Contribution of quorum-sensing system to hexadecane degradation and biofilm formation in Acinetobacter sp. strain DR1

Abstract

Aims: To investigate roles of quorum‐sensing (QS) system in Acinetobacter sp. strain DR1 and rifampicin‐resistant variant (hereinafter DR1R). Methods and 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 C12‐AHL. Conclusions: The QS system in strain DR1 contributes to hexadecane degradation and biofilm formation. Significance and Impact of the Study: 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.

Complete Genome Sequence of the Diesel-Degrading Acinetobacter sp. Strain DR1

“…Interestingly, DR1 possesses a quorum sensing (QS) system, which has been shown to play a significant role in biofilm formation and hexadecane biodegradation. The results of proteomic studies have demonstrated that the QS system regulates a broad variety of proteins (6). Collectively, our findings demonstrate that DR1 has profound potential for environmental applications and is an environmental isolate distinct from pathogenic strains, thus indicating that the whole-genome sequencing of DR1 is a worthwhile pursuit.…”

“…There are 6 rRNA operons with a 16S, tRNA-Ile, tRNAAla, 23S, 5S organization. The genes studied previously were clearly identified via genome sequencing (4,5,6). The availability of the complete genome sequence of Acinetobacter sp.…”

Comparative Genomic Analysis of Acinetobacter oleivorans DR1 To Determine Strain-Specific Genomic Regions and Gentisate Biodegradation

“…The genetics and physiology of strain DR1 (with respect to activities such as biodegradation of diesel fuel, biofilm formation, natural transformation, quorum sensing, and oxidative stress) have only begun to be investigated (16,19,20,21,30). The availability of the complete genome of strain DR1 (16) provides the opportunity for a comparative study.…”

Novel hydrocarbonoclastic metal-tolerant Acinetobacter and Pseudomonas strains from Aconcagua river oil-polluted soil

“…Although n-hexadecane degradation by Acinetobacter strains has been widely reported (Koma et al, 2001;Kang and Park, 2010), reports of Acinetobacter strains possessing heavy metal tolerance together with PAH degradation abilities are scarce. Acinetobacter strains tolerant to chromium, nickel and cadmium that are useful for heavy metal bioremediation have been described (Bhattacharya and Gupta, 2013).…”