Ipek, Dilvin2025-01-272025-01-2720232528-9691https://doi.org/10.23902/trkjnat.1276562https://search.trdizin.gov.tr/tr/yayin/detay/1201954https://hdl.handle.net/20.500.12428/23660This study aimed to show presence of Quorum Sensing (QS) signals of Gramnegative and Gram-positive biofilm producing bacteria isolated from real dairy process lines. Defining the profile and chemical composition of QS-signals is an important factor in control of microbial resistance and biofilm production. We especially focused on unusual behaviour of Gram-positive and Gram-negative isolates. Long-chain acyl-homoserine lactones (AHLs) signals (C14-HSL, C16-HSL and C18-HSL) and DFD (4,5-dihidroksi-2,3-pentanedione)-AI2 signals of the isolates were studied by High-performance liquid chromatography (HPLC) and Liquid Chromatography with tandem mass spectrometry (LC-MSMS) methods. All Gram-positive isolates were defined as AHL-producers. All Gram-negative isolates, formerly defined as non-AHL producers by both biosensors and HPLC methods, were identified as AHL-producers. DFD signal was only detected from Gram-negative Klebsiella pneumonia, Enterobacter cloacae and Klebsiella oxytoca isolates. The results demonstrated that the QS system is a complex system and biosensor microorganism may not be the best method for QS-signal identification. The results also provided new insights in defining the profile and chemical composition of QS-signals importance for interrupting the chemical communication completely to reduce biofilm formation and prevent resistance gain of microorganisms.eninfo:eu-repo/semantics/openAccessAHL SignalsAI-2 SignalsBiofilmBiosensorsHPLCLC-MSMSEVALUATION OF QUORUM SENSING SIGNALS OF STRONG BIOFILM PRODUCING BACTERIA VIA LC-MSMS, HPLC AND BIOSENSORSArticle242233010.23902/trkjnat.1276562N/AWOS:0010881779000032-s2.0-852055898941201954N/A