A new acidic sphingoglycolipid has been isolated from a Gram-negative, glucose-non-fermentative (obligatory aerobic) bacterium, Flavobacterium, devorans ATCC 10829, by thin-layer chromatography on silica gel after mild alkaline hydrolysis of the cellular lipids. Chemical degradation studies, thin-layer chromatographic behavior, IR and mass-spectrometric analysis of the original and reduced glycolipid with LiALH₄ revealed that the lipid contained glucornic acid, long-chain bases, and fatty acids in a molar ratio of approximately 1: 1: 1. The major long-chain bases were identified by gas chromatography-mass spectrometry as dihydrosphingosine (d-18: 0) and longer homologues, while the N-acyl group was exclusively 2-hydroxymyristic acid. The most probable structure of this glycolipid appeared to be a ceramide glucuronic acid (N-acyl dihydrosphingosine 1-glucuronic acid).