Laccase-mediator systems

In Vitro Study with Laccase-Mediator System. 

Table 1 Deca-BDE degradation obtained by laccase and laccase-mediator system with an initial pollutant concentration of 2 mg L 1 at 38 h...

Baiocco P, Barreca AM, Fabbrini M, Galli C and Gentili P. 2003. Promoting laccase activity towards non-phenolic substrates a mechanistic investigation with some laccase—mediator systems. Org Biomol Chem 1(1) 191—197. 

Morozova OV, Shumakovich GP, Shleev SV and Yaropolov YI. 2007. Laccase-mediator systems and their applications a review. Appl Biochem Microbiol 43(5) 523-535. 

Call FIP, Mucke I (1997) Minireview history, overview and applications of mediated ligni-nolytic systems, especially laccase-mediator-systems (Lignozym-Process). J Biotechnol 53 163-202... 

SCHEME 14. The oxidation cycle of a laccase/mediator system with non-phenoUc substrates. Redrawn from Reference 69 by permission of The Royal Society of Chemistry on behalf of the Centre National de la Recherche Scientifique... 

Balakshin, M., Capanema, E., Chen, C. L., Gratzl, J., Kirkman, A., and Gracz, H. (2001) Biobleaching of pulp with dioxygen in the laccase-mediator system Reaction mechanisms for degradation of residual lignin. J. Mol. Catalysis B-Enzymatic 13(1-3), 1-16. 

To better understand the mechanisms for the oxidation of lignin by a laccase mediator system, a laccase from Polyporous sp, kindly provided by Novozymes, was used in combination with 1-HBT. The redox mediator was found to be partly regenerated during the oxidation of lignin dimer 1 in the presence of laccase. A free radical of 1-HBT generated by laccase was probably responsible for the oxidation of I [146]. The free radical of 1-HBT was, however, transformed to benzotriazole, which could not mediate the oxidation of I. A proposed mechanism for the laccase mediator oxidation of nonphenolic lignins is given in Scheme 14.1. 

HP Call. Further improvements of the Laccase-Mediator-System (LMS) for enzymatic delignification (bleaching) and resnlts from large scale trials. Proceedings of Int Non-Chlorine Bleach Conf, Amelia Island, Florida, 1995. 

K Poppius-Levlin, W Wang, M Ranua, ML Niku-Paavola, L Viikari. Biobleaching of chemical pulps by laccase/mediator systems. Proceedings of TAPPl Biological Sciences Symposium, San Francisco, 1997, pp. 329-333. 

FS Chakar, AJ Ragauskas. Biobleaching of high lignin content kraft pulps via laccase-mediator systems. Proceedings of Tappi Pulping Conference, Atlanta, 1998, pp. 109-118. 

C Johannes, A Majcherczyk, A Huttermann. Oxidation of acenaphthene and acenaphthylene by laccase of Trametes versicolor in a laccase-mediator system. J. Biotech. 61(2) 151-156, 1998. 

A Potthast, T Rosenau, K Fischer. Oxidation of benzyl alcohols by the laccase-mediator system (LMS) - a comprehensive kinetic description. HolTforschung 55(l) 47-56, 2001. 

MY Balakshin, CL Chen, JS Gratzl, AG Kirkman, H Jakob. Kinetic studies on oxidation of veratryl alcohol by laccase-mediator system. Part 1. Effects of mediator concentration. Holzforschung 54(2) 165-170, 2000. 

A Potthast, H Koch, K Fischer. The laccase-mediator-system Reaction with model compounds and pulp. Proceedings of 9th International Symposium on Wood and Pulping Chemistry, Montreal, 1997, pp. F2-l. ... 

It should be pointed out here that the laccase-mediator system still is far from being economically feasible. 

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