Low dose UV-B radiation induced mild oxidative stress impact on physiological and nutritional competence of Spirulina (Arthrospira) species

Abstract

Among the various Spirulina species, Spirulina maxima (S. maxima) and Spirulina platensis (S. platensis) are used mainly as human dietary supplements, whole food, and feed supplement in aquaculture, aquarium and poultry industries due to their potential nutritional and medicinal benefits. Therefore, our study was undertaken to ascertain the impact of mild stress conditions via exposure of different mild fluence rates of ultraviolet-B (UV-B) radiation (exposure of 0.016, 0.065 and 0.196 Jm−2s−1 or Wm−1 denoted as UV-B1, UV-B2 and UV-B3) on exponentially grown cultures of two species of Spirulina, i.e. S. maxima and S. platensis. Mild stressing induced by low dose, i. e. UV-B1 showed positive impacts as a resilience response, resulting in increased physiological and nutritional competencies in growth, pigment content, photosynthetic oxygen yield, fluorescence parameters, protein, carbohydrates, and antioxidative properties in the test organisms analyzed after 72 h of experiments. Such mild stress adapted elite strains with enhanced competencies under mild stressing may pave the way for potential application from the prospects of functional food development when utilized as a functional ingredient to incorporate in them.