Assessment of phosphate solubilization and indole acetic acid production in plant growth promoting bacteria isolated from green house soils of Gonju-Gun, South Korea

Phosphate solubilizing and indole acetic acid (IAA) producing bacteria are considered to be beneficial microorganisms as they have a profound effect on plant growth. A total of 35 phosphate solubilizing bacterial strains were isolated and screened for the production of IAA. Two best performing Enterobacter species were selected and employed in elucidating their phosphate solubilizing potential and IAA production under different conditions. Both strains were found to increase available phosphorus content in the medium profusely (640 μg/ml in E. ludwigii and 621 μg/ml in E. hormaechei). They recorded the maximum IAA production (240 and 332 μg/ml respectively in E. ludwigii and E. hormaechei), in NB medium supplemented with tryptophan (0.8% and 0.6% respectively in E. ludwigii and E. hormaechei) at 30oC. It is evident from results that both strains possess great potential to be developed as bio-fertilizers which could enhance soil fertility and plant growth through phosphate solubilization and IAA production.