Contribution of quorum-sensing system to hexadecane degradation and biofilm formation in Acinetobacter sp. strain DR1.
OBJECTIVE
To investigate roles of quorum-sensing (QS) system in Acinetobacter sp. strain DR1 and rifampicin-resistant variant (hereinafter DR1R).


RESULTS
The DR1 strain generated three putative acyl homoserine lactones (AHLs), while the DR1R produced only one signal and QS signal production was abrogated in the aqsI (LuxI homolog) mutant. The hexadecane-degradation and biofilm-formation capabilities of DR1, DR1R, and aqsI mutants were compared, along with their proteomic data. Proteomics analysis revealed that the AHL lactonase responsible for degrading QS signal was highly upregulated in both DR1R and aqsI mutant, also showed that several proteins, including ppGpp synthase, histidine kinase sensors, might be under the control of QS signalling. Interestingly, biofilm-formation and hexadecane-biodegradation abilities were reduced more profoundly in the aqsI mutant. These altered phenotypes of the aqsI mutant were restored via the addition of free wild-type cell supernatant and exogenous C(12) -AHL.


CONCLUSIONS
The QS system in strain DR1 contributes to hexadecane degradation and biofilm formation.


CONCLUSIONS
This is the first report to demonstrate that a specific QS signal appears to be a critical factor for hexadecane degradation and biofilm formation in Acinetobacter sp. strain DR1.
Kang
Y-S
YS
Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea.
Park
W
W
D000150:Acinetobacter / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D054742:Acyl-Butyrolactones / Q000378:metabolism; D000473:Alkanes / Q000378:metabolism* / Q000494:pharmacology; D018441:Biofilms; D002448:Cell Adhesion; D005798:Genes, Bacterial / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D009154:Mutation; D010641:Phenotype; D040901:Proteomics; D053038:Quorum Sensing / Q000502:physiology*; D015398:Signal Transduction; D014874:Water Pollutants, Chemical / Q000494:pharmacology
D054742:Acyl-Butyrolactones; D000473:Alkanes; D014874:Water Pollutants, Chemical; C007932:n-hexadecane