MICROALGAE FROM ARID ENVIRONMENT AS A SOURCE OF BIOACTIVE POLYSACCHARIDES WITH POTENTIAL HEALTH BENEFITS

Abstract

Abstract.- Recently, microalgae have emerged as a sustainable source of diverse bioactive compounds with extremely high added-value. Among the valuable macromolecules of microalgal biomass, polysaccharides have already proved to be very promising for human interest. An advantage of working with microalgae is the fact that they are easy to grow and culturing, and harvesting does not depend on the climate or season. Being easily controlled, it enables the production of polysaccharides, or whichever other compounds with similar properties, either chemical or physical, all year. Sulfated or not, polysaccharides such as fucoidans in brown algae, carrageenans in red algae and ulvans in green algae exhibit many biological activities such as anticoagulant, antiviral, antioxidative, anticancer and immunomodulating activities. Affected by water temperature, nutrient and light availability; some microalgae species living in arid environment such as Cylindrotheca closterium, Navicula sp. and Arthospira platensis secrete much more polysaccharides for their protection against desiccation. This mechanism can be used to produce significant amounts of exopolysaccharides which after purification processes show many biological applications. In this communication, first, some strains present in the Algerian desert with high polysaccharides content are described. Then their bioactivity including therapeutic applications will be discussed. Finally, i will try to identify the major gaps and opportunities in this field that should be exploited in arid zone in the near future.