Bioeffects of chromium(III) on the growth of Spirulina platensis and its biotransformation

BACKGROUND: In this study the bioeffects of chromium(III) (Cr(III)) on the growth of Spirulina platensis and its biotransformation were investigated. Spirulina platensis was batch cultured in Zarrouk medium containing different concentrations of CrCl3 center dot 6H(2)O. Total and organic Cr contents in S. platensis were determined by inductively coupled plasma mass spectrometry (ICP-MS), and Cr speciation was assayed by high-performance liquid chromatography/ICP-MS. RESULTS: Results based on the dry weight, growth curve, chlorophyll yield and morphology change of S. platensis indicated that the growth of S. platensis was facilitated by Cr(III) below 4.51 mol L-1 and inhibited by a higher concentration of Cr(III). It was found that Cr(III) could be accumulated efficiently in S. platensis, with a highest Cr yield of 173.17 g kg(-1) and a highest organic Cr proportion of 50.19 g kg(-1) (96.04% of the total concentration of Cr). No evidence of oxidation of Cr(III) to Cr(VI) in S. platensis cells was found. CONCLUSION: The results of this study suggest that S. platensis could potentially be used as a safe food carrier to accumulate Cr(III) through so-me metabolic process. (c) 2009 Society of Chemical Industry