Characterization of N-acylhomoserine lactone-degrading bacteria associated with the Zingiber officinale (ginger) rhizosphere: Co-existence of quorum quenching and quorum sensing in Acinetobacter and Burkholderia

Abstract

BackgroundCell-to-cell communication (quorum sensing (QS)) co-ordinates bacterial behaviour at a population level. Consequently the behaviour of a natural multi-species community is likely to depend at least in part on co-existing QS and quorum quenching (QQ) activities. Here we sought to discover novel N-acylhomoserine lactone (AHL)-dependent QS and QQ strains by investigating a bacterial community associated with the rhizosphere of ginger (Zingiber officinale) growing in the Malaysian rainforest.ResultsBy using a basal growth medium containing N-(3-oxohexanoyl)homoserine lactone (3-oxo-C6-HSL) as the sole source of carbon and nitrogen, the ginger rhizosphere associated bacteria were enriched for strains with AHL-degrading capabilities. Three isolates belonging to the genera Acinetobacter (GG2), Burkholderia (GG4) and Klebsiella (Se14) were identified and selected for further study. Strains GG2 and Se14 exhibited the broadest spectrum of AHL-degrading activities via lactonolysis while GG4 reduced 3-oxo-AHLs to the corresponding 3-hydroxy compounds. In GG2 and GG4, QQ was found to co-exist with AHL-dependent QS and GG2 was shown to inactivate both self-generated and exogenously supplied AHLs. GG2, GG4 and Se14 were each able to attenuate virulence factor production in both human and plant pathogens.ConclusionsCollectively our data show that ginger rhizosphere bacteria which make and degrade a wide range of AHLs are likely to play a collective role in determining the QS-dependent phenotype of a polymicrobial community.

AmiE, a Novel N -Acylhomoserine Lactone Acylase Belonging to the Amidase Family, from the Activated-Sludge Isolate Acinetobacter sp. Strain Ooi24

“…Although AHL lactonase activity has been detected in Acinetobacter sp. strain GG2, isolated from the rhizosphere of ginger (13), no reports of the cloning of AHL acylase genes from the genus Acinetobacter have been published. In this study, we report the cloning and characterization of a gene that encodes a novel AHL acylase from Acinetobacter sp.…”

The Role of Heavy Metals-Resistant Bacteria Acinetobacter sp. in Copper Phytoremediation using Eichhornia crasippes [(Mart.) Solms]

“…The bacteria have high resistance to some heavy metals such as copper, zinc, cadmium, mercury, and lead might be due to the selective pressure by pollution of industrial wastewater at Rungkut, the location from where the strain has been isolated. Chan et al [18] reported that Acinetobacter can ussually isolated from polluted environment. Acinetobacter species are important biotechnological tools, and have been utilized extensively in the synthesis of enzymes and other life-sustaining macromolecules and for degradation of recalcitrant compounds [18].…”

“…Chan et al [18] reported that Acinetobacter can ussually isolated from polluted environment. Acinetobacter species are important biotechnological tools, and have been utilized extensively in the synthesis of enzymes and other life-sustaining macromolecules and for degradation of recalcitrant compounds [18]. Genus Acinetobacter was a member of bacterial community in rhizosphere of E. crassipes and in wetland water samples [19].…”

Inhibition of quorum sensing-controlled virulence factors in Pseudomonas aeruginosa by human serum paraoxonase

“…Interruption of QS, also known as quorum quenching, can be achieved by targeting the signalling molecule itself (Chan et al, 2010(Chan et al, , 2011) the transcriptional activator (Manefield et al, 1999) or the autoinducer synthase (Parsek et al, 1999). Thus, anti-QS treatment may be a plausible way to attenuate bacterial virulence without killing the pathogens, thus potentially preventing the acquisition of drug resistance by the bacteria (Adonizio et al, 2006).…”