Table 1. Screening for biosurfactant production and plant growth promotion by Streptomyces spp.
| Isolate | EI (%) | EA (EumL-1) | Surface Tension (mN/m) | IAA production (μg/mL) | P solubilization (μg/mL) | HCN production | Ammonia production |
|---|---|---|---|---|---|---|---|
| RHPR3 | 58±(0.1)d | 180±(0.1)b | 42.5 | 38.2±(0.2)b | 442.1±(0.1)d | ++ | ++ |
| RHPR9 | 78±(0.2)a | 223±(0.2)a | 38.5 | 41.2±(0.1)a | 749.1±(0.2)a | +++ | +++ |
| RHPR14 | 70±(0.2)b | 159±(0.2)d | 57.1 | 35.1±(0.2)c | 522.7±(0.1)c | + | + |
| RHPR25 | 62±(0.1)c | 171±(0.2)c | 49.3 | 26.8±(0.2)d | 612.2±(0.1)b | + | + |
The superscribed values, a–f, indicate highest to lowest of significance; the same superscribed values a-f according to Fischer’s least significance difference test (p<0.05) are insignificant. Values in the brackets indicate a standard error, values in a column are the mean of two experiments 6 replications.
+, ++, +++ indicate weak, moderate and heavy producers respectively based on visual rating.
EI, EA, IAA, HCN indicate emulsification index, indole acetic acid and hydrogen cyanide respectively.