Figure 4.

Insoluble phosphate degradation and phytases production by B. altitudinis WR10: (a), phenotypic degradation on agar plate; (b), free phosphorus in medium under different treatments; (c). phytases activity in the medium under different levels of P. For phenotypic assays, two microliters of pre-cultured B. altitudinis WR10 was spotted on LB agar supplemented with insoluble Ca₃(PO₄)₂ or Ca–phytate and incubated at 37 °C for 24 h. Culture medium was used for assay of free phosphorus after centrifugation. For phytase enzyme activity assays, B. altitudinis WR10 was grown in LB broth supplemented with different concentrations of KH₂PO₃ (0, 10, 100, 500 μM) and incubated at 37 °C by agitating for 24 h. Supernatants were collected for enzymatic assay using the Phytex method. Data were mean of three independent experiments.)