A system for studying the in vivo activity of Rhizobium NodC protein in Escherichia coli has been developed. Using thin-layer chromatography, high-performance liquid chromatography, and mass spectrometry, we show that in this system R. leguminosarum bv. viciae NodC protein directs the synthesis of chitinpentaose, chitintetraose, chitintriose, and two as yet unidentified modified chitin oligosac...

Electrotransformation of Rhizobium leguminosarum was successfully carried out with a 15.1-kb plasmid, pMP154 (Cmr), containing a nodABC-lacZ fusion by electroporation. The maximum transformation efficiency, 10(8) transformants/microg of DNA, was achieved at a field strength of 14 kV/cm with a pulse of 7.3 ms (186 Omega). The number of transformants was found to increase with increasing cell den...

Bacteria from nodules of the legume Acaciella angustissima native to the south of Mexico were characterized genetically and their nodulation and competitiveness were evaluated. Phylogenetic studies derived from rpoB gene sequences indicated that A. angustissima is nodulated by Sinorhizobium mexicanum, Rhizobium tropici, Mesorhizobium plurifarium and Agrobacterium tumefaciens and by bacteria rel...

The Rhizobium leguminosarum h o s t-range (Sym) plasmid, pJB5JI, is a 130 Mdal conjugative plasmid which carries the genes for host-specificity (i.e., for peas) and some of the genes for ni trogen-fixation. We have t ransferred plasmid pJB5JI into different species of Rhizobium and examined the symbiotic propert ies of the result ing transconjugants. The donor strain R. leguminosarum 6015 (pJB5...

An unusual α-(1,1)-galacturonic acid (GalA) lipid A modification has been reported in the lipopolysaccharide of a number of interesting Gram-negative bacteria, including the nitrogen-fixing bacteria Azospirillum lipoferum, Mesorhizobium huakuii and M. loti, the stalk-forming bacterium Caulobacter crescentus and the hyperthermophilic bacterium Aquifex aeolicus. However, the α-(1,1)-GalA transfer...