The apparent sulfur oxidation activities of four pure thermophilic archaea, Acidianus brierleyi （JCM 8954）, Metallosphaera sedula （YN 23）, Acidianus manzaensis （YN 25） and Sulfolobus metallicus （YN 24） and the...The apparent sulfur oxidation activities of four pure thermophilic archaea, Acidianus brierleyi （JCM 8954）, Metallosphaera sedula （YN 23）, Acidianus manzaensis （YN 25） and Sulfolobus metallicus （YN 24） and their mixture in bioleaching chalcopyrite were compared, which were characterized indirectly by the evolution of the cells concentration, pH value and sulfate ions concentration in solution. The results show that the mixed culture contributed significantly to the raising of leaching rate, which suggests that the mixed culture had a higher sulfur oxidation activity than the pure culture. Meanwhile, the results also indicate that the changes of parameters characterizing the sulfur oxidation activity of thermophilic archaea are often influenced by many factors, so it is hard to reflect accurately the specific sulfur oxidation activities among the different sulfur-oxidizing microbes when bioleaching chalcopyrite at different conditions. Accordingly, an efficient method to characterize microbial sulfur oxidation activity appears to be desirable.展开更多
This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（1...This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（10.7±0.6） years old）, were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units （OTUs）. Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera （i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus） were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria （class）, Methanobacteriales （order）, Methanobacteriaceae （family）, and Methanobrevibacter （genus） in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.展开更多
The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot ...The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot for N cycling. Here we found high spatial heterogeneity in the nitrification rate and abundance of ammonia oxidizers in the five sampling sites. The bacterial amoA gene was numerically dominant in most of the surface soil but decreased dramatically in deep layers. Higher nitrification potentials were detected in two sites near the land/water interface at 4.4–6.1 μg NO2-N/（g dry weight soil·hr）, while only 1.0–1.7 μg NO2-N/（g dry weight soil·hr） was measured at other sites. The potential nitrification rates were proportional to the amoA gene abundance for AOB, but with no significant correlation with AOA. The NH4＋ concentration was the most determinative parameter for the abundance of AOB and potential nitrification rates in this study. Higher richness in the surface layer was found in the analysis of biodiversity. Phylogenetic analysis revealed that most of the bacterial amoA sequences in surface soil were affiliated with the genus of Nitrosopira while the archaeal sequences were almost equally affiliated with Candidatus ‘Nitrososphaera gargensis’ and Candidatus ‘Nitrosocaldus yellowstonii’. The spatial distribution of AOA and AOB indicated that bacteria may play a more important role in nitrification in the littoral buffer zone of a N-rich lake.展开更多
As a major reservoir of antibiotics,animal manure contributes a lot to the augmented environmental pressure of antibiotic resistance genes(ARGs).This might be the first study to explore the effects of different ventil...As a major reservoir of antibiotics,animal manure contributes a lot to the augmented environmental pressure of antibiotic resistance genes(ARGs).This might be the first study to explore the effects of different ventilation types on the control of ARGs and to identify the relationships between archaeal communities and ARGs during the composting of dairy manure.Several ARGs were quantified via Real-time qPCR and microbial communities including bacteria and archaea were analyzed by High-throughput sequencing during vacuum-type composting(VTC) and positive-pressure composting(PPC).The total detected ARGs and class I integrase gene(intI1) under VTC were significantly lower than that under PPC during each stage of the composting(p <0.001).The relative abundance of potential human pathogenic bacteria(HPB) which were identified based on sequencing information and correlation analysis decreased by 74.6% and 91.4% at the end of PPC and VTC,respectively.The composition of archaeal communities indicated that methane-producing archaea including Methanobrevibacter,Methanocorpusculum and Methanosphaera were dominant throughout the composting.Redundancy analysis suggested that Methanobrevibacter and Methanocorpusculum were positively correlated with all of the detected ARGs.Network analysis determined that the possible hosts of ARGs were different under VTC and PPC,and provided new sights about potential links between archaea and ARGs.Our results showed better performance of VTC in reducing ARGs and potential HPB and demonstrated that some archaea could also be influential hosts of ARGs,and caution the risks of archaea carrying ARGs.展开更多
The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves.Thirty-six newborn Holstein bull calves were a...The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves.Thirty-six newborn Holstein bull calves were assigned to 1 of 3 treatments:(1)conventional weaning(d 56)and fed a high proportion of solid feed(CWS);(2)conventional weaning(d 56)and fed a high proportion of liquid feed(CWL);(3)early weaning(d 42)and fed with a high proportion of solid feed(EWS).High-throughput sequencing of the methyl coenzyme M reductase(mcr A)gene,which encodes theα-subunit of methyl coenzyme M reductase-the enzyme that catalyzes the final step in methanogenesis was used to determine the composition and diversity of rumen methanogens.No significant difference(P>0.05)was observed for operational taxonomic units(OTUs)or richness indices,but diversity indices increased(P<0.05)for calves fed high dietary solids.Predominant families across the three treatments were Methanobacteriaceae,Thermoplasmataceae and Methanomassiliicoccaceae.Calves in the EWS treatment had a higher(P<0.05)relative abundance of Methanobrevibacter sp.strain AbM4 and Methanosphaera stadtmanae,while calves in the CWL treatment had a higher(P<0.05)abundance of Methanosphaera sp.strain SM9.A positive(P<0.05)relationship was identified between butyrate and Methanobrevibacter sp.strain AbM4.In conclusion,the composition and diversity of methanogens in the rumen of Holstein calves varied under the different weaning methods.This study identified a positive relationship between butyrate and Methanobrevibacter sp.strain AbM4,potentially reflecting correlations between ruminal fermentation variables and methanogenesis function.These in-depth analyses provide further understanding of weaning methods for intensified production systems.展开更多
