干旱区生态环境知识资源中心

There are hundreds of thousands to millions of microalgal species, most of which have not been isolated or characterized. Organisms isolated from extreme environments (extremophiles) often possess unique physiological responses that enable their survival in stressful conditions such as extreme light, temperatures or pH, nutrient limitation or high salinity. Algeria hosts the largest desert in the world, with a surface of 450000 km2 and is submitted to a large range of climatic environments from Saharan arid to temperate climates, where the high diversity of microalgae strains remains almost completely undiscovered. The present study reports the pigment characterization of 17 microalgae species isolated from a large longitudinal range of different ecological habitats in Algeria. Algal isolation was performed using a three different selective media (3NBBM, BG11 and diatom medium) under standardized growth conditions. Identification was done using microscopic observations, supported by screening and identification of several 18S DNA and 16S DNA sequencings. Chlorophycean and Cyanophycean were the most dominant of all the isolated algal groups. The highest number of isolated strains was hosted by the Afilal habitat located in the national park of Hoggar in the heart of the Sahara, and Temekrest experimenting intense solar radiation and a large range of temperatures. This study highlights the importance adaptation mechanisms developed by some rare strains isolated in natural guelta under saharan climate, such as Carteria crucifera or Pachycladella umbrina, or cyanobacterial species such as Synechocystis salina. These study highlights the assessment of some species have attracted interest in the field of algal biotechnology, and represent a step toward the development of strains suitable for exteremophiles arid area at the industrial scale.