Diversity, activity, and effectiveness of bacteria as plant growth promoting rhizobacteria (PGPR) isolated from Dieng, central Java.

BACKGROUND AND OBJECTIVES

This study was aimed to isolate spp., from the plant rhizosphere and to investigate their effects on the growth of peanut ( L.) as plant growth-promoting rhizobacteria (PGPR).

MATERIALS AND METHODS

The isolates were characterized using YEMA, YEMA + Congo Red, and YEMA + Bromothymol blue (BTB) media. The was tested qualitatively for their ability to produce indole acetic acid (IAA), siderophores, proteases, nitrogenases as well as phosphate solubilizing activity. A greenhouse experiment was carried out to elucidate the effect of inoculation on L. growth.

RESULTS

Eleven isolates were obtained in YEMA media and they were red-pink in the YEMA + Congo Red media. The YEMA + BTB test showed that 2 isolates were slow-growing and the rest were fast-growing isolates. Seven isolates produced siderophores, 5 were capable of phosphate solubilizing, 9 isolates produced protease enzyme, 4 isolates could produce IAA, and 7 isolates could fix nitrogen. The B1 and the combination of some high trait-isolate treatments in Y gave the best results on L. growth.

CONCLUSION

These isolates can be developed as biological fertilizer agents for the peanut plant.