Detoxification of wood hydrolysates with laccase and peroxidase from the white-rot fungus Trametes versicolor

Abstract Fermentation of wood hydrolysates to desirable products, such as fuel ethanol, is made difficult by the presence of inhibitory compounds in the hydrolysates. Here we present a novel method to increase the fermentability of lignocellulosic hydrolysates: enzymatic detoxification. Besides the detoxification effect, treatment with purified enzymes provides a new way to identify inhibitors by assaying the effect of enzymatic attack on specific compounds in the hydrolysate. Laccase, a phenol oxidase, and lignin peroxidase purified from the ligninolytic basidiomycete fungus Trametes versicolor were studied using a lignocellulosic hydrolysate from willow pretreated with steam and SO2. Saccharomyces cerevisiae was employed for ethanolic fermentation of the hydrolysates. The results show more rapid consumption of glucose and increased ethanol productivity for samples treated with laccase. Treatment of the hydrolysate with lignin peroxidase also resulted in improved fermentability. Analyses by GC-MS indicated that the mechanism of laccase detoxification involves removal of monoaromatic phenolic compounds present in the hydrolysate. The results support the suggestion that phenolic compounds are important inhibitors of the fermentation process.

[1]  D. C. Smith,et al.  p-Hydroxybenzoate groups in the lignin of aspen (populus tremula) , 1955 .

[2]  L. Sennerby-Forsse,et al.  The swedish programme for intensive shortrotation forests , 1994 .

[3]  M. Galbe,et al.  Simulation of ethanol production processes based on enzymatic hydrolysis of lignocellulosic materials using aspen plus , 1992 .

[4]  L. Jönsson,et al.  Characterization of a laccase gene from the white-rot fungus Trametes versicolor and structural features of basidiomycete laccases. , 1995, Biochimica et biophysica acta.

[5]  B. Reinhammar,et al.  63/65Cu and 1/2H2O isotope shifts in the low-temperature resonance Raman spectrum of fungal laccase. , 1986, Biochimica et biophysica acta.

[6]  C. Romming,et al.  Formation of Aromatic Compounds from Carbohydrates. Part III. Reaction of D-Glucose and D-Fructose in Slightly Acidic, Aqueous Solution. , 1976 .

[7]  M. Galbe,et al.  The influence of SO2 and H2SO4 impregnation of willow prior to steam pretreatment , 1995 .

[8]  M. M. Bradford.  A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. , 1976, Analytical biochemistry.

[9]  C. Thurston.  The structure and function of fungal laccases , 1994 .

[10]  K. Eriksson,et al.  Laccase and the Deposition of Lignin in Vascular Plants , 1994 .

[11]  Isamu Arai,et al.  Identification of aromatic monomers in steam-exploded poplar and their influences on ethanol fermentation by Saccharomyces cerevisiae , 1986 .

[12]  L. Olsson,et al.  Fermentation of lignocellulosic hydrolysates for ethanol production. , 1996 .

[13]  Bärbel Hahn-Hägerdal,et al.  Fermentation of lignocellulose hydrolysates with yeasts and xylose isomerase , 1989 .

[14]  Guido Zacchi,et al.  Simultaneous detoxification and enzyme production of hemicellulose hydrolysates obtained after steam pretreatment , 1997 .

[15]  A. Kuiters,et al.  Leaching of phenolic compounds from leaf and needle litter of several deciduous and coniferous trees , 1986 .

[16]  J. Rowe.  Natural Products of Woody Plants , 1989, Springer Series in Wood Science.

[17]  Markku Saloheimo,et al.  Heterologous Production of a Ligninolytic Enzyme: Expression of the Phlebia Radiata Laccase Gene in Trichoderma Reesei , 1991, Bio/Technology.

[18]  Guido Zacchi,et al.  Cost Analysis of Ethanol Production from Willow Using Recombinant Escherichia coli , 1994, Biotechnology progress.

[19]  M. Bardet,et al.  On the reactions and degradation of the lignin during steam hydrolysis of aspen wood , 1985 .

[20]  Johanna Buchert,et al.  Improvement in the fermentability of steamed hemicellulose hydrolysate by ion exclusion , 1990 .

[21]  L. Jönsson,et al.  Trametes versicolor ligninase: Isozyme sequence homology and substrate specificity , 1989, FEBS letters.

[22]  Robert A. Blanchette,et al.  Microbial and Enzymatic Degradation of Wood and Wood Components , 2012, Springer Series in Wood Science.

[23]  Lisbeth Olsson,et al.  Fermentative performance of bacteria and yeasts in lignocellulose hydrolysates , 1993 .

[24]  O. Theander,et al.  Monoaryl Natural Products , 1989 .

[25]  O. Theander,et al.  Formation of Aromatic Compounds from Carbohydrates , 1972 .

[26]  Mats Galbe,et al.  The effect of water-soluble inhibitors from steam-pretreated willow on enzymatic hydrolysis and ethanol fermentation , 1996 .

[27]  J. Rowe.  Natural products of woody plants. I and II: Chemicals extraneous to the lignocellulosic cell wall. , 1989 .

[28]  E. Sjöström,et al.  Wood Chemistry: Fundamentals and Applications , 1981 .

[29]  R. Pezet,et al.  Evidence for oxidative detoxication of pterostilbene and resveratrol by a laccase-like stilbene oxidase produced by Botrytis cinerea , 1991 .

[30]  L. Ehrenberg,et al.  Large scale production and purification of laccase from cultures of the fungus Polyporus versicolor and some properties of laccase A. , 1967, Acta chemica Scandinavica.

[31]  M. Sjöström,et al.  Purification of ligninase isozymes from the white-rot fungus Trametes versicolor , 1987 .