Ice nucleation activity of bacteria isolated from cloud water
Ice nucleation activity of bacteria isolated from cloud water
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DOI：
10.1016/j.atmosenv.2013.01.027
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发表时间：
2013-05-01
影响因子：
5
通讯作者：
Delort, Anne-Marie
中科院分区：
文献类型：
--
作者：
Joly, Muriel;Attard, Eleonore;Delort, Anne-Marie
一些伽玛变形杆菌可以催化冰的形成，从而潜在地促进过冷云中的降水，并随后导致细菌沉积。从云水中筛选出44株细菌，对其诱导冻结的能力进行了筛选。有7株(16%)在-8℃或更高温度下有活性，经鉴定为丁香假单胞菌、黄单胞菌。和假黄单胞菌(Pusoxanthomonas sp.)系统发育分析显示，普伊德穹顶云层中的紫丁香疫霉菌株属于在环境中最不常见的分支之一，而广泛存在的分支则表明，采样点的细菌存在一定程度的选择或不寻常的生物地理特征。三个菌株在-3摄氏度诱导结冰，而其他菌株在-4摄氏度至-6摄氏度成核。冰冻剖面显示，根据菌株的不同，活动峰值集中在-3.5摄氏度、-5摄氏度和/或-8.5摄氏度左右。在-6℃时，每个细胞的冰核(IN)频率一般低于0.5%，其中一个菌株的冰核频率高达4.2%。我们估计，受植被覆盖地区影响的云层将携带不到1到500个细菌单位毫升(-1)的水，活跃度在-3摄氏度到-10摄氏度之间，具体取决于季节。这些数据将有助于模拟细菌IN对区域尺度降水的影响。(C)2013爱思唯尔有限公司。保留所有权利。
Some Gamma-Proteobacteria can catalyze ice formation thereby potentially contributing to the induction of precipitation in supercooled clouds and subsequently to bacterial deposition. Forty-four bacterial strains from cloud water were screened for their capacity to induce freezing. Seven strains (16%) were active at -8 degrees C or warmer and were identified as Pseudomonas syringae, Xanthomonas spp. and Pseudoxanthomonas sp. Phylogenetic analysis revealed that the P. syringae strains in clouds at the Puy de Dome belonged to clades that are among the most infrequently detected in the environment, while widespread clades were absent suggesting some extent of selection or unusual biogeography of the bacteria at the sampling site. Three strains induced freezing at -3 degrees C while the others nucleated ice at -4 degrees C to -6 degrees C. The freezing profiles revealed that the peaks of activity were centered around -3.5 degrees C, -5 degrees C and/or -8.5 degrees C depending on the strain. The frequency of ice-nuclei (IN) per cell at -6 degrees C was generally below 0.5% and reached up to 4.2% in one strain. We estimated that clouds influenced by vegetated areas would carry between less than 1 and similar to 500 bacterial IN mL(-1) of water active between -3 degrees C and -10 degrees C depending on the season. These data will contribute to modeling the impact of bacterial IN on precipitation at regional scales. (C) 2013 Elsevier Ltd. All rights reserved.