Insights in nodule-inhabiting plant growth promoting bacteria and their ability to stimulate Vicia faba growth

Figures & data

Table 1. The identification and characterization of plant growth promoting strains (P3, P4, P5, P7 and P8) obtained from Phaseolus vulgaris nodules. (+) mean +ve result and (-) mean – ve result

Isolate	Genus	Closest relatives	Length of sequence	Accession number	IAA	Ammonia	HCN	Siderophores	Protease	Lipase	Cellulase	Amylase
P3	Bacillus	Bacillus amyloliquefaciens AB255669	515 bp	MG214652	+	+	+	+	+	+	+	+
P4	Brevibacillus	Brevibacillus parabrevis AB112714	487 bp	MG214653	+	+	+	+	+	+	+	-
P5	Pseudomonas	Pseudomonas putida D84020	375 bp	MG214654	+	+	+	-	-	+	+	+
P7	Rhizobium	Rhizobium leguminosarum KY495212	409 bp	MG214656	+	+	-	+	+	+	+	-
P8	Pseudomonas	Pseudomonas hibiscicola AB021405	208 bp	MG214655	-	+	+	+	+	+	+	+

Figure 1. Cross inoculation of P4, P5 and P7 showing no signs of antagonism among them.

Figure 2. Time trajectory for growth of the isolates under investigation within bioreactor on the optimized cheap production medium under precise controlled conditions (28^°C, pH 7 and 150 rpm stirring). The dissolved oxygen DO was started from 100% and decreased with time. The microbial growth in fermentor is fold than that in flask.

Table 2. Effect of bacterial treatments on growth parameters of Vicia faba plant during the pre-flowering stage. P3: Bacillus MP3, P4: Brevibacillus MP4, P5: Pseudomonas MP5, P7: Rhizobium MP7 and P8: Pseudomonas MP8.

Treatments	Shoot length (cm/plant)	Root length (cm/plant)	Shoot dry wt. (g/plant)	Root dry wt. (g/plant)	Number of nodules/plant
Control	53.5 ± 0.76*^d	13.75 ± 0.38 ^bc	1.95 ± 0.41 ^b	0.45 ± 0.08 ^a	11.67 ± 1.20 ^e
P7	59 ± 3.21 ^cd	13 ± 0.58 ^c	2.37 ± 0.6 3 ^ab	0.51 ± 0.06 ^a	27.33 ± 2.96 ^c
P7+ P3	67.67 ± 2.33 ^ab	17.75 ± 0.80 ^abc	2.35 ± 0.0 7 ^ab	0.44 ± 0.01 ^a	19 ± 0.58 ^d
P7+ P4	68.73 ± 0.62 ^a	15.75 ± 0.25 ^abc	2.28 ± 0.13 ^ab	0.44 ± 0.09 ^a	22 ± 1.73 ^cd
P7+ P5	63 ± 2.89 ^abc	15.75 ± 1.69 ^abc	3.01 ± 0.24 ^ab	0.91 ± 0.35 ^a	26 ± 0.58 ^c
P7+ P8	60.33 ± 4.33 ^bcd	18.5 ± 1.50 ^ab	2.61 ± 0.56 ^ab	0.53 ± 0.06 ^a	35.33 ± 2.33 ^b
P7+ P4+ P5	71 ± 0.58 ^a	18.75 ± 2.88 ^a	3.23 ± 0.19 ^a	0.7 ± 0.17 ^a	57 ± 3.79 ^a
P7+ P3+ P4+ P5+ P8	65.25 ± 2.6 7 ^abc	17 ± 1.53 ^abc	2.56 ± 0.34 ^ab	0.48 ± 0.08 ^a	22.67 ± 1.45 ^cd
LSD	7.59	4.36	1.11	0.45	6.34

*Values are the mean of three replications ± standard error. Different letters within each column means values significant at P ≤ 0.05.

Table 3. The effect of bacterial treatments on photosynthetic pigments of Vicia faba during the pre-flowering stage. P3: Bacillus MP3, P4: Brevibacillus MP4, P5: Pseudomonas MP5, P7: Rhizobium MP7 and P8: Pseudomonas MP8.

