Isolation and Characterization of Plant Growth-Promoting Endophytic Bacteria Paenibacillus polymyxa SK1 from Lilium lancifolium

Table 3

Plant growth-promoting (PGP) traits of the isolated P. polymyxa SK1.

OA	IAA (μg/ml) at different tryptophan concentrations				ACC	Siderophores (psu) at different Fe(III) citrate concentrations			NA	PS
	0 mg ml^−1	2 mg ml^−1	4 mg ml^−1	6 mg ml^−1		0 μM	0.25 μM	3.0 μM
+++	15.17 ± 0.9	52.67 ± 2.6	79.50 ± 4.6	109.67 ± 5.8	++	41.23 ± 3.4	36.32 ± 1.4	18.23 ± 0.9	++	+

Note: results are means ± standard deviation of three independent experiments with each treatment measured three times. Organic acids (OA), ACC deaminase (ACC), Indole acetic acid (IAA), Nitrogenase activity (NA), and Phosphate solubilization (PS). Evaluation of the positivity to the tests: negative (−) shows the absence of activity, while (+) shows lower to the highest activity (+++).