Isolation and Characterization of Strains ofErwinia ananasfrom Honeydew Melons

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Abstract
Strains of a yellow-pigmented bacterium causing firm, brown lesions on honeydew melons (Cucumis melo L.) were isolated from shipments from South and Central America and from California [USA]. The bacteria were gram-negative, non-acid fast, motile, facultative anaerobic rods (0.5-1.0 .times. 1.0-2.5 .mu.m) that produced a yellow pigment on nutrient agar with major visible absorption peaks at 420, 446, and 467 nm, and Rf of 0.75-0.83 on silica gel plates with methanol as the solvent. Strains were positive for catalase, beta-galactosidase, gelatinase, beta-lactamase, phosphatase, H2S, and indole production and formed acid from cellobiose, glycerol, and melibiose. Erwinia ananas (ATCC 11530 and 23822), a pathogen of pineapple fruits, was identical to the melon isolates. All were pathogenic to pineapple and melon, had identical fatty acid profiles and mole percent guanine and cytosine in the DNA, and cross-reacted serologically. Strains isolated from California melons were highly pathogenic and differed in the intensity of indole and beta-lactamase reactions and in serological properties.