Four unnamed species of nonsymbiotic rhizobia isolated from the rhizosphere of Lotus corniculatus

Article Abstract:

Seven nonsymbiotic Lotus corniculatus rhizobial isolates, which do not have enough genetic information for nodulation or nitrogen fixation, have been characterized. The isolates hybridize to symbiotic gene probes but not to genomic DNA probes from Rhizobium loti. The 16S rRNA nucleotide sequence divergence fails to indicate the interdependence of the genetic distance estimates provided by multilocus enzyme electrophoresis and genomic DNA-DNA hybridization. The finding suggests that nonsymbiotic rhizobia acquire symbiotic genes from inoculant strains when legumes are introduced in soils.

Usage, Observations, Electrophoresis, Lotus, Lotus (Nelumbo)

Diversity among rhizobia effective with Robinia pseudoacacia L

Article Abstract:

Rhizobia that form symbioses with black locust (Robinia pseudoacacia L.) were isolated from many locations. There was great morphological and biochemical diversity among the isolates, as shown by their intrinsic antibiotic resistance, tolerance to NaCl and protein banding patterns. The isolates were classified based on data on carbohydrate utilization, activity of 6-phosphogluconate dehydrogenase and generation time. There was also great variation in nitrogen fixation and symbiotic host response.

Environmental aspects, Symbiosis

Purification and characterization of an alpha-glucosidase from Rhizobium sp. (Robinia pseudoacacia L.) strain USDA 4280

Article Abstract:

A study has revealed the production of a novel form of alpha-glucosidase derived from Rhibozium sp. strain USDA 4280 protein extracts. Native gel electrophoresis revealed native enzyme activity using fluorescence detection. A proposed two-step process involving synthesis of plant enzymes in response to Nod factors, followed by final degradation by rhizobial glycosidases, is discussed in full.

Glycoproteins, Plant cell walls, Cell walls, Glucosidases, Alpha glucosidases