Danner H, Madzingaidzo L, Thomasser C, Neureiter M, Braun R
Institute for Agrobiotechnology (IFA-Tulln), Konrad Lorenz Strasse 20, Austria.
Appl Microbiol Biotechnol. 2002 Jul;59(2-3):160-9. doi: 10.1007/s00253-002-0998-4. Epub 2002 May 1.
The thermophilic Bacillus strain BS119 was selected for this study to demonstrate the long term performance of lactic acid production and simultaneous pre-purification. Integrated continuous cell recycle cultivation using ultra-filtration membrane bioreactor (MBR) systems was investigated. The permeate from the MBR was routed to an on-line electrodialysis (ED) to recover, pre-purify and concentrate lactate. The cultivation and ED was operated at 60 degrees C for more than 1,000 h at a pH of 6.5. At lower dilution rate (0.02 h(-1)), lactate concentration reached a maximum of 55 g l(-1) with clearly lower residual glucose levels. At 0.04 h(-1), lactate concentration was significantly lower at 35 g l(-1). Maximal volumetric productivities of 1.38 g l(-1) h(-1) were achieved. Under stable conditions, lactic acid yield on consumed glucose appeared stable at around 80%. It could be demonstrated that the addition of supplements like yeast extract and peptone severely influences product formation. Integration of mono-polar ED with the MBR systems yields lactate solutions with concentrations of up to 115 g l(-1). Because of the low substrate feed concentrations (less than 50 g l(-1)), lactate flux was rather poor, reaching a low maximum of 140 g m(-2) h(-1); nevertheless, stack energy consumption was positive with an average of 0.49 kWh kg(-1) lactate.
本研究选用嗜热芽孢杆菌菌株BS119来展示乳酸生产及同步预纯化的长期性能。对使用超滤膜生物反应器（MBR）系统的集成连续细胞循环培养进行了研究。MBR的渗透液被输送至在线电渗析（ED），以回收、预纯化并浓缩乳酸。培养和ED在60℃、pH为6.5的条件下运行了超过1000小时。在较低稀释率（0.02 h⁻¹）下，乳酸浓度最高达到55 g l⁻¹，残余葡萄糖水平明显更低。在0.04 h⁻¹时，乳酸浓度显著降低至35 g l⁻¹。实现了1.38 g l⁻¹ h⁻¹的最大体积产率。在稳定条件下，消耗葡萄糖的乳酸产率在80%左右保持稳定。可以证明，添加酵母提取物和蛋白胨等补充剂会严重影响产物形成。单极ED与MBR系统集成可得到浓度高达115 g l⁻¹的乳酸溶液。由于底物进料浓度较低（低于50 g l⁻¹），乳酸通量相当低，最高仅达到140 g m⁻² h⁻¹；不过，堆叠能耗为正值，平均为0.49 kWh kg⁻¹乳酸。
Zotero 插件