The Laccase Production From Paecilomyces Sp. H-104-1 And Its Degradation Of 4-CP

In this dissertation, a new thermophlic strain Paecilomyces sp.H-104-1,which was isolated from soil sample was taken as tested strain. The optimal fermentation parameters of laccase which produced by Paecilomyces sp. H-104-1 in shaking flask were as follows: 1,5ml initial biomass (spore inoculation, about 2.0 × 10⁵spore/ml), 120ml culture media in 300ml flask;2, initial pH 6.0; 3,rotating speed 120 rpm 150 rpm, 4, culture temperature 40 ℃.Laccase activity of Paecilomyces sp.H-104-1 reached 18.63U/L with 0.008% Tween-80 in medium. And adding benzyl alcohol, diphenylamine and guaiacol, all of the three reagent can stimulated the production of laccase activity of Paecilomyces sp.H-104-1.Immobilized Paecilomyces sp.H-104-1 on active carbons supporter and cultured. It neither got higher laccase activity nor shortened laccase production period. But under immobilized culture, the laccase activity of Paecilomyces sp.H-104-1 got wider pH range, more temperature adaptability and heat-resistant ability.Applying the principle of the response surface analysis methodology (RSM), we decided the liquid medium ingredients for producing laccase by Paecilomyces sp.H-104-1.At the same time, we got a quadratic equation of extract of bran(X₁) and ammonium oxalate (X3):Y=88.36-1.39X₁-5.55X₃-18.78X₁²-12.91 X₃²+1.50X₁X₃The relative coefficient of the quadratic equation was 93%. The laccase activity which produced in the optimized medium was 89.00U/L, about 6 times over which was cultured in the unoptimized medium.Immobilized Paecilomyces sp.H-104-1 on active carbons supporter and cultured. It neither got higher laccase activity nor shortened laccase production period. But under immobilized culture, the laccase activity of Paecilomyces sp.H-104-1 got wider pH range, more temperature adaptability and heat-resistant ability.In experiment of degraded 4-CP with laccase of Paecilomyces sp.H-104-1, the optimal degrading temperature was 35℃.If the dosage of laccase was invariable , the effects of degrading didn't get very well in lower reagent concentration(<10mg/L), but higher reagent concentration(>500mg/L) also went against degrading effects even if prolonging the time of reaction. Degraded 4-CP Under different temperature and different reagent concentration, it revealed that 4-CP didn't degrade when the time over 10 hours, and in 10 hours degrading ratio follow one stair dynamics reaction.