Quantitative relationship between maximum growth rates and the intracellular pattern of α-esterase and β-esterase activity of leguminous infecting bacteria

Sixteen strains belonging to three families of the Rhizobiales order (Bradyrhizobiaceae, Phyllobacteriaceae and Rhizobiaceae) were evaluated according their specific growth rates (μ) and the activity of intracellular α-esterase and β-esterase isoenzymes. The average esterase activity of 48 isoenzymes assayed belonging to five strains with low (μmax = 0.08–0.12 h−1), four medium (μmax = 0.13–0.22 h−1) and seven high (μmax = 0.24–0.28 h−1) growth rate values were 22.1 ± 4.3; 8.7 ± 2.2 and 3.9 ± 1.7 U g−1 respectively. An inversely proportional relationship between the activity of the whole pattern of esterases and μmax was found. Our results illustrate a feature of intracellular esterases, ascribable in a variety of cellular functions, which might be related to characteristics μmax of legume infecting bacteria.