| Institution: | 1. Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China;2. Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China;1. Technology Platform Genomics, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstr. 27, 33615 Bielefeld, Germany;2. Senior Research Group Genome Research of Industrial Microorganisms, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstr. 27, 33615 Bielefeld, Germany;3. Bioinformatics Resource Facility, Centrum für Biotechnologie, Universität Bielefeld, Universitätsstr. 27, 33615 Bielefeld, Germany;4. Proteomics and Metabolomics, Department of Biology, Universität Bielefeld, Universitätsstr. 25, 33615 Bielefeld, Germany;5. Laboratory of Chemical Biotechnology, TU Dortmund University, Emil-Figge-Str. 66, D-44227 Dortmund, Germany;1. Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, Temuco, Chile;2. Centro de Excelencia en Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile;3. Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería y Ciencias, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile;4. Centro Biotecnológico de Estudios Microbianos (CEBEM), Universidad de La Frontera. Temuco, Chile |
| Abstract: | Methyl ketones present a group of highly reduced platform chemicals industrially produced from petroleum-derived hydrocarbons. They find applications in the fragrance, flavor, pharmacological, and agrochemical industries, and are further discussed as biodiesel blends. In recent years, intense research has been carried out to achieve sustainable production of these molecules by re-arranging the fatty acid metabolism of various microbes. One challenge in the development of a highly productive microbe is the high demand for reducing power. Here, we engineered Pseudomonas taiwanensis VLB120 for methyl ketone production as this microbe has been shown to sustain exceptionally high NAD(P)H regeneration rates. The implementation of published strategies resulted in 2.1 g Laq?1 methyl ketones in fed-batch fermentation. We further increased the production by eliminating competing reactions suggested by metabolic analyses. These efforts resulted in the production of 9.8 g Laq?1 methyl ketones (corresponding to 69.3 g Lorg?1 in the in situ extraction phase) at 53% of the maximum theoretical yield. This represents a 4-fold improvement in product titer compared to the initial production strain and the highest titer of recombinantly produced methyl ketones reported to date. Accordingly, this study underlines the high potential of P. taiwanensis VLB120 to produce methyl ketones and emphasizes model-driven metabolic engineering to rationalize and accelerate strain optimization efforts. |
