Genomic Insights into Phosphorus Solubilization of Pseudomonas extremaustralis

Pseudomonas extremaustralis was first isolated from Antarctica and gained interest for its ability to thrive in extreme environmental conditions and degrade recalcitrant compounds. Some strains have been identified as phosphobacteria, which play a significant role in phosphorus (P) cycling by solubilizing or mineralizing insoluble phosphate forms for plant uptake. However, there is limited knowledge about the genomic mechanisms involved in P-cycling in the species P. extremaustralis. In this study, we aimed to evaluate the genomic potential of P. extremautralis as a phosphobacteria species by screening genes related to P-cycling. Two P. extremaustralis strains from pisciculture sludge residues were selected to sequence their complete genomes based on their ability to solubilize inorganic P in vitro, and an in silico analysis with all the P. extremaustralis genomes was performed to identify the presence of phosphorus-cycling-related genes. Genes mainly involved in the metabolic processes of two-component systems and transporters, and genes involved in organic acid production and alkaline phosphatases, were identified. This study helps us to understand the metabolic potential of this species and its role as a solubilizer of phosphates and thus a facilitator of plant-available phosphorus, which could guide the use of this species of phosphobacteria in the development of sustainable agriculture.