BIOCHEMICAL CHANGES DURING THE DEVELOPMENT OF RESPIRATORY ACTIVITY IN ESCHERICHIA COLI

[摘要] The rate of oxidation of several substrates by cell-free extracts increased during the aeration of anaerobically grown Escherichia coli. Succinate oxidation by extracts from aerated cells was not suppressed by the addition of extracts from anaerobic cells. Dialysis of extracts from aerated or aerobiccells resulted in marked decrease of the oxidative activity, but the activity was restored to the original level by the addition of boiled extracts from anaerobic cells. The oxidative activity of dialyzed extracts from anaerobic cells showed little improvement by the addition of boiled extracts from aerated or aerobic cells. Uptake of fumarate by aerated cells occurred even when the oxidation of the substrate was completely inhibited by cyclohexanol, provided that glucose was present in the reaction mixture. No such uptake occurred in anaerobic cells or in aerobic cells grown in glucose-containing media.From these results, it was inferred that the development of respiration by aeration of anaerobic cells was caused by the increase of permeability to substrates and by the formation of high molecular substances (possibly enzyme proteins), but not by the increase of coenzyme content or by the disappearance of respiratory inhibitors.

[学科分类] 微生物学和免疫学