Sara Moens

UCLL

Azospirillum lipoferum 4B is a P.G.P.R. (Plant Growth Promoting Rhizobacteria) bacterium, isolated from rice rhizosphere (Thomas-Bauzon et al., 1982). Like A. brasilense and A. irakense species, A. lipoferum 4B displays a mixed flagellation: a single polar flagellum when growth in a liquid medium (swimming motility) and additional lateral flagella...

Azospirillum brasilense cells display two types of flagella: one constitutive polar flagellum, and inducible lateral flagella. Growth on an agar surface induces lateral flagella formation. On Bacto Nutrient Broth 0.6% agar plates, this results in swarming of the bacteria over the surface. Induction of expression of lateral flagella was studied usin...

Rather recently it has become clear that prokaryotes (Archaea and Bacteria) are able to glycosylate proteins. A literature survey revealed the different types of glycoproteins. They include mainly surface layer (S-layer) proteins, flagellins, and polysaccharide-degrading enzymes. Only in a few cases is structural information available. Many differe...

Bacteria of the genus Azospirillum are diazotrophs that colonize the roots of plants. Colonization patterns can be visualized by using strains equipped with a reporter gene (Vande Broek et al., 1993; Arsène et al., 1994). The initial steps of bacterial colonization are chemotaxis and adhesion to the root surface. In order to characterize the bacter...

The induction of the lateral flagella of Azospirillum brasilense Sp7 was studied by using a translational fusion between the laf1 promoter and gusA. The fusion was induced when cells were grown on solid media but not when they were grown in broth. The fusion was also induced by incubation of liquid-grown cells with an anti-polar flagellum polyclona...

Many bacterial species are motile by means of flagella. The structure and implantation of flagella seems related to the specific environments the cells live in. In some cases, the bacteria even adapt their flagellation pattern in response to the environmental conditions they encounter. Swarming cell differentiation is a remarkable example of this p...

Azospirillum brasilense can display a single polar flagellum and several lateral flagella. The A. brasilense Sp7 gene laf1, encoding the flagellin of the lateral flagella, was isolated and sequenced. The derived protein sequence is extensively similar to those of the flagellins of Rhizobium meliloti, Agrobacterium tumefaciens, Bartonella bacillifor...

The glycosylation of the flagellin of the polar flagellum of Azospirillum brasilense Sp7 is demonstrated in several ways: (1) by a decrease in apparent M(r) after chemical deglycosylation; (2) by sugar staining after SDS-PAGE; (3) by use of a sugar-specific monoclonal antibody in immunogold labelling coupled with transmission electron microscopy. I...

Azospirillum is probably the best studied example of beneficial plant rhizosphere bacteria. Studies in our laboratory focus on the identification of bacterial genes and gene products that are of importance in the physical and metabolic interaction of Azospirillum brasilense with plant roots. Here we report for Azospirillum brasilense, flagellation,...

Monoclonal antibodies (mAbs) with high specificity for Azospirillum brasilense Sp7, and which bind to different antigenic determinants, were characterized using Western blot techniques applied to one- and two-dimensional fingerprints of the outer-membrane components, and by immunogold labelling combined with transmission electron microscopy. One cl...

Azospirillum brasilense in a motile Gram-negative bacterium that can adapt its flagellation to different environments. Cells growing in a liquid culture possess only a single polar flagellum; growth on a solid surface additionally induces multiple lateral flagella. The polar flagellum is primarily used for swimming, i.e. locomotion of the bacterium...