Enterobacter aerogenes was examined for its ability to utilize a known lathyrogen or chemically related compounds for use in developing an in vitro model system to study experimental lathyrism. Enterobacter aerogenes grew in a minimal medium containing the lathyrogen, beta-aminopropionitrile fumarate. Related compounds or combinations of related compounds which together contained all the constituents of the lathyrogen failed to support growth. The specificity of this compound in supporting growth of this polysaccharide-producing microorganism suggests that this microorganism may be useful in developing an in vitro model system to study polysaccharide metabolism in experimental lathyrism.