Sugarcane/soybean intercropping with reduced nitrogen addition is an important sustainable agricultural pattern that can alter soil ecological functions,thereby affecting straw decomposition in the soil.However,the me...Sugarcane/soybean intercropping with reduced nitrogen addition is an important sustainable agricultural pattern that can alter soil ecological functions,thereby affecting straw decomposition in the soil.However,the mechanisms underlying changes in soil organic carbon(SOC)composition and microbial communities during straw decomposition under long-term intercropping with reduced nitrogen addition remain unclear.In this study,we conducted an in-situ microplot incubation experiment with^(13)C-labeled soybean straw residue addition in a two-factor(cropping pattern:sugarcane monoculture(MS)and sugarcane/soybean intercropping(SB);nitrogen addition levels:reduced nitrogen addition(N1)and conventional nitrogen addition(N2))long-term experimental field plot.The results showed that the SBN1 treatment significantly increased the residual particulate organic carbon(POC)and residual microbial biomass carbon(MBC)contents during straw decomposition,and the straw carbon in soil was mainly conserved as POC.Straw addition changed the structure and reduced the diversity of the soil microbial community,but microbial diversity gradually recovered with decomposition time.During straw decomposition,the intercropping pattern significantly increased the relative abundances of Firmicutes and Ascomycota.In addition,straw addition reduced microbial network complexity in the sugarcane/soybean intercropping pattern but increased it in the sugarcane monoculture pattern.Nevertheless,microbial network complexity remained higher in the SBN1 treatment than in the MSN1 treatment.In general,the SBN1 treatment significantly increased the diversity of microbial communities and the relative abundance of microorganisms associated with organic matter decomposition,and the changes in microbial communities were mainly driven by the residual labile SOC fractions.These findings suggest that more straw carbon can be sequestered in the soil under sugarcane/soybean intercropping with reduced nitrogen addition to maintain microbial diversity and contribute to the development of sustainable agriculture.展开更多
Pollution from heavy metals(HMs)(Cd,As,Cr,and Ni,etc.)has become a serious environmental issue in urban wetland ecosystems with more and more attention.Previous studies conducted in agricultural soils,rivers,and lakes...Pollution from heavy metals(HMs)(Cd,As,Cr,and Ni,etc.)has become a serious environmental issue in urban wetland ecosystems with more and more attention.Previous studies conducted in agricultural soils,rivers,and lakes demonstrated that microbial communities exhibit a response to HM pollution.Yet,little is known about the response of microbial communities to HM pollution in urban wetland ecosystems.We examined how heavy metals affect the stability of the microbial networks in the sediments of Sanyang wetland,Wenzhou,China.Key environmental parameters,including HMs,TC(total carbon),TN(total nitrogen),TP(total phosphorus),S,and pH,varied profoundly between moderately and heavily polluted areas in shaping microbial communities.Specifically,the microbial community composition in moderately polluted sites correlated significantly(P<0.05)with Ni,Cu,Cd and TP,whereas in heavily polluted sites,they correlated significantly with Cd,TN,TP,and S.Results show that the heavily polluted sites demonstrated more intricate and more stable microbial networks than those of the moderately polluted area.The heavily polluted sites exhibited higher values for various network parameters including total nodes,total links,average degree,average clustering coefficient,connectance,relative modularity,robustness,and cohesion.Moreover,the structural equation modeling analysis demonstrated a positive correlation between the stability of microbial networks and Cd,TN,TP,and S in heavily polluted sites.Conversely,in moderately polluted sites,the correlation was positively linked to Cd,Ni,and sediment pH.It implies that Cd could potentially play a crucial role in affecting the stability of microbial networks.This study shall enhance our comprehension of microbial co-occurrence patterns in urban wetland ecosystems and offer insights into the ways in which microbial communities respond to environmental factors in varying levels of HM pollution.展开更多
Healthy soil is crucial for sustainable agriculture with soil microbiomes being key to soil health.However,comprehensive assessments of soil health and microbial community structures under different wheat yields have ...Healthy soil is crucial for sustainable agriculture with soil microbiomes being key to soil health.However,comprehensive assessments of soil health and microbial community structures under different wheat yields have not been made.Therefore,soil samples were collected from wheat fields with differing yields at depths of 0-15 and 15-30 cm.The yields were categorized as low(Y1,3.75t·ha^(-1)),medium(Y2,6.00 t·ha^(-1)),high(Y3,8.25 t·ha^(-1)),and maximum(Y4,1o.1 t·ha^(-1)),and soil health and microbial communities determined.The results showed that both yield category and soil depth significantly influenced SOC,TN,mineral nitrogen,AP and AK,enzyme activity,and soil bacterial communities.The soil health index in Y4(0.51-0.87)was significantly higher than in Y3(0.39-0.63),Y2(0.27-0.45),and Y1(0.21-0.52)at both 0-15 and 15-30 cm(expect Y1).Significant correlation was only found between soil health index at 0-15 cm and wheat yield,not at 15-30 cm.The bacterial and fungal network structure in Y4 was more complex and densely connected.Actinobacteria,Thaumarchaeota,and Ascomycota were identified as key drivers of soil health.Based on these results,the regulation of microbes has the potential to improve soil health and crop yields.展开更多
Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations.However,the response of these indicators to petro...Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations.However,the response of these indicators to petroleum contamination remains under-investigated.The present study investigated the soil physicochemical features,metal(loid)s,microbial communities and networks,and phospholipid fatty acids(PLFAs)community structures in soil samples collected from long-(LC)and short-term(SC)petroleum-contaminated oil fields.The results showed that petroleum contamination increased the levels of soil total petroleum hydrocarbon,carbon,nitrogen,sulfur,phosphorus,calcium,copper,manganese,lead,and zinc,and decreased soil pH,microbial biomass,bacterial and fungal diversity.Petroleum led to a rise in the abundances of soil Proteobacteria,Ascomycota,Oleibacter,and Fusarium.Network analyses showed that the number of network links(Control vs.SC,LC=1181 vs.700,1021),nodes(Control vs.SC,LC=90 vs.71,83)and average degree(Control vs.SC,LC=26.244 vs.19.718,24.602)recovered as the duration of contamination increased.Petroleum contamination also reduced the concentration of soil PLFAs,especially bacterial.These results demonstrate that brief exposure to high levels of petroleum contamination alters the physicochemical characteristics of the soil as well as the composition of soil metal(loid)s andmicroorganisms,leading to a less diverse soilmicrobial network that is more susceptible to damage.Future research should focus on the culturable microbiome of soil under petroleum contamination to provide a theoretical basis for further remediation.展开更多
Soil nitrogen(N)cycling is one of the most critical biogeochemical cycles,and N cycling-related microorganisms are the primary driving force behind N cycling in natural environments.The large karst sinkholes in China,...Soil nitrogen(N)cycling is one of the most critical biogeochemical cycles,and N cycling-related microorganisms are the primary driving force behind N cycling in natural environments.The large karst sinkholes in China,known as Tiankengs,harbor abundant unique biological resources due to their particular environmental conditions.However,N cycling-related microorganisms in Tiankeng soils and their connection to ecosystem processes remain poorly studied.In this study,we investigated the distribution patterns and genomic diversity of N cycling-related microorganisms both inside and outside the Luohun cave Tiankeng in Guizhou,China,utilizing high-throughput sequencing and other techniques.The results indicated that the diversities and abundances of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea communities inside the Tiankeng were higher than those outside the Tiankeng;however,the microbial network relationships were more fragile inside the Tiankeng.The most abundant species of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea inside the Tiankeng were unclassified_p_Proteobacteria(47.8%),unclassified_k_norank(AOB,OTU121,37.3%),and unclassified_g_norank_f_norank_o_norank_c_environmental_samples(55.7%),respectively;outside the Tiankeng,they were unclassified_k_norank_d_bacteria(54.5%),unclassified_k_norank(AOB,OTU121,48.1%),and unclassified_k_norank(AOA,OTU70,49.6%),respectively.Additionally,the N content inside the Tiankeng was significantly lower(P<0.05)under the influence of these N cycling-related microorganisms,whereas the nutrient contents were higher than that outside the Tiankeng.To the best of our knowledge,this is the first report on the crucial microbial distribution patterns driving N cycling in karst Tiankengs and provides new insights into the structure and potential functions of N cycling-related microorganisms in the unique ecological environment of fragile Tiankeng ecosystems.展开更多
