乳酸在食品、醫藥和化妝品等工業中皆有廣泛應用，同時也是聚乳酸此一生物可降解塑膠的重要單體。本研究目的在於建立以番薯作為原料的D-乳酸和L-乳酸同步醣化醱酵程序的數學模式並找出最適合的操作模式以及操作條件。建模過程使用基因演算法做參數估計，並以適合度檢定(goodness-of-fit test)驗證模式誤差。操作模式最適化則使用非支配排序基因演算法，搜尋所有可能的相對最優解，並進一步引入模糊多目標規劃，協助決策者明確搜尋出一組最優解。實驗結果得到僅需十項參數便可準確預測的數學模式，而該數學模式經過模糊多目標規劃後所得的最佳操作模式亦較原批式操作程序更佳。

Lactic acid has wildly applications in food, pharmaceutical, and cosmetic industries, and it is also the monomer of polylactic acid which is biodegradable plastic. Developing a mathematical model of D- and L-lactic acid production from sweet potato via simultaneous saccharification and fermentation is the main purpose of this study. The other subject of this study is optimization of bioreactor operation. The parameter estimation of modeling procedure is developed by genetic algorithm, and we verify the model by goodness of fit test. The optimization of operating mode will be searched by non-dominated sorting genetic algorithm, and it will generate all possible solutions which are also known as Pareto set. To assist the decision makers choosing a best solution from Pareto set, we introduce the fuzzy multi-objective programming. After all the experiments we get a predictive model with only ten parameters, and formulate an operating mode of bioreactor by the fuzzy multi-objective programming. This modified mode is better than original batch system.

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