ROLE OF CARBOHYDRATES IN THE REGULATION OF ALKALINE PHOSPHATASE BIOSYNTHESIS IN WILD TYPE AND GAMMA-IRRADIATION RESISTANT MUTANTS OF ESCHERICHIA COLI

[摘要] The synthesis of alkaline phosphatase (APase) was found to be inducible in the wild type Escherichia coli P, and its γ-irradiation resistant mutants γ and 6γ, but constitutive in the 12γ strain. The specific activity of APase in γ, 6γ, and 12γ strains was two to five times greater than that of the P strain, even though the level of inorganic phosphate (Pi) to initiate the synthesis of this enzyme in the inducible strains was the same. Addition of different carbohydrates resulted in varying amounts of APase being synthesized by the inducible strains P, γ, and 6γ. This was not the case with the constitutive strain 12γ. In the absence of a carbohydrate, very little or no synthesis of APase was observed in the inducible strains but normal synthesis of this enzyme occurred in the constitutive strain. No differences were found in the catalytic properties of APase between the inducible and the constitutive strains of E. coli. These results suggest that carbohydrates, in addition to Pi, have an important role in the regulation of APase biosynthesis in inducible strains of E. coli.

[学科分类] 微生物学和免疫学