The sorbistin-producing organism, Pseudomonas sorbicinii sp. nov., was isolated from a soil sample by a psychrophilic pre-incubation technique. The organism resembles P. fluorescens in many respects but differs in some of the important physiological characteristics such as oxidase production, media specificity for the production of fluorescent pigment, and carbohydrate utilization pattern. The type strain, No. D946-B83, was deposited under the numbers ATCC 31086 and FERM-P 3328.