A collection of 16 bacterial strains isolated from root nodules of Lima bean (Phaseolus lunatus L.) in the Supe valley of Peru were characterised using phenotypic and molecular methods. The isolates were clustered into fastgrowing, alkalinising and extra-alkalinising slow-growing isolates with marked morphological differences, according to the rate of growth and alkalinisation of yeast extract mannitol (YEM) medium. Fast-growing isolates were salt tolerant and sensitive to 40 °C, while alkalinising slow-growing isolates behaved oppositely. Extra-alkalinising slow-growing isolates were sensitive to 8 °C and 40 °C and tolerated 1 % NaCl. Fastgrowing isolates also showed higher indole-3-acetic acid (IAA) production and tri-calcium phosphate solubilisation than the alkalinising slow-growing isolates. Half of the isolates were able to nodulate Phaseolus vulgaris and Vigna unguiculata. Indi...