Table 3.
Metal resistance, possibly resulting in decreased phytotoxicity, of cultivable strains isolated from the shoot, the roots and the rhizosphere of BR and TO willow clones growing on metal-contaminated soil
| BR | TO | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Identification | cfu/g | Cd (0.4) | Cd (0.8) | Zn (0.6) | Zn (1.0) | Identification | cfu/g | Cd (0.4) | Cd (0.8) | Zn (0.6) | Zn (1.0) | |
| Shoot | Bacillus pumilus | 1.14E+04 | − | − | − | − | Unc. rhodococcus | 7.50E+05 | − | − | − | − |
| Bacillus pumilus | 2.29E+04 | − | − | − | − | Unc. γ-proteobacterium | 1.98E+06 | − | − | − | − | |
| Bacillus pumilus | 3.81E+03 | − | − | + | − | Bacillus cereus | 7.50E+05 | + | − | − | − | |
| Bacillus pumilus | 1.24E+03 | − | − | + | + | Bacillus cereus | 2.08E+05 | − | − | − | − | |
| Bacillus pumilus | 1.24E+03 | − | − | − | − | Bacillus cereus | 1.38E+05 | + | − | + | + | |
| Bacillus pumilus | 6.20E+02 | − | − | − | − | Bacillus cereus | 7.75E+01 | − | − | + | + | |
| Paenibacillus lactis | 2.15E+05 | − | − | − | − | Bacillus subtilis | 7.75E+01 | − | − | − | − | |
| Paenibacillus lactis | 8.39E+02 | − | − | − | − | Bacillus pumilis | 7.75E+01 | + | − | + | + | |
| Paenibacillus lactis | 8.39E+02 | − | − | − | − | Bacillus sp. | 7.50E+05 | − | − | + | + | |
| Pseudomonas syringae | 8.12E+02 | − | − | − | − | Bacillus sp. | 6.25E+04 | − | − | − | − | |
| Pantoea agglomerans | 2.89E+04 | − | − | − | − | Bacillus sp. | 2.08E+04 | − | − | − | − | |
| Pantoea agglomerans | 7.22E+03 | − | − | − | − | Bacillus sp. | 7.75E+01 | − | − | + | − | |
| Micrococcus sp. | 2.08E+05 | + | − | − | − | |||||||
| Acinetobacter johnsonii | 2.67E+05 | − | − | − | − | |||||||
| Chryseobacterium hominis | 1.33E+05 | − | − | − | − | |||||||
| Staphylococcus pasteuri | 1.39E+06 | − | − | − | − | |||||||
| Total (%) | 2.95E+05 | 0.00 | 0.00 | 1.71 | 0.42 | Total (%) | 6.65E+06 | 16.48 | 0.00 | 13.35 | 13.35 | |
| Root | Caulobacter sp. | 7.85E+05 | − | − | − | − | Bacillus cereus | 2.13E+04 | + | − | + | + |
| Caulobacter sp. | 1.96E+05 | − | − | − | − | Bacillus cereus | 1.50E+04 | − | − | + | + | |
| Bacillus pumilus | 2.10E+05 | − | − | − | − | Bacillus sp. | 1.10E+04 | − | − | + | − | |
| Bacillus pumilus | 5.26E+04 | − | − | − | − | Bacillus sp. | 2.75E+03 | − | − | + | + | |
| Bacillus pumilus | 5.26E+04 | − | − | − | − | Staphylococcus sp. | 1.25E+03 | + | − | − | − | |
| Rhizobium radiobacter | 5.58E+05 | − | − | − | − | Staphylococcus sp. | 3.75E+03 | − | − | − | − | |
| Staphylococcus sp. | 5.75E+03 | − | − | − | − | |||||||
| Staphylococcus sp. | 1.25E+03 | + | + | + | − | |||||||
| Staphylococcus sp. | 1.25E+03 | − | − | + | − | |||||||
| Streptomyces sp. | 1.73E+04 | − | − | + | − | |||||||
| Streptomyces punicolor | 1.38E+04 | + | + | + | − | |||||||
| Pseudomonas sp. | 5.75E+04 | + | + | − | − | |||||||
| Pseudomonas sp. | 1.88E+04 | + | + | − | − | |||||||
| Pseudomonas sp. | 1.25E+03 | + | − | + | − | |||||||
| Arthrobacter gandavensis | 1.25E+03 | − | − | − | − | |||||||
| Caulobacter sp. | 1.25E+03 | − | − | − | − | |||||||
| Total (%) | 1.85E+06 | 0.00 | 0.00 | 0.00 | 0.00 | Total (%) | 1.74E+05 | 66.00 | 52.37 | 48.64 | 22.38 | |
| Rhizosphere | Streptomyces sp. | 8.00E+05 | − | − | − | − | Unc. γ-proteobacteria | 2.59E+05 | − | − | + | − |
| Leifsonia sp. | 1.28E+06 | + | + | − | − | Unc. γ-proteobacteria | 1.18E+05 | − | − | + | − | |
| Dermacoccus sp. | 4.80E+05 | − | − | − | − | Bacillus sp. | 2.35E+05 | − | − | + | − | |
| Bacillus pumilus | 8.35E+05 | − | − | − | − | Bacillus sp. | 2.82E+05 | − | − | + | + | |
| Bacillus pumilus | 4.18E+05 | + | + | − | − | Bacillus sp. | 4.24E+05 | − | − | − | − | |
| Paenibacillus lactis | 1.33E+06 | − | − | − | − | Bacillus sp. | 1.18E+05 | − | − | − | − | |
| Caulobacter sp. | 2.00E+05 | − | − | − | − | Bacillus sp. | 3.53E+05 | + | − | + | + | |
| Caulobacter sp. | 2.00E+05 | − | − | − | − | Staphylococcus epidermis | 1.41E+05 | + | + | − | − | |
| Luteibacter rhizovicinus | 4.80E+05 | − | − | − | − | Staphylococcus capitis | 3.06E+05 | − | − | − | − | |
| Staphylococcus sp. | 1.18E+05 | − | − | + | − | |||||||
| Burkholderia pyrrocinia | 1.41E+05 | + | + | + | + | |||||||
| Burkholderia sp. | 4.00E+05 | + | + | + | − | |||||||
| Leifsonia spec. | 3.76E+05 | + | + | + | + | |||||||
| Variovorax sp. | 2.35E+05 | − | − | + | − | |||||||
| Caulobacter sp. | 1.18E+05 | − | − | − | − | |||||||
| Total (%) | 6.02E+06 | 28.20 | 28.20 | 0.00 | 0.00 | Total (%) | 3.62E+06 | 38.95 | 29.22 | 69.49 | 31.81 | |
cfu/g: colony-forming units per gram fresh weight; 284 medium with addition of carbon mix and respectively 0.4 mM CdSO4, 0.8 mM CdSO4, 0.6 mM ZnSO4 and 1 mM ZnSO4.
+: good growth; −: no growth. Total: cfu/g: total amount of isolated bacteria in shoot, root or rhizosphere; Cd (0.4), Cd (0.8), Zn (0.6) and Zn (1.0): percentage of bacteria associated with the shoot, root and rhizosphere that tested positive.