In this study, the co‐metabolism of glycerol and octanoate by Pseudomonas putida KT2440 significantly increased the production of medium‐chain‐length polyhydroxyalkanoate (mcl‐PHA). This was achieved through optimization of various parameters such as substrate concentration, nitrogen concentration, and other mixing conditions related to dissolved oxygen level. Experiments were performed in shake flasks and 5 L fermenter with findings assessed through single factor analysis and response surface methodology. The optimal concentration of substrates to improve mcl‐PHA production were determined to be 40 g glycerol/L, 12.23 g octanoate/L, and 1 g (NH₄)₂SO₄/L. Indirect regulation of dissolved oxygen was achieved by controlling the mixing conditions such as the initial medium volume (50 mL) (shake flask experiment), agitation speed (500 rpm), and aeration rate (10 L/minutes) (fermenter experiment). Optimized process parameters resulted in an mcl‐PHA titer of 8.47 g/L, which was significantly higher than that observed under un‐optimized conditions (3.95 g/L). The response surface method can be efficiently used to determine the optimal level of several factors related to mcl‐PHA production.

中文翻译：

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甘油和辛酸酯共代谢对恶臭假单胞菌KT2440中链长度多羟基链烷酸酯生产的优化

在这项研究中，恶臭假单胞菌KT2440与甘油和辛酸酯的共代谢显着提高了中链长度的聚羟基链烷酸酯（mcl-PHA）的产量。这是通过优化各种参数（例如底物浓度，氮浓度和其他与溶解氧水平有关的混合条件）来实现的。实验在摇瓶和5 L发酵罐中进行，通过单因素分析和响应面方法评估发现。确定提高mcl-PHA产量的最佳底物浓度为40 g甘油/L、12.23 g辛酸酯/ L和1 g（NH ₄）₂ SO ₄/升 通过控制混合条件，例如初始培养基体积（50 mL）（摇瓶实验），搅拌速度（500 rpm）和充气速率（10 L /分钟）（发酵罐实验），可以间接调节溶解氧。优化的工艺参数产生的mcl-PHA滴度为8.47 g / L，显着高于未优化条件下的观测值（3.95 g / L）。响应面法可以有效地用于确定与mcl-PHA生产相关的几个因素的最佳水平。