Plant health and performance are highly dependent on the root microbiome.The impact of agricultural management on the soil microbiome has been studied extensively.However,a comprehensive understanding of how soil type...Plant health and performance are highly dependent on the root microbiome.The impact of agricultural management on the soil microbiome has been studied extensively.However,a comprehensive understanding of how soil types and fertilization regimes affect both soil and root microbiome is still lacking,such as how fertilization regimes affect the root microbiome's stability,and whether it follows the same patterns as the soil microbiome.In this study,we carried out a longterm experiment to see how different soil types,plant varieties,and fertilizer regimens affected the soil and root bacterial communities.Our results revealed higher stability of microbial networks under combined organic-inorganic fertilization than those relied solely on inorganic or organic fertilization.The root microbiome variation was predominantly caused by total nitrogen,while the soil microbiome variation was primarily caused by pH and soil organic matter.Bacteroidetes and Firmicutes were major drivers when the soil was amended with organic fertilizer,but Actinobacteria was found to be enriched in the soil when the soil was treated with inorganic fertilizer.Our findings demonstrate how the soil and root microbiome respond to diverse fertilizing regimes,and hence contribute to a better understanding of smart fertilizer as a strategy for sustainable agriculture.展开更多
Intensive management is known to markedly alter soil carbon(C)storage and turnover in Moso bamboo forests compared with extensive management.However,the effects of intensive management on soil respiration(RS)component...Intensive management is known to markedly alter soil carbon(C)storage and turnover in Moso bamboo forests compared with extensive management.However,the effects of intensive management on soil respiration(RS)components remain unclear.This study aimed to evaluate the changes in different RScomponents(root,mycorrhizal,and free-living microorganism respiration)in Moso bamboo forests under extensive and intensive management practices.A1-year in-situ microcosm experiment was conducted to quantify the RScomponents in Moso bamboo forests under the two management practices using mesh screens of varying sizes.The results showed that the total RSand its components exhibited similar seasonal variability between the two management practices.Compared with extensive management,intensive management significantly increased cumulative respiration from mycorrhizal fungi by 36.73%,while decreased cumulative respiration from free-living soil microorganisms by 8.97%.Moreover,the abundance of arbuscular mycorrhizal fungi(AMF)increased by 43.38%,but bacterial and fungal abundances decreased by 21.65%and 33.30%,respectively,under intensive management.Both management practices significantly changed the bacterial community composition,which could be mainly explained by soil pH and available potassium.Mycorrhizal fungi and intensive management affected the interrelationships between bacterial members.Structural equation modeling indicated that intensive management changed the cumulative RSby elevating AMF abundance and lowering bacterial abundance.We concluded that intensive management reduced the microbial respiration-derived C loss,but increased mycorrhizal respiration-derived C loss.展开更多
Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical ...Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical N fertilizer.However,existing studies typically focus on individual soil functions,neglecting the fact that multiple functions occur simultaneously.It remains unclear how PSOF influences multiple soil functions and whether these impacts are related to soil microbial communities.Here,we examined the impacts of partial substitutions(25%–50%)of chemical N fertilizer with organic form(pig manure or municipal sludge)in a vegetable field on soil multifunctionality,by measuring a range of soil functions involving primary production(vegetable yield and quality),nutrient cycling(soil enzyme activities,ammonia volatilization,N leaching,and N runoff),and climate regulation(soil organic carbon sequestration and nitrous oxide emission).We observed that PSOF improved soil multifunctionality,with a 50%substitution of chemical N fertilizer with pig manure being the best management practice;the result was strongly related to the diversities and network complexities of bacteria and fungi.Random forest analysis further revealed that soil multifunctionality was best explained by the bacterial-fungal network complexity,followed by available phosphorus level and bacterial diversity.The PSOF also shifted the composition of bacterial and fungal communities,with increased relative abundances of dominant bacteria phyla,such as Bacteroidetes,Gemmatimonadetes,and Myxococcota,and fungal phyla,such as Basidiomycota and Olpidiomycota.The observed increases in soil multifunctionality were consistent with significant increases in the relative abundances of keystone taxa such as Blastocladiomycota,Chaetomiaceae,and Nocardiopsaceae.Together,these findings indicate that PSOF can enhance interactions within and among microbial communities and that such practices have the potential to improve soil ecosystem multifunctionality and contribute to the development of sustainable agriculture.展开更多
Effluents from wastewater treatment plants（WWTPs） containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been wel...Effluents from wastewater treatment plants（WWTPs） containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16 S and 18 S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be ＂biofilm-specific＂, with only a few dominant operational taxonomic units（OTUs） shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.展开更多
Fe(Ⅱ)is an essential trace element for anaerobic ammonium oxidation bacteria(AAOB)metabolism,and can improve the nitrogen removal efficiency of anaerobic ammonia oxidation(Anammox).Here we oper-ated two identical exp...Fe(Ⅱ)is an essential trace element for anaerobic ammonium oxidation bacteria(AAOB)metabolism,and can improve the nitrogen removal efficiency of anaerobic ammonia oxidation(Anammox).Here we oper-ated two identical expanded granular sludge bed(EGSB)reactors at low temperature(15±3℃)for 154 days.Reactor 1(R_(1))received additional Fe(Ⅱ)(0.12 mmol/L)during the late startup phase,while reactor 0(R_(0))served as the control and did not receive extra Fe(Ⅱ).Nitrogen removal in R_(1)became stable at 55 d of operation,ten days earlier than R_(0).The nitrogen removal rate(NRR)of R_(1) was 1.64 kg N m^(−3)d^(−1)and its TN removal rate was as high as 89%,while R_(0)only reached 75%.The addition of Fe(Ⅱ)was fur-ther beneficial to aggregation and stability of the granular sludge,and the used sludge of both reactors showed enrichment for AAOB populations compared to the inoculum,for instance,increased abundance of Candidatus-Kuenenia and in particular of Candidatus-Brocadia(from 0.17%to 10.10%in R_(0)and 7.79%in R_(1)).Diverse microbial species and complex microbial network structure in R_(1)compared to R_(0)promoted the coupled denitrogenation by Anammox,dissimilatory nitrate reduction to ammonium(DNRA),nitrate-dependent Fe oxidation(NDFO),and ferric ammonium oxidation(Feammox).In addition,the microbial community in R_(1)was more resistant to short-term low temperature(2-7℃)starvation,illustrating a further positive effect of adding Fe(Ⅱ)during the startup phase of an Anammox reactor.展开更多
