Journal of Molecular Catalysis B: Enzymatic 115 (2015) 59–65 Contents lists available at ScienceDirect Journal of Molecular Catalysis B: Enzymatic j ourna l ho me pa ge: www.elsevier.com/locate/molcatb Chemoselective biohydrogenation of ,- and ,,,-unsaturated ketones by the marine-derived fungus Penicillium citrinum CBMAI 1186 in a biphasic system Irlon M. Ferreira, Eloá B. Meira, Isac G. Rosset, André L.M. Porto ∗ Laboratório de Química Orgânica e Biocatálise, Instituto de Química de São Carlos, Universidade de São Paulo, Av. João Dagnone, 1100, Ed. Química Ambiental, Jd. Santa Angelina, São Carlos, SP 13563-120, Brazil a r t i c l e i n f o Article history: Received 30 January 2014 Received in revised form 25 January 2015 Accepted 26 January 2015 Available online 7 February 2015 Keywords: Biocatalysis Enoate reductases ,-Unsaturated ketones Marine microorganisms a b s t r a c t To broaden the range of applicability of a reduction reaction mediated by the marine fungal strain Penicil- lium citrinum CBMAI 1186 to organic chemical processes, the ability of whole mycelia to grow in biphasic mixtures with organic solvents was tested with acetone, ethyl acetate, n-butanol, dichloromethane, n- hexane and toluene. n-Hexane was the least toxic solvent according to the amount of mycelial mass grown in an artificial sea water medium mixed with each solvent. Therefore, whole hyphae of P. citrinum CBMAI 1186 were used as biocatalysts in the chemoselective biotransformation of the carbon–carbon double bond in ,-, di-,-, and mono-,,,-unsaturated ketones (3a, 3c–f) in a biphasic system of phosphate buffer and n-hexane (9:1). Only the di-,,,-unsaturated ketone (3b) was not biocatalyzed under these conditions. In general, there were good conversions of saturated ketones by the enoate reductase enzymes of P. citrinum CBMAI 1186. © 2015 Elsevier B.V. All rights reserved. 1. Introduction In recent years, biocatalysis has emerged as a viable alterna- tive to conventional chemical methods, owing to its high product selectivity, mild process conditions, low cost and little environ- mental damage; in short, inexpensive production matching green chemistry with high efficiency [1–3]. A disadvantage of biotransformation as a tool for organic synthe- sis is the low solubility of most organic compounds in the reaction mixtures because the process is generally carried out in an aqueous medium. To overcome this limitation, biphasic systems have been increasingly used in biotransformation reactions [4]. A very important criterion on which to choose a non-aqueous solvent is its biocompatibility ratio, expressed as the logarithm of the partition coefficient ratio for a standard two-phase system, log P. Solvents with log P > 4 tend to be less toxic to a biological system [5]. Biphasic systems consisting of an organic and an aque- ous phase represent valuable tools for the biotransformation of hydrophobic substrates. Furthermore, such system can be used to avoid inhibition effects by substrate and/or product and can help ∗ Corresponding author. Tel.: +55 16 33738103; fax: +55 16 33739952. E-mail address: almporto@iqsc.usp.br (A.L.M. Porto). to guide equilibrium reactions into the desired direction enhancing stereoselectivity. A crucial step is the choice of the organic sol- vent, which depends on several factors, including toxic or inhibitory effects of the solvent on the cells and substrate, and product solu- bility [6]. Biocatalytic reductions of ,-unsaturated ketones, mediated by the bacterium Micrococcus luteus CCT 2283 in a biphasic sys- tem of water/[(BMIn)PF 6 ], provided better diastereoselectivities and enantioselectivities than in pure water [7]. In another study, strains of the yeast Saccharomyces cerevisiae employed in biphasic systems for the biotransformation of unsaturated ketones achieved better conversions than in pure water [8,9]. Few studies have focused on the biotransformation of organic compounds by fungal mycelia in a biphasic system. Some examples are Candida krusei SW2026, used as a biocatalyst in the efficient reduction of ethyl 2-oxo-4-phenylbutyrate, and Rhizopus nigricans, used in the biotransformation of 16,17-epoxyprogesterone car- ried out in a [BMIm][PF 6 ]-water two-phase system [10,11]. However, no studies involving organic solvents in biphasic sys- tems with marine-derived fungi have been reported. Recently, we have investigated the use of whole mycelia of Penicillium cit- rinum CBMAI 1186 immobilized on biopolymers for the reduction of ,-unsaturated ketones [12]. Herein, we decided to explore the multienzymatic system of this marine-derived fungus in the http://dx.doi.org/10.1016/j.molcatb.2015.01.017 1381-1177/© 2015 Elsevier B.V. All rights reserved.