Identification and Nutritional Differentiation of the Erwinia Sugar Beet Pathogen from Members ofErwinia carotovoraandErwinia chrysanthemi

Abstract

A disease of sugar beet denoted by soft rot and vascular necrosis is caused by a distinct group of E. carotovora strains and is named E. carotovora ssp. betavasculorum ssp. nov. A comparative study was made of the nutritional properties of 99 strains of identified and unidentified soft-rotting Erwinia spp. from several hosts, including sugar beet. Seventy-one strains were placed either in E. carotovora ssp. carotovora, E. carotovora ssp. atroseptica, E. carotovora ssp. betavasculorum or one unclassified group in this species depending on similarities of nutritional properties. Nutritional and physiological tests useful for distinguishing subspecies of betavasculorum from one or more of the other Erwiniae include: growth of .alpha.-methylglucoside, D-lactate, ethanol, L-lysine, maltose, palatinose, D-asparagine and ethanol; either no, or very slow, growth on cellobiose, galacturonate, melibiose, malonate and raffinose; no indole or phosphatase production; no gas from glucose; resistant to erythromycin; growth at 36.degree. C; and the production or reducing substances from sucrose. Twenty-eight strains were placed into E. chrysanthemi and divided into 6 subdivisions. These 2 subdivisions corresponded to previously described species varieties or formae speciales and are generally equated with the host from which they were originally isolated.