The synthesis o f /?-galactosidase in Rhizobium meliloti W U60 was found to be inducible by lactose and its non-metabolizable analogue, isopropyl-ß-D-thiogalactoside (IPTG). In contrast to Escherichia coli, galactose and melibiose were very weak inducers o f this enzyme in R. meliloti. The maximum level o f /3-galactosidase in this bacterium is 2% o f that in fully induced E. coli. In addition ...

Rhizobium meliloti can occupy at least two distinct ecological niches; it is found in the soil as a free-living saprophyte, and it also lives as a nitrogen-fixing intracellular symbiont in root nodules of alfalfa and related legumes. One approach to understanding how R. meliloti alters its physiology in order to become an integral part of a developing nodule is to identify and characterize gene...

The gene encoding a denitrification enzyme, nitrous oxide reductase (EC 1.7.99.6), in Rhizobium meliloti and other gram-negative bacteria was detected by hybridization to an internal 1.2-kb PstI fragment of the structural gene (nosZ) cloned from Pseudomonas stutzeri Zobell (W.G. Zumft, A. Viebrock-Sambale, and C. Braun, Eur. J. Biochem. 192:591-599, 1990). Homology to the probe was detected in ...

In this study dairy sludge was evaluated as an alternative cultivation medium for Rhizobium. Growth of bacterial strains at different concentrations of Dairy sludge was monitored. Maximum growth of all strains was observed at 60% Dairy sludge concentration. At 60% optical density (OD) values are 0.804 for Rhizobium trifolii (MTCC905), 0.825 for Rhizobium trifolii (MTCC906), and 0.793 for Rhizob...