State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China.
Bioprocess Biosyst Eng. 2014 Jun;37(6):1127-32. doi: 10.1007/s00449-013-1104-2. Epub 2013 Dec 29.
Arachidonic acid (ARA)-rich oil production by Mortierella alpina is a high oxygen demand and shear-sensitive process. In the aerobic fermentation process, oxygen supply is usually a limiting factor owing to the low solubility of oxygen in the fermentation broth. Two kinds of perforated ring gas distributors and a novel microporous ceramic membrane gas distributor were designed and applied to improve oxygen supply. With the decrease of the orifice diameter of perforated ring gas distributors, dry cell weight (DCW), lipids concentration, and ARA content in total fatty acid increased from 17.86 g/L, 7.08 g/L, and 28.08 % to 25.67 g/L, 11.94 g/L, and 36.99 %, respectively. Furthermore, the effect of different dissolved oxygen (DO) on ARA-rich oil production with membrane gas distributor was also studied. The maximum DCW, lipid concentration, and ARA content using membrane gas distributor with DO controlled at 40 % reached 29.67 g/L, 16.74 g/L, and 49.53 %, respectively. The ARA titer increased from 1.99 to 8.29 g/L using the membrane gas distributor to substitute the perforated ring gas distributor. In the further experiment, a novel tubular titanium metal membrane gas distributor was successfully applied in a 7,000 L bioreactor and the results demonstrated that membrane gas distributor was industrially practical.
富含花生四烯酸（ARA）的枝顶孢霉菌的生产是一个高需氧和剪切敏感的过程。在好氧发酵过程中，由于氧在发酵液中的低溶解度，氧的供应通常是一个限制因素。设计并应用了两种穿孔环式气体分布器和一种新型微孔陶瓷膜气体分布器来改善供氧。随着穿孔环式气体分布器的孔径减小，干细胞重量（DCW）、脂类浓度和总脂肪酸中的 ARA 含量从 17.86 g/L、7.08 g/L 和 28.08%增加到 25.67 g/L、11.94 g/L 和 36.99%。此外，还研究了膜气体分布器中不同溶解氧（DO）对富含 ARA 油生产的影响。用 DO 控制在 40%的膜气体分布器获得的最大 DCW、脂类浓度和 ARA 含量分别达到 29.67 g/L、16.74 g/L 和 49.53%。用膜气体分布器代替穿孔环式气体分布器，ARA 浓度从 1.99 增加到 8.29 g/L。在进一步的实验中，新型管状钛金属膜气体分布器成功应用于 7000L 生物反应器中，结果表明膜气体分布器具有工业实用性。
