Changes of the Total Lipid and Omega-3 Fatty Acid Contents in two Microalgae Dunaliella Salina and Chlorella Vulgaris Under Salt Stress

Abstract

Effect of salt stress on biomass, cell number, contents of total lipid, omega-3 fatty acids, including ALA (Alpha Linolenic Acid), EPA (Eicosapentaenoic Acid) and DHA (Docosahexaenoic Acid) and their biosynthetic pathway intermediates (palmitic acid, stearic acid, oleic acid and linoleic acid) of two microalgae Dunaliella salina and Chlorella vulgaris were investigated. Dilution stress from 1.5 to 0.5 M NaCl and salt stress from 1.5 to 3 M NaCl were incorporated into the D. salina medium. Salt stress of 200 mM NaCl was also applied to C. vulgaris culture. Results indicated that increasing salt concentration resulted in the reduced growth rate of C. vulgaris and substantial increase of the total lipid content in both species. Proper growth rate of D. salina observed at 1.5 M of NaCl, but higher and lower concentrations led to the decreased growth rate of D. salina. In addition, considerable increase in the degree of fatty acid unsaturation and thereby the total omega 3 fatty acid content of D. salina was observed under salt stress. Salt stress had little positive effect on the amount of total omega-3 fatty acid of C. vulgaris due to the slight increase of the EPA content. Results showed that salt stress is an effective way for enhancing the total lipid and omega-3 fatty acid production in D. salina.

Comparative study on growth, survival and pigmentation ofSolea aegyptiacalarvae by using four different microalgal species with emphasize on water quality and nutritional value

“…In the current study, the water source was significantly affected, biomass, biomass productivity and biochemical composition especially fatty acids, and this could be due to the sensitivity and adaptability of each species to the physico-chemical properties of water. This finding was in agreement with a previous study of Rismani and Shariati (2017), who observed that fatty acid content was altered in two…”

Investigation of nutraceutical potential of the microalgae Chlorella vulgaris and Arthrospira platensis

“…Regarding C. vulgaris, while observed contents of hexadecanoic (Lordan et al, 2011;Ferreira et al, 2017) and 9,12,15-octadecatrienoic acids (Lordan et al, 2011) are relatively similar to those found in other Chlorella species, levels of octadec-9-enoic acid were much lower than in C. vulgaris biomass (Lordan et al, 2011) and C. homosphaera biomass (Ferreira et al, 2017). Though Chlorella is not rich in DHA, there are studies (Ferreira et al, 2017;Rismani & Shariati, 2017) reporting some amount of this n3 PUFA beneficial to human health in C. vulgaris. Wide variations in octadeca-9,12-dienoic acid contents in C. homosphaera or C. minutissima have also been measured (Ferreira et al, 2017).…”

“…Nonetheless, any given FA composition can only be partially ascribed to the genome and phylogenetics' positioning of microalgae. The FA profile of microalgae is largely a function of cultivation conditions and growth phase at the harvest time, as is the case of the well-studied strain I. galbana or C. vulgaris (Ferreira et al, 2017;Rismani & Shariati, 2017) and other Chlorella species (Ferreira et al, 2017). Rismani & Shariati (2017) observed an increase of EPA and DHA concentrations in C. vulgaris with higher salt content.…”

“…The FA profile of microalgae is largely a function of cultivation conditions and growth phase at the harvest time, as is the case of the well-studied strain I. galbana or C. vulgaris (Ferreira et al, 2017;Rismani & Shariati, 2017) and other Chlorella species (Ferreira et al, 2017). Rismani & Shariati (2017) observed an increase of EPA and DHA concentrations in C. vulgaris with higher salt content. It has also been observed an inverse relation between n3 PUFA levels and growth temperature in Isochrysis as well as in other microalgae.…”

Microalgae: Cultivation Aspects and Bioactive Compounds

“…Despite an increase of contamination susceptibility [47], usage of an organic carbon source offers the opportunity to dramatically reduce microalgae cultivation by reusing surplus nutrient found in several factory effluents [48][49][50] or domestic wastewater [34]. Such potential led researchers to combine microalgae cultivation with wastewater treatment, yielding reports which describe the outstanding production of lipids [51] and biomass [52] as well as nitrogen and phosphorus assimilation [53], when growing under heterotrophic mode.…”