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
Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a po...Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a potential role during this critical transitional period.However,its involvement in post-weaning diarrhea remains poorly understood.Here,we aim to elucidate the role and underlying mechanisms of Prevotella in alleviating diarrhea in weaned piglets.Results To model unsanitary housing conditions,piglets were housed in uncleaned pens containing residual fecal matter from previous occupants and exposed to cold stress by maintaining the ambient temperature at 19℃,below the optimal 28℃.Under these conditions,piglets were orally administered either a blank medium(CON,n=10×2)or Prevotella copri at 1×10^(8)CFU(Pc,n=10×2)on d 1,3,and 5.After 28 d,cold stress induced a diarrhea incidence of 33.45%in the CON group,while P.copri supplementation significantly reduced the diarrhea rate to 19.73%.Treatment with P.copri markedly improved intestinal morphology in the small intestine,decreased serum levels of lipopolysaccharide(LPS)and intestinal fatty acid-binding protein(i-FABP),and enhanced total antioxidant capacity(T-AOC)and catalase(CAT)activity.Quantitative PCR and 16S rRNA gene sequencing revealed that P.copri significantly increased the colonic abundance of Prevotella,reshaping both the composition and functional profile of the gut microbiota.Moreover,P.copri enhanced the modularity and robustness of microbial ecological networks.Untargeted metabolomic profiling of colonic contents revealed a significant enrichment of metabolites involved in the arachidonic acid pathway following P.copri supplementation.In parallel,untargeted metabolomics of P.copri culture supernatants identified differential metabolic pathways including metabolic pathways,biosynthesis of secondary metabolites,and biosynthesis of antibiotics.In vitro assays demonstrated that P.copri-derived metabolites inhibited the growth of three common porcine intestinal pathogens.Furthermore,both P.copri metabolites and arachidonic acid enhanced intestinal barrier integrity and suppressed TNF-α-induced inflammation and apoptosis in Caco-2 cells through activation of the AHR–Nrf2 signaling pathway.Conclusions These findings highlight the role of P.copri in maintaining gut homeostasis and provide new insights into microbiota-based interventions for early-life intestinal disorders.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
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 National Natural Science Foundation of China(31730091,32372900,32072743)Natural Science Foundation of Sichuan Province(2023NSFSC0237)Major Science and Technology Projects in Sichuan Province(2021ZDZX0009)。
文摘Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a potential role during this critical transitional period.However,its involvement in post-weaning diarrhea remains poorly understood.Here,we aim to elucidate the role and underlying mechanisms of Prevotella in alleviating diarrhea in weaned piglets.Results To model unsanitary housing conditions,piglets were housed in uncleaned pens containing residual fecal matter from previous occupants and exposed to cold stress by maintaining the ambient temperature at 19℃,below the optimal 28℃.Under these conditions,piglets were orally administered either a blank medium(CON,n=10×2)or Prevotella copri at 1×10^(8)CFU(Pc,n=10×2)on d 1,3,and 5.After 28 d,cold stress induced a diarrhea incidence of 33.45%in the CON group,while P.copri supplementation significantly reduced the diarrhea rate to 19.73%.Treatment with P.copri markedly improved intestinal morphology in the small intestine,decreased serum levels of lipopolysaccharide(LPS)and intestinal fatty acid-binding protein(i-FABP),and enhanced total antioxidant capacity(T-AOC)and catalase(CAT)activity.Quantitative PCR and 16S rRNA gene sequencing revealed that P.copri significantly increased the colonic abundance of Prevotella,reshaping both the composition and functional profile of the gut microbiota.Moreover,P.copri enhanced the modularity and robustness of microbial ecological networks.Untargeted metabolomic profiling of colonic contents revealed a significant enrichment of metabolites involved in the arachidonic acid pathway following P.copri supplementation.In parallel,untargeted metabolomics of P.copri culture supernatants identified differential metabolic pathways including metabolic pathways,biosynthesis of secondary metabolites,and biosynthesis of antibiotics.In vitro assays demonstrated that P.copri-derived metabolites inhibited the growth of three common porcine intestinal pathogens.Furthermore,both P.copri metabolites and arachidonic acid enhanced intestinal barrier integrity and suppressed TNF-α-induced inflammation and apoptosis in Caco-2 cells through activation of the AHR–Nrf2 signaling pathway.Conclusions These findings highlight the role of P.copri in maintaining gut homeostasis and provide new insights into microbiota-based interventions for early-life intestinal disorders.
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.
