Diversity Of Bacteriaand Archaea In Intertidal And Subtidal Sediments Of Meltwater Areas In The Ny-(?)lesund Region,arctic

In this study,36 soil sediment samples collected from 12 stations in the intertidal and subtidal zones of six different characteristic meltwater areas in the Ny-（?）lesund region of Arctic were analyzed for the diversity composition of bacteria and archaea using high-throughput sequencing of 16S r DNA regions V3-V4 and V4-V5.At the same time,the relationships between the diversities and physicochemical factors of samples were analyzed.In addition,a combination analysis approach of RDA,SPSS,LEfse,and WGCNA software was used to find the core bacteria and archaea flora.The aim is The aim is,taking the Ny-（?）lesund region as an example,to understand the composition structure of bacteria,archaea and the influences of environmental factors,which can provide a reference for predicting ecological changes in the Arctic caused by climate warming in the future.The analysis results of bacteria showed:（1）A total of 19258 bacteria were identified from 36 samples,which were distributed in 59 phyla,156 classes,266 orders,443families,and 1440 genera.Among all the samples,Proteobacteria,Actinobacteria,Acidobacteria,Gemmatimonadetes,Bacteroidetes,and Chloroflexi were the highest relative abundance.In all meltwater areas,the abundances of Actinobacteria in intertidal samples were higher than that of subtidal samples,but the abundances of Aminicenantes in intertidal samples were lower than that of subtidal samples.（2）There were high correlation between the bacterial community composition and the Si O₄^2--Si,NH₄⁺-N,MC of soil sediment samples,and the NH₄⁺-N was an important factor.（3）Through SPSS software and LEfse analysis,the dominant genera were Bacteroidetes vadin HA17＿norank,Thiobacillus,Nitrosomonadaceae,Sphingomonadales,Alcaligenaceae＿uncultured,Acidimicrobiales＿norank,Gemmatimonadaceae＿uncultured,SC-I-84＿norank and Subgroup6＿norank et al.They had strongly correlated with the contents of MC,Or C and Si O₄^2--Si in soil,followed by Or N,NH₄⁺-N,NO₃^--N,NO₂^--N,p H,and a few were significantly correlated with the contents of PO₄^3--P.（4）After combination analysis by RDA and WGCNA,the core bacteria flora which had strong correlation with soil physicochemical factors and nitrogen metabolism were mainly distributed in the intertidal zone samples.At the door level,Proteobacteria and Bacteroidetes were the core bacteria flora.At the genus level,43F-1404R,Nitrosomonadaceae,Nitrospira,Sphingomonas,Hyphomicrobium,Leptolyngbya,Saprospiraceae,Phormidium,sphingobacteraceae and Gemmatimonadaceae were the core dominant flora.These core bacteria flora were significantly correlated with the contents of NH₄⁺-N,NO₃^--N,NO₂^--N and Si O₄^2--Si.The analysis results of archaea showed:（1）A total of 3342 archaea were identified from 36 samples,which distributed in 11 classes,12 orders,20 families and 651 genera.Among them,Nitrososphaeria,Methanomicrobia,Nanoarchaeia were dominant classes of archaea,and Candidatus＿Nitrocosmicus,Rice＿Cluster＿II and Woesearchaeales were dominant genera of archaea.The archaea community structure was different among all the stations.Among them,the diversities of archaea community in glacier meltwater zone（BZS station,BZX station）and reservoir bay meltwater zone（WZS station,WZX station）were higher than that in other meltwater zones.（2）The archaea community diversities in all meltwater samples were significantly correlated with MC,Si O₄^2--Si,NH₄⁺-N,and Or C.（3）Some archaea were not only the core archaea flora of the sample,but also the significant difference archaea flora.Such as Methanobacterium in the subtidal zone of the Bayou meltwater zone（station WZX）,Methanosarcina and Methanosaeta in the subtidal zone of the tundra meltwater zone（station TZX）,Rice＿Cluster＿II in the subtidal zone of the Sandstone meltwater zone（station SZX）,Methanoregula in the intertidal zone of the sandstone meltwater zone（SZS station）.Candidatus＿Nitrososphaera in the subtidal zone of the London Lough meltwater zone（station LZX）,Halobacterales in the intertidal zone of the London Lough meltwater zone（station LZS）,etc.These core dominant archaea flora were significantly correlated with the contents of MC,NH₄⁺-N and Si O₄^2--Si in the samples.