Wetlands concentrate biodiversity, particularly in arid regions. Chott Ech Chergui (Algeria), one of the biggest wetlands of the north African desert, presents extreme temperatures and salinity conditions. We initiated a physico-chemical and microbiological survey at seven sites encompassing various conditions (salt lakes, freshwater lakes and hot springs), through a one-year monthly sampling campaign. Four sites under the influence of the spring showed little temporal physio-chemical variation. Three sites displayed higher variation and the aridity level, high from late spring until autumn, was a strong predictor of water chemistry. We evidenced extremophile bacteria. Among 320 bacterial isolates tested for thermo-, acido- and alcalino- tolerance, 39, affiliated to Firmicutes and Proteobacteria, were successfully maintained and underwent physiological, biochemical and molecular characterizations. Thermotolerance was recorded up to 100 °C for a water isolate affiliated to Geobacillus stearothermophilus. Halotolerance was recorded up to 30% NaCl (w:v) for soil isolates affiliated to Salinicola zeshunii, Chromohalobacter beijerinckii and Virgibacillus halodenitrificans. Acido- and alcalo- tolerance were recorded for a pH range from 5 to 11 for several soil and water isolates affiliated to Exiguobacterium, Bacillus, Salinicola and Chromohalobacter genus. Our results comfort the interest of studying extremophile diversity in wetlands of the highly arid Sahara region.

湿地集中了生物多样性，特别是在干旱地区。Chott Ech Chergui（阿尔及利亚）是北非沙漠最大的湿地之一，具有极端的温度和盐度条件。我们通过为期一年的每月采样活动，在涵盖不同条件（盐湖、淡水湖和温泉）的七个地点启动了物理化学和微生物调查。受泉水影响的四个地点几乎没有表现出时间上的物理化学变化。三个地点表现出较高的变化，从春末到秋季的干旱水平较高，是水化学的有力预测因子。我们证明了极端微生物。在对 320 种细菌分离株进行了耐热、耐酸和耐碱测试后，其中 39 种属于厚壁菌门和变形菌门，已成功保存并进行了生理、生化和分子表征。隶属于嗜热脂肪地芽孢杆菌的水分离株的耐热性高达 100 °C 。对于属于Salinicola zeshunii、Chromohalobacter beijerinckii和Virgibacillus halodepregnans的土壤分离株，记录了高达 30% NaCl (w:v) 的耐盐性。记录了属于微小杆菌属、芽孢杆菌属、盐杆菌属和色盐杆菌属的几种土壤和水分离株在 5 至 11 的 pH 范围内的耐酸和耐碱能力。我们的结果激发了研究高度干旱的撒哈拉地区湿地极端微生物多样性的兴趣。