Print Email Facebook Twitter H2O2 Production in Species of the Lactobacillus acidophilus Group: A Central Role for a Novel NADH-Dependent Flavin Reductase Title H2O2 Production in Species of the Lactobacillus acidophilus Group: A Central Role for a Novel NADH-Dependent Flavin Reductase Author Hertzberger, R. Arents, J. Dekker, H.L. Pridmore, D. Gysler, C. Kleerebezem, M. Teixeira de Mattosa, M.J. Faculty Applied Sciences Department Biotechnology Date 2014-01-31 Abstract Hydrogen peroxide production is a well-known trait of many bacterial species associated with the human body. In the presence of oxygen, the probiotic lactic acid bacterium Lactobacillus johnsonii NCC 533 excretes up to 1 mM H2O2, inducing growth stagnation and cell death. Disruption of genes commonly assumed to be involved in H2O2 production (e.g., pyruvate oxidase, NADH oxidase, and lactate oxidase) did not affect this. Here we describe the purification of a novel NADH-dependent flavin reductase encoded by two highly similar genes (LJ_0548 and LJ_0549) that are conserved in lactobacilli belonging to the Lactobacillus acidophilus group. The genes are predicted to encode two 20-kDa proteins containing flavin mononucleotide (FMN) reductase conserved domains. Reductase activity requires FMN, flavin adenine dinucleotide (FAD), or riboflavin and is specific for NADH and not NADPH. The Km for FMN is 30 ± 8 ?M, in accordance with its proposed in vivo role in H2O2 production. Deletion of the encoding genes in L. johnsonii led to a 40-fold reduction of hydrogen peroxide formation. H2O2 production in this mutant could only be restored by in trans complementation of both genes. Our work identifies a novel, conserved NADH-dependent flavin reductase that is prominently involved in H2O2 production in L. johnsonii. To reference this document use: http://resolver.tudelft.nl/uuid:45277a14-40de-4827-bb21-7534743b7f91 DOI https://doi.org/10.1128/AEM.04272-13 Publisher American Society for Microbiology ISSN 1098-5336 Source Appl. Environ. Microbiol. April 2014 vol. 80 no. 7 2229-2239 Part of collection Institutional Repository Document type journal article Rights © 2014 American Society for Microbiology Files PDF H2O2_Production_in_Specie ... p_a....pdf 410.54 KB Close viewer /islandora/object/uuid:45277a14-40de-4827-bb21-7534743b7f91/datastream/OBJ/view