Study of Bacterial Fluorescence in Various Media

Abstract

In the Pseudomonas fluorescens (Flugge) group it was found that Mg, phosphate and sulphate were necessary, besides N, for pigment production. These results disagree with those of previous workers, who were undoubtedly led astray by the fact that minute traces of the above inorganic constituents are sufficient to permit pigment formation, and such traces are present even in the best of chemicals. If soft-glass culture tubes are used, enough Mg may be dissolved to give erroneous results. The following medium is suggested as most satisfactory for production of fluorescence: anhydrous MgSO4, 0.5 gm.; anhyd. K2HPO4, 0.5 gm.; asparagine, 3.0 gm.; dist. H2O,1000 cc.