Thermodynamics enhancement of Alternaria tenuissima KM651985 laccase by covalent coupling to polysaccharides and its applications.

ABSTRACT

This study full filed in enhancement of catalytic, thermodynamics and storage stability of Alternaria tenuissima KM651985 laccase by conjugation to sodium periodate oxidized starch. The starch conjugated A. tenuissima KM651985 laccase was active over a wide range of temperatures and pHs with the highest activity at 60 °C and 4, respectively. The thermal stability of conjugated A. tenuissima KM651985 laccase was indicated by, high T1/2 values (half life) 1076.16, 382.42 and 191.23 min at 50, 60 and 70 °C, respectively, low Kd (denaturation rate constant) 6.44 × 10-4, 18.13 × 10-4 and 36.25 × 10-4 min-1 at the same temperatures, high D-values (decimal reduction time) 3575.56, 1270.61 and 635.38 min at the same temperatures. Also, the thermal stability of conjugated A. tenuissima KM651985 laccase was emphasized by high ΔHd (enthalpy), high ΔGd (free energy) and low ΔSd (entropy). The conjugated A. tenuissima KM651985 laccase showed high effectiveness in dyes decolorization of Remazol Brilliant Blue R (RBBR) and Malachite Green (MG). Moreover, the addition of conjugated A. tenuissima KM651985 laccase with hemicellulolytic enzymes cocktail improved the saccharification of corn cobs, rice straw, corn cobs leaves and water hyacinth with the highest reducing sugar production 847.44 ±â€¯19.17 mg from corn cops.