[Denitrifying activity and generation time in 4 species of Rhizobium]

Denitrifying capacity and doubling time were measured among 44 strains of Rhizobium belonging to 4 species: B. japonicum, R. lupini, R. meliloti et R. leguminosarum. There was no correlation between doubling time and the rate of production of N2O in the presence of C2H2 in B. japonicum and R. lupini. In 38 other strains, only denitrifying capacity was measured. The percentage of strains showing denitrification capacity varied according to the species: 70% in B. japonicum, 90% in R. lupini, 37% in R. meliloti and 14% in R. leguminosarum. The strains of the latter species showed a very low level of denitrifying activity in comparison with the strains of the 3 other species.