黑曲霉产柠檬酸菌种最优发酵条件探究

结合发酵工程实验教学改革，将实验室收集保存的产柠檬酸菌株11株，进行初筛、复筛后，选取产酸量相对较高的2112菌株进行了正交实验、稳定性实验。得到的较好发酵条件为：玉米淀粉16％，（NH4）2SO40．1％，麸皮0．6％，pH4．0。发酵温度35℃，发酵时间96h。经5次稳定性实验，该菌株产酸率最高达9．92％，已能满足实验教学的需要，为开展柠檬酸发酵系列实验提供了保证。

Research on the Optimization of Fermentation Conditions of Aspergillus Niger Citric-acid-producing Strains

Based on the teaching needs of fermentation engineering experiments, 11 citric-acid-producing strains are collected and preserved. After primary and secondary screenings, a highly citric-acid-producing strain 2 112 is selected and conducted with orthogonal experiments and stability experiments. The findings show that the best fermentation condition is： corn starch（ 16）, （NH4 ）2SO4 （0. 1 ）, bran（0. 6）, pH（4. 0）, temperature： 35℃ and time： 96k. According to the results of the five stable experiments, the eitrie-aeid-predueing rate of the strain reached 9 - 92, which completely meets the need of the instructions and ensures the progress of the serial citric-acid fermentation experiments.