The blue pigment of Corynebacterium insidiosum

Summary The alfalfa wilt bacterium, Corynebacterium insidiosum, produces a water-insoluble blue substance which accumulates extracellularly. A number of factors (among them strain variation, temperature, p_H, nutrition, crowding) have a considerable influence upon pigment production. Proper control of these factors led to a method for large-scale cultivation of C. insidiosum under conditions of good pigmentation.On the bases of absorption spectrum, solubility characteristics, and the properties of crystalline acetyl and benzoyl derivatives, the C. insidiosum pigment is believed to be identical with indigoidine—a pigment of unknown composition previously reported in Pseudomonas indigofera.