Thermo stable tyrosinase purified from Pleurotus djamor grown in biomimetic calcium carbonate: A biological strategy to industrial waste remediation

Abstract

A novel, neutral and heat-tolerant tyrosinase produced from Pleurotus djamor (P. djamor) using biomimetic calcium carbonate which was further used for the biodegradation of the phenolic waste of industrial effluents. Carbon-dioxide was sequestered/captured into calcium carbonate (CaCO 3 ) using carbonic anhydrase (2.1 U/mg protein) of Oceanobacillus with sequestration capacity as 24.7 CaCO 3 /mg protein in 25 s. This CaCO 3 was used as a substrate for cultivation of P. djamor (a mushroom) which was the potential source of tyrosinase. Mushroom tyrosinase was purified up to 51.7 folds purity which shown a molecular weight ∼ 90 kDa on SDS-PAGE. The optimal thermal and pH activity of the tyrosinase was observed at 50 °C and 7.0, respectively. The tyrosinase was stable within a pH range of 6.0–8.0, temperature 35 °C–55 °C and showed high substrate specificity for L-DOPA. Tyrosinase activity was drastically enhanced by Cu 2 + , Ca 2 + and Mn 2 + metal ions. K + ions were also found to inhibit the tyrosinase activity up to the moderate level. Mushroom tyrosinase was used to degrade phenol from industry effluents with 90% removal in 6 h. Extracellular nature as well as tyrosinase stability in the extreme conditions (temperature, pH, and presence of heavy metals) makes it preferable candidate for phenol bioremediation from industrial effluents. • Sequestration of carbon di oxide into calcium carbonate is clearly shown. • Biomimetically precipitated calcium carbonate is first time used for mushroom production. • Tyrosinase is purified from pre-mature phase of Pleurotus djamor . • Feasibility of degradation of phenol from industrial effluents by mushroom tyrosinase is presented. • A comprehensive mechanism for complete carbon-di-oxide utilization have been hypothesized.