Antagonistic activity evaluation of Eucalyptus camaldulensis essential oil in control of algae and associated microorganisms

This study includes isolation, purification, and identification of algae from different environmental places (Tigris River and canal around AlJadriah) during February 2008. Nine unialgal cultures were obtainedwhich included 4 species of blue-green algae, 4 species of green algae, and 1 species of diatoms. However, contaminant bacteria and fungi were isolated from 4 of these algal cultures which were Anabaena circinalis, Microcystis aeruginosa, Scenedesmus quardicauda and Chlorella vulgaris. The contaminant bacteria included nine different species which were Stenotrophomonas maltophilia and Bacillus polymyxa which isolated from all the selected algal cultures, while the rest Kocuria varians/rosa, Aerococcus viridians, Micrococcus sp., Staphylococcus auricularis, Staphylococcus capitis, Kocuria kristanae and Staphylococcus cohnii varied in their presence and absence in these algal cultures. The contaminant fungi of the four algal cultures were Aspergillus flavus which was isolated from M. aeruginosa culture, Asp.niger isolated from C. vulgaris culture , Cryptococcus albidus that isolated from S. quardicauda culture, whilst Penicillium sp. isolated from A. circinalis culture. However, Eucalyptus camaldulensis essential oil was extracted and subsequently showed highly activity when tested against six species of the isolated algae and against the isolated contaminant bacteria and fungi species. Chemical composition of the extracted oil was analyzed by HPLC (High Performance Liquid Chromatography).