BACKGROUND Colorectal polyps that develop via the conventional adenoma-carcinoma sequence[e.g.,tubular adenoma(TA)]often progress to malignancy and are closely associated with changes in the composition of the gut mic...BACKGROUND Colorectal polyps that develop via the conventional adenoma-carcinoma sequence[e.g.,tubular adenoma(TA)]often progress to malignancy and are closely associated with changes in the composition of the gut microbiome.There is limited research concerning the microbial functions and gut microbiomes associated with colorectal polyps that arise through the serrated polyp pathway,such as hyperplastic polyps(HP).Exploration of microbiome alterations asso-ciated with HP and TA would improve the understanding of mechanisms by which specific microbes and their metabolic pathways contribute to colorectal carcinogenesis.AIM To investigate gut microbiome signatures,microbial associations,and microbial functions in HP and TA patients.METHODS Full-length 16S rRNA sequencing was used to characterize the gut microbiome in stool samples from control participants without polyps[control group(CT),n=40],patients with HP(n=52),and patients with TA(n=60).Significant differences in gut microbiome composition and functional mechanisms were identified between the CT group and patients with HP or TA.Analytical techniques in this study included differential abundance analysis,co-occurrence network analysis,and differential pathway analysis.RESULTS Colorectal cancer(CRC)-associated bacteria,including Streptococcus gallolyticus(S.gallolyticus),Bacteroides fragilis,and Clostridium symbiosum,were identified as characteristic microbial species in TA patients.Mediterraneibacter gnavus,associated with dysbiosis and gastrointestinal diseases,was significantly differentially abundant in the HP and TA groups.Functional pathway analysis revealed that HP patients exhibited enrichment in the sulfur oxidation pathway exclusively,whereas TA patients showed dominance in pathways related to secondary metabolite biosynthesis(e.g.,mevalonate);S.gallolyticus was a major contributor.Co-occurrence network and dynamic network analyses revealed co-occurrence of dysbiosis-associated bacteria in HP patients,whereas TA patients exhibited co-occurrence of CRC-associated bacteria.Furthermore,the co-occurrence of SCFA-producing bacteria was lower in TA patients than HP patients.CONCLUSION This study revealed distinct gut microbiome signatures associated with pathways of colorectal polyp development,providing insights concerning the roles of microbial species,functional pathways,and microbial interactions in colorectal carcinogenesis.展开更多
China's progressing space program,as evidenced by the formal operation of the China Space Station(CSS),has provided great opportunities for various space missions.Since microbes can present potential risks to huma...China's progressing space program,as evidenced by the formal operation of the China Space Station(CSS),has provided great opportunities for various space missions.Since microbes can present potential risks to human health and the normal operation of spacecraft,the study on space-microorganisms in the CSS is always a matter of urgency.In addition,the knowledge on the interactions between microorganisms,astronauts,and spacecraft equipment will shed light on our understanding of life activities in space and a closed environment.Here,we present the first comprehensive report on the microbial communities aboard the CSS based on the results of the first two survey missions of the CSS Habitation Area Microbiome Program(CHAMP).By combining metagenomic and cultivation methods,we have discovered that,in the early stage of the CSS,microbial communities are dominated by human-associated microbes,with strikingly large differences in both composition and functional diversity compared to those found on the International Space Station(ISS).While the samples from two missions of CHAMP possessed substantial differences in microbial composition,no significant difference in functional diversity was found,although signs of accumulating antibiotic resistance were evident.Meanwhile,strong bacteria co-occurrence was noted within the station's microbiota.At the strain level,environmental isolates from the CSS exhibited numerous genomic mutations compared to those from the Assembly,Integration,and Test(AIT)center,potentially linked to the adaptation to the unique conditions of space.Besides,the intraspecies variation within four high-abundance species suggests possible propagation and residency effects between sampling sites.In summary,this study offers critical insights that not only advance our understanding of space microbiology but also lay the groundwork for effective microbial management in future long-term human space missions.展开更多
Straits are ideal models to investigate the bacterial community assembly in complex hydrological environments. However, few studies have focused on bacterial communities in them. Here, comparable bacterial communities...Straits are ideal models to investigate the bacterial community assembly in complex hydrological environments. However, few studies have focused on bacterial communities in them. Here, comparable bacterial communities in costal shallow Bohai Strait(BS) and oceanic deep Fram Strait(FS) were studied. The Shannon and Chao1 indices were both higher in BS than in FS. The relative abundances of the classes Deltaproteobacteria and Bacilli and the family Halieaceae were higher in BS than in FS, in contrast to the families OM1_clade and JTB255_marine_benthic_group, revealing typical characteristics of bacterial communities in coastal and oceanic regions. Cluster analysis based on the Bray-Curtis index showed that samples were clustered by depth layer in FS and BS, indicating that structures of bacterial communities would diff er with increasing water depth in straits. Additionally, the cluster relationships among samples in abundant and rare communities were both similar to those in entire communities. However, the dissimilarities among samples showed a descending order as rare communities, entire communities and abundant communities. Network analysis indicated that the BS network was obviously more complex than the FS network. Filamentous bacteria Desulfobulbaceae exhibited high degree values in BS but not in FS, indicating key roles of Desulfobulbaceae in the BS. Our study provides different and common evidences for understanding microbial ecology in coastal shallow and oceanic deep straits.展开更多
Background Soil erosion affects the stability of terrestrial ecosystems and ecosystem services by directly or indirectly impacting the cycling of soil materials and energy and reducing the fertility of grassland soils...Background Soil erosion affects the stability of terrestrial ecosystems and ecosystem services by directly or indirectly impacting the cycling of soil materials and energy and reducing the fertility of grassland soils.However,research on microbial adaptation to grazing and soil erosion is limited,particularly in relation to grassland ecosystem restora-tion.Here,we assess microbial communities subjected to simulated soil erosion and grazing in a semi-arid grassland of Inner Mongolia,China.Results No significant change was observed in soil variables.However,the structure of the soil microbial commu-nity underwent significant changes as a result of soil erosion and soil erosion plus grazing,leading to a significant increase in the relative abundance of Cyanobacteria(116.80%vs 116.38%).Wind erosion and deposition contributed to an increase in the network complexity of soil bacterial and fungal communities.However,much of this effect was alleviated by grazing.Simultaneously,aeolian processes and grazing regulate soil microbial community assembly,leading to inconsistent patterns of change in bacterial and fungal communities.Under wind erosion and deposi-tion,the relative contribution of deterministic processes(4.44%vs 31.11%)in bacterial communities increased,while the relative contribution of stochastic processes(2.23%vs 20%)in fungal communities reduced.Grazing resulted in a decrease in the relative contribution of deterministic processes(8.89%)in the bacterial community and an increase in the relative contribution of stochastic processes(8.89%)in the fungal community.Conclusion This study presents a comprehensive investigation of the response of soil microbial communities to aeolian erosion–deposition and grazing in a semi-arid grassland.Our findings indicate that microbial communities in the semi-arid grassland show resistance to external disturbances and that light grazing mitigates the effects of aeo-lian erosion–deposition on microbial communities,which is essential for maintaining the stability and biodiversity of grassland ecosystems.展开更多
