Blueprint for a global morality--the work of Robert Rapoport 1924-1996.

Always an idealist, in his last work Robert Rapoport argues that we can achieve a global ethic in line with the UN Charter and that the inculcation of values must--and does--start in the home. This reviewer, while in sympathy with his aims, considers that the obstacles to agreement about ethical issues also need to be set out.

Genetic diversity among bradyrhizobium isolates that effectively nodulate peanut (Arachis hypogaea).

Symbiotic gene diversity and other measures of genetic diversity were examined in Bradyrhizobium isolates that form an effective symbiosis with peanut (Arachis hypogaea). Initially, restriction fragment length polymorphism (RFLP) analysis using a nitrogenase (nif) gene probe was performed on 33 isolates along with one Bradyrhizobium elkanii and two Bradyrhizobium japonicum strains. Considerable diversity was observed among the RFLP patterns of many of the isolates, especially those from South America.

Bradyrhizobium (Arachis) sp. strain NC92 contains two nodD genes involved in the repression of nodA and a nolA gene required for the efficient nodulation of host plants.

The common nodulation locus and closely linked nodulation genes of Bradyrhizobium (Arachis) sp. strain NC92 have been isolated on an 11.0-kb EcoRI restriction fragment.

Oxygen Uptake and Hydrogen-Stimulated Nitrogenase Activity from Azorhizobium caulinodans ORS571 Grown in a Succinate-Limited Chemostat.

Succinate-limited continuous cultures of an Azorhizobium caulinodans strain were grown on ammonia or nitrogen gas as a nitrogen source. Ammonia-grown cells became oxygen limited at 1.7 muM dissolved oxygen, whereas nitrogen-fixing cells remained succinate limited even at dissolved oxygen concentrations as low as 0.

Growth, Respiration, and Polypeptide Patterns of Bradyrhizobium sp. (Arachis) Strain 3G4b20 from Succinate- or Oxygen-Limited Continuous Cultures.

Succinate- or oxygen-limited continuous cultures were used to study the influences of different concentrations of dissolved oxygen and ammonia on the growth, respiration, and polypeptide patterns of Bradyrhizobium sp. (Arachis) strain 3G4b20. During succinate-limited growth, molar growth yields on succinate (Y(succ)) ranged from 38.

Relationship of the Presence and Copy Number of Plasmids to Exopolysaccharide Production and Symbiotic Effectiveness in Rhizobium fredii USDA 206.

Rhizobium fredii USDA 206 harbors four large plasmids, one of which carries nodulation and nitrogen fixation genes. Previously isolated groups of plasmid-cured derivatives of strain USDA 206 were compared with each other to determine possible plasmid functions. Mutant strain 206CANS was isolated as a nonmucoid (Muc) derivative of strain 206CA, a mutant that was cured of two plasmids.

Characterization of a Mannitol-Utilizing, Nitrogen-Fixing Bradyrhizobium japonicum USDA 110 Derivative.

We have isolated a colonial derivative of Bradyrhizobium japonicum USDA 110 (designated MN-110) that is both mannitol utilizing and N(2) fixing. Derivative MN-110 showed growth on mannitol and glucose similar to that of non-N(2)-fixing, mannitol-utilizing L2-110. Derivative MN-110 showed high constitutive and induced d-mannitol dehydrogenase activity (similar to L2-110) relative to N(2)-fixing, non-mannitol-utilizing I-110.

Analysis of the Symbiotic Performance of Bradyrhizobium japonicum USDA 110 and Its Derivative I-110 and Discovery of a New Mannitol-Utilizing, Nitrogen-Fixing USDA 110 Derivative.

Previously, Bradyrhizobium japonicum USDA 110 was shown to contain colony morphology variants which differed in nitrogen-fixing ability. Mannitol-utilizing derivatives L1-110 and L2-110 have been shown to be devoid of symbiotic nitrogen fixation ability, and non-mannitol-utilizing derivatives I-110 and S-110 have been shown to be efficient at nitrogen fixation. The objectives of this study were to determine the effect of media carbon sources on the symbiotic N(2)-fixing ability of strain USDA 110 and to compare the effectiveness of strain USDA 110 and derivative I-110.

Symbiotic Effectiveness and Host-Strain Interactions of Rhizobium fredii USDA 191 on Different Soybean Cultivars.

Nodulation, acetylene reduction activity, dry matter accumulation, and total nitrogen accumulation by nodulated plants growing in a nitrogen-free culture system were used to compare the symbiotic effectiveness of the fast-growing Rhizobium fredii USDA 191 with that of the slow-growing Bradyrhizobium japonicum USDA 110 in symbiosis with five soybean (Glycine max (L.) Merr.) cultivars.

Restriction Endonuclease and nif Homology Patterns of Bradyrhizobium japonicum USDA 110 Derivatives With and Without Nitrogen Fixation Competence.

DNAs from Bradyrhizobium japonicum USDA 110 derivatives that differ in nitrogen-fixing ability produced similar electrophoretic patterns with five different restriction enzymes. Our data support the hypothesis of common ancestry for these derivatives. Derivatives I-110 and L1-110 differed as much as 100-fold in acetylene reduction activity when they were tested with several soybean cultivars in both greenhouse and field experiments.

Evidence for plasmid- and chromosome-borne multiple nif genes in Rhizobium fredii.

