OPTIMIZATION OF L-MALIC ACID PRODUCTION BY ASPERGILLUS-FLAVUS IN A STIRRED FERMENTER
OPTIMIZATION OF L-MALIC ACID PRODUCTION BY ASPERGILLUS-FLAVUS IN A STIRRED FERMENTER
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DOI：
10.1002/bit.260371117
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发表时间：
1991-05-01
影响因子：
3.8
通讯作者：
GOLDBERG, I
中科院分区：
文献类型：
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作者：
BATTAT, E;PELEG, Y;GOLDBERG, I
在16 L搅拌发酵罐中研究了营养和环境因素对丝状真菌黄曲霉积累有机酸（主要是L-苹果酸）的影响。 L-苹果酸的摩尔产率（每摩尔消耗的葡萄糖产生的摩尔酸）的提高主要通过增加搅拌速率（至350 rpm）和Fe（z+）离子浓度（至12 mg/L）以及通过降低培养基中的氮（至271 mg/L）和磷酸盐浓度（至1.5 mM）来获得。 这些变化导致L-苹果酸和总C4酸（L-苹果酸、琥珀酸和富马酸）的摩尔产率分别为128%和155%。 获得的高摩尔产率（高于100%）是三羧酸循环的还原分支的一部分在A积累L-苹果酸中起作用的额外证据。黄的 使用上述因素和培养基中9%CaCO3开发的发酵条件导致高浓度（113 g/L L-苹果酸，来自利用的120 g/L葡萄糖）和高的L-苹果酸总生产率（0.59g/L·h）。 酸积累的这些变化与NAD+-苹果酸脱氢酶、脱氢酶和柠檬酸合酶的活性增加一致。
Effects of various nutritional and environmental factors on the accumulation of organic acids (mainly L-malic acid) by the filamentous fungus Aspergillus flavus were studied in a 16-L stirred fermentor. Improvement of the molar yield (moles acid produced per moles glucose consumed) of L-malic acid was obtained mainly by increasing the agitation rate (to 350 rpm) and the Fe(z+) ion concentration (to 12 mg/L) and by lowering the nitrogen (to 271 mg/L) and phosphate concentrations (to 1.5 mM) in the medium. These changes resulted in molar yields for L-malic acid and total C4 acids (L-malic, succinic, and fumaric acids) of 128 and 155%, respectively. The high molar yields obtained (above 100%) are additional evidence for the operation of part of the reductive branch of the tricarboxylic acid cycle in L-malic acid accumulation by A. flavus. The fermentation conditions developed using the above mentioned factors and 9% CaCO3 in the medium resulted in a high concentration (113 g/L L-malic acid from 120 g/L glucose utilized) and a high overall productivity (0.59 g/L h) of L-malic acid. These changes in acid accumulation coincide with increases in the activities of NAD+-malate dehydrogenase, fumarase, and citrate synthase.