2′-Deoxymugineic(DMA),a phytosiderophore secreted by Poaceae species,can improve iron nutrition in plants.However,little is known about how DMA influences beneficial bacteria in rhizosphere microecosystem.To address ...2′-Deoxymugineic(DMA),a phytosiderophore secreted by Poaceae species,can improve iron nutrition in plants.However,little is known about how DMA influences beneficial bacteria in rhizosphere microecosystem.To address this gap,the DMA analog proline-2′-deoxymugineic(PDMA)was used to evaluate its positive effect on peanut rhizobacterial communities and network structure.This study demonstrated that PDMA can promote the absorption of several mineral nutrients in plants and activate micronutrients in the rhizosphere.Specifically,PDMA led to significant impact on the bacterial community structure in the peanut rhizosphere,resulting in a substantial increase in the relative abundance of Actinobacteriota with six beneficial rhizobacterial genera in this phylum.The Cellulosimicrobium and Marmoricola of Actinobacteriota recruited by PDMA may enhance micronutrient availability both to peanut plants and in soil.PDMA application led to the development of a tight,stable microbial network,as indicated by higher topological parameters and a greater variety of keystone genera.Functional prediction revealed that PDMA fosters microbial communication in the rhizosphere.Overall,PDMA was shown to recruit beneficial bacteria and to modulate bacterial network structure in the peanut rhizosphere.It is concluded that these findings demonstrate that phytosiderophore might promote plant growth and nutrition absorption by regulating plant–soil microecosystem.展开更多
Soil microbial community's responses to climate warming alter the global carbon cycle.In temperate ecosystems,soil microbial communities function along seasonal cycles.However,little is known about how the respons...Soil microbial community's responses to climate warming alter the global carbon cycle.In temperate ecosystems,soil microbial communities function along seasonal cycles.However,little is known about how the responses of soil microbial communities to warming vary when the season changes.In this study,we investigated the seasonal dynamics of soil bacterial community under experimental warming in a temperate tall‐grass prairie ecosystem.Our results showed that warming significantly(p=0.001)shifted community structure,such that the differences of microbial communities between warming and control plots increased nonlinearly(R^(2)=0.578,p=0.021)from spring to winter.Also,warming significantly(p<0.050)increased microbial network complexity and robustness,especially during the colder seasons,despite large variations in network size and complexity in different seasons.In addition,the relative importance of stochastic processes in shaping the microbial community decreased by warming in fall and winter but not in spring and summer.Our study indicates that climate warming restructures the seasonal dynamics of soil microbial community in a temperate ecosystem.Such seasonality of microbial responses to warming may enlarge over time and could have significant impacts on the terrestrial carbon cycle.展开更多
The application of biochar to soil is widely recognized as a promising strategy for enhancing the accumulation and stability of soil organic carbon(SOC),which is crucial in mitigating climate change.However,the influe...The application of biochar to soil is widely recognized as a promising strategy for enhancing the accumulation and stability of soil organic carbon(SOC),which is crucial in mitigating climate change.However,the influence of interactions between plants and biochar on soil microbial communities and their involvement in SOC mineralization and stability remains unclear.This understanding is essential for optimizing carbon(C)sequestration in systems involving plants,soil,and biochar.In this study,employing a 13C natural abundance approach,we investigated the effect of biochar on the maize rhizosphere priming effect(RPE)in paddy soil.We also examined alterations in microbial communities and functional genes related to C degradation and fixation.Over the 99 days of maize growth,biochar application increased RPE and total SOC while decreasing dissolved organic C.It also elevated soil pH,resulting in shifts in fungal and bacterial community structure,favoring oligotrophic species.Fungal and bacterial assemblies were dominated by deterministic and stochastic processes,respectively.While the abundance of fungal guilds varied irregularly,bacterial guilds were uniformly enriched under biochar-plant interactions.Functional traits such as ecoenzymatic activities,bacterial guilds,and functional genes predominantly affected RPE under biochar application.Bacterial functional genes associated with C degradation and fixation were concurrently enhanced with biochar application.Our results indicate that interactions between plants and biochar can enhance native SOC mineralization and accumulation in a short timeframe by modulating functional traits of soil microorganisms,particularly the bacterial community involved in C degradation and fixation.展开更多
Background The temperate grasslands are facing numerous pressures from global change.Despite their essential ecological and economic role,how their microbial communities react to multiple varying factors remain obscur...Background The temperate grasslands are facing numerous pressures from global change.Despite their essential ecological and economic role,how their microbial communities react to multiple varying factors remain obscure.In this study,we simulated three global change drivers,i.e.,nitrogen deposition(ambient N vs.elevated N,a N vs.e N),precipitation increase(ambient precipitation vs.elevated precipitation,a P vs.e P),and mowing,represented experimentally by clipping(unclipped vs.clipped,u C vs.CL),together in all possible combinations in a temperate semi-arid grassland ecosystem.Results Nitrogen addition had negative effects on the richness of bacterial and fungal communties,significantly changed their structures(P<0.05)and increased their dissimilarities(P<0.05),while water addition had positive effects on fungal and protist communities and significantly stimulated theα-diversity of protist communities under N addition without clipping,which was in contrast to the effect in clipped plots.Clipping had a marginal effect on fungal communities and significantly affected protist communities(P<0.05).A notable interactive effect of N and precipitation on the structure of bacterial communities and a significant interactive effect of clipping and precipitation on protists were found.Combination effects of N with precipitation or clipping on module aggregation of metanetworks were also observed between u C and CL,as well as a P and e P meta-networks.Bacterial,fungal,and protist communities varied in their assembly mechanisms,and their assembly processes differed in response to the three global change factors.Conclusions Overall,N,water addition,and clipping individually and/or interactively,in distinct degrees,altered soil microbial interaction,community structure,and the potential function in a semi-arid steppe.These findings enhance our understanding of soil microbial community assembly and provide a scientific basis for managing temperate grasslands,particularly in the context of global change's impact on ecosystem function and stability.展开更多
基金supported by the China National Key R&D Program during the 14th Five-year Plan Period(2022YFD1901603)。
文摘Sugarcane/soybean intercropping with reduced nitrogen addition is an important sustainable agricultural pattern that can alter soil ecological functions,thereby affecting straw decomposition in the soil.However,the mechanisms underlying changes in soil organic carbon(SOC)composition and microbial communities during straw decomposition under long-term intercropping with reduced nitrogen addition remain unclear.In this study,we conducted an in-situ microplot incubation experiment with^(13)C-labeled soybean straw residue addition in a two-factor(cropping pattern:sugarcane monoculture(MS)and sugarcane/soybean intercropping(SB);nitrogen addition levels:reduced nitrogen addition(N1)and conventional nitrogen addition(N2))long-term experimental field plot.The results showed that the SBN1 treatment significantly increased the residual particulate organic carbon(POC)and residual microbial biomass carbon(MBC)contents during straw decomposition,and the straw carbon in soil was mainly conserved as POC.Straw addition changed the structure and reduced the diversity of the soil microbial community,but microbial diversity gradually recovered with decomposition time.During straw decomposition,the intercropping pattern significantly increased the relative abundances of Firmicutes and Ascomycota.In addition,straw addition reduced microbial network complexity in the sugarcane/soybean intercropping pattern but increased it in the sugarcane monoculture pattern.Nevertheless,microbial network complexity remained higher in the SBN1 treatment than in the MSN1 treatment.In general,the SBN1 treatment significantly increased the diversity of microbial communities and the relative abundance of microorganisms associated with organic matter decomposition,and the changes in microbial communities were mainly driven by the residual labile SOC fractions.These findings suggest that more straw carbon can be sequestered in the soil under sugarcane/soybean intercropping with reduced nitrogen addition to maintain microbial diversity and contribute to the development of sustainable agriculture.
