Determination of MIC by visual analysis
The ethanol extract was later tested to determine the Minimal Inhibitory Concentration (MIC) for each
bacterial strain. Freshly, grown bacterial strains 100 μL (106
cells/mL) in nutrient broth was inoculated in tubes
with nutrient broth supplemented with different concentrations (10 – 500 μL) from the stock extract (1 mg/ml)
and antibiotic, respectively and incubated for 24 h at 37 °C. Presence of turbidity denoted presence of micro
organism in the test tube after the period of incubation where as the complete absence of any turbidity indicates
complete inhibition of microbial growth. The test tube with the lowest dilution with no detectable growth by
visual inspection was considered the MIC. The MIC was calculated for the individual bacterial species.