Microbial　pectinases　are　important　sources　due　to　the　ease　of　production　and　unique　physicochemical　properties.　Here,　DY2,　a　strain　of　Bacillus　licheniformis,　was　identified　from　14　strains　of　bacteria　as　a　pectinase-producing　bacterium　with　good　application　potential.　Optimized　carbon　sources　of　submerged　fermentation　led　to　the　identification　of　glucose　as　an　ideal　carbon　source　for　activity　and　production　of　P-DY2,　the　pectinase　produced　by　DY2.　GC-MS　based　metabolomics　was　used　to　explore　metabolic　mechanisms　mediated　by　glucose,　showing　the　frustrated　TCA　cycle　is　necessary　to　elevate　the　activity　and　production　of　P-DY2.　Decreased　activity　of　α-ketoglutaric　dehydrogenase　and　succinate　dehydrogenase　of　DY2　in　glucose-treated　samples　supports　the　conclusion　that　P-DY2　production　is　the　TCA　cycle-independent.　These　results　reveal　a　metabolic　mechanism　of　high-activity　pectinase　mediated　by　exogenous　glucose.　These　findings　highlight　the　way　to　understand　metabolic　mechanisms　and　promote　pectinase　yield　through　metabolomics　approach　and　metabolic　modulation,　respectively.　©　2019,　The　Korean　Society　for　Biotechnology　and　Bioengineering　and　Springer.