论文标题：Genomic evidence for the degradation of terrestrial organic matter by pelagic Arctic Ocean Chloroflexi bacteria

期刊：Communications Biology

作者：David A. Walsh et al

发表时间：2018/07/05

数字识别码：10.1038/s42003-018-0086-7

原文链接：https://www.nature.com/articles/s42003-018-0086-7?utm_source=Other_website&utm_medium=Website_linksWebsite_links&utm_content=RenLi-MixedBrand-OAB-Multidisciplinary-China&utm_campaign=OAB_USG_JRCN_RL_article_promotion_sciencenet_Sep_1st

北冰洋仅占全球海洋体积的1.4%，但是它却接收着全球河水流量的11%。在北冰洋里有近33%的溶解有机物来自于陆地(terrestrial dissolved organic matter (tDOM))，其中来自碳含量丰富的泥土和泥炭地的有机物占了绝大比例。随着气温升高，北极圈多年冻土的解冻及沉积物的增多，可以预见，淡水径流及由河流运输至北冰洋的有机物也将增多，这势必增加tDOM的流量及含量。额外的tDOM为北冰洋的微生物群落带来了碳源与能源，使得呼吸作用增加，北极圈便成为了海洋里溶解性无机碳的来源。有近50%的北冰洋tDOM会在进入大西洋前被移除，其中一部分由微生物作用造成。随着tDOM的增加，了解这些微生物的作用对理解北极的碳循环起到了至关重要的作用。

在《通讯-生物学》发表的一篇名为Genomic evidence for the degradation of terrestrial organic matter by pelagic Arctic Ocean Chloroflexi bacteria的文章里，加拿大康考迪亚大学生物系的 David Walsh带领的团队针对这个问题对SAR202（绿弯菌门分枝细菌）进行了研究。SAR202占暗海中所有的浮游生物的10%，也同时存在于北冰洋的上层海水，学界广泛推测其有分解难降解有机物的能力。所以 David Walsh 的团队设想SAR202有降解tDOM的功能。

图1：SAR202有众多分解芳香化合物的基因

作者们针对西北冰洋中的加拿大海盆进行了宏基因组调查，结果显示来自北冰洋的SAR202有非常多的芳香化合物降解基因。这些基因部分由陆地细菌横向转移而来。作者的研究结果意味着海洋绿弯菌门细菌具有利用陆地有机物的能力。随着北极圈变暖及水文循环的变化，他们角色的重要性也可能随之增加。

摘要：The Arctic Ocean currently receives a large supply of global river discharge and terrestrial dissolved organic matter. Moreover, an increase in freshwater runoff and riverine transport of organic matter to the Arctic Ocean is a predicted consequence of thawing permafrost and increased precipitation. The fate of the terrestrial humic-rich organic material and its impact on the marine carbon cycle are largely unknown. Here, a metagenomic survey of the Canada Basin in the Western Arctic Ocean showed that pelagic Chloroflexi from the Arctic Ocean are replete with aromatic compound degradation genes, acquired in part by lateral transfer from terrestrial bacteria. Our results imply marine Chloroflexi have the capacity to use terrestrial organic matter and that their role in the carbon cycle may increase with the changing hydrological cycle.

阅读论文全文请访问：https://www.nature.com/articles/s42003-018-0086-7?utm_source=Other_website&utm_medium=Website_linksWebsite_links&utm_content=RenLi-MixedBrand-OAB-Multidisciplinary-China&utm_campaign=OAB_USG_JRCN_RL_article_promotion_sciencenet_Sep_1st

期刊介绍：Communications Biology is an open access journal from Nature Research publishing high-quality research, reviews and commentary in all areas of the biological sciences. Research papers published by the journal represent significant advances bringing new biological insight to a specialized area of research.

（来源：科学网）