Phosphorus recycling mediated by Pseudomonas aeruginosa from eutrophic biochar

Abstract

Present study focused on Phosphorus (P) enriched i.e., eutrophic biochar and its solubilization utilizing Pseudomonas aeruginosa (NCIM 8650). Previously established processes for lesser toxic and P rich biochar production (T-B-400, T-B-600 and T-B-800) using phosphogypsum pond wastewater soaked banana peduncles at three different pyrolysis temperatures (400, 600 and 800 °C) were utilized for the experiments. Bacteria inoculated in biochar loaded Pikovskaya (PVK) broth (modified: 0.2 g biochar/100 ml) was analyzed for 15 days about P solubilization along with control (modified broth without Pseudomonas aeruginosa). Gradual increase of P solubilization was observed with maximum values for T-B-400 and T-B-600 on 9th day in variation to 11th day of T-B-800. Different organic acids (Carbamic, Propanoic and Stearic hydrazide) ascertained through GCMS analysis along with significant pH change (7 to 3.41, 4.1 and 3.26 for T-B-400, T-B-600 and T-B-800 respectively) played major role toward P solubilization of modified PVK broth and highlighted significantly (p < 0.05) high release of P from T-B-400 (76%) than T-B-600 (65%) and T-B-800 (71%) over control. The FE-SEM, FTIR and XRD analysis (9th day: T-B-400/T-B-600; 11th day: T-B-800) of biochar residues in modified broth showed distinct morphological, structural and mineralogical changes in comparison to control. The findings highlights the potential of P solubilization by Pseudomonas aeruginosa from euthophic biochar, and hence provide opportunities for nutrients recovery from wastes.