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This Article Full Text Full Text (PDF) Supplementary data All Versions of this Article: mic.0.025031-0v1 155/9/3055    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Vanderlinde, E. M. Articles by Yost, C. K. PubMed PubMed Citation Articles by Vanderlinde, E. M. Articles by Yost, C. K. Agricola Articles by Vanderlinde, E. M. Articles by Yost, C. K.

Rhizobium leguminosarum biovar viciae 3841, deficient in 27-hydroxyoctacosanoate-modified lipopolysaccharide, is impaired in desiccation tolerance, biofilm formation and motility

Artur Muszyski²

Joe J. Harrison^3,

¹ Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
² Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
³ Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
⁴ Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada

The lipopolysaccharide (LPS) of the Gram-negative legume symbiont Rhizobium leguminosarum biovar viciae 3841 contains several unique modifications, including the addition of a 27-hydroxyoctacosanoic acid (27OHC28 : 0), also termed the very long chain fatty acid (VLCFA), attached at the 2' position of lipid A. A transposon mutant that lacks expression of two putative 3-oxo-acyl [acyl-carrier protein] synthase II genes, fabF1 and fabF2, from the VLCFA biosynthetic cluster, was isolated and characterized. MS indicated that the lipid A of the mutant lacked the VLCFA modification, and sodium deoxycholate (DOC)-PAGE of the LPS indicated further structural alterations. The mutant was characteristically sensitive to several stresses that would be experienced in the soil environment, such as desiccation and osmotic stresses. An increase in the excretion of neutral surface polysaccharides was observed in the mutant. This mutant was also altered in its attachment to solid surfaces, and was non-motile, with most of the mutant cells lacking flagella. Despite the pleiotropic effects of the mutation, these mutants were still able to nodulate legumes and fix atmospheric nitrogen. This report emphasizes that a structurally intact VLCFA-containing lipid A is critical to cellular traits that are important for survival in the rhizosphere.

Correspondence
Christopher K. Yost
chris.yost{at}uregina.ca

Present address: Department of Microbiology, University of Washington School of Medicine, Box 357242, 1959 NE Pacific Street, Seattle, WA 98195-7242, USA.

A supplementary figure, showing alignments of portions of Rhizobium leguminosarum biovar viciae 3841 FabF1 and FabF2 with Escherichia coli W3110 FabF, and FabF2 protein sequences from members of the Rhizobiales, and a supplementary table listing sequences of primers used with accompanying references, are available with the online version of this paper.