Updated publication reference for PubMed record(s): 27965289. In this study, we have applied the top-down approach to reduce the genome of B. subtilis in order to obtain minimal strains with robust growth on complex medium at 37°C. For this purpose, we have evaluated the function of each gene of the B. subtilis genome and identified essential, important and dispensable genomic regions. Using an efficient markerless and scarless deletion method and a system allowing induction of genetic competence in the complete cell population, we have constructed two genome-reduced strains lacking about 36% of dispensable genetic information. Multi-omics analyses with the genome-reduced strains revealed substantial changes in the transcriptome, the proteome and in the metabolome. The massive reorganization of metabolism in the two genome-reduced strains can be explained by the underlying genotypes that were determined by genome re-sequencing. Moreover, the transcriptome and proteome analyses uncovered novel dispensable genomic regions that can be removed to further streamline the B. subtilis genome. In conclusion, both minimal strains show interesting metabolic features and they serve as excellent starting points to generate an ultimate reduced-genome B. subtilis cell containing only genes required for robust growth on complex medium.