Salinity Induced the Growth and Proximate Composition of Euglena sp., Local Strain from Dieng, Indonesia

Abstract

AbstractHigh salinity is a challenging environmental stress for organisms to overcome. This study studied the effect of NaCl and KCl with various concentrations (0, 100 mM and 200 mM) for 13 days to explore the physiological, morphological and proximate composition of Euglena sp. Euglena sp. exhibited a significant decrease in growth rate, photosynthetic pigment, and increasing salinity. Meanwhile, the highest biomass, protein and carbohydrate content were found in KCl 100 mM with values; of 0.586 mg/mL, 0.050 μg/mL and 904.589 mg/mL, respectively. The highest lipid content was found in treatment with 200 mM NaCl with 0.42 mg/mL. Euglena sp. treated with salt type NaCl and KCl with a concentration of 200 mM showed an increase in SFA content but a decrease in PUFA content. PUFA content shows many variations of fatty acids. Still, the number of fatty acids like methyl linoleate and methyl linolenate does not exceed the limit of 12% (wt) of the European B100 biodiesel standard. It shows that the salt stress approach with salt type NaCl and KCl effectively increases biofuel production in Euglena sp. Therefore, Euglena sp. is suitable for high-salinity cultivation and biofuel production.