The Characterizations of Growth and Lipid Accumulation in Phormidium and Scenedesmus Isolated from Taiwan

• Main Authors: CHOU, SHENG-FENG, 周聖峰
• Other Authors: LEE, MONG-CHUAN
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/50174663040496078867

碩士 === 中臺科技大學 === 生物科技暨醫學工程研究所 === 105 === In recent years, biodiesel has gained huge popularity and used in industrial processes, due to the advantage of its ecofriendly property. Biodiesel was considered to have the potential to replace traditional fossil Energy. Biodiesel is a mixture of fatty acid methyl esters (FAME) which can be transferred from vegetable oil, animal fat sources, waste cooking oil and microalgae. The aims of this study was to (1) observe the microalgae growth changes at different concentrations of nitrogen source, (2) optimize a medium for the lipid production by adding carbon source and (3) examine microalgae cells by using Nile red staining and fluorescence microscopy. The microalgae strains used in this study designated as FGA326S (Secnedesmus), PBRL (Phormidium) and PBR (Synechocystis) were all isolated from central Taiwan. Strains were autotrophic cultured by BG-11 medium supplied with 0.05% and 0.1% of sodium nitrate, respectively. After 48 days of incubations, each cultured strain was firstly determined its growth characteristics along with the cell dry weight, respectively. Secondly, the lipids of algae were extracted by modified Bligh and Dyer’s method, and percentage contents of lipid were calculated after the dry cell mass determined. Thirdly, for heterotrophic study, the cultured strains were transferred in 100 ml BG-11 medium supplied with sodium acetate as the carbon source for 7 days. Finally, algae cells were studied by Nile red staining and fluorescence microscopic examination. Simultaneously, the lipid of algae cells were extracted by modified Bligh and Dyer’s method, and percentage contents of lipid were determined. In the study of different concentration of nitrogen supplies, for 0.05% sodium nitrate added, the dry weight of FGA326, PBRL and PBR were 0.51 g, 0.462 g, and 0.375 g, and lipid contents were 3.85%, 8.38% and 4.49%, respectively. For 0.1% sodium nitrate added, the dry weight of FGA326, PBRL and PBR were 0.426 g, 0.428 g, and 0.379 g, and lipid contents were 5.48%, 7.8%, and 4.48%, respectively. For heterotrophic study, the high level production of microalgae lipid in situ was observed at 7th day. At the same time, for 0.05% sodium nitrate supplied, the cell dry weight of FGA326, PBRL and PBR were 0.68 g, 0.418 g, and 0.48 g, the lipid contents were 10.04%, 14.9% and 17.92%, respectively. And for 0.1% sodium nitrate supplied, the cell dry weight were 0.724 g, 0.582 g, and 0.526 g, and the lipid contents were 11.46%, 11.25%, and 14.49%, respectively. In this study, all three microalgae strains showed increased level of lipid production after transferring the culture condition from autotrophic into heterotrophic. Significantly, under the 0.05% nitrate supplied and heterotrophic condition, the lipid contents of all strains reached the highest level.