Biofilm inhibitory activity of metallo-protein AHL-lactonase from cell-free lysate of endophytic Enterobacter species isolated from Coscinium fenestratum Gaertn. (March 2019)

• Record Type: Journal Article
• Authors: Shastry, Rajesh P.; Rekha, P.D.; Rai, V. Ravishankar
• Is Part Of: Biocatalysis and agricultural biotechnology. Number 18(2019)
• Publication Date: 2019-03
• Subjects: Quorum quenching -- Endophytic bacteria -- Enterobacter -- Molecular docking -- AHL-Lactonase -- Aeromonas hydrophila; Agricultural biotechnology -- Periodicals; Enzymes -- Biotechnology -- Periodicals; 660.6
• DOI: 10.1016/j.bcab.2019.01.047
• Languages: English
• ISSNs: 1878-8181

Abstract

Abstract: The quorum sensing mechanism is widely distributed in microorganisms to regulate the threshold population and controls the QS regulated genes. The aim of the present study was to evaluate the ability of metalloprotein AHL-lactonase which is homologous to aiiA gene to reduce the biofilm formation in Aeromonas hydrophila . Quorum quenching activity of endophytic bacteria associated with Coscinium fenestratum was explored using biosensor bioassay. Based on the screening, the genes coding for metalloprotein AHL-lactonase was amplified. Multiple alignment and in silico structural analysis was performed to test the presence of AHL-lactonase. The enzyme was purified by column chromatography and applied against biofilm formation of A. hydrophila. The endophytic bacterial strain isolates belonged to genera Enterobacter and exhibited significance quorum quenching activity. Endophytic bacteria from Coscinium fenestratum exhibited significantly (p < 0.001) high N-Acyl homoserine lactones (AHLs) degrading activity. Multiple sequence alignment suggested presence of AHL-lactonase gene and presence of conserved motif for dinuclear zinc binding sites as shown by metallo-β-lactamase superfamily. Molecular docking and stimulated interactions between predicted AHL-lactonase and AHLs revealed the possible mechanisms of enzyme-substrate interactions and active sites responsible for degradation of AHLs. The metallo-protein AHL-lactonase significantly inhibited formation of biofilm by A. hydrophila, suggesting possible biotechnological application. Highlights: Novel AHL-lactonase was identified from Enterobacter species. Multiple alignment analysis revealed the presence of conserved motif "HXHXDH". The AHL-lactonase was purified by anion exchange chromatography having size of 30 kDa. Purified lactonase exhibited significant antibiofilm activity (p < 0.001) on Aeromonas hydrophila.