基金Supported by the Major Program of Institute for Eco-environmental Research of Sanyang Wetland(No.SY2022ZD-1001-05)。
文摘Pollution from heavy metals(HMs)(Cd,As,Cr,and Ni,etc.)has become a serious environmental issue in urban wetland ecosystems with more and more attention.Previous studies conducted in agricultural soils,rivers,and lakes demonstrated that microbial communities exhibit a response to HM pollution.Yet,little is known about the response of microbial communities to HM pollution in urban wetland ecosystems.We examined how heavy metals affect the stability of the microbial networks in the sediments of Sanyang wetland,Wenzhou,China.Key environmental parameters,including HMs,TC(total carbon),TN(total nitrogen),TP(total phosphorus),S,and pH,varied profoundly between moderately and heavily polluted areas in shaping microbial communities.Specifically,the microbial community composition in moderately polluted sites correlated significantly(P<0.05)with Ni,Cu,Cd and TP,whereas in heavily polluted sites,they correlated significantly with Cd,TN,TP,and S.Results show that the heavily polluted sites demonstrated more intricate and more stable microbial networks than those of the moderately polluted area.The heavily polluted sites exhibited higher values for various network parameters including total nodes,total links,average degree,average clustering coefficient,connectance,relative modularity,robustness,and cohesion.Moreover,the structural equation modeling analysis demonstrated a positive correlation between the stability of microbial networks and Cd,TN,TP,and S in heavily polluted sites.Conversely,in moderately polluted sites,the correlation was positively linked to Cd,Ni,and sediment pH.It implies that Cd could potentially play a crucial role in affecting the stability of microbial networks.This study shall enhance our comprehension of microbial co-occurrence patterns in urban wetland ecosystems and offer insights into the ways in which microbial communities respond to environmental factors in varying levels of HM pollution.
基金supported by the National Key R&D Program of China(2023YFD1901501).
文摘Healthy soil is crucial for sustainable agriculture with soil microbiomes being key to soil health.However,comprehensive assessments of soil health and microbial community structures under different wheat yields have not been made.Therefore,soil samples were collected from wheat fields with differing yields at depths of 0-15 and 15-30 cm.The yields were categorized as low(Y1,3.75t·ha^(-1)),medium(Y2,6.00 t·ha^(-1)),high(Y3,8.25 t·ha^(-1)),and maximum(Y4,1o.1 t·ha^(-1)),and soil health and microbial communities determined.The results showed that both yield category and soil depth significantly influenced SOC,TN,mineral nitrogen,AP and AK,enzyme activity,and soil bacterial communities.The soil health index in Y4(0.51-0.87)was significantly higher than in Y3(0.39-0.63),Y2(0.27-0.45),and Y1(0.21-0.52)at both 0-15 and 15-30 cm(expect Y1).Significant correlation was only found between soil health index at 0-15 cm and wheat yield,not at 15-30 cm.The bacterial and fungal network structure in Y4 was more complex and densely connected.Actinobacteria,Thaumarchaeota,and Ascomycota were identified as key drivers of soil health.Based on these results,the regulation of microbes has the potential to improve soil health and crop yields.
基金supported by Guangxi Key Research and Development Program(No.AB24010136)the Pre-project from Guangxi Bureau of Geology and Mineral Exploration and Development(No.2024051)Guangxi Geochemistry and Environmental Restoration and Management Research Talent Highland.
文摘Evaluating petroleum contamination risk and implementing remedial measures in agricultural soil rely on indicators such as soil metal(loid)s and microbiome alterations.However,the response of these indicators to petroleum contamination remains under-investigated.The present study investigated the soil physicochemical features,metal(loid)s,microbial communities and networks,and phospholipid fatty acids(PLFAs)community structures in soil samples collected from long-(LC)and short-term(SC)petroleum-contaminated oil fields.The results showed that petroleum contamination increased the levels of soil total petroleum hydrocarbon,carbon,nitrogen,sulfur,phosphorus,calcium,copper,manganese,lead,and zinc,and decreased soil pH,microbial biomass,bacterial and fungal diversity.Petroleum led to a rise in the abundances of soil Proteobacteria,Ascomycota,Oleibacter,and Fusarium.Network analyses showed that the number of network links(Control vs.SC,LC=1181 vs.700,1021),nodes(Control vs.SC,LC=90 vs.71,83)and average degree(Control vs.SC,LC=26.244 vs.19.718,24.602)recovered as the duration of contamination increased.Petroleum contamination also reduced the concentration of soil PLFAs,especially bacterial.These results demonstrate that brief exposure to high levels of petroleum contamination alters the physicochemical characteristics of the soil as well as the composition of soil metal(loid)s andmicroorganisms,leading to a less diverse soilmicrobial network that is more susceptible to damage.Future research should focus on the culturable microbiome of soil under petroleum contamination to provide a theoretical basis for further remediation.
基金supported by the National Natural Science Foundation of China(No.31860023)the Light of West China Program of Chinese Academic of Sciences(No.[2019]90)+1 种基金the Basic Research Fund of Guangxi Academy of Sciences,China(No.CQZ-D-1904)the Fundamental Research Fund of the Guangxi Institute of Botany,China(Guizhiye Nos.24010 and 24012).
