微藻生長快速且能經由光合作用固定大氣中的二氧化碳，將二氧化碳轉化生成生物質，故培養微藻來吸收太陽能並進行二氧化碳的固定，同時作為生產生質能源的生產者，是相當具有發展潛力。因此，本研究為獲得高微藻生物質量與油脂量產率，設計新型光生化反應器以提供小球藻更佳的培養光環境，並探討最佳培養條件以及培養方式，再以透過培養策略操作的最佳化，建立量產小球藻的培養系統與方法。
本研究中設計三款透明矩型槽放置於開放式微藻培養池中(TRC1，TRC2，TRC3)，可有效增加微藻培養系統的光照面積，並將外部光源重新分散光強度再導入微藻培養系統中等特性，改變培養系統內的光分佈情況。所設計的光生化反應器TRC3中，可提供最高的照光面積對體積比值與最佳的光環境條件。實驗結果顯示，在13天批次培養下，TRC3可獲得最高的微藻細胞濃度與微藻產率，分別為3.745 g L-1與0.340 g L-1 d-1，並且TRC3中的微藻光合作用效率高於開放式培養池的光合作用效率56%。因此，所設計的透明矩型槽，為一簡單的裝置，可有效的方式增加微藻培養系統的光使用效率，並提高微藻的產能。
在最佳培養條件探討方面，於光照強度為600 μ mol photon m-2 s-1、培養溫度為30℃、鹽度為33.3 g L-1、二氧化碳濃度為2.0%(v/v)以及初始尿素濃度為0.100 g L-1培養條件下，小球藻可生產最高的油脂量為0.713 g L-1。此外，對於小球藻培養策略方面，實驗結果顯示，利用重覆批次培養方式，並以25%置換比例（補充0.025 g L-1尿素）培養小球藻，可獲得高油脂產率為0.139 g d-1 L-1，與批次培養方式相比其油脂產率增加26.4%。這實驗結果證實重覆批次培養策略，可有效地增加小球藻油脂產量。
為有效提高小球藻生物質量產率與油脂產率，研究中建立邏輯生長模型與Luedeking-Piret油脂生成模型，以精確描述小球藻的生長與油脂生成量。再經由最佳化程序，求得獲得最高生物質量之重覆批次培養操作條件：前批次培養時間為1.5天，置換比例31%與置換培養時間0.5天，預測可達到最高藻體產率為0.499 g L-1 d-1。經由實驗培養結果，可獲得的生物質量產率為0.481 g L-1 d-1，與預測結果相對誤差為4.0%。然而，求得獲得最高油脂量之重覆批次培養操作條件：前批次培養時間為2天，置換比例27%與置換培養時間0.5天下，預測可達到最高油脂生成量產率為0.144 g L-1 d-1。從實驗結果可知，本研究中透過光生化反應器的設計，培養條件與培養策略操作的最佳化，能有效提高製程上小球藻生長速率與油脂產能，並提升培養微藻生產生質油脂的經濟效益。

The bio-fuel production from photosynthetic microorganisms is considered as a process to produce renewable energy for global warming mitigation. For mass production of bio-fuel, the economic feasibility of microalgal culture greatly depends on the productivity of biomass and lipids. In this study, an open tank photobioreactor containing transparent rectangular chambers (TRCs) was developed to improve the photosynthetic efficiency of microalgal cultivation. The average irradiance, Iav, was calculated by Lambert-Beer’s law, and was used to determine the light conditions in the cultivation system. The photobioreactor provided large areas of illumination that improved the effective utilization of light energy for microalgae growth and created a good artificial environment for a high rate of cell growth, even at low Iav. The biomass concentration of Chlorella sp. reached 3.745 g L-1 on the 13th day, with biomass productivity of 0.340 g L-1d-1. The total biomass obtained was 56% more than that of similar culture systems without TRCs. Different cultivation modes can affect the growth rate and biochemical composition of microalgae. In fed-batch cultivation, the highest lipid content was obtained by feeding 0.025 g L-1 of urea during the stationary phase. However, a repeated batch culture was carried out by harvesting the culture and renewing urea at 0.025 g L-1 each time when the cultivation achieved the early stationary phase. The maximum lipid productivity of 0.139 g d-1 L-1 in the repeated batch culture was highest in comparison with those in the batch and fed-batch cultivations. For maximizing the biomass and lipid production, the operating conditions of the culture system are determined by using Logistic model and Luedeking-Piret equation - parametric equations describing the growth of microalgae and lipid production, respectively. The objective of the optimal operation for the repeated batch culture is to determine the highest biomass yield. The optimal operating conditions of the preliminary batch culture time, cycle time, and renewal rate are 1.5 days, 0.5 days and 31%, respectively. And the highest biomass productivity of Chlorella sp. was 0.481 g L-1 d-1. The predicted results are in good agreement with the experimental ones in the cultivation as demonstrated having a relative error of 4.0%. The optimal operating conditions of the preliminary batch culture time, cycle time, and renewal rate are 2.0 days, 0.5 days and 27%, respectively. And the highest lipid productivity of Chlorella sp. was 0.144 g L-1 d-1. Consequently, mass production of biomass and lipid from microalgae for bio-fuel production can be successfully accomplished by the photobioreactor design and using an optimal operation of repeated batch culture.

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