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In December 2016 EFSA and BfR stepped into a Framework Partnership Agreement (FPA) to work jointly on the development, improvement and dissemination of global food safety tools. As outlined in the Specific Agreement #7 of this FPA one specific objective was to work towards the development of a fully operational online model repository that includes features to create, upload, download and execute models with user‐defined inputs for the predefined model parameters. The user interface of the so‐called FSK‐Web model repository had to be designed such, that it is user‐friendly and usable on various end‐user devices and web browser software. The developed "FSK‐Web 1.0" platform now even contains additional services, e.g. to link models with EFSA's Knowledge Junction (KJ) or to join up to four models in a graphical user‐interface (GUI) online. Detailed manuals, video tutorials and an online e‐learning course were developed to support the use of the FSK‐Web repository. A repository disclaimer and a model curation policy were drafted and will be released after being agreed with EFSA. The project created three key outcomes: (1) an operational curated web‐based food safety model repository, and a significant number of executable QMRA models in FSKX format relevant for risk assessment; (2) improved usability and annotation of the various services offered by the FSK‐Web model repository including manuals and online resources explaining the functionality and use of all aspects of the model repository; (3) provision of the possibility to link different FSKX models to create new combined models, including the option to combine models programmed in different scripting languages (also execution of combined R / Python models supported). [ABSTRACT FROM AUTHOR]

New enzymes of nicotine catabolism instrumental in the detoxification of the tobacco alkaloid by Arthrobacter nicotinovorans pAO1 have been identified and characterized. Nicotine breakdown leads to the formation of nicotine blue from the hydroxylated pyridine ring and of γ- N-methylaminobutyrate (CH3-4-aminobutyrate) from the pyrrolidine ring of the molecule. Surprisingly, two alternative pathways for the final steps in the catabolism of CH3-4-aminobutyrate could be identified. CH3-4-aminobutyrate may be demethylated to γ- N-aminobutyrate by the recently identified γ- N-methylaminobutyrate oxidase [Chiribau et al. (2004) Eur J Biochem 271, 4677–4684]. In an alternative pathway, an amine oxidase with noncovalently bound FAD and of novel substrate specificity removed methylamine from CH3-4-aminobutyrate with the formation of succinic semialdehyde. Succinic semialdehyde was converted to succinate by a NADP+-dependent succinic semialdehyde dehydrogenase. Succinate may enter the citric acid cycle completing the catabolism of the pyrrolidine moiety of nicotine. Expression of the genes of these enzymes was dependent on the presence of nicotine in the growth medium. Thus, two enzymes of the nicotine regulon, γ- N-methylaminobutyrate oxidase and amine oxidase share the same substrate. The Km of 2.5 mm and kcat of 1230 s−1 for amine oxidase vs. Km of 140 µm and kcat of 800 s−1 for γ- N-methylaminobutyrate oxidase, determined in vitro with the purified recombinant enzymes, may suggest that demethylation predominates over deamination of CH3-4-aminobutyrate. However, bacteria grown on [14C]nicotine secreted [14C]methylamine into the medium, indicating that the pathway to succinate is active in vivo. [ABSTRACT FROM AUTHOR]