文摘Soil nitrogen(N)cycling is one of the most critical biogeochemical cycles,and N cycling-related microorganisms are the primary driving force behind N cycling in natural environments.The large karst sinkholes in China,known as Tiankengs,harbor abundant unique biological resources due to their particular environmental conditions.However,N cycling-related microorganisms in Tiankeng soils and their connection to ecosystem processes remain poorly studied.In this study,we investigated the distribution patterns and genomic diversity of N cycling-related microorganisms both inside and outside the Luohun cave Tiankeng in Guizhou,China,utilizing high-throughput sequencing and other techniques.The results indicated that the diversities and abundances of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea communities inside the Tiankeng were higher than those outside the Tiankeng;however,the microbial network relationships were more fragile inside the Tiankeng.The most abundant species of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea inside the Tiankeng were unclassified_p_Proteobacteria(47.8%),unclassified_k_norank(AOB,OTU121,37.3%),and unclassified_g_norank_f_norank_o_norank_c_environmental_samples(55.7%),respectively;outside the Tiankeng,they were unclassified_k_norank_d_bacteria(54.5%),unclassified_k_norank(AOB,OTU121,48.1%),and unclassified_k_norank(AOA,OTU70,49.6%),respectively.Additionally,the N content inside the Tiankeng was significantly lower(P<0.05)under the influence of these N cycling-related microorganisms,whereas the nutrient contents were higher than that outside the Tiankeng.To the best of our knowledge,this is the first report on the crucial microbial distribution patterns driving N cycling in karst Tiankengs and provides new insights into the structure and potential functions of N cycling-related microorganisms in the unique ecological environment of fragile Tiankeng ecosystems.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFD1700900)the National Natural Science Foundation of China(Grant No.31972519)the Taishan Industry Leading Talents HighEfficiency Agriculture Innovation Project(Grant No.LJNY202125).
文摘Plant health and performance are highly dependent on the root microbiome.The impact of agricultural management on the soil microbiome has been studied extensively.However,a comprehensive understanding of how soil types and fertilization regimes affect both soil and root microbiome is still lacking,such as how fertilization regimes affect the root microbiome's stability,and whether it follows the same patterns as the soil microbiome.In this study,we carried out a longterm experiment to see how different soil types,plant varieties,and fertilizer regimens affected the soil and root bacterial communities.Our results revealed higher stability of microbial networks under combined organic-inorganic fertilization than those relied solely on inorganic or organic fertilization.The root microbiome variation was predominantly caused by total nitrogen,while the soil microbiome variation was primarily caused by pH and soil organic matter.Bacteroidetes and Firmicutes were major drivers when the soil was amended with organic fertilizer,but Actinobacteria was found to be enriched in the soil when the soil was treated with inorganic fertilizer.Our findings demonstrate how the soil and root microbiome respond to diverse fertilizing regimes,and hence contribute to a better understanding of smart fertilizer as a strategy for sustainable agriculture.
基金financially supported by the National Natural Science Foundation of China(Nos.31971631,41977083,and 41671252)。
文摘Intensive management is known to markedly alter soil carbon(C)storage and turnover in Moso bamboo forests compared with extensive management.However,the effects of intensive management on soil respiration(RS)components remain unclear.This study aimed to evaluate the changes in different RScomponents(root,mycorrhizal,and free-living microorganism respiration)in Moso bamboo forests under extensive and intensive management practices.A1-year in-situ microcosm experiment was conducted to quantify the RScomponents in Moso bamboo forests under the two management practices using mesh screens of varying sizes.The results showed that the total RSand its components exhibited similar seasonal variability between the two management practices.Compared with extensive management,intensive management significantly increased cumulative respiration from mycorrhizal fungi by 36.73%,while decreased cumulative respiration from free-living soil microorganisms by 8.97%.Moreover,the abundance of arbuscular mycorrhizal fungi(AMF)increased by 43.38%,but bacterial and fungal abundances decreased by 21.65%and 33.30%,respectively,under intensive management.Both management practices significantly changed the bacterial community composition,which could be mainly explained by soil pH and available potassium.Mycorrhizal fungi and intensive management affected the interrelationships between bacterial members.Structural equation modeling indicated that intensive management changed the cumulative RSby elevating AMF abundance and lowering bacterial abundance.We concluded that intensive management reduced the microbial respiration-derived C loss,but increased mycorrhizal respiration-derived C loss.
基金supported by the National Natural Science Foundation of China(Nos.41961124004,42207361,and42061124001)。
文摘Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical N fertilizer.However,existing studies typically focus on individual soil functions,neglecting the fact that multiple functions occur simultaneously.It remains unclear how PSOF influences multiple soil functions and whether these impacts are related to soil microbial communities.Here,we examined the impacts of partial substitutions(25%–50%)of chemical N fertilizer with organic form(pig manure or municipal sludge)in a vegetable field on soil multifunctionality,by measuring a range of soil functions involving primary production(vegetable yield and quality),nutrient cycling(soil enzyme activities,ammonia volatilization,N leaching,and N runoff),and climate regulation(soil organic carbon sequestration and nitrous oxide emission).We observed that PSOF improved soil multifunctionality,with a 50%substitution of chemical N fertilizer with pig manure being the best management practice;the result was strongly related to the diversities and network complexities of bacteria and fungi.Random forest analysis further revealed that soil multifunctionality was best explained by the bacterial-fungal network complexity,followed by available phosphorus level and bacterial diversity.The PSOF also shifted the composition of bacterial and fungal communities,with increased relative abundances of dominant bacteria phyla,such as Bacteroidetes,Gemmatimonadetes,and Myxococcota,and fungal phyla,such as Basidiomycota and Olpidiomycota.The observed increases in soil multifunctionality were consistent with significant increases in the relative abundances of keystone taxa such as Blastocladiomycota,Chaetomiaceae,and Nocardiopsaceae.Together,these findings indicate that PSOF can enhance interactions within and among microbial communities and that such practices have the potential to improve soil ecosystem multifunctionality and contribute to the development of sustainable agriculture.
基金supported by the National Key Research and Development Program of China (No. 2016YFC0502801)
文摘Effluents from wastewater treatment plants（WWTPs） containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16 S and 18 S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be ＂biofilm-specific＂, with only a few dominant operational taxonomic units（OTUs） shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.
基金supported by the State Key Laboratory of Geo-hazard Prevention and Geoenvironment Protection Foundation(No.SKLGP2022Z012)the National Natural Science Foundation of China(No.41502333).
