Burkholderia sp. KCTC 11096BP as a newly isolated gibberellin producing bacterium

We isolated 864 bacteria from 553 soil samples and bioassayed them on cucumber and crown daisy for plant growth promotion. A new bacterial strain, Burkholderia sp. KCTC 11096BP gave maximum growth promotion and was selected for further investigations. The culture filtrate of this bacterium was thus analyzed for the presence of gibberellins and we found physiologically active gibberellins were found (GA₁, 0.23 ng/100 ml; GA₃, 5.11 ng/100 ml and GA₄, 2.65 ng/100 ml) along with physiologically inactive GA∧9, GA∧12, GA∧15, GA∧20, and GA∧24. The bacterial isolate also solubilised tricalcium phosphate and lowered the pH of the medium during the process. The isolate was identified as a new strain of Burkholderia through phylogenetic analysis of 16S rDNA sequence. Gibberellin production capacity of genus Burkholderia is reported for the first time in current study.