The Production of Fluorescent Pigment by Bacteria

Abstract

A CONSIDERABLE number of different "species" of bacteria have been described as endowed with the property of forming a blue-green fluorescent pigment in suitable media. I append a list, perhaps not complete, of the various " fluorescent bacteria" already discovered. It is not at all likely that the fifty names bestowed upon these cultures represent as many totally distinct microorganisms , and in some cases it is practically certain that the same bacterium masquerades under several different titles. The experiments recorded in the present paper embody a series of attempts to discover the conditions under which fluor-escence is produced, and especially the nature and amount of the chemical substances essential to the formation of the fluor-escing body. I have chosen for this purpose six different cultures.' Four of these do not liquefy gelatin and were sent to me from Kral's Laboratorium under the names B. fluorescens albus, B. fluorescens tennis, B. fluorescens mesentericus, and B. fluorescens putridus. The two others liquefy gelatin; one of them was sent by Kral with the name B. viridans, and the second was isolated by me from the water of Lake Michigan and identified as B.fluorescens lique-faciens (description by Kruse in Fluigge's Die Mikroorganismen 2: 292). I. B. FL. ALBUS.-A bacillus was first described under this name by Zimmermann who found it in the D6beln water supply.2 The culture bear-I I have also made some experiments with B. pyocyaneus, but, owing to the complication due to the formation of at least two pigments by this bacillus, I am led to reserve my statements on this head for a subsequent communication. 2O. E. R. Zimmerman, Die Bakterien unserer Trink-und Nutzwdsser i8. Chemnitz, i890. I899] I9