title: Effect of valinomycin on ion transport in bacterial cells and on bacterial growth.
abstract: The antimicrobial action of valinomycin relative to the K+ and Na+ contents of the medium has been investigated in several species of bacteria, particularly in Streptococcus faecalis, which effects energy-linked transport exclusively via degradation of glycolytic ATP, Micrococcus lysodeikticus, effecting active ion transport by respiration and Staphylococcus aureus, the energy-dependent ion transport of which is due to both glycolytic ATP degradation and respiration. It was demonstrated that valinomycin does not act on K+ transport in the glycolysing cells in the same manner as it does on respiring cells under similar conditions. Addition of valinomycin to respiring cells leads to an increase in K+ influx against the concentrational gradient in both growing and resting cells. In contrast to this, antibiotic-treated glycolysing cells experience passive K+ outflow down the concentrational gradient. It was thus concluded that the electrical potential cannot be the driving force for the energy-linked K+ transport in glycolysing cells.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001693:Biological Transport, Active / Q000187:drug effects; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000378:metabolism; D006019:Glycolysis; D008837:Micrococcus / Q000187:drug effects* / Q000378:metabolism; D010085:Oxidative Phosphorylation; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013210:Staphylococcus / Q000187:drug effects* / Q000378:metabolism; D014634:Valinomycin / Q000494:pharmacology*
chemical_list: D014634:Valinomycin; D000255:Adenosine Triphosphate; D012964:Sodium; D011188:Potassium