| Summary: | 碩士 === 東海大學 === 化學工程與材料工程學系 === 99 === Rhodotorula glutinis (BCRC 22360) is an oleaginous yeast that can accumulate copious quantities of lipids. R. glutinis grew fast to obtain high biomass concentration, and comparable with plant seed oil, therefore it is all potential alternative oil resources for biodiesel production. This investigation used different fermentation strategies to enhance the growth of R. glutinis and accumulation of oil, thereby increasing overall oil productivity.
In the flask batch experiment with glucose as the carbon source that is easier on the cell growth and fat accumulation. Under conditions of high dissolved oxygen (low medium volume or high shaking speed), irradiation and 24~30℃, will contribute to cell growth. On the contrary, under conditions of low dissolved oxygen (high medium volume, low shaking speed), no irradiation (dark), higher carbon concentration, lower nitrogen concentration and 24℃, will contribute to fat accumulation.
From the batch (change initial glucose concentration, dissolved oxygen control, two-stage dissolved oxygen control and light intensity control) and fed-batch (change glucose concentration, two-stage dissolved oxygen control and three LED light source irradiation, the strategy are two-stage dissolved oxygen control with one feeding and three LED light source irradiation with continuous feeding, can obtain better results. In the microbial oil productivity and the commercial point of view, the three LED light source irradiation with continuous feeding strategy will more beneficial to follow-up research and development. Results of the three LED light source irradiation with continuous feeding strategy could lead to the highest cell growth rate of 0.88 g/l/hr and the good average lipid content of 54.5％, then got better oil productivity of 0.39 g/l/hr.
In addition, the main composition of the microbial lipid from R. glutinis were oleic acid (C18:1) of 50~60％ and palmitic acid (C16:0) of 20~30％, which was similar with that of vegetable oil.
Keywords: R. glutinis、microbial oil、impact factor、fermentation strategy
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