Biomineralization Potential of Priestia aryabhattai, a Freshwater Isolate for Phosphorus Recovery through Struvite Production from Municipal Wastewater

This study investigated the biomineralization potential of Priestia aryabhattai, a freshwater isolate from Kerala, India, for the effective production of struvite from secondary treated municipal wastewater (MW). The isolate exhibited a recovery rate of 92% and 94% for phosphate (PO43-) removal from MW and simulated media (SM) respectively, highlighting its remarkable nutrient recovery potential. The bacterial extracellular polymeric substances (EPS) produced (2.3 +/- 0.08 g/L) in MW demonstrated a significant influence on struvite production. The influence of PO43-, magnesium (Mg2+), and ammonium (NH4+) content was studied for EPS and struvite production. In comparison, double the ratio of NH4+ led to low yields in EPS and struvite of 2.98 +/- 0.19 g/L and 2.3 +/- 0.34 g/L. In addition, the produced EPS and struvite were characterized for XRD, FTIR, TGA-DSC, and SEM. Furthermore, the produced struvite was studied for its fertilizing potential in the test plant Trigonella foenum-graecum L. Struvite increased plant growth compared to commercial fertilizers, with faster P release in soil at 0.23 mg/kg and pH 5. The research highlights the potential of Priestia aryabhattai in sustainable P recovery through struvite production.