Effects of ultraviolet radiation on production of photoprotective compounds in microalgae of the genus Pediastrum from high Andean areas of Peru

Abstract

This study aims to collect microalgae from high Andean areas and evaluate their potential as natural ingredients in the cosmetics industry. The cell growth, pigment concentration, antioxidant activity, and polyphenols content of two microalgae of the genus Pediastrum (IMP-BG288 and IMP-BG255) collected from high Andean lagoons of more than 3,000 m.a.s.l. (Ayacucho, Peru) were evaluated. The cultures were exposed to photosynthetically active radiation (PAR) (400-700 nm) and PAR with ultraviolet radiation A and B (PAB) (280-700 nm) in 2 l photobioreactors. Cultures of the genus Pediastrum sp. subjected to PAB radiation showed greater growth until the sixth day, when they reached the end of their exponential phase. The maximum concentrations of lutein and chlorophyll a and b were 6.96 ± 0.21, 1.64 ± 0.05, and 0.84 ± 0.06 mg/g, respectively; total antioxidant activity and total polyphenol content were 221.7 ± 11.76 µmol eq. Trolox/g and 7.36 ± 0.53 mg GAE/g, respectively, after being subjected to PAR. Conclusively, high Andean microalgae possess adaptation mechanisms that help them to cope with a high radiation flux. The high concentrations of antioxidants and pigments in the strain taken from 4,400 m.a.s.l (IMP-BG288) suggest its greatest cosmetic potential.