Phosphate solubilisation and indole acetic acid production by bacteria isolated from root system of dipterocarpus alatus

Abstract

Background and Objectives: Phosphate solubilizing bacteria could potentially benefit sustainable organic farming systems and reduce the utilization of agrochemicals in agricultural fields. PSB isolation have been termed important prior to the use of biofertilizer in crop productions. This study was conducted to isolate and determine the potential of PSB from the root system of D. alatus in Northeast Thailand. In order to understand the impact of the ecosystem services of D. alatus in a land use system, we must address the absence of knowledge on the influence of soil fertility on biological processes within the soil. Materials and Methods: PSB isolated from soil in different provinces of Northeast Thailand, where soils are mainly sandy and retain a P deficiency. PSB isolates were tested using different P sources [Tri-calcium phosphate (Ca3(PO4)2) and ferric phosphate (FePO4)] on specific culture media [National Botanical Research Institute Phosphate Growth Medium, (NBRIP)] under controlled conditions. Results: Our results indicated that PSB isolated from Amnat Charoen, Khon Kaen and Mukdahan provinces solubilized higher amounts of FePO4. The highest solubilisation activity was achieved for FePO4, which is the main form of insoluble phosphate in acidic sandy soil. Indole acetic acid (IAA) production was also observed. These results provide essential information on the influence of soil fertility upon D. alatus ecosystem services. Conclusion: Nguyenibacter vanlangensis was the most abundant and solubilized a wide range of FePO4 concentrations better than Ca3(PO4)2 and also produced indole-3-acetic acid.