Abstract

The semi-arid Sahelian region of Africa, characterized by its deleterious agro-climatic conditions, is also subject to agricultural overexploitation to support human and livestock food. This situation has strongly accentuated the continuous degradation of arable land. However, green biotechnologies are often proposed to promote more sustainable agricultural systems. Thus, the soil microbiome is explored for the production of biofertilizers that are able to ensure the growth and biocontrol of cultivated plants. For this purpose, plant growth promoting rhizobacteria (PGPR) were widely used. In order to increase the production of fodder for livestock, the production of biofertilizers is undertaken using indigenous PGPR strains able to sustainably improve agricultural productivity. From soil samples collected in the investigated zone, rhizobacteria are isolated and characterized in vitro for a selection of elite strains. Thus, a collection of 71 isolates presenting a great phenotypic and physiological diversity was established. The most efficient strains were selected for their ability to promote plant growth by the production of catalase and siderophores, auxin synthesis and soil P bioavailability. At the end of this study, candidate strains for the formulation of a suitable biofertilizer were highlighted on the basis of the correlations between the highest PGP activities of bacterial strains.

Key words: Biofertilizers, plant growth promoting (PGP) traits, Rhizobacteria, Sahelian zone.