Involvement of ligninolytic enzymes in degradation of wheat straw by Trametes trogii.

AIMS: Wheat straw is generated in billions of tons around the world every year and has not been fully used. This study sought to evaluate the delignification capacity and enzyme production of Trametes trogii MT strain and to clarify the changes of structure and chemical composition of wheat straw during the decay process. METHODS AND RESULTS: The results obtained revealed that the T. trogii MT strain has the ability to degrade lignin, cellulose as well as hemicellulose of wheat straw simultaneously. The strain can produce high activities of laccase, manganese peroxidase, xylanase, carboxymethylcellulase and feruloyl esterase but no lignin peroxidases during the decay process of a 60-day incubation period on wheat straw. Scanning electron microscopy observation and infrared spectroscopy analysis showed the lignin and carbohydrate of wheat straw were degraded with no obvious different levels. The low molecular mass fractions collected from the culture of the MT strains grown in wheat straw powder liquid medium showed high Fe(3+) chelating, reducing capacity and hydroxyl radical and hydrogen peroxide generation. CONCLUSIONS: Trametes trogii MT has a complex mechanism to degrade lignocellulose, in addition to the extracellular enzymatic systems, and has great potential as an attractive micro-organism used for the biological degradation of waste straws. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed the dynamic changes of the ligninolytic enzymes of T. trogii MT during the degradation of wheat straw, and suggested that the decay patterns of wheat straw by T. trogii MT had some simultaneous type characteristics.