COLI‐AEROGENES BACTERIA ISOLATED FROM EARS AND PANICLES OF CEREAL CROPS

Abstract

SUMMARY: Aerogenes‐cloacae and Intermediate types of coli‐aerogenes bacteria were found to be normal inhabitants of ears and panicles of growing cereals. Coli‐aerogenes bacteria, producing acid and gas in MacConkey's broth within 5 days at 30°, were isolated from 73% of the 148 samples, the number being as high as 105/g in a third. The number of organisms increased during the growing season.Less than a third of the samples contained 37° positive strains, but approximately 10% were positive in 10‐3g or less at this temperature.A high proportion (71.1%) of the 180 classifiable cultures did not produce acid and gas in MacConkey's broth in 2 days at 37°. Organisms of the aerogenes‐cloacae types were dominant, constituting 80.6% of the classifiable strains at 30° and 80.8% of the 37° positive strains. Intermediate type I, particularly 37° negative and gelatin liquefying variants, was the next most common type.