Effect of copper ions on mould morphology and citric acid productivity by Aspergillus niger using molasses based media
Effect of copper ions on mould morphology and citric acid productivity by Aspergillus niger using molasses based media
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DOI：
10.1016/s0032-9592(01)00322-3
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发表时间：
2002-05-01
影响因子：
4.4
通讯作者：
Iqbal, J
中科院分区：
文献类型：
--
作者：
Haq, IU;Ali, S;Iqbal, J
以甘蔗糖蜜碳水化合物150 g/l为基础发酵培养基，研究了铜离子对黑曲霉GCB-47及其突变衍生物GCMC-7霉菌形态和柠檬酸产量的影响。该突变体的柠檬酸产量比对照增加1.26倍，比野生型增加2.82倍。在发酵培养基中添加2.0 × 10(-5) M CuSO4，通过抵消其对真菌生长的有害影响，降低了Fe2+离子浓度。铜离子还诱导了松散颗粒状的生长（0.5 mm，直径），降低了生物量浓度（12.5 g/l），提高了一水柠檬酸的体积生产力（92.0 +/- g/l）。通过对体积底物摄取速率（Qs）和比摄取速率（Qs）、体积生产力、理论产量和比产物形成速率等动力学参数的比较，发现该突变体是生长较快的生物（Yx/s = 0.938 +/- 0.03 g/g），并具有过量生产柠檬酸的能力（Yp/s = 0.938 +/- 0.03 g/g）。(C) 2002 Elsevier Science Ltd.版权所有。
The present study deals with the effect of copper ions on mould morphology and citric acid productivity by Aspergillus niger GCB-47 and its mutant derivative GCMC-7, using 150 g/l carbohydrates of cane-molasses as the basal fermentation media. The mutant showed a 1.26-fold increase in citric acid production over the control and 2.82 times the wild-type culture. The addition of 2.0 x 10(-5) M CuSO4 to the fermentation medium reduced the Fe2+ ions concentration by counteracting its deleterious effect on fungal growth. The copper ions also induced a loose-pelleted form of growth (0.5 mm, diameter), reduced the biomass concentration (12.5 g/l) and increased the volumetric productivity of citric acid monohydrate (92.0 +/- g/l). On the basis of comparison of kinetic parameters, namely the volumetric substrate uptake rate (Qs) and specific uptake rate (qs), the volumetric productivity, theoretical yield and specific product formation rate, it was observed that the mutant was faster growing organism (Yx/s = 0.938 +/- 0.03 g/g) and had the ability to overproduce citric acid (Yp/s = 0.938 +/- 0.03 g/g). (C) 2002 Elsevier Science Ltd. All rights reserved.