Ghanmi Fadoua, Carré-Mlouka Alyssa, Vandervennet Manon, Boujelben Ines, Frikha Doniez, Ayadi Habib, Peduzzi Jean, Rebuffat Sylvie, Maalej Sami
Unité Biodiversité et Ecosystèmes Aquatiques Environnementaux (UR11ES/72), Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000, Sfax, Tunisia.
Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245 CNRS-MNHN), Sorbonne Universités, Muséum national d'Histoire naturelle, Centre national de la Recherche scientifique (CNRS), CP 54, 57 rue Cuvier, 75005, Paris, France.
Extremophiles. 2016 May;20(3):363-74. doi: 10.1007/s00792-016-0827-9. Epub 2016 Apr 13.
Thirty-five extremely halophilic microbial strains isolated from crystallizer (TS18) and non-crystallizer (M1) ponds in the Sfax solar saltern in Tunisia were examined for their ability to exert antimicrobial activity. Antagonistic assays resulted in the selection of eleven strains that displayed such antimicrobial activity and they were further characterized. Three cases of cross-domain inhibition (archaea/bacteria or bacteria/archaea) were observed. Four archaeal strains exerted antimicrobial activity against several other strains. Three strains, for which several lines of evidence suggested the antimicrobial activity was, at least in part, due to peptide/protein agents (Halobacterium salinarum ETD5, Hbt. salinarum ETD8, and Haloterrigena thermotolerans SS1R12), were studied further. Optimal culture conditions for growth and antimicrobial production were determined. Using DNA amplification with specific primers, sequencing and RT-PCR analysis, Hbt. salinarum ETD5 and Hbt. salinarum ETD8 were shown to encode and express halocin S8, a hydrophobic antimicrobial peptide targeting halophilic archaea. Although the gene encoding halocin H4 was amplified from the genome of Htg. thermotolerans SS1R12, no transcript could be detected and the antimicrobial activity was most likely due to multiple antimicrobial compounds. This is also the first report that points to four different strains isolated from different geographical locations with the capacity to produce identical halocin S8 proteins.
对从突尼斯斯法克斯太阳能盐场的结晶池（TS18）和非结晶池（M1）中分离出的35株极端嗜盐微生物菌株进行了抗菌活性检测。拮抗试验筛选出11株具有抗菌活性的菌株，并对其进行了进一步鉴定。观察到3例跨域抑制情况（古菌/细菌或细菌/古菌）。4株古菌菌株对其他几种菌株具有抗菌活性。对3株菌株（盐生盐杆菌ETD5、盐生盐杆菌ETD8和嗜热嗜盐碱杆菌SS1R12）进行了进一步研究，有几条证据表明其抗菌活性至少部分归因于肽/蛋白质类物质。确定了生长和抗菌物质产生的最佳培养条件。使用特异性引物进行DNA扩增、测序和RT-PCR分析，结果表明盐生盐杆菌ETD5和盐生盐杆菌ETD8编码并表达了嗜盐菌素S8，这是一种靶向嗜盐古菌的疏水性抗菌肽。尽管从嗜热嗜盐碱杆菌SS1R12的基因组中扩增出了编码嗜盐菌素H4的基因，但未检测到转录本，其抗菌活性很可能归因于多种抗菌化合物。这也是首次报道从不同地理位置分离出的4株不同菌株能够产生相同的嗜盐菌素S8蛋白。
