CYTOCHROME AND CATALASE PATTERNS DURING GROWTH OF HAEMOPHILUS PARAINFLUENZAE

Abstract

By following the cytochrome and catalase concentrations during the growth cycle and under various growth conditions in Haemophilus parainfluenzae, a rapid increase in the cytochrome oxidases and a large increase in cytochrome c1 concentration can be demonstrated between log-phase and stationary-phase cells and between vigorously aerated and anaerobic growth conditions. The three cytochrome oxidases develop differentially under various growth conditions. The principal oxidase formed in vigorously aerated cultures is cytochrome o. With limited aeration, maximal development of cytochrome a2 occurs; with anaerobically grown cells, there is a marked increase in the concentration of cytochrome a1. With the rapid increase in cytochrome c1 concentration, soluble, nonenzymatically reducible cytochrome c1 is also formed which remains in the bacterial cell sap. From these data it is postulated that the electron-transport system is assembled from individual components which can be modified by the growth conditions. The cytochrome c1 may be synthesized in the cell sap and then incorporated into the electron-transport system.