biostudies-literatureGu YNational Natural Science Foundation of China35855-35862https://www.ebi.ac.uk/biostudies/studies/S-EPMC9088196biostudies-literatureUnknown8(62)Microthrix parvicella (M. parvicella) is a filamentous bacterium that induces bulking in activated sludge. Here, we used the affinity of long-chain fatty acids (LCFA) for M. parvicella to create a novel fluorescent probe of carbazole modified by LCFA. The structure was characterized by 1H NMR spectroscopy and mass spectrometry. The spectral properties, photostability, and hydrophobic properties of the probe were also characterized. Fluorescent-labeling results showed that it can label M. parvicella in situ and could be biodegraded via metabolism. The stable docking mode of carbazole probes with different fatty acid chains and lipases was also docked by the density functional tight-binding (DFTB) method.RSC advancesA novel fluorescent long-chain fatty acid-substituted dye: labeling and biodegrading of Microthrix parvicella.PMC908819611604238515783602150213751778398Ren XGu YLin DWang CFei XYang QTang YfalseA novel fluorescent long-chain fatty acid-substituted dye: labeling and biodegrading of Microthrix parvicella.Microthrix parvicella (M. parvicella) is a filamentous bacterium that induces bulking in activated sludge. Here, we used the affinity of long-chain fatty acids (LCFA) for M. parvicella to create a novel fluorescent probe of carbazole modified by LCFA. The structure was characterized by 1H NMR spectroscopy and mass spectrometry. The spectral properties, photostability, and hydrophobic properties of the probe were also characterized. Fluorescent-labeling results showed that it can label M. parvicella in situ and could be biodegraded via metabolism. The stable docking mode of carbazole probes with different fatty acid chains and lipases was also docked by the density functional tight-binding (DFTB) method.2018-01-01T00:00:00Z2018 Oct2025-04-04T10:01:41.488Z2025-04-04T10:01:41.488ZS-EPMC90881963554790010.1039/c8ra06986g