Type I Baeyer-Villiger monooxygenase (Type I BVMO) has been intensively studied due to its high potential for industrial applications as it can catalyze a Baeyer-Villiger oxidation (oxidation of ketone). Discovery of a BVMO with novel biocatalytic activities (e.g., novel substrates, stability, etc.) is, therefore, of importance for industrial applications. As enzymes from genus Microbacterium are rarely studied in detail, in this study, a Type I BVMO named as BVMO1MES (discovered in a genome of a unique BTEX- and naphthalene-degrading Microbacterium esteraromaticum SBS1-7) was cloned and subsequently expressed in Escherichia coli. In order to obtain the maximum BVMO1MES in soluble form, an expression was performed in various E. coli hosts including BL21 (DE3), SHuffle^® and origami B. Moreover, various factors affecting a yield of a soluble target protein - including (1) an IPTG concentration (0.05, 0.1, 0.25 and 0.5 mM), (2) an induction start point (OD₆₀₀ = 0.4, 0.8 and 1.2), (3) an induction temperature (16 and 20°C) and (4) an induction time (12, 16 and 24 h) - were optimized in detail. The highest yield of soluble BVMO1MES could be obtained from E. coli BL21 (DE3) clone when an induction was performed at OD₆₀₀ of 1.2 with 0.1 mM IPTG at 20°C for 12 h. Catalytic activity of a crude extract containing BVMO1MES was evaluated using a ketone substrate 2-methylcyclohexanone. Fragmentation pattern obtained from a gas chromatography–mass spectrometry (GC-MS/MS) confirmed a formation of an expected product (7-methyloxepan-2-one). To reveal its substrate preference, BVMO1MES will be evaluated with a wider range of substrates in the future.