الفهرس | Only 14 pages are availabe for public view |
Abstract The present study is an endeavor towards the production of antibacterial active substances by some species of blue green (cyanobacteria). One species of blue-green algae was tested for algae capacity to produce antibacterial substances. Cyanobacteria (bluegreen algae) are a group of extraordinary diverse Gram-negative prokaryotes that originated 3.5 billion years ago. The medicinal and nutrient qualities of cyanobacteria were first appreciated as early as 1500 BC, when Nostoc species were used to treat gout, fistula and several forms of cancer (Liu and Chen, 2003). Various workers had studied the antimicrobial properties of Cyanobacteria. In different studies, various crude extracts from Fischerella sp. (Asthana et al., 2006), Oscillatoria anguistisima and Calothrix parietina (Issa,1999), Anabaena, Oscillatoria, Pseudoanabaena, Synechocystis (Kreitlow et al., 1999),Nostoc (Bloor and England, 1989),Phormedium (Fish and Codd, 1994),Fischerella ambigua (Ghasemi et al., 2004), Spirulina Platensis (Kaushik and Chauhan, 2008) were evaluated for their antimicrobial effects on pathogenic microorganisms. They have also reported that the extracts prepared in different solvents were effective against both Gram-positive and Gram-negative organisms. Algae have a significant attraction as natural source of bioactive molecules with a broad range of biological activities, including antimicrobial, antiviral, anticancer, antioxidant, and anti-inflammatory effects (Tuney et al., 2006 and Patra et al., 2008). Algae contain minerals, polysaccharides, amino acid derivatives, carotenoids, and phenolic compounds. Some of these compounds can display antioxidant properties at very low concentrations (Yuan and Walsh, 2006). Microalgae have the potential to produce natural bioactive compounds (in culture), which are difficult to be produced by chemical synthesis (Goud et al., 2007). Phenolic compounds, including flavonoids, phenolic acids, and tannins are considered to be the major contributors to the antioxidant property of higher plants. These compounds also possess diverse biological activities, such as antiinflammatory, anti-atherosclerotic, and anti-carcinogenic activities (Fresco et al., 2006). |