Desiccation tolerance and growth-temperature requirements of Coccomyxa (Trebouxiophyceae, Chlorophyta) strains from Antarctic biological soil crusts
Desiccation tolerance and growth-temperature requirements of Coccomyxa (Trebouxiophyceae, Chlorophyta) strains from Antarctic biological soil crusts
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南极生物土壤结皮球菌门（Trebouxiophyceae、Chlorophyta）菌株的干燥耐受性和生长温度要求
DOI：
10.1127/algol_stud/2016/0245
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Gustavs
中科院分区：
文献类型：
--
作者：
Borchhardt;Karsten;Gustavs
Coccomyxa属经常出现在温带地区的生物土壤结皮中，但也在南极土壤中发现。来自大陆南部维多利亚地的菌株NIES 2166（Coccomyxa subellipsoidea）被描述为冷适应的模式生物（Blanc等人，2012年），尽管它已经在人工条件下培养了50多年。为了检验该分离物是否仍保持南极条件下的生理特性或表现出驯化/适应培养，将其与最近从南极半岛采集的土壤样品中分离的3个球粘菌菌株进行生理生态学比较。此外，还对所调查的菌株进行了潜在特有性测试。基于ITS rDNA的分子生物学分析表明，这3个新分离的菌株也属于C.近椭圆形。在短期控制干燥过程中（在相对空气湿度c。10%）和再水化后。在4.6 - 34.8 ℃的温度梯度上测定生长速率.结果表明，所有测试菌株中的耐寒性和耐旱性在大陆菌株NIES 2166中稍微更发达，尽管自分离以来已经过去了50年。因此，可以认为NIES 2166菌株仍然可以被推荐用于测试冷适应性状，但嗜冷行为和特有性可以被排除在所有菌株之外。
The genus Coccomyxa is frequently present in biological soil crusts from temperate regions but has also been found in Antarctic soils. Strain NIES 2166 (Coccomyxa subellipsoidea) from continental South Victoria Land is described as a model organism for cold adaptation (Blanc et al. 2012) although it has been cultivated for more than 50 years under artificial conditions. In order to test whether this isolate still kept physiological traits for Antarctic conditions or exhibited acclimation/adaptation to culturing, it was ecophysiologically compared with three recently isolated Coccomyxa strains from soil samples collected at the Antarctic Peninsula. Additionally, the investigated strains were tested for potential endemism. Molecular analysis based on ITS rDNA identified the three newly isolated strains also as C. subellipsoidea. The effective quantum yield of photosynthesis was examined during controlled short-term desiccation (at relative air humidity c. 10%) and after rehydration. Growth rates were determined over a temperature gradient from 4.6 to 34.8 C. The results indicate cold tolerance and drought tolerance among all tested strains which are slightly more developed in the continental strain NIES 2166 although 50 years passed since isolation. Therefore it is assumed that strain NIES 2166 can still be recommended to test traits of cold adaptation but psychrophilic behavior, and therefore endemism, can be excluded among all str