AiiM, a Novel Class of N -Acylhomoserine Lactonase from the Leaf-Associated Bacterium Microbacterium testaceum

作者：Wen-Zhao Wang, Tomohiro Morohoshi, Masashi Ikenoya, Nobutaka Someya, Tsukasa Ikeda · 发表于：Applied and Environmental Microbiology · 年份：2010 · DOI：10.1128/aem.02738-09 · 被引用次数：146 · 研究领域：Bacterial biofilms and quorum sensing、Infections and bacterial resistance

N-Acylhomoserine lactones (AHLs) are used as quorum-sensing signal molecules by many Gram-negative bacteria. We have reported that Microbacterium testaceum StLB037, which was isolated from the leaf surface of potato, has AHL-degrading activity. In this study, we cloned the aiiM gene from the genomic library of StLB037, which has AHL-degrading activity and shows high homology with the alpha/beta hydrolase fold family from Actinobacteria. Purified AiiM as a maltose binding fusion protein showed high degrading activity of AHLs with both short- and long-chain AHLs with or without substitution at carbon 3. High-performance liquid chromatography analysis revealed that AiiM works as an AHL lactonase that catalyzes AHL ring opening by hydrolyzing lactones. In addition, expression of AiiM in the plant pathogen Pectobacterium carotovorum subsp. carotovorum reduced pectinase activity markedly and attenuated soft rot symptoms on potato slices. In conclusion, this study indicated that AiiM might be effective in quenching quorum sensing of P. carotovorum subsp. carotovorum.