摘要
黑曲霉（Ａｓｐｅｒｇｉｌｕｓ．ｎｉｇｅｒ）柠檬酸发酵培养基中添加０．０８～０．１５ｍｇ／Ｌ的ＭｇＣｌ２，对菌体浓度没显著性影响，但可使柠檬酸产率提高４％～７％，发酵旺盛期（３０ｈ）断氧３０ｍｉｎ的实验结果与正常发酵结果对照表明：添加０．１ｍｇ／ＬＭｇＣｌ２的摇瓶产酸率下降１６．２％；空白对照摇瓶产酸率则下降５６．８％，通过对柠檬酸合成酶［ＥＣ４．１．３．７］酶活测定及活体染色计数，我们认为，断氧条件下，０．１ｍｇ／ＬＭｇＣｌ２使黑曲霉存活率升高是造成上述差异的主要原因。
0.08-0.15 mg/L MgCl_2 in culture medium could increase the yield of citric acid by Asp. niger up to 4%-7%, but there was not remarkably effect on mycelium concentration. The experiments broken oxygen 30 minutes were done in fermentation peak period (30 h), The results in contrast to unbroken oxygen experiments indicated that the yield of citric acid in 0.1 mg/L MgCl_2 shaking flasks decreased by 16.2%; but in the same condition the yield of citric acid in blank shaking flasks was decreased by 56.8%. Through the determination of activity of citratesynthase [EC 4.1.3.7] and vivimycelium dyeing count, We thought it was important that 0.1 mg/L MgCl_2increased the vitality ratio of Asp. niger in broken oxygen.
关键词
黑曲霉
柠檬酸发酵
氯化镁
发酵法
生产
magnesium chloride (MgCl_2)\ Asp. niger\ citric acid fermentation\ broken oxygen
