Investigation of factors affecting lipid accumulation in fresh watermicroalgae for enhancement of biofuel productionAuthor(s): SanaaAbo El-Enin, EntesarAhmed3, SayedaM.Abdo, Rawheya S.El Din, GuzineElDiwani1,GamilaAli
Lipid accumulation is limited by several factors,nutrient composition, light type andillumination period. Three algal strains isolated fromRiverNile of Egypt were used Chlamydomonus variabills, Haematococcus pluvialis (green algae) andMicrocystis aeruginosa (blue green algae).The specieswere grown inBG11mediumunder continuous illumination (24hr) withwhitefluorescent light intensityïÂ»2500Luxandharvested at stationary phase. The factors studied were NaNO3 starvation,NaCl stress, different color ofLight Emittingdiodes,withdifferent light intensityandthe effect of illumination period.GC-analysiswere done to detect the fatty acids present at optimumcondition for each strain to knowwhich ismore suitable for biofuel production.Microcystisaeruginosa, recordedthemaximumlipid content (30%) at control and atNaCl stress 2.5g/l.Chlamydomonus variabills, showedmaximum lipid content 21%at control condition.Haematococcus pluvialis given total lipid content 10%at control and nitrate starvation 0.075 and 0.0 g/lwhile at salt stress 0.5g/l the lipid content increased to reach 25%. In addition the results showed that continues illumination periodisbetterwithwhite light florescent,while, the light / dark 16/8 cycle illumination is better for selected isolateswithLEDlight.