Straw lignin degradation by lignin peroxidase from Irpex Iacteus cooperated with enzymes and small molecules

Abstract ObjectivesLignin degradation is the result of synergistic action of many enzyme systems. The degradation capacity of a single enzyme is limited, which can not maximize the utility value of the enzyme. Some small molecules also affect the efficiency of lignin degradation by lignin peroxidase.MethodsUsing wheat straw as raw material and taking lignin degradation rate as index, it was found that laccase, glucose oxidase, malonic acid, citric acid, ZnSO4, CaCl2 could promote the lignin degradation by the lignin peroxidase from Irpex Iacteus, respectively. Moreover, glucose oxidase, malonic acid and CaCl2 had obvious synergy effects on lignin degradation by the lignin peroxidase.ResultsThe optimal conditions of lignin degradation were obtained by response surface experiment: 4% glucose oxidase, 0.74% malonic acid and 3.29% CaCl2 were added for synergistic degradation at 37℃ with 50% of water content. After 72h quickly enzymatic hydrolysis, the degradation rate of lignin was 45.84%.ConclusionsA new green and efficient method for lignin removal from straw was obtained, which provided a reference for the efficient utilization of straw and lignin peroxidase.