Influence of urea on butanol production from sugarcane juice by Clostridium beijerinckii TISTR 1461

5.43 g l-1). The result suggested that some nutrients in P2 medium might be necessary for butanol production. Due to the high cost of yeast extract, urea was used as the nitrogen source in subsequent experiments. The juice supplemented with P2 medium (excepted glucose and yeast extract) and varied urea concentrations ranged from 0.27-1.35 g l-1 were used as butanol production media. The results showed that the butanol and ABE concentrations were increased with increasing the urea concentration from 0.27-0.81 g l-1. The highest butanol (9.41 g l-1) and ABE (11.78 g l-1) concentrations were observed at 0.81 g l-1 of urea concentrations and showed 0.30 of butanol yield and 0.20 g l-1 h-1 of productivity. The results concluded that urea promotes butanol production efficiency and suitable for instead of yeast extract.

此前丁醇产量达5.43 g·L⁻¹。实验结果表明，P2培养基（P2 medium）中的部分营养物质为丁醇发酵所必需。鉴于酵母提取物（yeast extract）成本高昂，后续实验中以尿素作为氮源。本研究采用添加了P2培养基（不含葡萄糖与酵母提取物）且尿素浓度在0.27~1.35 g·L⁻¹范围内梯度变化的果汁作为丁醇发酵培养基。结果显示，当尿素浓度从0.27 g·L⁻¹提升至0.81 g·L⁻¹时，丁醇与ABE（丙酮-丁醇-乙醇）的浓度均随尿素浓度升高而上升。在尿素浓度为0.81 g·L⁻¹时，丁醇与ABE的浓度达到峰值，分别为9.41 g·L⁻¹和11.78 g·L⁻¹，对应丁醇产率为0.30，生产强度为0.20 g·L⁻¹·h⁻¹。综上，尿素可提升丁醇发酵效率，适合替代酵母提取物。