Increased rate of cyclic photophophorylation in preparations from Anabaena variabilis cells grown in the presence of diphenylamine

Cell free homogenates and membrane fractions prepared from Anabaena variabilis cells grown in the presence of diphenylamine have markedly higher activities for cyclic phosphorylation than similar preparations from normal cells. The preparations from diphenylamine-grown cells are also more active in system I mediated electron transport from reduced dichloroindophenol to oxygen or methyl viologen. The light intensity required to saturate phenazine methosulphate-supported cyclic phosphorylation, in such preparations, is higher than for preparations for normal cells.