronger light intensity, but the ratio of fucoxanthin to chlorophyll a raised at higher light intensity.
To avoid the cell concentration from the enhancement of high light intensity shaded the following growth and pigment composition response, we used the various degree of dilution to maintain the constant cell concentration during experiment period. We found the pigment declined with the increase of light intensity, same as pervious experiments without adjusting cell concentration. It is speculated that fucoxanthin in brown algae is playing as a photosynthesis accessory. Fucoxanthin also plays as a light protection agent, since the ratio of fucoxanthin to chlorophyll a is raised up under strong light intensity.
| Identifer | oai:union.ndltd.org:TW/095NTU05451008 |
| Date | January 2007 |
| Creators | Yu-Hui Chang, 張玉慧 |
| Contributors | 周宏農 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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