Phosphorus Solubilization and Mobilization: Mechanisms, Current Developments, and Future Challenge

Abstract

Plants require nutrients for their proper growth and development. After nitrogen phosphate is the second significant element required for plants. Phosphorus is commonly found in form of polyprotic phosphoric acid (H3PO4); however, phosphorus intake is naturally in the form of H2PO−4. The complete phosphorus conversion movements are mineralization and immobilization, weathering, and precipitation besides adsorption and desorption. Organic phosphate is liberated in soil environment by three groups of enzymes, while inorganic phosphate mineralization is achieved by microbial species. The solubilization of phosphate can be elaborated by acid production theory and proton and enzyme theory. The bioformulations of potent phosphorus-solubilizing microbes are used to stimulate the accessibility of phosphate to plant roots. Once potent strain is screened, the metabolic flux of that strain can be improvised, and more bioformulations can be prepared. Several phosphate-solubilizing microbial strains have already been commercialized as formulated products and sold as biofertilizer. However, the use of the biofertilizer is still insufficient. Despite of extensive research in past few decades, a cooperation of basic and applied approaches is still required to reveal hidden potentials of phosphate solubilizers which may not have documented until now.