Ten most efficient phosphate solubilizing bacteria and three fungi (PSM) isolated from maize rhizosphere were studied for
biochemical characteristics. PSM were grown in vitro for seven days on Pikovskaya,
s medium and following analyses were
carried out i.e. solubilization index, pH change, phosphorus (P) solubilized, P immobilized and organic acids produced under
in vitro conditions. P solubilization index of these isolates ranged from 1.63-3.29. Drop in pH of the medium ranged from 7 to
3.2 with the continuous growth of these isolates for seven days. Study showed that more P was immobilized (0.2-0.46%) than
solubilized (0.088-0.22%). Bacteria were found to be more active than fungi in conversion of insoluble P to soluble P. Citric
and oxalic acids were two common organic acids produced by PSM. Correlation studies suggested that besides organic acids
there might be other factors responsible for P solubilization.