e applied. Herein, we compared wet resting cells and lyophilized cells of recombinant E. coli regarding P450-catalyzed oxidation and identified out that lyophilized cells are well-appropriate as P450-biocatalysts. E. coli harboring CYP105D from Streptomyces platensis DSM 40041 was used as model enzyme and testosterone as model substrate. Conversion was initial enhanced by optimized handling of resting cells. Co-expression of the alcohol dehydrogenase from Rhodococcus erythropolis for cofactor regeneration did not impact P450 activity of wet resting cells (46 conversion) but was critical to obtain sufficient P450 activity with lyophilized cells reaching a conversion of 72 under the identical circumstances. The usage of recombinant lyophilized E. coli cells for P450 mediated oxidations is really a IP Activator Biological Activity promising beginning point towards broader application of these enzymes. Key phrases: Cytochrome P450, Whole-cell biotransformation, Lyophilized cells, Cofactor regeneration Introduction Cytochromes P450 (CYPs or P450s) are Bradykinin B2 Receptor (B2R) Antagonist list versatile hemecontaining enzymes that catalyze oxidation reactions in the presence of molecular oxygen and NAD(P)H. Due to their capacity to introduce one particular atom of molecular oxygen into a vast wide variety of organic molecules beneath mild reaction situations with typically higher chemo- and regioselectivity, these enzymes happen to be recognized as attractive targets with high possible for biotechnological applications (Bernhardt 2006; Girvan and Munro 2016; Kelly and Kelly 2013; Lundemo and Woodley 2015). Commonly, whole-cell biocatalysis appears attractive mainly because it allows avoiding cell lysis and enzyme isolation (WachtmeisterCorrespondence: [email protected] 1 Institute of Biochemistry, Heinrich-Heine University D seldorf, Universit sstra 1, 40225 D seldorf, Germany Complete list of author details is available in the finish from the articleand Rother 2016). Enzymes are protected by the cell atmosphere in the harmful influence of reaction components (Schrewe et al. 2013; Willrodt et al. 2015). In case of NADH and NADPH dependent enzymes like P450s, these cofactors is often constantly regenerated through metabolism in the host cell, or optionally by the usage of heterologous cofactor regenerating enzymes and co-substrates (Hanlon et al. 2007). With regard to P450 enzymes, whole-cell biocatalysis may be especially eye-catching due to the fact electrons from NAD(P)H are transferred by means of a single or two redox companion proteins to the catalytically active heme. Co-expression with the enzymes belonging to a P450 redox chain in one particular microbial cell seems more attractive than separate expression and isolation of many enzymes. In spite of the apparent benefits of whole-cell systems for P450-catalyzed reactions, their application is frequently associated with challenges like substrate/product toxicityThe Author(s) 2021. Open Access This article is licensed beneath a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give suitable credit for the original author(s) along with the source, offer a hyperlink towards the Creative Commons licence, and indicate if adjustments had been made. The images or other third party material in this post are incorporated inside the article’s Inventive Commons licence, unless indicated otherwise inside a credit line for the material. If material is just not included in the article’s Creative Commons licence and your intended use just isn’t permitted by statutory regulation or exceeds th