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投稿时间：2018-11-09
投稿时间：2018-11-09
中文摘要: 采用γ射线（Co60）及亚硝基胍复合诱变的方法对产柠檬酸黑曲霉菌株进行诱变。γ射线（Co60）诱变剂量为1 400 Gy，亚硝基胍的浓度为1 mg/mL，作用时间为4 min，在此条件进行复合诱变。经多轮筛选最终获得到一株产酸为15.5 g/dL且遗传稳定性高的菌株。并对黑曲霉发酵产柠檬酸的工艺进行优化。确定种子液的最适条件：氮源选取豆饼粉，糖浓度为10%；最适发酵条件：培养温度为35℃，初始pH值5～6，氮源选取豆饼粉且氮源用量为0.8%，在50 L发酵罐中进行中试试验，试验结果为周期63 h，产酸17.94 g/100 mL，转化率为99.7%，比出发菌株发酵周期缩短3 h，产酸提高10%，转化率提高5%。
Abstract:The Aspergillus niger strain was mutagenesis by radium flavum （Co60）and nitroguanidine.The compound mutation conditions were radiation（Co60）mutagenesis 1 400 Gy and nitroguanidine 1mg/mL，and the appropriate action time 4 min.Finally，a strain with 15.5 g/dL acid production and high genetic stability was obtained.The fermentation process of Aspergillus niger was optimized.The optimum conditions of seed solution were determined：soybean cake flour was selected as the nitrogen source，and the concentration of sugar was 10%；The optimal fermentation conditions：temperature of 35℃，the initial pH 5-6，Soybean cake powder was selected as the nitrogen source and its content was 0.8%.Pilot test was carried out in 50 L fermentation tank.The results showed that the period was 63 h，the acid production was 17.94 g/100 mL，and the conversion rate was 99.7%.The fermentation period of the original strain was shortened by 3 hours，the acid production was increased by 10%，and the conversion rate was increased by 5%.
文章编号：201917034 中图分类号： 文献标志码：
基金项目:山东省重点研发计划（领军人才培育项目）（2016GRC3201）
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