biostudies-literatureWei YDepartment of Science and Technology of Shandong ProvinceNational Science Foundation of Shandong ProvinceMOST | National Natural Science Foundation of China (NSFC)Shandong UniversityMOST | National Natural Science Foundation of ChinaTaishan Scholars Project of Shandong ProvinceShandong University (SDU)e0089024https://www.ebi.ac.uk/biostudies/studies/S-EPMC11267941biostudies-literatureUnknown90(7)Biological valorization of lignin, the second most abundant biopolymer on Earth, is an indispensable sector to build a circular economy and net-zero future. However, lignin is recalcitrant to bioupcycling, demanding innovative solutions. We report here the biological valorization of lignin-derived aromatic carbon to value-added chemicals without requesting extra organic carbon and freshwater via reprogramming the marine <i>Roseobacter</i> clade bacterium <i>Roseovarius nubinhibens</i>. We discovered the unusual advantages of this strain for the oxidation of lignin monomers and implemented a CRISPR interference (CRISPRi) system with the <i>lacI</i>-P_trc inducible module, nuclease-deactivated Cas9, and programmable gRNAs. This is the first CRISPR-based regulatory system in <i>R. nApplied and environmental microbiologyBlue valorization of lignin-derived monomers via reprogramming marine bacterium <i>Roseovarius nubinhibens</i>.PMC1126794122278246tstp20230604ZR2021ME0662022HWYQ-017U20A20146, 22378233Qilu Young Scholar ProgramWang S-GWei YXia P-FfalseBlue valorization of lignin-derived monomers via reprogramming marine bacterium <i>Roseovarius nubinhibens</i>.Biological valorization of lignin, the second most abundant biopolymer on Earth, is an indispensable sector to build a circular economy and net-zero future. However, lignin is recalcitrant to bioupcycling, demanding innovative solutions. We report here the biological valorization of lignin-derived aromatic carbon to value-added chemicals without requesting extra organic carbon and freshwater via reprogramming the marine <i>Roseobacter</i> clade bacterium <i>Roseovarius nubinhibens</i>. We discovered the unusual advantages of this strain for the oxidation of lignin monomers and implemented a CRISPR interference (CRISPRi) system with the <i>lacI</i>-P_trc inducible module, nuclease-deactivated Cas9, and programmable gRNAs. This is the first CRISPR-based regulatory system in <i>R. n2024-01-01T00:00:00Z2024 Jul2025-04-04T02:14:05.063Z2025-04-04T02:14:05.063ZS-EPMC112679413894056410.1128/aem.00890-24