碩士 / 國立中興大學 / 生命科學系所 / 98 / Spirulina platensis, a blue-green alga, is a rich source of γ-linolenic acid (GLA, 18:3n-6) which has been demonstrated to exhibit many beneficial health effects. GLA from glycerides, especially triglycerides (TG), is absorbed more easily than that from free fatty acids (FFA) or ethyl esters. In the first part of this study, we investigated the effects of light sources and the carbon and nitrogen supply on the growth and GLA content in S. platensis. The algae were cultivated in Zarrouk medium either with or without carbon and nitrogen limitation. The initial GLA concentration in S. platensis was approximately 30% of the total fatty acids. The results showed that light sources (fluorescent bulb vs. plant growing light tube) had no effect on biomass production. In addition, no significant difference was found in GLA content among algae cultivated under carbon (NaHCO3) and/or nitrogen (NaNO3)-limited conditions. In the second part of the study, attempts were made to synthesize GLA-enriched triglycerides by Candida antarctica lipase (Novozym 435)-catalyzed esterification. The GLA concentrate was obtained by saponification of S. platensis lipid and urea fractionation. The content of GLA increased from 33% (after saponification) to 55% (after urea fractionation) of the total fatty acids. Synthesis of GLA-enriched triglycerides was evaluated in lipase Novozym 435-catalyzed esterification of GLA concentrate and glycerol in hexane. The TG yield reached 26% after 24, 48, and 72 h of reaction and the resulting TG contained 26% GLA.
Identifer | oai:union.ndltd.org:TW/098NCHU5105019 |
Creators | Hsin-Hui Wang, 王星惠 |
Contributors | Yung-Sheng Huang, 黃永勝 |
Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
Language | zh-TW |
Detected Language | English |
Type | 學位論文 ; thesis |
Format | 98 |
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