Membrane associated, energy linked reactions in Bdellovibrio bacteriovorus

Abstract

Disrupted cells of B. bacteriovorus exhibited adenosine triphosphatase activity, 60 to 80% of which was in the soluble fraction. Dicyclohexylcarbodiimide did not inhibit the adenosine triphosphatase activity in membrane particles. The particles did not show energy linked transhydrogenase activity. The activity of non energy linked transhydrogenase as well as the rate of oxygen consumption were higher in membrane particles of the host independent strain than in the host dependent strains. The uptake of amino acids and phosphate by whole cells of Bdellovibrio was found to be an energy dependent process. Amino acid uptake was inhibited by cyanide and by carbonyl cyanide p trifluoromethoxyphenyl hydrazone. Valinomycin, in the presence of K+, did not inhibit the uptake, and only partial inhibition was exerted by arsenate and dicyclohexylcarbodiimide. Sulfhydryl reagents inhibited amino acid uptake.