The results indicate that overexpression of ribR gene greatly restrains the expression of riboflavin synthesis. But the FMN does not acuumulate in the cell.

• ribR基因的表达使细胞内核黄素-5-磷酸酯水平提高,强烈的抑制了核黄素操纵子的表达,造成核黄素合成能力显著下降。