An experiment was carried out to determine the converable carbon sources, tryptophane and adenine concentrations for growth regulators production by Azotobacter chroococcum and Bacillus megaterium var. phosphaticum. Obtained results showed that the mannitol and glucose were the best carbon sources for PGRs production by A. chroococcum and B. megaterium var. phosphaticum, respectively. Also, the produced amounts of indole butyric acid (IBA) was higher than IAA with different applied carbon sources. A. chroococcum produced higher amounts of zeatin
and kinetin compared to those produced by B. megaterium var. phosphaticum. While, B. megaterium var. phosphaticum produced higher amounts of (9R) benzyl adenine and (9G) benzyl adenine compared with those produced by A. chroococcum. Production of auxins, gibberellic acid (GA3) and cytokinins was increased with increasing tryptophan concentration. The highest amounts of PGRs produced by the two strains were obtained with tryptophan addition at 10-3 molar. Highest amounts of PGRs were produced by A. chroococcum and B. megaterium var. phosphaticum when adenine was applied with 10-5 and 10-4 molar to the both strains, respectively. The two strains produced IBA amounts higher than IAA. Also, A. chroococcum produce higher amount of gibberellic acid and cytokinin rather than that given by B. megaterium var. phosphaticum. Generally, obtained data from investigation showed that the application of the optimal conditions together gave highest amounts of PGRs as compared with the other individual treatments. This result is logic and was anticipated.
Keywords: PGPR, PGRs, carbon sources, tryptophane, adenine, TLC, GLC, Azotobacter, Bacillus |