The relatedness between catalytic effect of activated carbon and passivation phenomenon during chalcopyrite bioleachingby mixed thermophilic Archaea culture(Acidianus brierleyi,Metallosphaera sedula,Acidianus manzaens...The relatedness between catalytic effect of activated carbon and passivation phenomenon during chalcopyrite bioleachingby mixed thermophilic Archaea culture(Acidianus brierleyi,Metallosphaera sedula,Acidianus manzaensis and Sulfolobusmetallicus)at65°C was studied.Leaching experiments showed that the addition of activated carbon could significantly promote thedissolution of chalcopyrite for both bioleaching and chemical leaching.The results of synchrotron-based X-ray diffraction,ironL-edge and sulfur K-edge X-ray absorption near edge structure spectroscopy indicated that activated carbon could change thetransition path of electrons through galvanic interactions to form more readily dissolved secondary mineral chalcocite at a low redoxpotential(?400mV)and then enhanced the copper dissolution.Jarosite accumulated immediately in the initial stage of bioleachingwith activated carbon but copper dissolution was not hindered.However,much jarosite precipitated on the surface of chalcopyrite inthe late stage of bioleaching,which might account for the decrease of copper dissolution rate.More elemental sulfur(S0)was alsodetected with additional activated carbon but the mixed thermophilic Archaea culture had a great sulfur oxidation activity,thus S0waseliminated and seemed to have no significant influence on the dissolution of chalcopyrite.展开更多
The corrosion behavior of 304 stainless steel(SS)in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated.After 14 days of immersion,no obvious pitting pit was observed on the SS surface ...The corrosion behavior of 304 stainless steel(SS)in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated.After 14 days of immersion,no obvious pitting pit was observed on the SS surface in the sterile medium.By contrast,the SS exhibited serious pitting corrosion with the largest pit depth of 5.0μm in the inoculated medium after 14 days.The results of electrochemical tests showed that the barrier property of the passive film decreased faster in the inoculated medium.The X-ray photoelectron spectroscopy results indicated that the detrimental Fe2+and Cr6+increased in the passive film under the influence of archaea N.tibetense,which resulted in the accelerated deterioration of passive film and promoted the pitting corrosion.Combined with the energy starvation tests,the microbiologically influenced corrosion mechanism of 304 SS caused by halophilic archaea N.tibetense was discussed finally.展开更多
Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as wel...Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant （WWTP） samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84× 10^6 to 9.45 × 10^7 copies/g in dry soil/sediment, and 6.06× 10^6 to 2.41 ×10^7 copies/L in water samples, were higher than ammonia-oxidizing bacteria （AOB） by 1-2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cycle.展开更多
The adsorption and leaching of chalcopyrite by two extreme thermophilic archaea(A.brierleyi and S.metallicus)and their mixture were studied.The results revealed that the chalcopyrite leaching rate of S.metallicus was ...The adsorption and leaching of chalcopyrite by two extreme thermophilic archaea(A.brierleyi and S.metallicus)and their mixture were studied.The results revealed that the chalcopyrite leaching rate of S.metallicus was slightly higher than that of A.brierleyi;the mixed system showed the highest rate.Community structure analysis during the leaching process showed that S.metallicus was maintained in a predominant state.However,the proportion of A.brierleyi in the community increased during leaching.Copper concentrations,which increased faster in the mixed system than in the single-organism systems during later stages,was related to the change of A.brierleyi in the community.Langmuir parameter analysis revealed no competitive adsorption between these two thermophilic archaea.Furthermore,qPCR(quantitative polymerase chain reaction)confirmed that adsorption was promoted between A.brierleyi and S.metallicus during mixed leaching.These findings can improve our understanding of the adsorption behaviors of mixed extreme microbial populations on mineral surfaces.展开更多
The community structure of methanogenic archaea is relatively stable,i.e.,it is sustained at a high abundance with minimal changes in composition,in paddy field soils irrespective of submergence and drainage.In contra...The community structure of methanogenic archaea is relatively stable,i.e.,it is sustained at a high abundance with minimal changes in composition,in paddy field soils irrespective of submergence and drainage.In contrast,the abundance in non-methanogenic oxic soils is much lower than that in paddy field soils.This study aimed to describe methanogenic archaeal community development following the long-term submergence of non-methanogenic oxic upland field soils in pot and field experiments.In the pot experiment,a soil sample obtained from an upland field was incubated under submerged conditions for 275 d.Soil samples periodically collected were subjected to culture-dependent most probable number(MPN)enumeration,polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)analysis of archaeal 16 S r RNA gene,and quantitative PCR analysis of the methyl-coenzyme M reductase alpha subunit gene(mcr A)of methanogenic archaea.The abundance of methanogenic archaea increased from 102 to 103 cells g-1 dry soil and 104 to 107 copies of mcr A gene g-1 dry soil after submergence.Although no methanogenic archaeon was detected prior to incubation by the DGGE analysis,members from Methanocellales,Methanosarcinaceae,and Methanosaetaceae proliferated in the soils,and the community structure was relatively stable once established.In the field experiment,the