Comparative genomic analysis of Thermus provides insights into the evolutionary history of an incomplete denitrification pathway  

作　　者：Jian-Yu Jiao Zheng-Han Lian Meng-Meng Li Nimaichand Salam En-Min Zhou Lan Liu Hong Ming Guoxing Nie Wensheng Shu Guoping Zhao Brian P.Hedlund Wen-Jun Li 

机构地区：[1]State Key Laboratory of Biocontrol,Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),School of Life Sciences,Sun Yat-Sen University,Guangzhou,China [2]International Joint Research Center for Karstology,School of Earth Sciences,Yunnan University,Kunming,China [3]Synthetic Biology Engineering Laboratory of Henan Province,College of Life Sciences and Technology,Xinxiang Medical University,Xinxiang,China [4]College of Fisheries,Henan Normal University,Xinxiang,China [5]Institute of Ecological Science,School of Life Science,South China Normal University,Guangzhou,China [6]Institute of Synthetic Biology,Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,Shenzhen,China [7]School of Life Sciences,University of Nevada,Las Vegas,Nevada,USA [8]Nevada Institute of Personalized Medicine,University of Nevada,Las Vegas,Nevada,USA [9]State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi,China

出　　处：《mLife》2022年第2期198-209,共12页微生物（英文）

基　　金：supported by funding from the National Natural Science Foundation of China(Nos.91951205,92051108,31850410475,and 31970122);the National Science and Technology Fundamental Resources Investigation Program of China(2021FY100900);the U.S.National Science Foundation(DEB 1557042 and DEB 1841658).

摘　　要：Biological denitrification is a crucial process in the nitrogen biogeochemical cycle,and Thermus has been reported to be a significant heterotrophic denitrifier in terrestrial geothermal environments.However,neither the denitrification potential nor the evolutionary history of denitrification genes in the genus Thermus or phylum Deinococcota is well understood.Here,we performed a comparative analysis of 23 Thermus genomes and identified denitrification genes in 15 Thermus strains.We confirmed that Thermus harbors an incomplete denitrification pathway as none of the strains contain the nosZ gene.Ancestral character state reconstructions and phylogenetic analyses showed that narG,nirS,and norB genes were acquired by the last common ancestor of Thermales and were inherited vertically.In contrast,nirK of Thermales was acquired via two distinct horizontal gene transfers from Proteobacteria to the genus Caldithermus and from an unknown donor to the common ancestor of all known Thermus species except Thermus filiformis.This study expands our understanding of the genomic potential for incomplete denitrification in Thermus,revealing a largely vertical evolutionary history of the denitrification pathway in the Thermaceae,and supporting the important role for Thermus as an important heterotrophic denitrifier in geothermal environments.

关 键 词：comparative genomics DENITRIFICATION evolutionary history THERMUS 

分 类 号：Q93[生物学—微生物学]