Abstract

Studies on Indole acetic acid production and phosphate solubilization from forest soil bacteria

Author(s): N.Senthil, K.Elangovan, S.Rajkumar, M.Bavya

Indole acetic acid (IAA) is a naturally occurring auxin with broad physiological process including cell enlargement and cell division, tissue differentiation and responses to light and gravity. Phosphate solubilizing bacteria (PSB) solubilize insoluble phosphate andmake it available to the plants. In this study, sample was collected from two different areas, Thirupathi and Kerala. Totally 30 bacterial colonieswere selected and used for further screening process. The isolated strain ware screened for IAA production by using SolawaskiÂ’s reagent in nutrient broth. The color change shows the production of IAAproduction. Out of 30 isolates, three (TS2, TS13 and KS3) strains showed pink color which is positive for IAAproduction. TS2, TS13 and KS3 are extracted using separating funnel and the extract was dissolved in methanol and kept in cool temperature. The crude compound was separated by using TLC and the Rf value was noted. Estimation of IAA shows TS2 that strain able to produce maximumIAA ranges between 11.31-26.5µg/ml in the absence and presence of tryptophan. In vitro studies, showed amaximumgrowth in the plants containing TS2, TS13 andKS3 isolates than that of normal plants. Among 30 isolates, 12 strains showed good phosphate solubilization activity in the Pikovskaya medium.