β-carotene involving in free radicals annihilation in spirulina biomass cultivated under the oxidative stress conditions

Abstract

Carotenoids are a group of pigments that play multiple structural and functional roles. They are molecules with conjugated double bonds, allowing them to participate in photosynthetic functions. The most abundant carotenoids in cyanobacteria are β-carotene, essential component of cytoplasmic and thylakoid membranes. As photosynthetic pigments, β-carotene has a protective role of trapping the singlet oxygen in thylakoid membranes. The stress-induced light experiences during Spirulina platensis cultivation showed carotene involvement to maintain membrane function. Cell membrane integrity was determined by modifying the values of the assay of the thiobarbituric acid-reactive products in Spirulina biomass cultivated under light stress that was induced by shortening the duration of light from 24 to 4 hours during 4 days of the 10 days cultivation cycle.