The aim of this work was to determine the biochemical compounds andevaluate the biological activities of Chlorella vulgaris cultivated under a bioticstress condition (various Zinc and Cupper conc.). The growth rate was recordedas well as determination of active compounds, pigments and defense enzymes,in addition to the biological activities as antioxidant, antimicrobial andanticancer. The obtained results revealed that, higher copper concentrations[0.632 mg /L (Cu)] showed an inhibitory effect to growth while 1.76 mg /L (Zn)enhanced growth which reached its maximum at 25th day of cultivation.Furthermore, combination of 0.88mg/L (Zn) and 0.316mg /L (Cu) induced anincrease in growth rate, catalase, tannins, lipid peroxidation and glutathione-S-transferase and a decrease in flavonoids, phenolic content, protein andantioxidant activity. Also, the results of antioxidant activity showed that,elevation of Zn conc. induced an augmentation of antioxidant activity eitherby DPPH(2, 2 diphenyl-1-picrylhydrazyl) or ABTS (2, 2’- azino-bisethylbenzthiazoline-6-sulfonic acid), with maximum activity at 0.88 mg/L Zincconc. (89.91%) even exceeded those of control (85.62%). While more elevatedZn conc. (1.76 mg/L) induced lower activity when compared with syntheticantioxidant standard (Butylated hydroxyl toluene, BHT). Concerningantimicrobial activity, Gram +ve bacteria, Staphylococcusaureus recordedmoderate activity in sulfur-contained extract. Cytotoxicity of three cancer celllines was inversely proportional to extracts conc. used, where the higher conc.(500μg/ml) showed the lowest cell viability of the tested cell lines which rangedfrom 22.06 to 69.89%. 0.316 mg/L (Cu) of conc. 500 μg/ml recorded the lowest
عماد احمد شلبي | Emad Ahmed Shalaby | 899