文摘Fe(Ⅱ)is an essential trace element for anaerobic ammonium oxidation bacteria(AAOB)metabolism,and can improve the nitrogen removal efficiency of anaerobic ammonia oxidation(Anammox).Here we oper-ated two identical expanded granular sludge bed(EGSB)reactors at low temperature(15±3℃)for 154 days.Reactor 1(R_(1))received additional Fe(Ⅱ)(0.12 mmol/L)during the late startup phase,while reactor 0(R_(0))served as the control and did not receive extra Fe(Ⅱ).Nitrogen removal in R_(1)became stable at 55 d of operation,ten days earlier than R_(0).The nitrogen removal rate(NRR)of R_(1) was 1.64 kg N m^(−3)d^(−1)and its TN removal rate was as high as 89%,while R_(0)only reached 75%.The addition of Fe(Ⅱ)was fur-ther beneficial to aggregation and stability of the granular sludge,and the used sludge of both reactors showed enrichment for AAOB populations compared to the inoculum,for instance,increased abundance of Candidatus-Kuenenia and in particular of Candidatus-Brocadia(from 0.17%to 10.10%in R_(0)and 7.79%in R_(1)).Diverse microbial species and complex microbial network structure in R_(1)compared to R_(0)promoted the coupled denitrogenation by Anammox,dissimilatory nitrate reduction to ammonium(DNRA),nitrate-dependent Fe oxidation(NDFO),and ferric ammonium oxidation(Feammox).In addition,the microbial community in R_(1)was more resistant to short-term low temperature(2-7℃)starvation,illustrating a further positive effect of adding Fe(Ⅱ)during the startup phase of an Anammox reactor.
基金Supported by Chulabhorn Royal Academy(Fundamental Fund:Fiscal year 2022 by National Science Research and Innovation Fund),No.FRB650039/0240 Project Code 165422.
文摘BACKGROUND Colorectal polyps that develop via the conventional adenoma-carcinoma sequence[e.g.,tubular adenoma(TA)]often progress to malignancy and are closely associated with changes in the composition of the gut microbiome.There is limited research concerning the microbial functions and gut microbiomes associated with colorectal polyps that arise through the serrated polyp pathway,such as hyperplastic polyps(HP).Exploration of microbiome alterations asso-ciated with HP and TA would improve the understanding of mechanisms by which specific microbes and their metabolic pathways contribute to colorectal carcinogenesis.AIM To investigate gut microbiome signatures,microbial associations,and microbial functions in HP and TA patients.METHODS Full-length 16S rRNA sequencing was used to characterize the gut microbiome in stool samples from control participants without polyps[control group(CT),n=40],patients with HP(n=52),and patients with TA(n=60).Significant differences in gut microbiome composition and functional mechanisms were identified between the CT group and patients with HP or TA.Analytical techniques in this study included differential abundance analysis,co-occurrence network analysis,and differential pathway analysis.RESULTS Colorectal cancer(CRC)-associated bacteria,including Streptococcus gallolyticus(S.gallolyticus),Bacteroides fragilis,and Clostridium symbiosum,were identified as characteristic microbial species in TA patients.Mediterraneibacter gnavus,associated with dysbiosis and gastrointestinal diseases,was significantly differentially abundant in the HP and TA groups.Functional pathway analysis revealed that HP patients exhibited enrichment in the sulfur oxidation pathway exclusively,whereas TA patients showed dominance in pathways related to secondary metabolite biosynthesis(e.g.,mevalonate);S.gallolyticus was a major contributor.Co-occurrence network and dynamic network analyses revealed co-occurrence of dysbiosis-associated bacteria in HP patients,whereas TA patients exhibited co-occurrence of CRC-associated bacteria.Furthermore,the co-occurrence of SCFA-producing bacteria was lower in TA patients than HP patients.CONCLUSION This study revealed distinct gut microbiome signatures associated with pathways of colorectal polyp development,providing insights concerning the roles of microbial species,functional pathways,and microbial interactions in colorectal carcinogenesis.
基金supported by the China Space Station Engineering Aerospace Technology Experiment Program (2019HJS002)the general program of the National Natural Science Foundation of China (32170659)China Agricultural University Young Talent Program in Life Science (006)。
文摘China's progressing space program,as evidenced by the formal operation of the China Space Station(CSS),has provided great opportunities for various space missions.Since microbes can present potential risks to human health and the normal operation of spacecraft,the study on space-microorganisms in the CSS is always a matter of urgency.In addition,the knowledge on the interactions between microorganisms,astronauts,and spacecraft equipment will shed light on our understanding of life activities in space and a closed environment.Here,we present the first comprehensive report on the microbial communities aboard the CSS based on the results of the first two survey missions of the CSS Habitation Area Microbiome Program(CHAMP).By combining metagenomic and cultivation methods,we have discovered that,in the early stage of the CSS,microbial communities are dominated by human-associated microbes,with strikingly large differences in both composition and functional diversity compared to those found on the International Space Station(ISS).While the samples from two missions of CHAMP possessed substantial differences in microbial composition,no significant difference in functional diversity was found,although signs of accumulating antibiotic resistance were evident.Meanwhile,strong bacteria co-occurrence was noted within the station's microbiota.At the strain level,environmental isolates from the CSS exhibited numerous genomic mutations compared to those from the Assembly,Integration,and Test(AIT)center,potentially linked to the adaptation to the unique conditions of space.Besides,the intraspecies variation within four high-abundance species suggests possible propagation and residency effects between sampling sites.In summary,this study offers critical insights that not only advance our understanding of space microbiology but also lay the groundwork for effective microbial management in future long-term human space missions.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020403)the National Natural Science Foundation of China(Nos.41576165,41376138)
文摘Straits are ideal models to investigate the bacterial community assembly in complex hydrological environments. However, few studies have focused on bacterial communities in them. Here, comparable bacterial communities in costal shallow Bohai Strait(BS) and oceanic deep Fram Strait(FS) were studied. The Shannon and Chao1 indices were both higher in BS than in FS. The relative abundances of the classes Deltaproteobacteria and Bacilli and the family Halieaceae were higher in BS than in FS, in contrast to the families OM1_clade and JTB255_marine_benthic_group, revealing typical characteristics of bacterial communities in coastal and oceanic regions. Cluster analysis based on the Bray-Curtis index showed that samples were clustered by depth layer in FS and BS, indicating that structures of bacterial communities would diff er with increasing water depth in straits. Additionally, the cluster relationships among samples in abundant and rare communities were both similar to those in entire communities. However, the dissimilarities among samples showed a descending order as rare communities, entire communities and abundant communities. Network analysis indicated that the BS network was obviously more complex than the FS network. Filamentous bacteria Desulfobulbaceae exhibited high degree values in BS but not in FS, indicating key roles of Desulfobulbaceae in the BS. Our study provides different and common evidences for understanding microbial ecology in coastal shallow and oceanic deep straits.
