Seasonal changes of bacterial communities in the rhizosphere of Acacia senegal mature trees inoculated with Ensifer strains in Burkina Faso and Niger

► Acacia senegal tree produces gum arabic, an important source of income for farmers. ► Rhizobial inoculation enhance gum production in Niger but not in Burkina Faso. ► Inoculation had a negative effect on microbial biomass in Niger. ► A significant seasonal effect on the soil total bacterial diversity was observed in Niger. ► In Burkina Faso, there was no effect of both season and inoculation on bacterial diversity.