STUDIES ON THE LOCALIZATION, FUNCTION, AND FORMATION OF THE CAROTENOID PIGMENTS OF A STRAIN OF <i>MYCOBACTBRIUM MARINUM</i>

Abstract

Abstract— Aninvestigation was made of the location, function and characteristics of production of carotenoid pigments of a strain of Mycobacterium marinum , an organism which produces its pigments only when exposed to light. It was found that light‐grown cells of this organism contain only one pigment. The intracellular location of this pigment was found to be the cell envelope. The pigment was found to be capable of protecting the cells against lethal photo‐oxidations mediated by the dye, toluidine blue. These studies also revealed that in dark‐grown cells exposed to light, pigment production occurred after a short lag and then remained constant during logarithmic growth. Pigment was produced by starved cells, but to a lesser degree than son‐starved cells; the addition of a carbon or nitrogen source to starved cells increased pigmentation to the level in non‐starved cells. Pigmentation did not occur in the absence of oxygen. Cells exposed to light at 4°C were not pigmented immediately after exposure, but became so if incubated at 30°C. Production of pigment was found to obey the Bunsen‐Roscoe reciprocity law. The determination of an action spectrum for the production of pigment indicates that maximum pigment productiion occurs in the vicinity of 410 and 439 mµ, with smaller maxima in the vicinity of 502 , 528 and 560 mµ.