Laccase-mediator catalyzed conversion of model lignin compounds

Authors: Rich, Joseph; Anderson, Amber; Berhow, Mark

Submitted to: Biocatalysis and Agricultural Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2016
Publication Date: 1/7/2016
Citation: Rich, J.O., Anderson, A.M., Berhow, M.A. 2016. Laccase-mediator catalyzed conversion of model lignin compounds. Biocatalysis and Agricultural Biotechnology. 5:111-115.

Interpretive Summary: Enzymes, including laccases, play an important role in the biological synthesis and breakdown of lignocellulosic biomass. We examined a variety of laccases for ability to transform three model compounds that represent the structural subunits of lignin. We identified reaction conditions that led to the conversion of p-coumaryl alcohol and sinapyl alcohol to p-hydroxybenzaldehyde and 2,6-dimethoxybenzoquinone , respectively. These products have been previously reported to result from the chemical conversion of lignin. The enzymatic approach affords the opportunity for a biological approach to the conversion of lignin to valuable specialty chemicals that have use in a variety of industrial, consumer and pharmaceutical applications. This research will benefit researchers and producers in the development of novel biobased chemicals derived from lignin.

Technical Abstract: Laccases play an important role in the biological breakdown of lignin and have great potential in the deconstruction of lignocellulosic feedstocks. We examined a variety of laccases, both commercially prepared and crude extracts, for their ability to oxidize three model lignol compounds (p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol). We identified both mediated and non-mediated laccase-catalyzed reactions that converted p-coumaryl alcohol and sinapyl alcohol to p-hydroxybenzaldehyde and 2,6-dimethoxybenzoquinone , respectively. Interestingly, the products produced by the concerted action of the laccase mediator system on lignol substrates are the same as those produced by chemical catalytic approaches. The enzymatic approach affords the opportunity for a biological approach to the conversion of lignin to valuable specialty chemicals that have use in a variety of industrial, consumer and pharmaceutical applications.