THE TEMPERATURE-PRESSURE-INHIBITOR RELATIONS OF BACTERIAL LUMINESCENCE IN VITRO

Abstract

Intensity of luminescence in cell-free extracts of Achromobacter fischeri with the addition of reduced diphosphopyridine nucleotide (DPN), flavin monoucleotide, and decaldehyde is reversibly affected by hydrostatic pressure, and the changes due to pressure are influenced by temperature both in the same manner and to very nearly the same extent as in the living bacterial cells steady-state levels are lowered by pressure at temperatures below the normal optimum, are only slightly affected at the optimum, and are raised by pressure at temperatures above the optimum. The influence of pressure and temperature on the inhibition of luminescence by given concentrations of sulfanilamide and alcohol, respectively, is likewise similar in the extracts and cells, in that the sulfanilamide inhibition is scarcely affected by pressure but decreases with rise in temperature, whereas the alcohol inhibition is decreased by pressure and is increased by a rise in temperature. Diminution in luminescence intensity at temperatures above the normal optimum is reversible on cooling after brief exposures to the high temperatures, and it is partially reversed by pressure, as it is in cells. Evidence is presented that the luminescent oxidation of flavin mononucleotide by the extracted system, in the presence of decaldehyde, proceeds with a small volume decrease of activation, whereas the reduction of flavin mononucleotide by DPN in this system proceeds with a large volume increase of activation. In the absence of decaldehyde, the intensity of luminescence is much less, and the effects of pressure on the intensity of luminescence are greatly reduced.