Identification of Quorum-Sensing Molecules of N-Acyl-Homoserine Lactone in Gluconacetobacter Strains by Liquid Chromatography-Tandem Mass Spectrometry.

Ling-Pu Liu,Yan-Yan Xie,Cheng Zhong,Xiao-Tong Ding,Lin Yan,Shi-Ru Jia,Yu-Jie Dai,Long-Hui Huang

doi:10.3390/molecules24152694

Ling-Pu Liu, Yan-Yan Xie + Show 6 more

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https://doi.org/10.3390/molecules24152694

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Abstract

Many Gram-negative bacteria can regulate gene expression in a cell density-dependent manner via quorum-sensing systems using N-acyl-homoserine lactones (AHLs), which are typical quorum-sensing signaling molecules, and thus modulate physiological characteristics. N-acyl-homoserine lactones are small chemical molecules produced at low concentrations by bacteria and are, therefore, difficult to detect. Here, a biosensor system method and liquid chromatography-tandem mass spectrometry were combined to detect and assay AHL production. As demonstrated by liquid chromatography-tandem mass spectrometry, Gluconacetobacter xylinus CGMCC No. 2955, a Gram-negative acetic acid-producing bacterium and a typical bacterial cellulose (BC) biosynthesis strain, produces six different AHLs, including N-acetyl-homoserine lactone, N-butanoyl-homoserine lactone, N-hexanoyl-homoserine lactone, N-3-oxo-decanoyl-homoserine lactone, N-dodecanoyl-homoserine lactone, and N-tetradecanoyl-homoserine lactone. Gluconacetobacter sp. strain SX-1, another Gram-negative acetic acid-producing bacterium, which can synthesize BC, produces seven different AHLs including N-acetyl-homoserine lactone, N-butanoyl-homoserine lactone, N-hexanoyl-homoserine lactone, N-3-oxo-octanoyl-homoserine lactone, N-decanoyl-homoserine lactone, N-dodecanoyl-homoserine lactone, and N-tetradecanoyl-homoserine lactone. These results lay the foundation for investigating the relationship between BC biosynthesis and quorum-sensing systems.

Highlights

Bacterial quorum-sensing systems are regulatory mechanisms that perceive cell density and activate cognate gene expression to regulate bacterial group behavior [1]
SX-1, Gluconacetobacter xylinus (G. xylinus) CGMCC no. 2955, and P. aeruginosa PAK all produced acyl-homoserine lactones (AHLs), which served as autoinducers of the quorum-sensing systems in Gram-negative bacteria
Taken findings suggest the existence of a relationship between bacterial cellulose (BC) biosynthesis and quorum-sensing systems together, these findings suggest the existence of a relationship between BC biosynthesis and in Gluconacetobacter strains

Summary

Introduction

Bacterial quorum-sensing systems are regulatory mechanisms that perceive cell density and activate cognate gene expression to regulate bacterial group behavior [1]. Bacteria can regulate group behavior by cell-to-cell communication; this inter-bacterial communication system, known as quorum sensing, utilizes hormones, such as N-acyl-homoserine lactones (AHLs), oligopeptides, and furanosyl borate diester, to regulate bacterial gene expression and, subsequently, alter physiological characteristics [2,3,4,5]. Bacterial quorum sensing was first reported by Nealson et al [6] in 1970 They discovered that there was a positive correlation between the cell densities of Vibrio fischeri and their bioluminescence. When the cell densities reach a certain threshold, Vibrio fischeri can emit fluorescence. Few autoinducers are present, and no Molecules 2019, 24, 2694; doi:10.3390/molecules24152694 www.mdpi.com/journal/molecules

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