积累L-苹果酸的米根霉突变株酶活性初探

The Study of Enzymatic Activity of Mutant Strain Rhizopus oryzae with L-Malic Acid Accumulation

摘要:

对富马酸产生菌株—米根霉ME-F10进行诱变育种的过程中, 得到一株性能稳定的高效积累L-苹果酸的突变株ME-M15。该菌株发酵96 h平均L-苹果酸产量达16.3 g/L, 较出发菌株L-苹果酸积累量平均提高3倍, 而富马酸和乙醇的积累量大幅下降。对突变株代谢途径关键酶活研究表明, 突变株富马酸酶胞质途径同功酶和乙醇脱氢酶活力较之出发菌株酶活力明显减弱, 而丙酮酸羧化酶活力无明显差别。

Abstract:

A stable and efficient L-Malic acid accumulation mutant strain Rhizopus oryzae ME-M15 was discovered occasionally in the mutation breading for fumaric acid producers. Rhizopus oryzae ME-M15 gave a L-Malic acid output of 16.3 g/L on average after fermentation for 96 hours, more than 3 times than that of the parent strain ME-F10. In addition, other metabolites such as ethanol and fumaric acid were remarkably decreased in accordance with the depressed activity of the cytosolic isoenzyme of fumarase and alcohol dehydrogenase in strain ME-M15, while the activity of the pyruvate carboxylase had no significant difference.