Chemical characterization of effective and ineffective strains of Rhizobium leguminosarum bv. viciae.

Chemical composition of lipopolysaccharide (LPS) isolated from an effective (97) and ineffective (87) strains of R. l. viciae has been determined.

Nodulation genes in the Rhizobium--plant signal exchange.

The process of the host-plant recognition by rhizobia is complex and multi-step. The interaction between legumes and microorganisms results in the induction of the root nodule. This symbiotic interaction is highly host-specific.

Candida sp. infection-late complication of a double valve replacement.

Severe complications prolonged the original hospital stay to over 2 months. After 5 months intermittent fever lead to readmission, but no cause could be found. After 7 months severe fever and heart failure developed.

Siderophore containing 2,3-dihydroxybenzoic acid and threonine formed by Rhizobium trifolli.

An iron-binding compound was isolated from ethyl acetate extract of culture supernatant fluid of Rhizobium trifolii AR6 and was purified by iron-exchange chromatography. The compound was characterized by UV and IR. It contained 2,3-dihydroxy-benzoic acid and threonine and was accumulated during stationary phase of growth in iron-deficient media.

Use of the intraluminal vascular prosthesis for the repair of aneurysm of the ascending aorta.

We present the case of a 49-year-old patient with aneurysm of the ascending aorta as well as mitral and aortic valvar insufficiency treated surgically. Preoperatively the patient was in NYHA functional class IV. We implanted mitral and aortic valvar prostheses and an intraluminal vascular graft in the ascending aorta above the coronary ostia.

Superior vena caval stenosis: a rare complication in permanent transvenous cardiac pacing.

An unusual case of superior vena caval stenosis associated with a permanent transvenous cardiac pacing wire and its successful treatment by surgical reconstruction using a pericardial patch is reported.

Characterization of the lipopolysaccharide from the nod mutant of Rhizobium trifolii.

Lipopolysaccharides (LPS) from the non-nodulating Rhizobium trifolii 24SM 15 and from the nodulating R. trifolii 24SM 13 were isolated and examined by means of gas-liquid chromatography and mass spectrometry. Analysis of LPS showed these preparations from both strains examined contained Lipid A, 2-keto-3-deoxyoctonate, neutral sugars, amino sugars, and trace amounts of amino acids.

Characterization of the in vitro constructed plasmid composed of the nif gene cluster of Lignobacter and RP4.

The nitrogen fixation of Lignobacter K17 is plasmid mediated. Nif plasmid was transferred from Lignobacter to other bacterial species and the transposon Tn9 was inserted into it. The molecular weight of this plasmid designated pUCS101, is of 19.

Structure of the rigid-layer of rhizobium cell wall. II. Evidence for a covalent bond between peptidoglycan and cellodextrins.

Covalent linkages between peptidoglycan and cellodextrins in the cell walls of Rhizobium were defined by the analysis of lysozyme split products. Digestion of peptidoglycan with lysozyme resulted in the liberation, beside disaccharide tetrapeptide fragments composed of glucosamine, muramic acid, alanine, glutamic acid and diaminopimelic acid in a molar ratio 1:1:2:1:1, also significant amounts of glucose and its polymers. The neutral carbohydrates composed of glucose, were further purified and determined as cellobiose, cellotriose and cellotetrose.

Structure of rigid-layer of Rhizobium cell wall. I. Purification on the peptidoglycan from the cellulose microfibrils.

The bag shaped peptidoglycan layer of Rhizobium cell wall was isolated from intact cells after treatment with sodium dodecylsulfate and trypsin, chymotrypsin or pepsin digestion. Results of chemical analysis of acid hydrolyzed peptidoglycan revealed beside two amino sugars: glucosamine and muramic acid, three major amino acids; alanine, glutamic acid and 2,6-diaminopimelic acid and also significant amount of glucose. Evidence were provided that the polyglucose found in peptidoglycan preparations of three strains of Rhizobium trifolii, one of Rhizobium leguminosarum and one of Rhizobium meliloti consist of cellulose microfibrils.

Structural studies of the lipopolysaccharide from Salmonella typhimurium 902 (ColIb drd2).

Salmonella typhimurium infected with the plasmid ColIb drd2 gave rise to changes in the composition of the bacterial lipopolysaccharide. Bacteria carrying the wild-type ColIb, the revertant of drd2 to the wild type, or the noncolicinogenic strain resulting from the elimination of ColIb drd2, showed no changes in the sugar composition of the lipopolysaccharide. The structure of the O-specific side chains of the lipopolysaccharide produced by S.

Restriction enzyme analysis of the plasmid ColIb DNA.

Plasmid ColIb (61.5 Mdal) was digested with restriction enzymes EcoRI and HindIII. The DNA digestion products were separated by electrophoresis on 1.

Transfer of RP4 and R68.45 factors to Rhizobium.

Two R factor were introduced by conjugation into Rhizobium trifolii and Rhizobium meliloti strains at a frequency of 10(-5) to 10(-6). Plasmids RP4 from Escherichia coli J53 and R68.45 from Pseudomonas aeruginosa PAO.

Detection of small cryptic plasmids in Salmonella typhimurium strain LT2.

Small cryptic plasmids of molecular weights ranging from 1 to 3 Mdal were detected by electron microscopy in Salmonella typhimurium strain LT2 (ColIb). They were divided into different size classes. Two of the cryptic plasmids were transferred simultaneously with ColIb to Escherichia coli.

Genetic mapping of the chromosome of Rhizobium trifolii.

Cultures of the wild strain and auxotrophic mutants of Rhizobium trifolii T37 synchronized by means of phenylethanol have been mutagenized with nitrosoguanidine. Fifteen genetic markers were characterized in respect of their order and the time of replication based on the peaks of mutations of the genes. The time of R.

Genetic transformation in Rhizobium trifolii.

Markers controlling the synthesis of amino acids and organic bases as well as streptomycin resistance and sensitivity to acriflavine were transformed in Rhizobium trifolii. The results indicate that the str marker was transformed independently of leu, his, ade and trp markers. Co-transformation of leu and utra markers ranged from 3 to 7%, whereas that of thi and acr was 10%.

Nitrogen fixation by Rhizobium in pure cultures.

Strains of Rhizobium trifolii and Rhizobium meliloti were tested for their asymbiotic nitrogen fixation ability. From among ten tested strains two R. trifolii and one R.