Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science University of Malaya, 50603 Kuala Lumpur, Malaysia.
National Antarctic Research Centre (NARC), Institute of Postgraduate Studies, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Sci Rep. 2017 Feb 22;7:42968. doi: 10.1038/srep42968.
Planococcus is a Gram-positive halotolerant bacterial genus in the phylum Firmicutes, commonly found in various habitats in Antarctica. Quorum quenching (QQ) is the disruption of bacterial cell-to-cell communication (known as quorum sensing), which has previously been described in mesophilic bacteria. This study demonstrated the QQ activity of a psychrotolerant strain, Planococcus versutus strain L10.15, isolated from a soil sample obtained near an elephant seal wallow in Antarctica. Whole genome analysis of this bacterial strain revealed the presence of an N-acyl homoserine lactonase, an enzyme that hydrolyzes the ester bond of the homoserine lactone of N-acyl homoserine lactone (AHLs). Heterologous gene expression in E. coli confirmed its functions for hydrolysis of AHLs, and the gene was designated as aidP (autoinducer degrading gene from Planococcus sp.). The low temperature activity of this enzyme suggested that it is a novel and uncharacterized class of AHL lactonase. This study is the first report on QQ activity of bacteria isolated from the polar regions.
节杆菌是厚壁菌门中的革兰氏阳性耐盐细菌属，通常存在于南极洲的各种生境中。群体感应淬灭（Quorum Quenching，QQ）是破坏细菌细胞间通讯（称为群体感应）的过程，之前在嗜温菌中已有描述。本研究展示了一种耐冷菌株 Planococcus versutus 菌株 L10.15 的 QQ 活性，该菌株是从南极洲象海豹水坑附近的土壤样本中分离出来的。对该细菌菌株的全基因组分析表明，存在 N-酰基高丝氨酸内酯酶，该酶水解 N-酰基高丝氨酸内酯（AHLs）的高丝氨酸内酯的酯键。在大肠杆菌中的异源基因表达证实了其对 AHLs 的水解功能，该基因被命名为 aidP（来自 Planococcus sp. 的自动诱导物降解基因）。该酶的低温活性表明它是一种新型的、尚未被描述的 AHL 内酯酶。本研究是首次报道从极地地区分离的细菌的 QQ 活性。
