Abstract
A Gram-negative rod, conforming; to Pseudomonas viscosa (Frankland and Frankland) Migula, was isolated in practically pure culture from a sample of wheat that did not show the usual mixture of epiphytes. In vitro studies revealed an unusual antibiotic spectrum against a variety of Gram-positive and -negative bacteria as well as against Helminthosporium sativum and Fusarium culmorum. Comparative.studies of the organism and P. aeruginosa, P. fluorescens, and P. chlororaphis indicated that it possessed greater antibiotic activity than any of these three species of Pseudomonas. Application to the control of some plant pathogenic organisms is suggested.