. 2021 Nov 2;12:719504. doi: 10.3389/fpls.2021.719504

TABLE 1.

Qualitative and quantitative solubilization of manganese by rhizobacterial strains isolated from maize rhizosphere.

Strains	MSD (mm)	BGD (mm)	MSI	MSE (%)	SMC (μg mL^–1)
Control	ND	ND	ND	ND	3.42 ± 0.11^e
ASH4	26.00 ± 0.70^c	10.50 ± 0.35^b−e	3.47 ± 0.01^b	247.73 ± 1.60^b	3.59 ± 0.02^e
ASH6	25.54 ± 0.35^cd	14.00 ± 1.41^b	2.86 ± 0.07^b	186.46 ± 21.36^b	10.73 ± 0.59^a
ASH7	9.50 ± 0.03^g	8.45 ± 0.03^cde	2.12 ± 0.03^b	111.80 ± 0.49^b	3.66 ± 0.12^e
ASH8	8.05 ± 0.01^g	7.02 ± 0.01^e	2.14 ± 0.01^b	114.30 ± 0.01^b	3.80 ± 0.17^e
ASH9	7.50 ± 0.03^g	6.50 ± 0.03^e	2.15 ± 0.02^b	115.50 ± 0.84^b	3.69 ± 0.04^e
ASH10	29.50 ± 0.35^b	12.21 ± 1.41^bcd	3.52 ± 0.12^b	252.14 ± 26.76^b	3.79 ± 0.14^e
ASH11	12.45 ± 0.03^f	11.00 ± 0.02^b−e	2.14 ± 0.03^b	113.60 ± 3.21^b	6.58 ± 0.27^b
ASH12	26.00 ± 0.01^c	13.00 ± 0.21^bc	3.11 ± 0.13^b	211.73 ± 34.47^b	3.80 ± 0.02^e
ASH17	23.55 ± 1.06^d	13.50 ± 0.35^b	2.74 ± 0.06^b	173.90 ± 3.30^b	3.56 ± 0.13^e
ASH19	14.03 ± 0.01^ef	12.00 ± 0.01^bc	2.17 ± 0.02^b	116.70 ± 0.02^b	4.89 ± 0.06^c
ASH20	29.00 ± 0.70^b	7.50 ± 2.47^de	5.86 ± 1.26^a	486.36 ± 151.06^a	10.08 ± 0.35^a
ASH22	35.51 ± 1.06^a	19.00 ± 0.70^a	2.87 ± 0.05^b	186.94 ± 1.37^b	5.87 ± 0.13^bc
ASH24	16.01 ± 0.01^e	9.50 ± 1.06^b−e	2.73 ± 0.08^b	172.73 ± 19.28^b	3.59 ± 0.12^e
LSD	1.09	2.27	0.89	88.72	0.31

The strains showed qualitative and quantitative solubilization of manganese (Mn) and were termed Mn-solubilizing bacterial (MSB) strains; qualitative Mn solubilization by MSB strains was determined by spot inoculating bacterial biomass on MnO₂-amended nutrient agar media and Mn solubilization diameter (MSD) was recorded after 48 h of incubation; Mn solubilization index (MSI) and Mn solubilization efficiency (MSE) were calculated by using MSD and bacterial growth diameter (BGD); quantitative Mn solubilization was estimated through inoculating the strains in MnO₂-amended nutrient broth media and solubilized Mn concentration (SMC) was detected through inductively coupled plasma optical emission spectroscopy; data presented are the mean of three replications ± standard error and least significant difference (LSD) test was performed at 5% (p ≤ 0.05) probability level; the means in a vertical line for each attributes sharing common letters were considered statistically similar to each other; ND, not detected.