Discovery and characterization of novel fungal Baeyer-Villiger monooxygenases

MASCOTTI, ML; DUDEK, HM; JURI AYUB, M; KURINA SANZ, M; FRAAIJE, MW

Groningen

Congreso; EMBO conference: Catalytic Mechanisms by biological systems; 2012

EMBO

In the last few years a large number of microorganisms that contain Baeyer-Villiger monooxygenases (BVMOs) have been discovered. Only a few of these enzymes have been successfully cloned and overexpressed and are now available as recombinant biocatalysts. It is interesting to note that, except for one example, all these recombinant BVMOs originate from bacteria. Although genome sequence analysis has revealed that fungi are relatively rich in BVMO-encoding genes, only one fungal BVMO has been recently cloned and overexpressed [1].Species of the Aspergillus genus have the ability to produce aflatoxins. These secondary metabolites are known for its toxicity and its biosynthesis has been extensively studied. It has been postulated that BVMOs may be involved in these biosynthetic reactions, although this has been experimentally confirmed. In addition, there have been various reports on Baeyer-Villiger activity of different filamentous fungi on a diverse range of substrates [2].The aim of this study was to identify novel fungal BVMOs, to produce the respective biocatalysts and to explore their biocatalytic potential. Based in our previous studies on whole-cell biotransformations of a broad range of substrates, encompassing steroids, cyclic ketones and sulfides [3], two fungal species, A. fumigatus and A. parasiticus, were chosen to work on. In-silico search on genomic databases using as a probe the BVMO-typifying sequence motif, led to the identification of several putative BVMOs. After PCR amplification and cloning, the fungal BVMO have been expressed in Escherichia coli and subsequently purified. Their properties as biocatalysts for conversion of a broad range of substrates were evaluated.References[1] Leipold, F., Wardenga, R., Bornscheuer, U.  Appl Microbiol Biotechnol 2012, 94:705-717[2] Kolek, T., Szpineter, A., Swizdor, A. Steroids 2008, 73, 1441-1445[3] Mascotti, M.L., Orden, A., Bisogno, F.R., de Gonzalo, G., Kurina-Sanz, M. J Mol Catal B 2012, 82, 32-36