Covalent immobilization of Alternaria tenuissima KM651985 laccase and some applied aspects

•Alternaria tenuissima KM651985 laccase was covalently immobilized.•The immobilization process stabilized the enzyme and improved its properties.•The immobilized form could be used in different aspects to reverse dyes toxicity.

Alternaria tenuissima KM651985 laccase was immobilized in Ca2+(AlgChG) beads with 93% immobilization yield. Optimum temperature for the free enzyme was 60 °C while the immobilized form showed a broad optimum temperature from 40 to 60 °C. The optimum pH was shifted from 4 to 5 for the free and immobilized enzyme, respectively. The immobilization process improved the enzyme thermal stability to great instant. The immobilized form could be reused for 19 times with 68% loss. Shelf stability reported that free and immobilized enzyme kept 61% and 84% of their original activities for 42 days, respectively. Some kinetic studies were achieved such as km, Vmax, and EA. The catalytic activity of immobilized laccase was also demonstrated by decolorization of two reactive dyes (Congo red dye and Crystal violet dye) and it's efficiently in reversed toxicity of two dyes on wheat seeds germination. Our result recommended A. tenuissima KM651985 laccase to be used in industrial scale.