Rhizobium fredii is a fast-growing rhizobium isolated from the primitive Chinese soybean cultivar Peking and from the wild soybean Glycine soja. This rhizobium harbors nif genes on 150- to 200-megadalton plasmids. By passage on acridine orange plates, we obtained a mutant of R.

Effect of Sym Plasmid Curing on Symbiotic Effectiveness in Rhizobium fredii.

A mutant, USDA 206C, of Rhizobium fredii USDA 206 was obtained by passage on acridine plates. This mutant was cured of its 197-megadalton Sym plasmid but retained its symbiotic effectiveness. Multiple plasmid and chromosomally borne nif gene copies have previously been shown in R.

Modified Fluorescent Technique, Using Rhodamine, for Studies of Rhizobium japonicum-Soybean Symbiosis.

Rhodamine-conjugated capsular polysaccharides isolated from Rhizobium japonicum 61A76NS were used to examine binding between the labeled polysaccharides and soybean roots. Fluorescein-labeled polysaccharides were not satisfactory because soybean root hairs autofluoresce in the fluorescein region.

Multiple antibiotic resistance in Rhizobium japonicum.

A total of 48 strains of the soil bacterium Rhizobium japonicum were screened for their response to several widely used antibiotics. Over 60% of the strains were resistant to chloramphenicol, polymyxin B, and erythromycin, and 47% or more of the strains were resistant to neomycin and penicillin G, when tested by disk assay procedures. The most common grouping of resistances in strains was simultaneous resistance to tetracycline, penicillin G, neomycin, chloramphenicol, and streptomycin (25% of all strains tested).

Method for correcting laboratory model deep-well disposal system data for hydrostatic pressure effects.

A pressure chamber for determining the effect of increased hydrostatic pressure on growth and metabolic activities of groundwater bacteria is described. The chamber was used to show that moderate increases in pressure (to about 100 atmospheres) result in increased growth of mixed cultures of industrial-injection-well bacteria and in the more complete degradation of formate and nitrate by these bacteria, as compared with identical cultures at atmospheric pressure.

The role of ammonia, L-glutamate, and cyclic adenosine 3',5'-monophosphate in the regulation of ammonia assimilation in Rhizobium japonicum.

The effects of three factors (ammonia, L-glutamate, and cyclic adenosine 3',5'-monophosphate) on the ammonia assimilatory processes in aerobically grown Rhizobium japonicum colony derivatives were examined. Ammonia repressed glutamine synthetase activity and increased the average state of adenylylation of this enzyme. The addition of L-glutamate drastically decreased growth and strongly repressed glutamate synthase levels.

Comparison of colony morphology, salt tolerance, and effectiveness in Rhizobium japonicum.

Four strains of Rhizobium japonicum, two of which produce slimy and non-slimy colony types and two others which produce large and small colony types, were isolated and cloned. All were infective and nodulated Lee soybean host plants. Each colony type was characterized as to its salt sensitivity to Na+ and K+ ions, relative level of symbiotic nitrogen fixation, and relative level of free-living nitrogen fixation.

The role of 6-phosphogluconate dehydrogenase in Rhizobium.

A nicotinamide adenine dinucleotide (NAD) linked 6-phosphogluconate (6-PG)dehydrogenase has been detected in Rhizobium. The enzyme activity is similar in both slow- and fast-growing rhizobia. The nicotinamide adenine dinucleotide phosphate (NADP) dependent 6-PG dehydrogenase was detected only in the fast growers and was more than twice as active as the NAD-linked enzyme.

Glucose catabolism in two derivatives of a Rhizobium japonicum strain differing in nitrogen-fixing efficiency.

Radiorespirometric and enzymatic analyses reveal that glucose-grown cells of Rhizobium japonicum isolates I-110 and L1-110, both derivatives of R. japonicum strain 3I1b110, possess an active tricarboxylic acid cycle and metabolize glucose by simultaneous operation of the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways. The hexose cycle may play a minor role in the dissimilation of glucose.

Rhizobium japonicum derivatives differing in nitrogen-fixing efficiency and carbohydrate utilization.

Four derivatives of Rhizobium japonicum 110 were isolated on the basis of morphologically different colonies formed on yeast extract-mannitol-HM salts medium. All are able to nodulate Lee soybeans. The bacteria-plant associations formed by each clone have measurable acetylene-reducing activity, but those formed by two of these clones (designated L1-110 and L2-110) are 5- to 10-fold less efficient than those formed by the others (designated I-110 and S-110).

Role of pectic and cellulolytic enzymes in the invasion of the soybean by Rhizobium japonicum.

Past workers have suggested pectic enzyme involvement in the invasion of legumes by Rhizobium. However, no role for pectic acid, pectin, or methyl cellulose depolymerase enzymes in the invasion of R. japonicum was suggested by the current study.

Transmissible resistance to penicillin G, neomycin, and chloramphenicol in Rhizobium japonicum.

The genetic basis for resistance to a number of antibiotics was examined in Rhizobium japonicum. Resistance to penicillin G, neomycin, and chloramphenicol appears to be mediated by an extrachromosomal element similar to that found in the Enterobacteriaceae. Resistance to these antibiotics was eliminated from cells by treatment with acridine orange, and resistance to all three antibiotics could be transferred en bloc to Agrobacterium tumefaciens under conditions excluding transformation or transduction as possible genetic mechanisms.