Optimization of Indole-3-Acetic Acid Production by Diazotrophic B. subtilis DR2 (KP455653), Isolated from Rhizosphere of Eragrostis cynosuroides
Sonali Kumari, C. Prabha, A. Singh, S. Kumari, and S. Kiran
Department of Botany, Patna University, Patna-800005, India
Abstract—Diazotrophic rhizobacteria, trigger and enhance plant growth as well as yield through various mechanisms, so their use can reduce the application frequency of chemical fertilizers. Indole-3-acetic acid (IAA), a most common natural auxin influences several physiological processes of the plant’s health. The present study is aimed to optimize the conditions for IAA production, along with assay for plant growth promoting traits of Bacillus subtilis DR2 (KP455653), which is a diazotrophic Gram positive, rod bacterium, isolated from rhizosphere of road side weed, Eragrostis cynosuroides from Danapur, Patna, Bihar, India. The screening for IAA production was done in JNFbˉ broth with tryptophan (1 g.l-1) and without tryptophan at pH 5.8, 30±2 °C temperature and 48 h incubation. 137.81 µg.ml-1 and 100.26 µg.ml-1 IAA was produced in Trp+ and Trp- media, respectively. Under various optimized conditions, maximum IAA was produced at 96 h incubation (137.81 µg.ml-1), 35 °C temperature (141.92 µg.ml-1), pH 7 (158.79 µg.ml-1), mannitol as carbon (160.85 µg.ml-1) and ammonium sulfate as nitrogen (162.93 µg.ml-1) sources with tryptophan at final concentration of 1.2 µg.ml-1 (168.09 µg.ml-1), which enhanced the production by 1.2 fold. The findings suggest that B. subtilis DR2 is a potent organism to be used as biofertilizer.
Index Terms— DR2, IAA, PGP, rhizobacteria
Cite: Sonali Kumari, C. Prabha, A. Singh, S. Kumari, and S. Kiran, "Optimization of Indole-3-Acetic Acid Production by Diazotrophic B. subtilis DR2 (KP455653), Isolated from Rhizosphere of Eragrostis cynosuroides," International Journal of Pharma Medicine and Biological Sciences, Vol. 7, No. 2, pp. 20-27, April 2018. doi: 10.18178/ijpmbs.7.2.20-27
Index Terms— DR2, IAA, PGP, rhizobacteria
Cite: Sonali Kumari, C. Prabha, A. Singh, S. Kumari, and S. Kiran, "Optimization of Indole-3-Acetic Acid Production by Diazotrophic B. subtilis DR2 (KP455653), Isolated from Rhizosphere of Eragrostis cynosuroides," International Journal of Pharma Medicine and Biological Sciences, Vol. 7, No. 2, pp. 20-27, April 2018. doi: 10.18178/ijpmbs.7.2.20-27