Catalytic activity of soluble versus immobilized cauliflower (Brassica oleracea) bud peroxidase-concanavalin A complex and its application in dye color removal

•Immobilized enhanced remarkable resistance to thermal, pH and catalytic activity.•Considerable color removal from disperse dyes in continuous two reactor system.•Total organic carbon analysis was quite comparable to color loss.•Entrapped CBP–Con A complex were reusable upto ten cycles in dye color removal.

Biocatalytic activity of soluble against immobilized cauliflower (Brassica oleracea) bud peroxidase (CBP) on calcium alginate gel beads have been assessed; internal conditions including temperature, pH and stability with denaturants optimized for application in removing color of textile industrial effluent. CBP–concanavalin A complex expressed ~84% of original peroxidase whereas in entrapped state on calcium alginate pectin gel the activity reduced to ~64%. Immobilized CBP–Con A complex retained ~56.6% activity even at 70 °C which was achieved at pH 4.0. Prolonged urea treatment resulted in activity loss of entrapped CBP-Con A complex by ~19.8%. With dioxane at 50% (v/v), entrapped CBP-Con A complex exhibited an activity of over 58.7%; whereas an increasing concentration of dimethylformide caused reduction in peroxidase activity to 35.8% at 80% (v/v). With immobilized proteins there was considerable color removal upto ~90.6% and ~81.1% from disperse red 19 and dye mixture (disperse red 19+disperse black 9) respectively, in continuous two reactor system and total organic carbon analysis was quite comparable to color loss. Entrapped CBP-Con A complex were reusable upto ten cycles in dye color removal. This study suggests that immobilized and entrapped CBP catalytic system can be efficiently exploited for dye color removal from industrial effluent due to its sustainability, durability and reusability over its soluble counterpart.

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