number of viable methanogenic archaea in a rice paddy field converted from meadow(reclaimed paddy field)was monitored by MPN enumeration over five annual cycles of field operations.Viability was also determined simultaneously in a paddy field where the plow layer soil from a farmer’s paddy field was dressed onto the meadow(dressed paddy field)and an upland crop field converted from the meadow(reclaimed upland field).The number of viable methanogenic archaea in the reclaimed paddy field was below the detection limit before the first cultivation of rice and in the reclaimed upland field.Then,the number gradually increased over five years and finally reached 103–104 cells g-1 dry soil,which was comparable to that in the dressed paddy field.These findings showed that the low abundance of autochthonous methanogenic archaea in the non-methanogenic oxic upland field soils steadily proliferated,and the community structure was developed following repeated and long-term submergence.These results suggest that habitats suitable for methanogenic archaea were established in soil following repeated and long-term submergence.展开更多
The abundance of ammonia-oxidizing bacteria and archaea and their amo A genes from the aerobic activated sludge tanks,recycled sludge and anaerobic digesters of a full-scale wastewater treatment plant(WWTP)was determi...The abundance of ammonia-oxidizing bacteria and archaea and their amo A genes from the aerobic activated sludge tanks,recycled sludge and anaerobic digesters of a full-scale wastewater treatment plant(WWTP)was determined.Polymerase chain reaction and denaturing gradient gel electrophoresis were used to generate diversity profiles,which showed that each population had a consistent profile although the abundance of individual members varied.In the aerobic tanks,the ammonia-oxidizing bacterial(AOB)population was more than 350 times more abundant than the ammonia-oxidizing archaeal(AOA)population,however in the digesters,the AOA population was more than 10 times more abundant.Measuring the activity of the amo A gene expression of the two populations using RT-PCR also showed that the AOA amo A gene was more active in the digesters than in the activated sludge tanks.Using batch reactors and dd PCR,amo A activity could be measured and it was found that when the AOB amo A activity was inhibited in the anoxic reactors,the expression of the AOA amo A gene increased fourfold.This suggests that these two populations may have a cooperative relationship for the oxidation of ammonia.展开更多
Ammonia-oxidizing bacteria(AOB)and archaea(AOA)are two microbial groups mediating nitrification,yet little is presently known about their abundances and community structures at the transcriptional level in wastewater ...Ammonia-oxidizing bacteria(AOB)and archaea(AOA)are two microbial groups mediating nitrification,yet little is presently known about their abundances and community structures at the transcriptional level in wastewater treatment systems(WWTSs).This is a significant issue,as the numerical abundance of AOA or AOB at the gene level may not necessarily represent their functional role in ammonia oxidation.Using amo A genes as molecular markers,this study investigated the transcriptional abundance and community structure of active AOA and AOB in 14 WWTSs.Quantitative PCR results indicated that the transcriptional abundances of AOB amo A(averaged:1.6×10^(8)copies g^(-1)dry sludge)were higher than those of AOA(averaged:3.4×10^(7)copies g^(-1)dry sludge)in all WWTSs despite several higher abundances of AOA amo A at the gene level.Moreover,phylogenetic analysis demonstrated that Nitrosomonas europaea and unknown clusters accounted for 37.66%and 49.96%of the total AOB amo A transcripts,respectively,suggesting their dominant role in driving ammonia oxidation.Meanwhile,AOA amo A transcripts were only successfully retrieved from 3 samples,and the Nitrosospaera sister cluster dominated,accounting for 83.46%.Finally,the substrate utilization kinetics of different AOA and AOB species might play a fundamental role in shaping their niche differentiation,community composition,and functional activity.This study provides a basis for evaluating the relative contributions of ammonia-oxidizing microorganisms(AOMs)to nitrogen conversions in WWTSs.展开更多
Erhualian and Landrace breeds are typical genetically obese and lean pigs, respectively. To compare the fecal methanogenic Archaeal community between these two pig breeds, fecal samples from different growth phase pig...Erhualian and Landrace breeds are typical genetically obese and lean pigs, respectively. To compare the fecal methanogenic Archaeal community between these two pig breeds, fecal samples from different growth phase pigs were collected and used for PCR-denaturing gradient gel electrophoresis （DGGE） with two primer pairs （344fGC/519r and 519f/915rGC） and real-time PCR analysis. Results showed that a better separation and higher quality of bands pattern were obtained in DGGE proifles using primers 344fGC/519r as compared with primers 519f/915rGC. Sequencing of DGGE bands showed that the predominant methanogens in the feces of Erhualian and Landrace pigs belonged to Methanobrevibacter spp. and Methanosphaera spp. Real-time PCR analysis revealed that there was no signiifcant difference in the numbers of fecal total methanogens between Erhualian and Landrace pigs;however, pig growth phase affected the numbers of 16S rRNA genes of total methanogens and Methanobrevibacter smithii. Dissociation curves of methyl coenzyme-M reductase subunit A （mcrA） gene fragments ampliifed with real-time PCR showed all samples possessed a single peak at 82＆#176;C, which might be associated with M. smithii. Samples from the same growth phase of each breed showed good replicative dissociation curves. The results suggest that the growth phase （including diet factor） other than genotype of pig may affect the fecal methanogenic Archaeal community of pigs.展开更多
