Impact of heavy metals in the microalga Chlorella sorokiniana and assessment of its potential use in cadmium bioremediation

The chlorophyte microalga Chlorella sorokiniana was tested for the bioremediation of heavy metals pollution. It cultured with different concentrations Cu2+, Cd2+, As (III) and (V), showing a significant inhibition on its growth at 500 µM 250 750 AsO33- 5 mM AsO43- or higher. Moreover, consumption ammonium also studied, differences higher than 1 Cu2+ (III), (V). determination intracellular concentration revealed that is an outstanding Cd accumulator organism, able to accumulate 11,232 mg kg−1 Cd, removing 65% initial this metal. Finally, antioxidant enzymes, such as catalase (CAT) ascorbate peroxidase (APX), enzymes involved in production glutamate cysteine, glutamine syntethase (GS), dehydrogenase (GDH), O-acetylserine (thiol) lyase (OASTL) NAD-isocitrate (NAD-IDH) were studied both gene expression enzymatic activity levels. These exhibited grades upregulation, especially response stress. However, GS downregulated when presence these metals.