Plants constantly interact with a multitude of microorganisms that they select among other things through their roots. Some bacteria, known as plant growth promoting rhizobacteria (PGPR), are able to stimulate growth and control plant diseases, thanks to the expression of a wide range of beneficial properties to the plant. The aim of this work was to search for biofertilizing, plant-stimulating and biocontrol potentials in PGPR in central and northern Benin. To achieve this goal, the metabolic properties, especially phosphate solubilization, the production of indole acetic acid, hydrogen cyanide, ammonia, exopolysaccharides, certain enzymes and antifungal activity were investigated on nine rhizobacteria strains: Bacillus polymysa, Bacillus anthracis, Bacillus circulans, Bacillus thuringiensis, Bacillus panthothenicus, Pseudomonas cichorii, Pseudomonas putida, Pseudomonas syringae and Serratia marcescens. The results reveal that the three genera of rhizobacteria were producers of hydrogen cyanide, indole acetic acid, catalase and solubilized phosphate. All Pseudomonas and Serratia isolates were producers of exopolysaccharides, protease and lipase while 80% of Bacillus strains were lipase producers and 60% produced exopolysaccharides and protease. As regards the production of ammonia by rhizobacteria, 100% by S. marcescens, 78% of Pseudomonas strains and 80% of Bacillus strains produce them. These results show the possibility of using these rhizobacteria as biological fertilizers to stimulate growth, control fungal diseases and improve crop productivity in Benin.

Integrated production in sustainable agriculture aims to improve the efficiency of biological inputs through plant-based bioformulations or microorganisms, which are an excellent source of natural fertilisers. A variety of plant stimulants are increasingly used in crop production for environmentally sustainable agriculture. These products have different names and the designations are confusing. The aim of this work is to clarify what is meant by biofertilizer and biostimulant. A biofertilizer is a bacterial or fungal inoculant applied to plants with the aim of increasing the availability of nutrients and their use by plants, regardless of the nutrient content of the inoculant itself. A plant biostimulant is substance or microorganism applied to plants for the purpose of improving the nutritional efficiency, abiotic stress tolerance and/or quality characteristics of crops, regardless of its nutrient content. By extension, plant biostimulants also refer to commercial products containing mixtures of these substances and/or microorganisms. Plant Growth Promoting Rhizobacteria (PGPR) can be called biofertilisers or biostimulants; PGPR formulations are biostimulants. It can be noted that biofertilisers are included in biostimulants.