CTP synthase(CTPS)is an important metabolic enzyme that catalyzes the rate-Iimiting reaction of nucleotide CrP de novo synthesis.Since 2010,a series of studies have demonstrated that CTPS can form filamentous structur...CTP synthase(CTPS)is an important metabolic enzyme that catalyzes the rate-Iimiting reaction of nucleotide CrP de novo synthesis.Since 2010,a series of studies have demonstrated that CTPS can form filamentous structures in bacteria and eukaryotes,which are termed cytoophidia.However,it is unknown whether cytoophidia exist in the third domain of life,archaea.Using Haloarcula hispanica as a model system,here we demonstrate that CTPS forms distinct intracellular compartments in archaea.Under stimulated emission depletion microscopy,we find that the structures of H.hispanica CTPS are elongated,similar to cytoophidia in bacteria and eukaryotes.When Haloarcula cells are cultured in lowsalt medium,the occurrence of cytoophidia increases dramatically.In addition,treatment of H.hispanica with a glutamine analog or overexpression of CTPS can promote cytoophidium assembly.Our study reveals that CTPS can fo rm cytoophidia in all three domains of life,suggesting that forming cytoophidia is an ancient property of CTPS.展开更多
It has been well-documented that the distribution of ammonia-oxidizing bacteria(AOB) and archaea(AOA) in soils can be affected by heavy metal contamination, whereas information about the impact of heavy metal on these...It has been well-documented that the distribution of ammonia-oxidizing bacteria(AOB) and archaea(AOA) in soils can be affected by heavy metal contamination, whereas information about the impact of heavy metal on these ammonia-oxidizing microorganisms in freshwater sediment is still lacking. The present study explored the change of sediment ammonia-oxidizing microorganisms in a freshwater reservoir after being accidentally contaminated by industrial discharge containing high levels of metals. Bacterial amoA gene was found to be below the quantitative PCR detection and was not successfully amplified by conventional PCR. The number of archaeal amoA gene in reservoir sediments were 9.62 × 10~2–1.35 × 10~7 copies per gram dry sediment. AOA abundance continuously decreased, and AOA richness, diversity and community structure also considerably varied with time. Therefore, heavy metal pollution could have a profound impact on freshwater sediment AOA community. This work could expand our knowledge of the effect of heavy metal contamination on nitrification in natural ecosystems.展开更多
RNA silencing plays crucial roles in both bacteria and eukaryotes, yet its machinery appears to differ in these two kingdoms. A couple of Argonaute protein homologs have been reported in some archaeal species in recen...RNA silencing plays crucial roles in both bacteria and eukaryotes, yet its machinery appears to differ in these two kingdoms. A couple of Argonaute protein homologs have been reported in some archaeal species in recent years. As Argonaute protein is the key component of eukaryotic RNA silencing pathways, such findings suggested the possibility of existence of eukaryotic RNA silencing like pathways in Archaea, which present the life forms between prokaryotes and eukaryotes. To further explore such hypothesis, we systematically screened 71 fully sequenced archaeal genomes, and identified some proteins containing homologous regions to the functional domains of eukaryotic RNA silencing pathway key proteins. The phylogenetic relationships of these proteins were analyzed. The conserved functional amino acids between archaeal and eukaryotic Piwi domains suggested their fimctional similarity. Our results provide new clues to the evolution of RNA silencing pathways.展开更多
Depth-dependent distribution patterns of bacterial and archaeal communities in deep sea water column around the Ninetyeast Ridge in the Indian Ocean were investigated using 16S rRNA gene profiling.Sampling was conduct...Depth-dependent distribution patterns of bacterial and archaeal communities in deep sea water column around the Ninetyeast Ridge in the Indian Ocean were investigated using 16S rRNA gene profiling.Sampling was conducted at the northern Ninetyeast Ridge(1°59.89′N–9°59.70′S,87°58.90′E–88°00.03′E)from September to November 2016 where samples were collected from the bathyal(1000 m)to bathypelagic depths(>4000 m)in four different stations.A total of 1565405 clean data falling into 6712 bacterial OTUs and 1452727 clean data falling into 806 archaeal OTUs based on 97%similarity level were analyzed.Most of the bacterial 16S rRNA gene sequences were affiliated with Gammaproteobacteria,followed by Alphaproteobacteria and Bacteroidia.The archaeal 16S rRNA gene sequences mostly affiliated to Nitrososphaeria(Thaumarchaeota)dominated with relative abundances ranging from 52.68%to 97.2%,followed by Thermoplasmata(Euryarchaeota).Vertical partitioning of bacterial and archaeal communities among different water layers was observed.Canonical correspondence analysis(CCA)and Spearman’s correlations revealed that depth(P=0.003),dissolved oxygen(P=0.019),and nitrite(P=0.033)were the main environmental factors affecting bacterial community structure at genus level in the Ninetyeast Ridge.On the other hand,the first two CCA axes accounted for 74.4%of the explained total variance,it seems that the archaeal communities at genus level were heavily influenced by the environmental variables including depth,dissolved oxygen(DO),nitrite,salinity,phosphate,ammonia,nitrate,and silicate,but none of them exhibited any significant correlation on the structuring(P>0.1).展开更多
基金Project(50974140) supported by the National Natural Science Foundation of ChinaProject(20090162110054) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘The apparent sulfur oxidation activities of four pure thermophilic archaea, Acidianus brierleyi （JCM 8954）, Metallosphaera sedula （YN 23）, Acidianus manzaensis （YN 25） and Sulfolobus metallicus （YN 24） and their mixture in bioleaching chalcopyrite were compared, which were characterized indirectly by the evolution of the cells concentration, pH value and sulfate ions concentration in solution. The results show that the mixed culture contributed significantly to the raising of leaching rate, which suggests that the mixed culture had a higher sulfur oxidation activity than the pure culture. Meanwhile, the results also indicate that the changes of parameters characterizing the sulfur oxidation activity of thermophilic archaea are often influenced by many factors, so it is hard to reflect accurately the specific sulfur oxidation activities among the different sulfur-oxidizing microbes when bioleaching chalcopyrite at different conditions. Accordingly, an efficient method to characterize microbial sulfur oxidation activity appears to be desirable.
