Lactobacillus plantarum為蔬菜、乳製品及肉製品等食品中常見之乳酸菌，可在人體及其它哺乳類腸道中存活及增殖，具改善腸道菌相、減少低密度膽固醇與調節免疫力等功效。本研究評估L. plantarum最適化培養條件與探討其儲藏條件，作為後續應用之參考依據。首先以生長曲線試驗評估菌株之生長情形；再以box-behnken design法設計最適化培養條件試驗，利用反應曲面法探討時間、溫度及培養基pH值等三個條件變數組合，為三變數三層階的中心旋轉之反應曲面設計，並以菌數、菌重、培養液pH值與乳酸產量變化為指標。最後評估乳酸菌與不同比例之豆奶、脫脂牛奶、海藻糖及麥芽糊精混合且經冷凍乾燥後其存活率之變化。結果顯示，L. plantarum菌數成長之對數期介於6至12小時間，並於24小時達最高之菌數9.23 ± 0.10 log CFU/mL與乳酸產量1.54%。反應曲面之結果顯示，乳酸菌之最適化培養條件為於pH值6.4培養基與33.2℃ 下培養33.6小時，其預測菌數可達10.17 log CFU/mL。在不同比例之豆奶、脫脂牛奶、海藻糖及麥芽糊精保護下，菌體於冷凍乾燥後之存活率皆可達96%以上，其中添加15%及30%之脫脂牛奶與30%之豆奶具有100%之存活率；而海藻糖僅需5%即具有99.35%之存活率。綜上所述，本研究找出最適化培養條件與合適之冷凍保護劑，以作為後續L. plantarum相關之研究與應用參考指標。

Lactobacillus plantarum is a species of lactic acid bacteria that exist in food. Usually present in vegetables, dairy, and meat products, they can survive and proliferate in the intestines of humans and other mammals and have the ability to improve intestine flora, reduce low-density cholesterol, and regulate the immune system. This study evaluated the optimal incubation and storage conditions of L. plantarum as reference for further research. First, a growth curve was used to evaluate the growth of L. plantarum. Subsequently, the Box-Behnken design was applied to optimize the growth condition. The response surface method was utilized to investigate the variable combinations of time, temperature, and pH of the medium. These three variables and three levels were central to the rotatable response surface design. The bacteria number, bacteria weight, pH value of the medium, and production of lactic acid were taken as the targets. Lastly, different ratios of soymilk, skim milk, trehalose, and maltodextrin mixed with lactic acid bacteria were freeze-dried to evaluate survival ability. The results showed the log phase of bacteria growth between 6 to 12 h and revealed the highest bacteria number (9.23 ± 0.10 log CFU/mL) and lactic acid production (1.54%) at 24 h. The response surface results showed the best incubation conditions were a medium with a pH value of 6.4, a temperature of 33.2°C, and an incubation time of 33.6 h. The subsequent bacteria number is predicted to reach 10.17 log CFU/mL. Under the protection of different ratios of soymilk, skim milk, trehalose, and maltodextrin, the survival ability of bacteria after freeze-drying was higher than 96%. The survival ability of the groups with 15% and 30% skim milk and the group with 30% soymilk could reach 100%. With only a 5% addition of trehalose, survival ability may reach 99.35%. As previously reported, this experiment investigated optimized growth conditions and appropriate freeze-dry protectants of L. plantarum and can be used as reference for future application and research.