The present study examines the possibility of increasing the levels of some bioactive compounds
(a-carotene, phycopiliprotein and total lipids) in Spirulina sp. isolated from Wadi El Natron lake (Egypt)
and cultivated in modified Zarrouk's medium under standard growth condition and abiotic stress
including change in culturing condition as (pH, temperature, light intensity), nutrient limitation (-N, -P, -S)
and salinity. The yield production of a-carotene was enhanced with 0.9M NaCl, phosphorus deficiency
and at pH 6. Total lipids were also enhanced in all conditions under tested especially with 0.9M NaCl,
light intensity 1 4.52 Xmol photon.m-2.s-1 . Phycobiliproteins fractions (phycocyanin, allophycocyanine and
phycoerethrine) were elevated with 0.3, 0.6M NaCl as well as phosphorus, nitrogen and sulphur
deficiency. Antioxidant enzymatic activities of Spirulina sp. were elevated with all studied abiotic stress
factor.