Flagellum formation by ubiquinone- and menaquinone-deficient mutant strains of Escherichia coli K-12 was studied under both aerobic and anaerobic growth conditions. Ubiquinone was found to be obligatory for aerobic flagellum formation but could be replaced by menaquinone for anaerobic flagellum formation. A mutant devoid of both quinones was immotile aerobically as well as anaerobically. Hence, the respective electron transport system is obligatory for flagellum formation in Escherichia coli.
|