基金the International Cooperation Project of the Ministry of Sciences and Technology of China(2014DFA32860)the National Natural Science Foundation of China(31402104)for their financial support
文摘This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（10.7±0.6） years old）, were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units （OTUs）. Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera （i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus） were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria （class）, Methanobacteriales （order）, Methanobacteriaceae （family）, and Methanobrevibacter （genus） in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.
基金supported by the National Natural Science Foundation of China (No. 20877086 21077119)+5 种基金the National Basic Research Program (973) of China (No. 2009CB421103)the National Water Project of China (No. 2009ZX07209-005 2008ZX07421-001 2008ZX07209-006-02)the support of Beijing Nova Program (No. 2011104)K. C. Wong Education Foundation, Hong Kong
文摘The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot for N cycling. Here we found high spatial heterogeneity in the nitrification rate and abundance of ammonia oxidizers in the five sampling sites. The bacterial amoA gene was numerically dominant in most of the surface soil but decreased dramatically in deep layers. Higher nitrification potentials were detected in two sites near the land/water interface at 4.4–6.1 μg NO2-N/（g dry weight soil·hr）, while only 1.0–1.7 μg NO2-N/（g dry weight soil·hr） was measured at other sites. The potential nitrification rates were proportional to the amoA gene abundance for AOB, but with no significant correlation with AOA. The NH4＋ concentration was the most determinative parameter for the abundance of AOB and potential nitrification rates in this study. Higher richness in the surface layer was found in the analysis of biodiversity. Phylogenetic analysis revealed that most of the bacterial amoA sequences in surface soil were affiliated with the genus of Nitrosopira while the archaeal sequences were almost equally affiliated with Candidatus ‘Nitrososphaera gargensis’ and Candidatus ‘Nitrosocaldus yellowstonii’. The spatial distribution of AOA and AOB indicated that bacteria may play a more important role in nitrification in the littoral buffer zone of a N-rich lake.
基金supported by the National Natural Science Foundation of China (No.31670507)the InterdisciplinaryInnovation Team Program of the Chinese Academy of Sciences(2015,the Team for the Directional Biotransformation of Environmental Pollutants)+1 种基金the Major Science and Technology Program for Water Pollution Control and Treatment of China (Nos.2015ZX07206-006,2014ZX07204-005)the Key Research Program of Chinese Academy of Sciences (No. ZDRW-ZS-2016-5).
文摘As a major reservoir of antibiotics,animal manure contributes a lot to the augmented environmental pressure of antibiotic resistance genes(ARGs).This might be the first study to explore the effects of different ventilation types on the control of ARGs and to identify the relationships between archaeal communities and ARGs during the composting of dairy manure.Several ARGs were quantified via Real-time qPCR and microbial communities including bacteria and archaea were analyzed by High-throughput sequencing during vacuum-type composting(VTC) and positive-pressure composting(PPC).The total detected ARGs and class I integrase gene(intI1) under VTC were significantly lower than that under PPC during each stage of the composting(p <0.001).The relative abundance of potential human pathogenic bacteria(HPB) which were identified based on sequencing information and correlation analysis decreased by 74.6% and 91.4% at the end of PPC and VTC,respectively.The composition of archaeal communities indicated that methane-producing archaea including Methanobrevibacter,Methanocorpusculum and Methanosphaera were dominant throughout the composting.Redundancy analysis suggested that Methanobrevibacter and Methanocorpusculum were positively correlated with all of the detected ARGs.Network analysis determined that the possible hosts of ARGs were different under VTC and PPC,and provided new sights about potential links between archaea and ARGs.Our results showed better performance of VTC in reducing ARGs and potential HPB and demonstrated that some archaea could also be influential hosts of ARGs,and caution the risks of archaea carrying ARGs.
基金supported by the Key Program for International S&T Cooperation Projects of China(2016YFE0109000)the National Key R&D Program of China(2017YFF0211702)+1 种基金the National Natural Science Foundation of China(41475126 and 31802085)the Young Scientist Lifting Project,China(2017–2019)
文摘The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves.Thirty-six newborn Holstein bull calves were assigned to 1 of 3 treatments:(1)conventional weaning(d 56)and fed a high proportion of solid feed(CWS);(2)conventional weaning(d 56)and fed a high proportion of liquid feed(CWL);(3)early weaning(d 42)and fed with a high proportion of solid feed(EWS).High-throughput sequencing of the methyl coenzyme M reductase(mcr A)gene,which encodes theα-subunit of methyl coenzyme M reductase-the enzyme that catalyzes the final step in methanogenesis was used to determine the composition and diversity of rumen methanogens.No significant difference(P>0.05)was observed for operational taxonomic units(OTUs)or richness indices,but diversity indices increased(P<0.05)for calves fed high dietary solids.Predominant families across the three treatments were Methanobacteriaceae,Thermoplasmataceae and Methanomassiliicoccaceae.Calves in the EWS treatment had a higher(P<0.05)relative abundance of Methanobrevibacter sp.strain AbM4 and Methanosphaera stadtmanae,while calves in the CWL treatment had a higher(P<0.05)abundance of Methanosphaera sp.strain SM9.A positive(P<0.05)relationship was identified between butyrate and Methanobrevibacter sp.strain AbM4.In conclusion,the composition and diversity of methanogens in the rumen of Holstein calves varied under the different weaning methods.This study identified a positive relationship between butyrate and Methanobrevibacter sp.strain AbM4,potentially reflecting correlations between ruminal fermentation variables and methanogenesis function.These in-depth analyses provide further understanding of weaning methods for intensified production systems.
