The effect of acidic pH on chlorophyll, carotenoids, and carotenoid derivatives of Euglena sp. as antioxidants

Euglena sp. is a microalgae species of the phylum Euglenozoa that lives in freshwater, in open, sunny areas. The potential of Euglena sp. as an innovative functional ingredient in the food and feed industry, as well as medicines and cosmetics, is closely related to the presence of pigments in Euglena sp. Euglena sp. contains chlorophyll pigments a and b, as well as carotenoids such as xanthophyll, astaxanthin, zeaxanthin, carotene, and beta-carotene. The pH is an essential factor in microalgal cultivation. The pH changes generally affect biomass, primary metabolites, and secondary metabolites in microalgae growth. In this study, Euglena sp. was cultivated on a Cramer-Myers medium and treated under different acidic conditions. This study aims to determine the effect of pH on the production of pigments in Euglena sp. Culture optimization of Euglena sp. was carried out on various acidic pH media at pH 2.5, 3.5, and 4.5. The production results of chlorophyll and total carotenoids, astaxanthin, and carotenoid derivatives of Euglena sp. were analyzed using One-Way ANOVA at a 95 confidence level, followed by Duncan's advanced test. Based on the analysis, the study results show that Euglena sp. at pH 4.5 has the most optimal production of chlorophyll and total carotenoids, astaxanthin, and carotenoid derivatives compared to the other pH treatments. In the pH treatment of 4.5, the average output of chlorophyll a was 12.898±0.357 μg mL-1, and the productions of chlorophyll b, total carotenoids, and astaxanthin were 7.563±1.800 μg mL-1, 3.244±0.235 μg mL-1, and 1.187x10-3 ±0.078 g L-1, respectively. © 2023, BIOFLUX SRL. All rights reserved.