REGULATION OF ENZYMES OF GLYOXYLATE PATHWAY IN ROOT-NODULE BACTERIA

[摘要] Activities of enzymes of glyoxylate bypass, isocitrate lyase (ICL) and malate synthase (MS), were assayed in strains of Rhizobium and Bradyrhizobium grown on different carbon sources. In Rhizobium, ICL activity was detected in presence of either acetate or glycerol. In contrast, the enzyme was absent in glycerol-grown cells of Bradyrhizobium. MS was found to be constitutive in nature. Succinate allowed highest observed rate of growth and caused reduction of ICL activity when added to cells of Rhizobium sp. (Cicer arietinum) BICC 620 growing on acetate. Addition of cAMP substantially relieved succinate-mediated catabolite repression of ICL activity.

[学科分类] 微生物学和免疫学