The study was conducted to evaluate the antibacterial , activities of the extracts of the green algae, Chlorella vulgaris.
The pathogenic bacteria was isolated and identified from different samples including urine , stool , ear swab , wound swab and one bacteria isolated from soil .The multiple antibiotic resistance of bacterial isolates was examined against different antibiotics used in this study , the results showed that Staphylococcus aureus E4 resistant to six antibiotics, where as Klebsiell pneuomoniae U1 appear resist to all antibiotics used .
The growth phases of algae were determined and the cultures were harvested at the end of logarithmic phase .The cultures of green algae gave 0.047gm/L..
Results showed that the extraction by ethanol 80% at 80Cْ for 4 h is the best method for extraction of crude materials from green algae .In spite of the appearance of some activity in the stationary phase ,results indicated that ethanolic extract of the green algae at the end of logarithmic phase have broad effects on gram positive and gram negative bacteria,which are resistant to different antibiotics .The results also showed that MIC of of ethanolic extract from the green algae Chlorella vulgaris is 0.9 mg/ml aginst E.coliU3 and Staphylococcus aureua U2.