PH-METHOD RESEARCH ON PHOSPHORUS METABOLISM IN LIVING CELLS OF NITROBACTER WINOGRADSKYI BUCH

1. Oxidative phosphorylation can be measured exactly using the pH-technique after adding small amounts of air to cell suspensions of Nitrobacter winogradskyi, shaken under nitrogen atmosphere. 2. The increase in pH depends on the content of labile PO4 in the cell. Cells without accumulated labile PO4 have no measurable oxidative phosphorylation. 3. After adding K2HPO4 to suspensions of resting, non-oxidizing cells the pH increase is corresponding to the incorporation of the PO4-anion. The PO4 is chiefly incorporated in the fraction of labile PO4. 4. Resting, non-oxidizing cells which have accumulated quantities of labile PO4 at the beginning of the experiment, do not adsorb further PO4. 5. The fraction of labile PO4 mainly consists of polyphosphates. 6. The oxidation of NO2′ inhibits the oxidative phosphorylation with endogenous substrate. © 1968 Springer-Verlag.