Importance of Microbial Exo-Metabolites as Postbiotics for Sustainable Agriculture

Plant growth-promoting (PGP) microorganisms are bacteria and fungi associated with the plant holobiont that can positively affect the health and growth of plants. Their beneficial activity is associated with a mixture of organic compounds produced and released outside the cell, including phytohormones such as auxins and auxin-related compounds. This mini-review describes the importance of using microbial exo-metabolites as postbiotics for developing innovative second-generation plant biostimulants for sustainable agriculture.