A practical method for studying the reversible phases of pyocyanin

Abstract

Cultures of Pseudomonas aeruginosa, are incubated in agar Slopes at 25°. C. 2,5 ml. choloroform are added to each tube to dissolve the pigment and Strips of Whatman Nº1 filter paper are introduced, letting the solution travel up the Strips. The latter are taken out and, being quicky dried in the air, are put into acetone which rises, carrying with it the blue pigment which gradually turn yellow, through bluegreen and yellow-green.To test if it is pyoxanhose, the strips are put into a 20 %. Hydrochloric acid solution, this being an easy and very illustrative method.

Cultivos de Pseudomonas aeruginosas en agar inclinado a 250 C. Añade a cada tubo cloroformo para disolver el pigmento e introduce tiras de papel Whatman núm. 1 dejando subir por ellas la solución: secado al aire. Introduce la tira en acetona y la deja que ascienda, arrastrando el pigmento azul, el cual cambia al amarillo, pasando por verde azulado y verde amarillento. Comprueba que se trata de Pioxantosa por el color rojo que toman las tiras del papel con ácido clorhídrico al 20%. Método fácil y muy demostrativo.