Department of Biochemical Technology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovakia, The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, London, United Kingdom, School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, Manchester, United Kingdom, CEA, LETI, Department of Technology for Life Sciences and Health Care, SBSC, Grenoble, France

BACKGROUND: Most biocatalysts currently involved in one-pot chemoenzymatic cascades are pure enzymes, while whole cells and crude enzyme extracts remain unexplored. This work aims to develop a chemo-biocatalytic one-pot two-step system involving whole cell monoamine oxidase (MAO, EC 1.4.3.4) coupled with a Cu-based oxidative system (CuI/H2O2) for the transformation of 1,2,3,4-tetrahydroisoquinoline (THIQ) to 3,4-dihydroisoquinolin-1(2H)-one (DHIO). RESULTS: MAO-N variants D9 and D11 were tested as whole cell and crude lysate biocatalysts for biological oxidation. Whole Escherichia coli OverExpress C43(DE3) cells expressing MAO-N D9 showed the best performance (Vmax = 36.58 mmol L?1 h?1, KM = 8.124 mmol L?1, maximum specific productivity 89.3 ?mol min?1 g? 1 DCW) and were employed in combination with CuI/H2O2 in a sequential one-pot two-step process. The biotransformation was scaled-up to the initial volume of 25 mL and after triple THIQ feeding, 48.2 mmol L?1 of the intermediate 3,4-dihydroisoquinoline (DHIQ) was obtained with a yield of 71.3%. Afterwards, chemical catalysts (1 mol% CuI and 10 eq. H2O2) were added to the biologically produced DHIQ, which was transformed to ?30 mmol L?1 DHIO at 69.4% overall yield. CONCLUSION: As MAO-N variants have wide substrate specificity, this work broadens the portfolio of one-pot chemoenzymatic processes employing whole cell biocatalysts, representing an alternative to using pure enzymes. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry

cascade reaction, chemo-biocatalysis, monoamine oxidase, whole cell biocatalysts

Biocatalysts, Cells, Chemical industry, Cytology, Escherichia coli, Biocatalysis, Biological oxidations, Cascade reactions, Monoamine oxidase, Oxidative systems, Specific productivity, Substrate specificity, Whole cell biocatalysts, Enzymes, amine, amine oxidase (flavin containing), lactam, tetrahydroisoquinoline, Article, biocatalyst, biomass production, biotransformation, catalyst, chemical industry, chemical reaction, chemical structure, controlled study, enzyme specificity, Escherichia coli, nonhuman, one pot synthesis, oxidation, oxidative stress, process optimization, protein expression, scale up, whole cell