CONTAMINATION AND DETERIORATION OF ALFALFA SPROUTS CAUSED BY A SEED-BORNE ISOLATE OF ERWINIA-HERBICOLA

A Gram negative, rod-shaped, yellow-pigmented bacterium was recovered from beneath the seed coats of surface-sterilized alfalfa seed from th ree seed lots used for the commercial production of sprouts. This bact erium was responsible for the deterioration of alfalfa sprouts markete d in film-wrapped plastic containers. Identity of the isolate was conf irmed as Erwinia herbicola (Lohnis) Dye (synonym Pantoea agglomerans c omb. nov.). The level of contamination by this bacterium in nonsurface -sterilized seed was 34.7% while in surface-sterilized seed it was 13. 2%. No other microorganisms were consistently recovered from surface-s terilized seed samples from these lots, or from other alfalfa seed sam ples assayed as controls. The bacterium was able To survive for more t han three years beneath the seed coats of contaminated seed. We recomm end that alfalfa sprout companies routinely assay samples for seedborn e microorganisms from lots intended for sprouting.