Treatment	Chl. A (mg/g dwt.)	Chl. B (mg/g dwt.)	Carotenoids (mg/g dwt.)
Control	4.76 ± 0.22*^c	3.53 ± 0.13 ^cd	2.98 ± 0.20 ^b
P7	5.74 ± 0.09 ^b	2.61 ± 0.12 ^d	2.55 ± 0.05 ^c
P7+ P3	5.80 ± 0.13 ^ab	6.72 ± 0.29 ^b	4.51 ± 0.07 ^a
P7+ P4	4.43 ± 0.24 ^c	3.95 ± 0.28 ^c	3.01 ± 0.13 ^b
P7+ P5	6.29 ± 0.20 ^ab	6.44 ± 0.42 ^b	4.66 ± 0.10 ^a
P7+ P8	6.32 ± 0.17 ^a	3.62 ± 0.7 ^cd 7	4.69 ± 0.20 ^a
P7+ P4+ P5	3.46 ± 0.16 ^d	7.12 ± 0.23 ^b	4.66 ± 0.12 ^a
P7+ P3+ P4+ P5+ P8	4.96 ± 0.14 ^c	8.59 ± 0.25 ^a	4.80 ± 0.07 ^a
LSD	0.52	1.09	0.38

*Values are the mean of three replications ± standard error. Different letters within each column means values significant at P ≤ 0.05.

Table 4. Effect of bacterial treatments on carbohydrates content of Vicia faba shoot and root during the pre-flowering stage. P3: Bacillus MP3, P4: Brevibacillus MP4, P5: Pseudomonas MP5, P7: Rhizobium MP7 and P8: Pseudomonas MP8.

Treatment	Glucose (mg/g dwt.)		Sucrose (mg/g dwt.)		Polysaccharides (mg/g dwt.)
	Shoot	Root	Shoot	Root	Shoot	Root
Control	5.11 ± 0.0 9*^cd	1.36 ± 0.15 ^e	48.62 ± 1.12 ^b	14.34 ± 0.62 ^f	126.48 ± 1.90 ^a	132.06 ± 0.70 ^cd
P7	5.39 ± 0.63 ^d	2.52 ± 0.28 ^d	17.83 ± 0.53 ^a	60.42 ± 2.50 ^b	93.52 ± 2.24 ^bc	113.26 ± 5.17 ^d
P7+ P3	5.79 ± 0.10 ^b	2.79 ± 0.62 ^cd	51.23 ± 11.54 ^bc	33.61 ± 2.79 ^d	123.27 ± 3.04 ^a	144.93 ± 3.61 ^bc
P7+ P4	6.23 ± 0.18 ^c	4.62 ± 0.49 ^ab	18.84 ± 7.74 ^b	63.28 ± 2.23 ^b	77.51 ± 6.23 ^d	83.58 ± 9.51 ^e
P7+ P5	7.43 ± 0.05 ^b	3.75 ± 0.25 ^bc	35.17 ± 0.75 ^bc	50.77 ± 1.56 ^c	94.95 ± 5.76 ^bc	91.88 ± 4.89 ^e
P7+ P8	8.49 ± 0.18 ^cd	4.45 ± 0.19 ^ab	51.02 ± 5.65 ^a	65.24 ± 1.22 ^b	98.45 ± 4.01 ^bc	161.23 ± 8.57 ^b
P7+ P4+ P5	7.01 ± 0.19 ^b	4.94 ± 0.19 ^a	44.33 ± 2.17 ^c	26.10 ± 2.58 ^e	92.80 ± 5.08 ^c	195.70 ± 9.02 ^a
P7+ P3+ P4+ P5+ P8	7.32 ± 0.18 ^a	4.13 ± 0.12 ^ab	55.85 ± 3.02 ^c	87.95 ± 3.45 ^a	106.67 ± 2.72 ^b	183.47 ± 5.11 ^a
LSD	11.72	0.98	51.17	6.86	12.50	19.41

*Values are the mean of three replications ± standard error. Different letters within each column means values significant at P ≤ 0.05.

