Effect of aluminum stress on the quality of Enteromorpha prolifera based on SEM-EDX and FT-IR

To clarify the effect of aluminum stress on the quality of Enteromorpha prolifera (E. prolifera) and to explore the mechanism of the combination of aluminum and E. prolifera, we analyzed changes in the nutrients, micromorphology, element distribution, and spectrum of E. prolifera treated with different concentrations of aluminum (0, 0.2, 2.0, and 20.0 mu mol.L-1) using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FT-IR). The biomass, protein, dietary fiber, and ash contents of E. prolifera initially increased and then subsequently decreased with an increasing concentration of aluminum. Meanwhile, the total amount of amino acids decreased. Scanning the surface of E. prolifera by SEM-EDX revealed that a high concentration of aluminum damaged the cells of E. prolifera. Additionally, the content of aluminum on the surface of E. prolifera cells increased and the absorption of other elements was also affected. The FT-IR analysis showed that aluminum might combine with the functional groups at the 3408 cm(-1), 2928 cm(-1), and 1072 cm(-1) peaks in E. prolifera and alter the characteristic of the different absorption peaks.