UTILIZATION OF A STABLE ISOTOPE OF OXYGEN BY PSEUDOMONAS FLUORESCENS.

Oxygen utilization is defined in this investigation as the terminal use of oxygen in respiration, i.e., the formation of water. A culture of Pseudomonas fluorescens was allowed to respire in an atmosphere of O(18). The production of H(2)O(18) was measured during two test runs of 124 and 232 min each. During the first run, 0.505 mmole of H(2)O(18) was produced. The second run produced 0.460 mmole of H(2)O(18). H(2)O(18) production took place throughout the course of each of the runs.