Are thermophilic microorganisms active in cold environments?
Are thermophilic microorganisms active in cold environments?
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DOI：
10.1017/s1473550414000433
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发表时间：
2015-07-01
影响因子：
1.7
通讯作者：
Rozitis, Ben
中科院分区：
文献类型：
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作者：
Cockell, Charles S.;Cousins, Claire;Rozitis, Ben
冰岛内陆的平均气温低于10摄氏度。然而，我们以前观察到的16S rDNA序列与嗜热谱系在冰岛玄武岩。对冰岛火成岩温度的测量表明，这些低熔点基底的太阳辐射达到了44.5摄氏度的表面峰值温度。我们从玄武岩中分离出7种嗜热土芽孢杆菌，其最佳生长温度与65 ℃相似。这些生物的最低生长温度与36摄氏度相似，表明它们可能在岩石环境中活跃。在40摄氏度的玄武岩溶解速率增加的存在下的一个分离物相比，非生物控制，显示其潜在的参与在环境温度下的活性地球化学。这些数据提出了在大气候寒冷的岩石环境中短暂活跃嗜热菌生长的可能性，这意味着活跃嗜热菌的地理分布可能比以前理解的要大。这些数据表明，在大尺度上测量或预测的温度本身并不足以评估微米尺度上极端微生物的生态位。
The mean air temperature of the Icelandic interior is below 10 degrees C. However, we have previously observed 16S rDNA sequences associated with thermophilic lineages in Icelandic basalts. Measurements of the temperatures of igneous rocks in Iceland showed that solar insolation of these low albedo substrates achieved a peak surface temperature of 44.5 degrees C. We isolated seven thermophilic Geobacillus species from basalt with optimal growth temperatures of similar to 65 degrees C. The minimum growth temperature of these organisms was similar to 36 degrees C, suggesting that they could be active in the rock environment. Basalt dissolution rates at 40 degrees C were increased in the presence of one of the isolates compared to abiotic controls, showing its potential to be involved in active biogeochemistry at environmental temperatures. These data raise the possibility of transient active thermophilic growth in macroclimatically cold rocky environments, implying that the biogeographical distribution of active thermophiles might be greater than previously understood. These data show that temperatures measured or predicted over large scales on a planet are not in themselves adequate to assess niches available to extremophiles at micron scales.