Occurrence of uronic acid in lipopolysaccharides of Vibrionaceae.

The occurrence of uronic acid as a sugar constituent of lipopolysaccharides (LPS) in Vibrionaceae was demonstrated for the first time. More than 100 strains were examined. Of five genera constituting Vibrionaceae, i.e., Vibrio, Aeromonas, Plesiomonas, Photobacterium, and Lucibacterium, the latter three contained uronic acid in LPS of all of their constituting members examined, while it was totally lacking in Aeromonas LPS so far tested. Only the members of genus Vibrio were found to be divided into uronic acid-containing and -lacking groups; V. parahaemolyticus, V. alginolyticus, V. fisheri, V. costicola, Beneckea ('Vibrio'), and V. fluvialis belonged to the former, while all four biotypes of V. cholerae regardless of their serotypes, V. vulnificus and V. anguillarum, belonged to the latter group. The uronic acid content of V. parahaemolyticus O1 to O12 LPS ranged from 1.6 to 4.2%. The uronic acid residue released from V. parahaemolyticus O1, O4, O10, and O12 LPS by heating in 5% acetic acid at 100 C for 2 hr was identified as galacturonic acid; in particular, that from O12 LPS was characterized as D-galacturonic acid.