BIOCHEMICAL CHANGES DURING THE DEVELOPMENT OF RESPIRATORY ACTIVITY IN ESCHERICHIA COLI

Abstract

The development in respiratory activity for several substrates during the aeration of anaerobically grown Escherichia coli was inhibited by fluoroacetate (FAA), but the inhibition was lessened if formate was further added to the aeration medium. During an aeration with FAA and formate, an enormous increase in the activity of aconitase was observed; under the anaerobic incubation aconitase activity did not show significant increase.The addition of FAA after a certain period of aeration induced a rapid increase in aconitase activity. Aeration before the addition of FAA made subsequent increase of the enzyme activity under anaerobic condition possible. The increase of aconitase activity- during the aeration of anaerobic cells with FAA was repressed by chloramphenicol or by the starvation of cells for amino acids. In pre-aerated cells, however, subsequent increase of enzyme activity by the addition of FAA was not inhibited by chloramphenicol or puromycin, and also not repressed by the starvation of cells for amino acids. During aeration, citrate accumulation in the cell suspension was caused not only by FAA but also by picolinate. However, the latter did not induce the development of aconitase activity.From these results the role of FAA and formate on the increase of aconitase activity in anaerobically grown cells is discussed.