探討微藻Chlorella sp.油脂生產較適培養條件

Optimal culture conditions of oil production by microalgae Chlorella sp.

葉修鋒(Hsiu-Feng Ye)

指導教授 ： 黃世傑

國立清華大學/工學院/化學工程學系/碩士(2009年)

摘要

由於人類活動及工業化發展消耗大量石化燃料，造成環境中溫室氣體累積以及原油供應量下降等問題，其中二氧化碳為造成全球暖化現象的主要溫室氣體。因此，開發一可再生、碳中和並能夠降低大氣中二氧化碳濃度的替代能源是必要的。
微藻為光合自營生物，可有效地利用二氧化碳作為碳源，透過光合作用將其轉化成脂質。目前已知有許多種類微藻，在不利的環境條件下可生產大量三酸甘油脂及脂肪酸儲存於細胞內。由此可見，微藻不僅可行固碳作用，亦可生產大量油脂作為生質柴油的原料來源。
小球藻 (Chlorella sp.)為油質性微藻，文獻指出其平均油脂含量為20-50 % dry cell weight，故Chlorella sp.可作為生質柴油良好的原料來源。為了獲得較高油脂產率，將針對環境條件及營養因子對Chlorella sp.細胞生長及油質生成的影響進行探討。本研究以杯瓶試驗探討Chlorella sp.較適培養條件，以獲得較高細胞及油脂產量。由實驗結果可知，Chlorella sp.在較適培養條件下 (pH 8、鹽度：8.5 g/L、通氣量：2 L/min、L/D：12/12、溫度：30 ℃、光照強度：12000 lux、CO2：5 %及0.1 g/L urea)，經14天培養，可獲得最大細胞濃度2.85 g/L以及油脂產率48.2 mg/L．day。

關鍵字

Chlorella sp. ； 藻類油脂 ； 生質柴油

並列摘要

Due to human activities and industrialization development consumption massive fossil fuels, resulting in the environment questions and so on greenhouse gas accumulation as well as crude oil supply drop, in which carbon dioxide is the main greenhouse gas for causing the phenomenon of global warming. Therefore, it is necessary to development a substitute energy source for petroleum which is renewable, carbon neutral and be able to reduce atmospheric carbon dioxide concentration.
Microalgae are photosynthetic autotrophs, which can efficiently utilize carbon dioxide as carbon source and convert it to lipid through photosynthesis. Many species of microalgae have the ability to produce large number of triacylglycerols and fatty acids in the adverse environmental conditions. Thus it can be seen, microalgae are not only for carbon dioxide fixation, but also can produce a large number of oils as a source of raw materials for biodiesel.
Chlorella sp. is oleaginous microalgae, literatures indicate that the average oil content is 20-50 % dry cell weight, therefore Chlorella sp. is excellent raw material for biodiesel production. In order to obtain a higher oil yield, the effects of environment conditions and nutrient factors on Chlorella sp. growth and oil production was investigated. In this study, we will confirm the optimal culture conditions to obtain higher biomass and oil productivity. The results show that Chlorella sp. grown on optimal culture conditions (pH 8, salinity: 8.5 g/L, air flow rate: 2 L/min, L/D: 12/12, temperature: 30 ℃, light intensity: 12000 lux, CO2: 5 % and 0.1 g/L urea) after 14 days, it could obtain maximum biomass (2.85 g/L) and oil productivity (48.2 mg/L．day).

並列關鍵字

Chlorella sp. ； Algae oil ； Biodiesel

參考文獻

Aaronson, S. 1973. Effect of incubation temperature on the macromolecular and lipid content of the phytoflagellate Ochromonas danica. J. Phycol. 9: 111-113.

Ackman, R.G., Tocher, C.S. and McLachlan, J. 1968. Marine phytoplankter fatty acids. J. Fish. Res. Board Can. 25: 1603-1620.

Ahmed, A.M., Hamada, A.M. and Desouky, S.A. 1995. Effect of exogenously added vitamins on photosynthesis and some related activities of salinized Chlorella vulgaris. In: Photosynthesis: From Light to Biosphere (Mathis, P., ed.). Vl. IV, Kluwer Acad. Pub. France: 749-752.

Aizawa, K. and Miyachi, S. 1986. Carbonic anhydrase and the CO2 concentrating mechanisms in microalgae and cyanobacteria. FEMS Microbiol. Rev. 39: 215-233.

Akkerman, I., Janssen, M., Rocha, J. and Wijffels, R.H. 2002. Photobiological hydrogen production: photochemical efficiency and bioreactor design. Int. J. Hydrogen Energy 27: 1195-1208.