Research Article
Bambara Nut Root-Nodules Bacteria from a Semi-Arid Region of South Africa and Their Plant Growth-Promoting Traits
Table 2
API 20E-based biochemical characterization of the bacterial isolates.
| Tests | Reaction | Negative | Positive | BA1 | BA2 | BA3 | BA4 | BA5 |
| ONPG | β-Galactosidase | Colourless | Yellow | + | − | + | − | − | ADH | Arginine dihydrolase | Yellow | Red or orange | + | + | + | + | + | LDC | Lysine decarboxylase | Yellow | Red or orange | + | − | − | − | − | ODC | Ornithine decarboxylase | Yellow | Red or orange | + | − | − | − | − | CIT | Citrate utilization | Pale green or yellow | Blue-green or blue | + | − | − | + | + | H2S | H2S production | Colourless or grey | Black deposit | − | − | − | − | − | URE | Urea hydrolysis | Yellow | Red or orange | + | − | − | − | − | TDA | Tryptophan deamination | Yellow | Reddish brown | + | + | + | + | + | IND | Indole production | Colourless pale green or yellow | Pink | − | − | − | − | − | VP | Acetoin production | Colourless | Pink or red | + | + | + | + | + | GEL | Gelatin hydrolysis | No diffusion | Diffusion of black pigment | + | + | + | − | − | GLU | Glucose fermentation | Blue or blue-green | Yellow or greyish yellow | + | + | + | + | + | MAN | Mannitol | Blue or blue-green | Yellow | − | − | − | − | − | INO | Inositol | Blue or blue-green | Yellow | − | − | − | − | − | SOR | Sorbitol | Blue or blue-green | Yellow | − | − | − | − | − | RHA | Rhamnose | Blue or blue-green | Yellow | − | − | − | + | + | SAC | Sucrose | Blue or blue-green | Yellow | − | − | − | − | − | MEL | Melibiose | Blue or blue-green | Yellow | + | − | − | + | + | AMY | Amygdalin | Blue or blue-green | Yellow | + | − | − | — | — | ARA | Arabinose | Blue or blue-green | Yellow | + | − | − | + | + |
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