LAUSR

Abstract In this study, the mechanism behind the effect of hydrostatic pressure on phosphorus solubilization from sediment to water was studied in culture experiments using reactors pressurized at 0.1, 0.2, 0.5, and 1.0 MPa. In the sterilized group, the phosphorus content in the sediment was not affected by the hydrostatic pressure. In the unsterilized group, the phosphorus release values were 162, 198, 253, and 289 mg kg−1 at 0.1, 0.2, 0.5, and 1.0 MPa, respectively. In addition, when the hydrostatic pressure was increased from 0.1 to 1 MPa, the activity of alkaline phosphatase increased from 210 to 357 mg kg−1 h−1. The abundance of inorganic phosphorus-solubilizing bacteria increased with rising hydrostatic pressure, but the abundance of organic phosphorus-solubilizing bacteria was highest when the hydrostatic pressure was 0.5 MPa. Pearson regression analysis indicated that the maximum organic phosphorus-solubilizing capacity was positively correlated with the alkaline phosphatase activity (R = 0.97, p