@misc{MartinezRuizDuenasGutierrezetal., author = {Mart{\´i}nez, Angel T. and Ruiz-Due{\~n}as, Francisco J. and Guti{\´e}rrez, Ana and R{\´i}o, Jos{\´e} C. del and Alcalde, Miguel and Liers, Christiane and Ullrich, Ren{\´e} and Hofrichter, Martin and Scheibner, Katrin and Kalum, Lisbeth and Vind, Jesper and Lund, Henrik}, title = {Search, engineering, and applications of new oxidative biocatalysts}, series = {Biofuels, Bioproducts and Biorefining}, volume = {8}, journal = {Biofuels, Bioproducts and Biorefining}, number = {6}, issn = {1932-1031}, doi = {10.1002/bbb.1498}, pages = {819 -- 835}, abstract = {Most industrial enzymes are hydrolases, such as glycosidases and esterases. However, oxidoreductases have an unexploited potential for substituting harsh (and scarcely selective) chemical processes. A group of basidiomycetes are the only organisms degrading the aromatic lignin polymer, enabling the subsequent use of plant polysaccharides. Therefore, these fungi and their ligninolytic peroxidases are the biocatalysts of choice for industrial delignification and oxidative biotransformations of aromatic and other organic compounds. The latter also include oxygenation reactions, which are catalyzed with high regio/stereo selectivity by fungal peroxygenases. In search for novel and more robust peroxidases/peroxygenases, basidiomycetes from unexplored habitats were screened, and hundreds of genes identified in basidiomycete genomes (in collaboration with the DOE JGI). The most interesting genes were heterologously expressed, and the corresponding enzymes structurally-functionally characterized. The information obtained enabled us to improve the enzyme operational and catalytic properties by directed mutagenesis. However, the structural-functional relationships explaining some desirable properties are not established yet and, therefore, their introduction was addressed by 'non-rational' directed evolution. Then, over 100 oxidative biotransformations were analyzed. Among them, it is noteworthy to mention the regio/stereo selective hydroxylation of long/short-chain alkanes (a chemically challenging reaction), epoxidation of alkenes, and production of hydroxy-fatty acids. Concerning aromatic oxygenations, the regioselective hydroxylation of flavonoids, and stereoselective hydroxylation/epoxidation of alkyl/alkenyl-benzenes were among the most remarkable reactions, together with enzymatic hydroxylation of benzene (as an alternative for harsh chemical process). Finally, peroxidases and peroxygenases also showed a potential as delignification biocatalysts and in the decolorization of contaminant dyes from textile industries.}, language = {en} } @misc{MartinezRuizDuenasCamareroetal., author = {Martinez, Angel T. and Ruiz-Duenas, Francisco J. and Camarero, Susana and Serrano, Ana and Linde, Dolores and Lund, Henrik and Vind, Jesper and Tovborg, Morton and Herold-Majumdar, Owik M. and Hofrichter, Martin and Liers, Christiane and Ullrich, Ren{\´e} and Scheibner, Katrin and Sannia, Giovanni and Piscitelli, Alessandra and Sener, Mehmet E. and Kilic, Sibel and Berkel, Willem J. H. van and Guallar, V{\´i}ctor and Lucas, Maria F{\´a}tima and Zuhse, Ralf and Ludwig, Roland and Hollmann, Frank and Fern{\´a}ndez-Fueyo, Elena and Record, Eric and Faulds, Craig B. and Tortajada, Marta and Winckelmann, Ib and Rasmussen, Jo-Anne and Gelo-Pujic, Mirjana and Guti{\´e}rrez, Ana and Rio, Jos{\´e} C. del and Rencoret, Jorge and Alcalde, Miguel}, title = {Oxidoreductases on their way to industrial biotransformations}, series = {Biotechnology Advances}, volume = {35}, journal = {Biotechnology Advances}, number = {6}, issn = {1873-1899}, doi = {10.1016/j.biotechadv.2017.06.003}, pages = {815 -- 831}, abstract = {Fungi produce heme-containing peroxidases and peroxygenases, flavin-containing oxidases and dehydrogenases, and different copper-containing oxidoreductases involved in the biodegradation of lignin and other recalcitrant compounds. Heme peroxidases comprise the classical ligninolytic peroxidases and the new dye-decolorizing peroxidases, while heme peroxygenases belong to a still largely unexplored superfamily of heme-thiolate proteins. Nevertheless, basidiomycete unspecific peroxygenases have the highest biotechnological interest due to their ability to catalyze a variety of regio- and stereo-selective monooxygenation reactions with H2O2 as the source of oxygen and final electron acceptor. Flavo-oxidases are involved in both lignin and cellulose decay generating H2O2 that activates peroxidases and generates hydroxyl radical. The group of copper oxidoreductases also includes other H2O2 generating enzymes - copper-radical oxidases - together with classical laccases that are the oxidoreductases with the largest number of reported applications to date. However, the recently described lytic polysaccharide monooxygenases have attracted the highest attention among copper oxidoreductases, since they are capable of oxidatively breaking down crystalline cellulose, the disintegration of which is still a major bottleneck in lignocellulose biorefineries, along with lignin degradation. Interestingly, some flavin-containing dehydrogenases also play a key role in cellulose breakdown by directly/indirectly "fueling" electrons for polysaccharide monooxygenase activation. Many of the above oxidoreductases have been engineered, combining rational and computational design with directed evolution, to attain the selectivity, catalytic efficiency and stability properties required for their industrial utilization. Indeed, using ad hoc software and current computational capabilities, it is now possible to predict substrate access to the active site in biophysical simulations, and electron transfer efficiency in biochemical simulations, reducing in orders of magnitude the time of experimental work in oxidoreductase screening and engineering. What has been set out above is illustrated by a series of remarkable oxyfunctionalization and oxidation reactions developed in the frame of an intersectorial and multidisciplinary European RTD project. The optimized reactions include enzymatic synthesis of 1-naphthol, 25-hydroxyvitamin D3, drug metabolites, furandicarboxylic acid, indigo and other dyes, and conductive polyaniline, terminal oxygenation of alkanes, biomass delignification and lignin oxidation, among others. These successful case stories demonstrate the unexploited potential of oxidoreductases in medium and large-scale biotransformations.}, language = {en} }