Plant Growth Promoting Bacteria (PGPB) are a group of beneficial microorganisms that can positively influence plant fitness and development by improving nutrient acquisition, influencing global plant hormone levels (direct effect), or by reducing the detrimental effects of various pathogens on plant development (indirect effect). The use of PGPB in agriculture as formulated bioinoculants is a potential approach to reduce the negative environmental impacts caused by the continuous application of chemical fertilizers and pesticides. The evaluation of a great number of bacteria in the laboratory for key traits involved in the improvement of plant fitness is a suitable strategy to find prospective candidates for bioinoculants. This chapter presents the main methods described in the literature to quickly screen potential candidates from a bacterial collection to directly and indirectly promote the plant growth.
Keywords: ACC deaminase; Biocontrol; Biological nitrogen fixation; Indole acetic acid; Phosphate solubilization.