Enhancement of citric acid production by Aspergillus niger using n-dodecane as an oxygen-vector
Enhancement of citric acid production by Aspergillus niger using n-dodecane as an oxygen-vector
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DOI：
10.1016/s0032-9592(00)00142-4
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发表时间：
2000-07-01
影响因子：
4.4
通讯作者：
Wang, JL
中科院分区：
文献类型：
--
作者：
Wang, JL
由于柠檬酸生产过程中需要大量的氧气，而氧气在水中的溶解度相对较低，因此曝气是至关重要的。研究了正十二烷作为氧载体改进黑曲霉产柠檬酸的可能性。氧矢量的体积分数对体积氧传递系数k(L)a影响较大。在发酵培养基中添加终浓度为5%的氧载体，k(L)a值达到最大值（130 h(-1)），是对照实验的2倍。添加5% （v/v）的正十二烷能促进柠檬酸积累，降低残糖浓度，促进菌丝生长。添加正十二烷对黑曲霉细胞无不良影响。酶学测定结果表明，两种菌丝无细胞提取物的柠檬酸合成酶活性无显著差异。(C) 2000 Elsevier Science Ltd.版权所有。
Due to the significant oxygen requirement during citric acid production and the relatively low solubility of oxygen in water, aeration is critical. The potential use of n-dodecane as an oxygen-vector for improvement of citric acid production by Aspergillus niger was studied. The volumetric fraction of oxygen-vector has a great influence on the volumetric oxygen transfer coefficient k(L)a. With the addition of an oxygen-vector to the fermentation medium with a final concentration of 5%, the k(L)a value reached a maximum value (130 h(-1)), which is twice that of the control experiment. The addition of 5% (v/v) n-dodecane enhanced citric acid accumulation, reduced residual sugar concentration and stimulated mycelial growth. Adding n-dodecane had no adverse effects on the cells of A. niger. The results of enzyme assays indicated that no significant differences were observed between the activity of citrate synthase of two kinds of mycelial cell-free extracts. (C) 2000 Elsevier Science Ltd. All rights reserved.