A blue discoloration of fleece wool caused by a pigment of Pseudomonas indigofera

Abstract

Specimens of fleece discoloured blue have been collected from the South Island of New Zealand. The pigmentation was usually confined to a single band 1–3 cm wide, and the area affected on the sheep varied from less than 10 cm in diameter to the whole fleece. The colouring matter was present as discrete particles which adhered to the wool fibres and could be removed by washing with petroleum ether. The pigment was recovered from the solvent by centrifugation and was purified by chromatography on alumina. A bacterium producing a blue pigment was isolated from blue fleece wool. This bacterium was grown on agar, and the pigment it produced was shown to have similar properties to the one extracted from the fleece. The bacterium was identified as Pseudomonas indigofera.