基金financially supported by grants from the National Natural Science Foundation of China(41930643,42273084,and 41673077)Key Scientific Research Projects of Henan Province(21B180011)
文摘Background Soil erosion affects the stability of terrestrial ecosystems and ecosystem services by directly or indirectly impacting the cycling of soil materials and energy and reducing the fertility of grassland soils.However,research on microbial adaptation to grazing and soil erosion is limited,particularly in relation to grassland ecosystem restora-tion.Here,we assess microbial communities subjected to simulated soil erosion and grazing in a semi-arid grassland of Inner Mongolia,China.Results No significant change was observed in soil variables.However,the structure of the soil microbial commu-nity underwent significant changes as a result of soil erosion and soil erosion plus grazing,leading to a significant increase in the relative abundance of Cyanobacteria(116.80%vs 116.38%).Wind erosion and deposition contributed to an increase in the network complexity of soil bacterial and fungal communities.However,much of this effect was alleviated by grazing.Simultaneously,aeolian processes and grazing regulate soil microbial community assembly,leading to inconsistent patterns of change in bacterial and fungal communities.Under wind erosion and deposi-tion,the relative contribution of deterministic processes(4.44%vs 31.11%)in bacterial communities increased,while the relative contribution of stochastic processes(2.23%vs 20%)in fungal communities reduced.Grazing resulted in a decrease in the relative contribution of deterministic processes(8.89%)in the bacterial community and an increase in the relative contribution of stochastic processes(8.89%)in the fungal community.Conclusion This study presents a comprehensive investigation of the response of soil microbial communities to aeolian erosion–deposition and grazing in a semi-arid grassland.Our findings indicate that microbial communities in the semi-arid grassland show resistance to external disturbances and that light grazing mitigates the effects of aeo-lian erosion–deposition on microbial communities,which is essential for maintaining the stability and biodiversity of grassland ecosystems.
基金supported by the National Key Research and Development Program of China(2022YFD1901500/2022YFD1901501)National Natural Science Foundation of China(32372810,31872183)。
文摘2′-Deoxymugineic(DMA),a phytosiderophore secreted by Poaceae species,can improve iron nutrition in plants.However,little is known about how DMA influences beneficial bacteria in rhizosphere microecosystem.To address this gap,the DMA analog proline-2′-deoxymugineic(PDMA)was used to evaluate its positive effect on peanut rhizobacterial communities and network structure.This study demonstrated that PDMA can promote the absorption of several mineral nutrients in plants and activate micronutrients in the rhizosphere.Specifically,PDMA led to significant impact on the bacterial community structure in the peanut rhizosphere,resulting in a substantial increase in the relative abundance of Actinobacteriota with six beneficial rhizobacterial genera in this phylum.The Cellulosimicrobium and Marmoricola of Actinobacteriota recruited by PDMA may enhance micronutrient availability both to peanut plants and in soil.PDMA application led to the development of a tight,stable microbial network,as indicated by higher topological parameters and a greater variety of keystone genera.Functional prediction revealed that PDMA fosters microbial communication in the rhizosphere.Overall,PDMA was shown to recruit beneficial bacteria and to modulate bacterial network structure in the peanut rhizosphere.It is concluded that these findings demonstrate that phytosiderophore might promote plant growth and nutrition absorption by regulating plant–soil microecosystem.
文摘Soil microbial community's responses to climate warming alter the global carbon cycle.In temperate ecosystems,soil microbial communities function along seasonal cycles.However,little is known about how the responses of soil microbial communities to warming vary when the season changes.In this study,we investigated the seasonal dynamics of soil bacterial community under experimental warming in a temperate tall‐grass prairie ecosystem.Our results showed that warming significantly(p=0.001)shifted community structure,such that the differences of microbial communities between warming and control plots increased nonlinearly(R^(2)=0.578,p=0.021)from spring to winter.Also,warming significantly(p<0.050)increased microbial network complexity and robustness,especially during the colder seasons,despite large variations in network size and complexity in different seasons.In addition,the relative importance of stochastic processes in shaping the microbial community decreased by warming in fall and winter but not in spring and summer.Our study indicates that climate warming restructures the seasonal dynamics of soil microbial community in a temperate ecosystem.Such seasonality of microbial responses to warming may enlarge over time and could have significant impacts on the terrestrial carbon cycle.
基金supported by the National Natural Science Foundation of China(No.31870419)the National Key Research and Development Program of China(No.2016YFD0300203-4).
文摘The application of biochar to soil is widely recognized as a promising strategy for enhancing the accumulation and stability of soil organic carbon(SOC),which is crucial in mitigating climate change.However,the influence of interactions between plants and biochar on soil microbial communities and their involvement in SOC mineralization and stability remains unclear.This understanding is essential for optimizing carbon(C)sequestration in systems involving plants,soil,and biochar.In this study,employing a 13C natural abundance approach,we investigated the effect of biochar on the maize rhizosphere priming effect(RPE)in paddy soil.We also examined alterations in microbial communities and functional genes related to C degradation and fixation.Over the 99 days of maize growth,biochar application increased RPE and total SOC while decreasing dissolved organic C.It also elevated soil pH,resulting in shifts in fungal and bacterial community structure,favoring oligotrophic species.Fungal and bacterial assemblies were dominated by deterministic and stochastic processes,respectively.While the abundance of fungal guilds varied irregularly,bacterial guilds were uniformly enriched under biochar-plant interactions.Functional traits such as ecoenzymatic activities,bacterial guilds,and functional genes predominantly affected RPE under biochar application.Bacterial functional genes associated with C degradation and fixation were concurrently enhanced with biochar application.Our results indicate that interactions between plants and biochar can enhance native SOC mineralization and accumulation in a short timeframe by modulating functional traits of soil microorganisms,particularly the bacterial community involved in C degradation and fixation.
基金financially supported by grants from the National Natural Science Foundation of China (41930643 and 42273084)Natural Science Foundation of Henan Province (242300421039)Science and Technology Development Plan Project of Henan Province (242102110186)
文摘Background The temperate grasslands are facing numerous pressures from global change.Despite their essential ecological and economic role,how their microbial communities react to multiple varying factors remain obscure.In this study,we simulated three global change drivers,i.e.,nitrogen deposition(ambient N vs.elevated N,a N vs.e N),precipitation increase(ambient precipitation vs.elevated precipitation,a P vs.e P),and mowing,represented experimentally by clipping(unclipped vs.clipped,u C vs.CL),together in all possible combinations in a temperate semi-arid grassland ecosystem.Results Nitrogen addition had negative effects on the richness of bacterial and fungal communties,significantly changed their structures(P<0.05)and increased their dissimilarities(P<0.05),while water addition had positive effects on fungal and protist communities and significantly stimulated theα-diversity of protist communities under N addition without clipping,which was in contrast to the effect in clipped plots.Clipping had a marginal effect on fungal communities and significantly affected protist communities(P<0.05).A notable interactive effect of N and precipitation on the structure of bacterial communities and a significant interactive effect of clipping and precipitation on protists were found.Combination effects of N with precipitation or clipping on module aggregation of metanetworks were also observed between u C and CL,as well as a P and e P meta-networks.Bacterial,fungal,and protist communities varied in their assembly mechanisms,and their assembly processes differed in response to the three global change factors.Conclusions Overall,N,water addition,and clipping individually and/or interactively,in distinct degrees,altered soil microbial interaction,community structure,and the potential function in a semi-arid steppe.These findings enhance our understanding of soil microbial community assembly and provide a scientific basis for managing temperate grasslands,particularly in the context of global change's impact on ecosystem function and stability.
