Extraction, purification and identification of bacterial signal molecules based on N‐acyl homoserine lactones

Abstract

SummaryBacteria possess an extraordinary repertoire for intercellular communication and social behaviour. This repertoire for bacterial communication, termed as quorum sensing (QS), depends on specific diffusible signal molecules. There are many different kinds of signal molecules in the bacterial community. Among those signal molecules, N‐acyl homoserine lactones (HSLs, in other publications also referred to as AHLs, acy‐HSLs etc.) are often employed as QS signal molecules for many Gram‐negative bacteria. Due to the specific structure and tiny amount of those HSL signal molecules, the characterization of HSLs has been the subject of extensive investigations in the last decades and has become a paradigm for bacteria intercellular signalling. In this article, different methods, including extraction, purification and characterization of HSLs, are reviewed. The review provides an insight into identification and characterization of new HSLs and other signal molecules for bacterial intercellular communication.

Anti-biofilm activity of ibuprofen and diclofenac against some biofilm producing Escherichia coli and Klebsiella pneumoniae uropathogens

“…The results show amide carbonyl bond absorptions I and II was found at 1547 and 1516 cm -1 and characteristic absorptions near 1678 and 1647 cm -1 these signals are attributable to the presence of γ-lactone and ketone carbonyls. The band bending vibration of the O=CN bond was found to 680 cm -1 (Wang et al, 2011;Yang et al, 2006). These outcomes support the activity data AHL and confirm the presence of a lactone ring in producing strains biofilm with high activity AHL; however the spectra obtained for the extracts have bands too broad and in some cases overlap with other bands, due to the presence of other compounds in the extracts.…”

Biocontrol of Bacterial Leaf Blight of Rice and Profiling of Secondary Metabolites Produced by Rhizospheric Pseudomonas aeruginosa BRp3

“…Although, Naureen et al (2017) have successfully purified the secondary metabolites (2-pentyl-4-quinolinecarboxylic acid and 1- methylcyclohexene) from Lysinibacillus sphaericus ZA9 but the chemistry of these metabolites is significantly different from the HAQs identified in the present study. A high-quality preparatory HPLC system may be required to purify various analogs of HAQs (Wang et al, 2011). …”

Presence of acyl‐homoserine lactones in 57 members of theVibrionaceaefamily

“…Although GC-MS has the advantage of being a rapid, simple and selective method, it is also associated with unwanted degradation of AHLs during the analysis, which results in low sensitivity (Osorno et al 2012). LC-MS is particularly useful in identifying/quantifying particular molecules in a mixture of different chemicals (Wang et al 2011). The technique has undergone significant development with respect to quantification levels with the utilization/refinement of, for example, nano-LC (Frommberger et al 2004;Fekete et al 2007) and Fourier transform ion cyclotron resonance MS (Cataldi et al 2009(Cataldi et al , 2013.…”