Complete genome sequence and characterization of the N-acylhomoserine lactone-degrading gene of the potato leaf-associated Solibacillus silvestris

• Published in: Journal of bioscience and bioengineering 2012, Vol.113 (1), p.20-25
• Main Authors: Morohoshi, Tomohiro, Tominaga, Yoshiaki, Someya, Nobutaka, Ikeda, Tsukasa
• Format: Article
• Language: English
• Subjects: Acyl-Butyrolactones - metabolism; Acylhomoserine lactone; Amino Acid Sequence; Bacillus cereus; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Base Sequence; Biological and medical sciences; Biological control; biological control agents; Biotechnology; Carboxylic Ester Hydrolases - genetics; Carboxylic Ester Hydrolases - metabolism; Cloning, Molecular; DNA, Bacterial - genetics; Escherichia coli; Fundamental and applied biological sciences. Psychology; genes; Genome, Bacterial; Gram-negative bacteria; Lactonase; lactones; Leaf-associated bacteria; leaves; maceration; maltose; Molecular Sequence Data; open reading frames; Pectobacterium carotovorum subsp. carotovorum; Planococcaceae - enzymology; Planococcaceae - genetics; plant pathogens; plasmids; polymerase chain reaction; potatoes; Quorum Sensing; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; sequence analysis; Sequence Analysis, DNA; Solanum tuberosum; Solanum tuberosum - microbiology; Solibacillus silvestris
• ISSN: 1389-1723; 1347-4421
• DOI: 10.1016/j.jbiosc.2011.09.006

N-Acylhomoserine lactones (AHLs) are used as quorum-sensing signal molecules by many gram-negative bacteria. We have reported that Solibacillus silvestris, which was isolated from the potato leaf, has AHL-degrading activity. To identify the AHL-degrading gene, whole genome sequencing of S. silvestris StLB046 was performed by using pyrosequencing technology. As the result of the BLAST search, one predicted ORF ( ahlS) showed slight similarity to AiiA-like AHL lactonase from Bacillus cereus group. Escherichia coli harboring the ahlS-expressing plasmid showed high AHL-degrading activity. The ahlS-cording region was also amplified by PCR from the other potato leaf-associated and AHL-degrading S. silvestris strains. Purified AhlS as a maltose binding fusion protein showed high AHL-degrading activity and catalyzes AHL ring opening by hydrolyzing lactones. In addition, expression of ahlS in plant pathogen Pectobacterium carotovorum subsp. carotovorum attenuated maceration of the potato slices. Our results suggest that AHL-degrading activity of ahlS might perform useful functions such as useful biocontrol agents.