Variation of chemical compositions and fatty acids profiles of Chlorella sp. utilizing physical shocks

Abstract

Abstract The biochemical compositions of microalgae are altered with the change in pH, temperature, photoperiod, salinity, and metal content in the culture media. This study aimed to evaluate the effect of different environmental shocks on the lipid, EPA, and DHA fatty acids levels in Chlorella sp. The algae were cultivated for 12 days using a Guillard medium for biomass production. At this stage, algae were reared under eight shock conditions for six days; T1 (control), T2 was subjected to salinity+pH+starvation, T3 to salinity, T4 to starvation, T5 to pH+starvation, T6 to salinity+pH, T7 to salinity+starvation and T8 to pH shocks. The samples were collected at the end of the dark or light period. The results revealed that the lipid content of Chlorella sp. was significantly affected by darkness in T6. The lipid content under salinity shock during the light period was significantly lower than T5 on day 18. The Arachidonic acid (ARA) and EPA in T4 and DHA in T6 during the dark period exhibited significant differences compared to other groups (p<0.05). Based on the results obtained highest lipid production and DHA synthesis in chlorella sp. were induced on day 18 during the dark period by T4 and T6, respectively.