基金Project(51274257) supported by the National Natural Science Foundation of ChinaProject(U1232103) supported by the Joint Funds of National Natural Science Foundation of China and Large Scientific Facility Foundation of Chinese Academy of Sciences+1 种基金Project(VR-12419) supported by the Beijing Synchrotron Radiation Facility Public User Program,ChinaProject(15ssrf00924) supported by the Shanghai Institute of Applied Physics Open Fund of Shanghai Synchrotron Radiation Facility,China
文摘The relatedness between catalytic effect of activated carbon and passivation phenomenon during chalcopyrite bioleachingby mixed thermophilic Archaea culture(Acidianus brierleyi,Metallosphaera sedula,Acidianus manzaensis and Sulfolobusmetallicus)at65°C was studied.Leaching experiments showed that the addition of activated carbon could significantly promote thedissolution of chalcopyrite for both bioleaching and chemical leaching.The results of synchrotron-based X-ray diffraction,ironL-edge and sulfur K-edge X-ray absorption near edge structure spectroscopy indicated that activated carbon could change thetransition path of electrons through galvanic interactions to form more readily dissolved secondary mineral chalcocite at a low redoxpotential(?400mV)and then enhanced the copper dissolution.Jarosite accumulated immediately in the initial stage of bioleachingwith activated carbon but copper dissolution was not hindered.However,much jarosite precipitated on the surface of chalcopyrite inthe late stage of bioleaching,which might account for the decrease of copper dissolution rate.More elemental sulfur(S0)was alsodetected with additional activated carbon but the mixed thermophilic Archaea culture had a great sulfur oxidation activity,thus S0waseliminated and seemed to have no significant influence on the dissolution of chalcopyrite.
基金the Beijing Nova Program(No.Z171100001117076)the National Natural Science Foundation of China(Nos.51871026,51771029)the National Environmental Corrosion Platform。
文摘The corrosion behavior of 304 stainless steel(SS)in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated.After 14 days of immersion,no obvious pitting pit was observed on the SS surface in the sterile medium.By contrast,the SS exhibited serious pitting corrosion with the largest pit depth of 5.0μm in the inoculated medium after 14 days.The results of electrochemical tests showed that the barrier property of the passive film decreased faster in the inoculated medium.The X-ray photoelectron spectroscopy results indicated that the detrimental Fe2+and Cr6+increased in the passive film under the influence of archaea N.tibetense,which resulted in the accelerated deterioration of passive film and promoted the pitting corrosion.Combined with the energy starvation tests,the microbiologically influenced corrosion mechanism of 304 SS caused by halophilic archaea N.tibetense was discussed finally.
基金supported by the National Natural Science Foundation of China (No. 50978069)
文摘Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant （WWTP） samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84× 10^6 to 9.45 × 10^7 copies/g in dry soil/sediment, and 6.06× 10^6 to 2.41 ×10^7 copies/L in water samples, were higher than ammonia-oxidizing bacteria （AOB） by 1-2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cycle.
基金Project (51774342) supported by the National Natural Science Foundation of ChinaProject (2016RS2016) supproted by the Hunan Provincial Science and Technology Leader (Innovation Team of Interface Chemistry of Efficient and Clean Utilization of Complex Mineral Resources),China
文摘The adsorption and leaching of chalcopyrite by two extreme thermophilic archaea(A.brierleyi and S.metallicus)and their mixture were studied.The results revealed that the chalcopyrite leaching rate of S.metallicus was slightly higher than that of A.brierleyi;the mixed system showed the highest rate.Community structure analysis during the leaching process showed that S.metallicus was maintained in a predominant state.However,the proportion of A.brierleyi in the community increased during leaching.Copper concentrations,which increased faster in the mixed system than in the single-organism systems during later stages,was related to the change of A.brierleyi in the community.Langmuir parameter analysis revealed no competitive adsorption between these two thermophilic archaea.Furthermore,qPCR(quantitative polymerase chain reaction)confirmed that adsorption was promoted between A.brierleyi and S.metallicus during mixed leaching.These findings can improve our understanding of the adsorption behaviors of mixed extreme microbial populations on mineral surfaces.
基金a Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) Fellows (No. 19 6611)JSPS KAKENHI (No. 24780318).
