Ghanmi Fadoua, Carré-Mlouka Alyssa, Zarai Zied, Mejdoub Hafedh, Peduzzi Jean, Maalej Sami, Rebuffat Sylvie
Laboratory Molecules of Communication and Adaptation of Microorganisms (MCAM) UMR 7245 CNRS-MNHN, Muséum national d'Histoire naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France; Laboratory of Biodiversity and Aquatic Ecosystems, Ecology and Planktonology, University of Sfax-Tunisia, Faculty of Sciences, BP 1171, Tunisia.
Laboratory Molecules of Communication and Adaptation of Microorganisms (MCAM) UMR 7245 CNRS-MNHN, Muséum national d'Histoire naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
Res Microbiol. 2020 Mar;171(2):80-90. doi: 10.1016/j.resmic.2019.09.003. Epub 2019 Sep 24.
The extremely halophilic archaeon Halobacterium salinarum strain ETD5 was previously isolated from the solar saltern of Sfax (Tunisia) and shown to encode and express halocin S8. The Hbt. salinarum ETD5 culture supernatant was shown here to exhibit high antimicrobial activity against several halophilic archaea and bacteria of different genera, showing a cross-domain inhibition. The antimicrobial activity was destroyed by proteases, thus pointing to halocins. A bioguided purification procedure was applied using two chromatography steps and antimicrobial assays directed against Halorubrum chaoviator ETR14. In-gel screening assay showed the presence of two antimicrobial bands of approximately 8 and 14 kDa, for which characterization was investigated by N-terminal sequencing and mass spectrometry. The full-length form of halocin S8 that contains 81 amino acids and differs from the 36 amino acid short-length halocin S8 previously described from an uncharacterized haloarchaeon S8a, was identified in the 8 kDa halocin band. A novel halocin that we termed halocin S14 was found in the 14 kDa band. It exhibits amino acid sequence identities with the N-terminally truncated region of the archaeal Mn-superoxide dismutase. These results show that Hbt. salinarum ETD5 produces multiple halocins, a feature that had not been described until now in the domain Archaea.
极端嗜盐古菌盐沼盐杆菌菌株ETD5先前是从突尼斯斯法克斯的太阳能盐场分离出来的，并被证明能够编码和表达盐菌素S8。本文显示，盐沼盐杆菌ETD5的培养上清液对几种不同属的嗜盐古菌和细菌具有高抗菌活性，表现出跨域抑制作用。抗菌活性被蛋白酶破坏，因此表明是盐菌素。采用两步色谱法和针对嗜盐嗜盐碱杆菌ETR14的抗菌测定法进行生物导向纯化。凝胶内筛选试验显示存在两条分子量约为8 kDa和14 kDa的抗菌条带，通过N端测序和质谱对其进行表征研究。在8 kDa的盐菌素条带中鉴定出了包含81个氨基酸的全长形式的盐菌素S8，它与先前从未知嗜盐古菌S8a描述的36个氨基酸的短长度盐菌素S8不同。在14 kDa条带中发现了一种新的盐菌素，我们将其命名为盐菌素S14。它与古菌锰超氧化物歧化酶的N端截短区域具有氨基酸序列同一性。这些结果表明，盐沼盐杆菌ETD5产生多种盐菌素，这一特征在古菌域中迄今尚未见报道。
