In situ approaches show the limitation of the spoilage potential of Juniperus phoenicea L. essential oil against cold-tolerant Pseudomonas fluorescens KM24

Appl Microbiol Biotechnol. 2021 May 14. doi: 10.1007/s00253-021-11338-3. Online ahead of print.ABSTRACTThe present study aimed to elucidate the effect of subinhibitory concentrations (sub-MICs) of juniper essential oil (EO), α-pinene, and sabinene on the quorum-sensing (QS)-mediated proteolytic and lipolytic properties of Pseudomonas fluorescens KM24. These activities were verified under in situ conditions, in which sub-MICs of the agents altered the morphology of KM24 cells. RNA-Seq studies revealed key coding sequences (CDSs)/genes related to QS and the proteolytic/lipolytic activities of pseudomonads. In this work, all the examined agents decreased autoinducer synthesis and influenced the mRNA expression of the encoding acyltransferase genes lptA, lptD, and plsB. The highest reduction on the 3rd and 5th days of cultivation was observed for the genes lptD (-5.5 and -5.61, respectively) and lptA (-3.5 and -4.0, respectively) following treatment with EO. Inhibition of the lptA, lptD, and plsB genes by singular constituents of EO was on average, from -0.4 to -0.7. At 5 days of cultivation the profile of AHLs of the reference P. fluorescens KM24 strain consisted of 3-oxo-C14-HSL, 3-oxo-C6-HSL, C4-HSL, and N-[(RS)-3-hydroxybutyryl]-HSL, the concentrations of which were 0.570, 0.018, 3.744, and 0.554 μg ml-1, respectively. Independent of the incubation time, EO, α-pinene, and sabinene also suppressed the protease genes prlC (-1.5, -0.5, and -0.5, respectively) and ctpB (-1.5, ...
Source: Applied Microbiology and Biotechnology - Category: Microbiology Authors: Source Type: research