文摘The community structure of methanogenic archaea is relatively stable,i.e.,it is sustained at a high abundance with minimal changes in composition,in paddy field soils irrespective of submergence and drainage.In contrast,the abundance in non-methanogenic oxic soils is much lower than that in paddy field soils.This study aimed to describe methanogenic archaeal community development following the long-term submergence of non-methanogenic oxic upland field soils in pot and field experiments.In the pot experiment,a soil sample obtained from an upland field was incubated under submerged conditions for 275 d.Soil samples periodically collected were subjected to culture-dependent most probable number(MPN)enumeration,polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)analysis of archaeal 16 S r RNA gene,and quantitative PCR analysis of the methyl-coenzyme M reductase alpha subunit gene(mcr A)of methanogenic archaea.The abundance of methanogenic archaea increased from 102 to 103 cells g-1 dry soil and 104 to 107 copies of mcr A gene g-1 dry soil after submergence.Although no methanogenic archaeon was detected prior to incubation by the DGGE analysis,members from Methanocellales,Methanosarcinaceae,and Methanosaetaceae proliferated in the soils,and the community structure was relatively stable once established.In the field experiment,the number of viable methanogenic archaea in a rice paddy field converted from meadow(reclaimed paddy field)was monitored by MPN enumeration over five annual cycles of field operations.Viability was also determined simultaneously in a paddy field where the plow layer soil from a farmer’s paddy field was dressed onto the meadow(dressed paddy field)and an upland crop field converted from the meadow(reclaimed upland field).The number of viable methanogenic archaea in the reclaimed paddy field was below the detection limit before the first cultivation of rice and in the reclaimed upland field.Then,the number gradually increased over five years and finally reached 103–104 cells g-1 dry soil,which was comparable to that in the dressed paddy field.These findings showed that the low abundance of autochthonous methanogenic archaea in the non-methanogenic oxic upland field soils steadily proliferated,and the community structure was developed following repeated and long-term submergence.These results suggest that habitats suitable for methanogenic archaea were established in soil following repeated and long-term submergence.
基金supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant (RGPIN/227565-2013) to K.A.G
文摘The abundance of ammonia-oxidizing bacteria and archaea and their amo A genes from the aerobic activated sludge tanks,recycled sludge and anaerobic digesters of a full-scale wastewater treatment plant(WWTP)was determined.Polymerase chain reaction and denaturing gradient gel electrophoresis were used to generate diversity profiles,which showed that each population had a consistent profile although the abundance of individual members varied.In the aerobic tanks,the ammonia-oxidizing bacterial(AOB)population was more than 350 times more abundant than the ammonia-oxidizing archaeal(AOA)population,however in the digesters,the AOA population was more than 10 times more abundant.Measuring the activity of the amo A gene expression of the two populations using RT-PCR also showed that the AOA amo A gene was more active in the digesters than in the activated sludge tanks.Using batch reactors and dd PCR,amo A activity could be measured and it was found that when the AOB amo A activity was inhibited in the anoxic reactors,the expression of the AOA amo A gene increased fourfold.This suggests that these two populations may have a cooperative relationship for the oxidation of ammonia.
基金supported by grants from the National Natural Science Foundation of China(No.41701278)Shanghai Committee of Science and Technology(No.19DZ1204302)the Fundamental Research Funds for the Central Universities(No.2019MS041)。
文摘Ammonia-oxidizing bacteria(AOB)and archaea(AOA)are two microbial groups mediating nitrification,yet little is presently known about their abundances and community structures at the transcriptional level in wastewater treatment systems(WWTSs).This is a significant issue,as the numerical abundance of AOA or AOB at the gene level may not necessarily represent their functional role in ammonia oxidation.Using amo A genes as molecular markers,this study investigated the transcriptional abundance and community structure of active AOA and AOB in 14 WWTSs.Quantitative PCR results indicated that the transcriptional abundances of AOB amo A(averaged:1.6×10^(8)copies g^(-1)dry sludge)were higher than those of AOA(averaged:3.4×10^(7)copies g^(-1)dry sludge)in all WWTSs despite several higher abundances of AOA amo A at the gene level.Moreover,phylogenetic analysis demonstrated that Nitrosomonas europaea and unknown clusters accounted for 37.66%and 49.96%of the total AOB amo A transcripts,respectively,suggesting their dominant role in driving ammonia oxidation.Meanwhile,AOA amo A transcripts were only successfully retrieved from 3 samples,and the Nitrosospaera sister cluster dominated,accounting for 83.46%.Finally,the substrate utilization kinetics of different AOA and AOB species might play a fundamental role in shaping their niche differentiation,community composition,and functional activity.This study provides a basis for evaluating the relative contributions of ammonia-oxidizing microorganisms(AOMs)to nitrogen conversions in WWTSs.
基金funding from the National Basic Research Program of China (2012CB124705,2013CB127603)the European Community’s Seventh Framework Programme (FP7/2007-2013) under the grant agreement n° 227549+1 种基金the Royal Dutch Academy of Sciences (KNAW) through Project 09CDP006the Fundamental Research Funds for the Central Universities,China (KYZ201153)
文摘Erhualian and Landrace breeds are typical genetically obese and lean pigs, respectively. To compare the fecal methanogenic Archaeal community between these two pig breeds, fecal samples from different growth phase pigs were collected and used for PCR-denaturing gradient gel electrophoresis （DGGE） with two primer pairs （344fGC/519r and 519f/915rGC） and real-time PCR analysis. Results showed that a better separation and higher quality of bands pattern were obtained in DGGE proifles using primers 344fGC/519r as compared with primers 519f/915rGC. Sequencing of DGGE bands showed that the predominant methanogens in the feces of Erhualian and Landrace pigs belonged to Methanobrevibacter spp. and Methanosphaera spp. Real-time PCR analysis revealed that there was no signiifcant difference in the numbers of fecal total methanogens between Erhualian and Landrace pigs;however, pig growth phase affected the numbers of 16S rRNA genes of total methanogens and Methanobrevibacter smithii. Dissociation curves of methyl coenzyme-M reductase subunit A （mcrA） gene fragments ampliifed with real-time PCR showed all samples possessed a single peak at 82＆#176;C, which might be associated with M. smithii. Samples from the same growth phase of each breed showed good replicative dissociation curves. The results suggest that the growth phase （including diet factor） other than genotype of pig may affect the fecal methanogenic Archaeal community of pigs.
