Antioxidant activity in Arthrospira platensis cells during the vital cycle in standard and strees condition

Abstract

The goal of this work was to determine the changes that occurred in the antioxidant status of cyanobacterium Spirulina platensis during its life cycle. For this Arthrospira platensis (A. platensis) CNM-CB-11 strain from National Collection of Nonpathogenic Microorganisms (Institute of Microbiology and Biotechnology of the Academy of Science of Moldova) was used. The standard cultivation of A. platensis cells was carried out in an open-type tank with a volume of 60 L in the SP-1 nutritive medium (NaNO3-2,5 g/L; NaHCO3-8,0 g/L; NaCl-1,0 g/L; K2SO4-1,0 g/L; Na2HPO4-0,2 g/L; MgSO4•7H2O-0,2 g/L; CaCl2-0,024 g/L; H3BO3-2,86 mg/L; MnCl2•4H2O-1,81 mg/L, CuSO4•5H2O -0,08 mg/L; MoO3 –0,015 mg/L; FeEDTA-1ml/L) at 32-35ºС, illumination 37-55 μmoles of photons/m2/s, рН 8-9 and constant mixing. Stress condition was induced by reducing the illumination period to 4 hours (from day 3 until day 7). Sampling was strictly performed every 24 hours, in order to exclude circadian variations involved in oxidative status of microalgae culture. Antiradical activity of extracts from Arthrospira platensis biomass during its life cycle was determined by applying ABTS assay (expressed in TEAC).