Spectroscopic insights exploring triacylglyceride accumulation in Scenedesmus sp. via biomolecular transitions

Abstract In current study, microalgae Scenedesmus sp. was treated with three different salts with varying levels from 10 to 100mM: Sodium chloride (NaCl), Magnesium chloride hexahydrate (MgCl2.6H2O) and Calcium chloride dihydrate (CaCl2.2H2O). NaCl (100mM) treated cells showed highest lipid accumulation in comparison to other salts. On the other hand, little improvement in lipid accumulation was also observed with varying concentrations of CaCl2.2H2O and MgCl2.6H2O. Further, Fourier Transform Infra-Red (FTIR) spectroscopy reveals biomolecular transitions leading to changes in Triacylglycerides (TAGs) and hydrocarbon (CH) stretches from the lipids. It is observed that the maximum TAG was accumulated when treated with NaCl (70mM). This was further confirmed through the ratio of TAGs to Amide and CH to Amide. Thus, in relevance to rapid analysis of algal samples for lipid accumulation and changes in biomolecular transitions of proteins and carbohydrates with salt treatment, FTIR can direct us to a noninvasive approach.