基金supported by ShanghaiTech University and National Natural Science Foundation of China(No.31771490)。
文摘CTP synthase(CTPS)is an important metabolic enzyme that catalyzes the rate-Iimiting reaction of nucleotide CrP de novo synthesis.Since 2010,a series of studies have demonstrated that CTPS can form filamentous structures in bacteria and eukaryotes,which are termed cytoophidia.However,it is unknown whether cytoophidia exist in the third domain of life,archaea.Using Haloarcula hispanica as a model system,here we demonstrate that CTPS forms distinct intracellular compartments in archaea.Under stimulated emission depletion microscopy,we find that the structures of H.hispanica CTPS are elongated,similar to cytoophidia in bacteria and eukaryotes.When Haloarcula cells are cultured in lowsalt medium,the occurrence of cytoophidia increases dramatically.In addition,treatment of H.hispanica with a glutamine analog or overexpression of CTPS can promote cytoophidium assembly.Our study reveals that CTPS can fo rm cytoophidia in all three domains of life,suggesting that forming cytoophidia is an ancient property of CTPS.
基金supported by Guangdong Province Science and Technology Project(No.2016B020240007)the Basic Scientific Research Business of Central Level Public Welfare Scientific Research Institution(No.PM-zx703-201803-070)
文摘It has been well-documented that the distribution of ammonia-oxidizing bacteria(AOB) and archaea(AOA) in soils can be affected by heavy metal contamination, whereas information about the impact of heavy metal on these ammonia-oxidizing microorganisms in freshwater sediment is still lacking. The present study explored the change of sediment ammonia-oxidizing microorganisms in a freshwater reservoir after being accidentally contaminated by industrial discharge containing high levels of metals. Bacterial amoA gene was found to be below the quantitative PCR detection and was not successfully amplified by conventional PCR. The number of archaeal amoA gene in reservoir sediments were 9.62 × 10~2–1.35 × 10~7 copies per gram dry sediment. AOA abundance continuously decreased, and AOA richness, diversity and community structure also considerably varied with time. Therefore, heavy metal pollution could have a profound impact on freshwater sediment AOA community. This work could expand our knowledge of the effect of heavy metal contamination on nitrification in natural ecosystems.
基金supported by grants from the Ministry of Science and Technology of China (No. 2006CB101605)the Chinese Academy of Sciences (No. KSCX2-YW- R-134) to X.-J. W. from the National Science Founda-tion of China (No. 90919010) to H. Guo
文摘RNA silencing plays crucial roles in both bacteria and eukaryotes, yet its machinery appears to differ in these two kingdoms. A couple of Argonaute protein homologs have been reported in some archaeal species in recent years. As Argonaute protein is the key component of eukaryotic RNA silencing pathways, such findings suggested the possibility of existence of eukaryotic RNA silencing like pathways in Archaea, which present the life forms between prokaryotes and eukaryotes. To further explore such hypothesis, we systematically screened 71 fully sequenced archaeal genomes, and identified some proteins containing homologous regions to the functional domains of eukaryotic RNA silencing pathway key proteins. The phylogenetic relationships of these proteins were analyzed. The conserved functional amino acids between archaeal and eukaryotic Piwi domains suggested their fimctional similarity. Our results provide new clues to the evolution of RNA silencing pathways.
基金Supported by the China Ocean Mineral Resources Research and Development Association Program(Nos.DY135-E2-1-01,DY135-E2-4-00)the China Global Sea-Atmosphere Interaction Research Program(No.GASI-02-IND-STSsum)the S&T Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ14)。
文摘Depth-dependent distribution patterns of bacterial and archaeal communities in deep sea water column around the Ninetyeast Ridge in the Indian Ocean were investigated using 16S rRNA gene profiling.Sampling was conducted at the northern Ninetyeast Ridge(1°59.89′N–9°59.70′S,87°58.90′E–88°00.03′E)from September to November 2016 where samples were collected from the bathyal(1000 m)to bathypelagic depths(>4000 m)in four different stations.A total of 1565405 clean data falling into 6712 bacterial OTUs and 1452727 clean data falling into 806 archaeal OTUs based on 97%similarity level were analyzed.Most of the bacterial 16S rRNA gene sequences were affiliated with Gammaproteobacteria,followed by Alphaproteobacteria and Bacteroidia.The archaeal 16S rRNA gene sequences mostly affiliated to Nitrososphaeria(Thaumarchaeota)dominated with relative abundances ranging from 52.68%to 97.2%,followed by Thermoplasmata(Euryarchaeota).Vertical partitioning of bacterial and archaeal communities among different water layers was observed.Canonical correspondence analysis(CCA)and Spearman’s correlations revealed that depth(P=0.003),dissolved oxygen(P=0.019),and nitrite(P=0.033)were the main environmental factors affecting bacterial community structure at genus level in the Ninetyeast Ridge.On the other hand,the first two CCA axes accounted for 74.4%of the explained total variance,it seems that the archaeal communities at genus level were heavily influenced by the environmental variables including depth,dissolved oxygen(DO),nitrite,salinity,phosphate,ammonia,nitrate,and silicate,but none of them exhibited any significant correlation on the structuring(P>0.1).
