Discovery and characterization of novel fungal Baeyer-Villiger monooxygenases

MASCOTTI ML; DUDEK H; JURI AYUB M; KURINA SANZ MB; FRAIJEE M

Nice

Encuentro; 4th EMBO meeting; 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 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 still has to be 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 strains, A. fumigatus and A. parasiticus, were chosen to work on. The PCR-based search for Aspergillus BVMOs was carried out using as a probe the BVMO-typifying sequence motif. After amplification of several BVMO-encoding genes, 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] Kołek, 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, http://dx.doi.org/10.1016/j.molcatb.2012.05.003