[Properties of a toxic substance from Erwinia carotovora var. citrullis].

The toxic substance of Erwinia carotovora, isolated in a pure form, is a protein-polysaccharide complex with molecular weight of 90000 daltons. The protein part of the complex contains 17 amino acids with the prevalence of dicarbonic acids and with insignificant quantities of thyrosine and phenylalanine, while the polysaccharide part of the complex contains 6 sugars. The antigenic specificity of the complex is linked with its hydrocarbon part, and the toxicity of the complex is determined by protein. The toxic complex is heat-resistant and most active at the neutral pH value of the culture medium.