Table 5. Effect of bacterial treatments on nitrogenous constitute of Vicia faba shoot and root during the pre-flowering stage. P3: Bacillus MP3, P4: Brevibacillus MP4, P5: Pseudomonas MP5, P7: Rhizobium MP7 and P8: Pseudomonas MP8.

Treatment	Nitrate (mg/g dry wt.)		Ammonia nitrogen (mg/g dry wt.)		Amino nitrogen (mg/g dry wt.)		Total nitrogen (mg/g dry wt.)
	Shoot	Root	Shoot	Root	Shoot	Root	Shoot	Root
Control	8.56 ± 0.72*^b	7.35 ± 20 ^b	10.84 ± 0.67 ^d	11.25 ± 0.44 ^c	60.89 ± 1.16 ^e	74.13 ± 2.61 ^c	175 ± 3.21 ^d	92.5 ± 5.97 ^d
P7	7.53 ± 0.51 ^bc	9.98 ± 0.82 ^a	15.99 ± 0.67 ^bc	14.39 ± 0.14 ^b	96.41 ± 3.58 ^cd	80.04 ± 2.23 ^c	192 ± 4.36 ^c	98.8 ± 5.70 ^d
P7+ P3	7.21 ± 0.48 ^bcd	10.65 ± 0.97 ^a	16.72 ± 0.65 ^b	10.73 ± 0.49 ^cd	162.79 ± 12.55 ^a	94.41 ± 2.46 ^b	193 ± 4.16 ^c	86.5 ± 4.27 ^de
P7+ P4	6.89 ± 0.60 ^bcde	11.25 ± 1.42 ^a	14.33 ± 0.33 ^c	9.22 ± 0.19 ^d	86.47 ± 2.76 ^d	90.18 ± 2.74 ^b	141 ± 5.20 ^e	75.5 ± 3.04 ^e
P7+ P5	12.35 ± 0.26 ^a	6.15 ± 0.84 ^b	6.98 ± 0.69 ^e	13.75 ± 0.32 ^b	112.12 ± 1.16 ^bc	55.96 ± 3.01 ^d	176 ± 4.73 ^d	125.6 ± 5.36 ^c
P7+ P8	5.53 ± 0.33 ^de	11.37 ± 0.65 ^a	19 ± 2.31 ^a	11.50 ± 1.06 ^c	51.02 ± 1.34 ^e	47.58 ± 0.57 ^d	226 ± 2.08 ^b	206 ± 4.93 ^b
P7+ P4+ P5	5.22 ± 0.53 ^e	12.22 ± 0.59 ^a	20.22 ± 3.49 ^a	16.69 ± 0.38 ^a	149.75 ± 3.07 ^a	105.66 ± 5.36 ^a	228 ± 3.21 ^b	211 ± 5.51 ^b
P7+ P3+ P4+ P5+ P8	6.25 ± 0.61 ^cde	6.32 ± 0.44 ^b	15.39 ± 0.52 ^bc	13.14 ± 0.40 ^b	126.29 ± 5.31 ^b	78.91 ± 0.47 ^c	262 ± 4.16 ^a	233.5 ± 1.76 ^a
LSD	1.57	2.45	1.83	1.51	15.72	8.45	11.99	14.30

*Values are the mean of three replications ± standard error. Different letters within each column means values significant at P ≤ 0.05.

Table 6. The obtained biomass (g/L) in co-culturing experiments and Multi-Way ANOVA for the results

Organisms combination	Dry weight (g/L)	Effect	Coefficient	T- value	P- value
P4	0.8	0.150	0.075	3.00	0.205
P5+ P4	0.8	−0.350	−0.175	−7.00	0.090
P7+ P4	0.4	−0.850	−0.425	−17.00	0.037
Control	0	-	-	-	-
P7+ P4+ P5	2.4	1.050	0.525	21.00	0.030
P5	1.2	−0.250	−0.125	−5.00	0.126
P7	1.8	−0.150	−0.0750	−3.0	0.205
P7+ P5	0.8	−0.050	−0.025	−0.06	0.963