Effect of Fungicides on Phosphate Solubilization by Klebsiella oxytoca and Enterobacter ludwigii

The aim of the present study was to isolate phosphate solubilizing bacteria (PSB) and to assess their potential tolerance to fungicides. Out of thirty PSB, two strains Klebsiella oxytoca and Enterobacter ludwigii were selected on the basis of their tolerance to fungicides. Both strains were assessed for their phosphate solubilizing ability using three different fungicides (difenoconazole, fluazinam and streptomycin) each with the concentrations of 0, 1, 2 or 3 times of the recommended rate. Both strains showed increased phosphate solubilization with difenoconazole at 1, 2 and 3 times of the recommended rate as compared to the phosphate solubilization of the control. The phosphate solubilization in Klebsiella oxytoca was recorded as 326, 538, 518 and 481 ${\mu}g\;mL^{-1}$ at 0, 1, 2 and 3 times of the recommended rate respectively, whereas in Enterobacter ludwigii it was recorded as 395, 499, 529 and 533 ${\mu}g\;mL^{-1}$ respectively at various doses. Based on the present findings, it may be concluded that both strains have the potential to be used as bio-inoculants which can solubilize phosphate even at the higher doses as compared to the recommended rate of fungicides.