Akademik Veri Yönetim Sistemi
TRAKYA UNIVERSITY JOURNAL OF NATURAL SCIENCES, cilt.24, sa.2, ss.8, 2023 (ESCI)
Abstract: This study aimed to show presence of Quorum Sensing (QS) signals of Gram-
negative 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)-AI-
2 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.