[KG(0.01mm]This study focuses on the community structure of aggregated bacteria in Lake Baikal and relationships with free-living bacteria. Fluorescent in situ hybridization (FISH) methods were used in samples of bact...[KG(0.01mm]This study focuses on the community structure of aggregated bacteria in Lake Baikal and relationships with free-living bacteria. Fluorescent in situ hybridization (FISH) methods were used in samples of bacteria taken in April, 2001. Bacterial counts of free-living bacteria by DAPI staining ranged from 0.2×10 6 to 3.2×10 6 cells·mL -1, decreasing with depth, whereas aggregated bacterial numbers dramatically increased with depth, ranging from 0.4×10 4 to 3.3×10 4 cells·mL -1. Ratios of EUB probe binding cells to DAPI counts ranged from 52.3 to 74.1% in free-living bacteria and from 39.6 to 66.7% in aggregated bacteria, respectively. Community composition of aggregated bacteria was very different from free-living bacteria, especially at 25m depth where highest phytoplankton numbers were observed. The vertical profile of aggregated bacteria community was very characteristic. Beta-Proteobacteria increased with depth down to 100m. At 250m, gamma-Proteobacteria was 44% of DAPI bound cells, while other groups were less than 1%. We conclude that community structures of free-living and aggregated bacteria were different, and they may sustain the ecosystem in independent ways.展开更多
【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact ...【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact of this soaking method on the fungal and bacterial community structures using next-generation sequencing technology(NGS).【Methods】Lily bulbs were soaked in a seed treating agent containing beneficial microbes(SP treatment)for 4 hours.Subsequently,they were planted in soil in July and sampled in September to assess plant growth,rhizosphere soil physicochemical properties,and microorganism community structures.In addition,we employed the software PICRUSt and FUNGuild to predict bacterial pathways and fungal functions.【Results】Under SP treatment,there were significant alterations in fungi and bacteria community structures,accompanied by improved soil nutrient status.Notably,the relative abundance of dominant microorganism groups,such as the fungi Basidiomycota,Pseudeurotium,Cladophialophora,Microascus,and Dactylonectria,as well as the bacteria Proteobacteria,Chloroflexi,Ochrobactrium,Lysobacter,and RB41,underwent notable changes.Microorganism function prediction results indicated a reduction in pathotrophic fungi(including plant pathogens)and an increase in endophytic and saprotrophic fungi under SP treatment.Among the top 20 metabolism pathways,80%were upregulated in SP treatment compared to the CK.【Conclusions】Seed soaking with beneficial microbial strain promotes the growth of Lanzhou lily bulbs.The beneficial microorganisms play a crucial role in regulating soil microbial structures,enhancing the accumulation of endophytic fungi,reducing the abundance of pathogens,and improving soil functions.Furthermore,specific microbial groups are found to be involved in maintaining soil health.展开更多
[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of...[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of fish resources and the characteristics of their diversity is crucial for the ecological management of the Pinglu Canal.[Methods]During the spring and autumn in 2021 and 2022,a survey of fish resources and species diversity in the Pinglu Canal was conducted using multi-mesh gill nets.A total of 125 fish species were collected,belonging to 10 orders,34 families,and 89 genera.[Results]The result showed that the Pinglu Canal contained three nationally protected Class II species,two endemic species of the Qinjiang River,three anadromous/migratory species,and eight invasive species,accounting for 2.4%,1.6%,2.4%,and 6.4%of the total species,respectively.The fish community primarily consisted of mid-and bottom-dwelling,adhesive-egg-laying,and omnivorous species.The Shannon-Wiener,Simpson,Margalef,and Pielou indices of the fish community in the Pinglu Canal ranged from 2.347 to 2.757,0.081 to 0.151,3.493 to 4.382,and 0.812 to 0.892,respectively.These indices showed relatively uniform distribution across different river reaches.[Conclusion]The result indicate that the fish community structure in the Pinglu Canal is relatively uniform.The reach from the Yujiang River to the Shaping River shows higher stability,while other river reaches experience moderate or severe disturbances.This study provides supplementary baseline data on the fish community structure in the Pinglu Canal and explores the potential impact of inter-basin connectivity on fish resources,aiming to provide a scientific basis for habitat restoration assessments after the channel straightening project.展开更多
Eleven acid mine drainage （AMD） samples were obtained from southeast of China for the analysis of the microbial communities diversity, and the relationship with geochemical variables and spatial distance by using a ...Eleven acid mine drainage （AMD） samples were obtained from southeast of China for the analysis of the microbial communities diversity, and the relationship with geochemical variables and spatial distance by using a culture-independent 16S rDNA gene phylogenetic analysis approach and multivariate analysis respectively. The principle component analysis （PCA） of geochemical variables shows that eleven AMDs can be clustered into two groups, relative high and low metal rich （RHMR and RLMR） AMDs. Total 1691 clone sequences are obtained and the detrended correspondence analysis （DCA） of operational taxonomic units （OTUs） shows that, ~,-Proteobacteria, Acidobacteria, Actinobacteria, Cyanobacteria, Firmicutes and Nitrospirae are dominant species in RHMR AMDs. In contrast, a-Proteobacteria, fl-Proteobacteria, Planctomycetes and Bacteriodetes are dominant species in RLMR AMD. Results also show that high-abundance putative iron-oxidizing and only putative sulfur-oxidizing microorganisms are found in RHMR AMD. Multivariate analysis shows that both geochemical variables （r=0.429 3, P=-0.037 7） and spatial distance （r=0.321 3, P=-0.018 1） are significantly positively correlated with microbial community and pH, Mg, Fe, S, Cu and Ca are key geochemistry factors in shaping microbial community. Variance partitioning analysis shows that geochemical variables and spatial distance can explain most （92%） of the variation.展开更多
基金the Korea Science and Engineering Foundation(2002-201-02-2)
文摘[KG(0.01mm]This study focuses on the community structure of aggregated bacteria in Lake Baikal and relationships with free-living bacteria. Fluorescent in situ hybridization (FISH) methods were used in samples of bacteria taken in April, 2001. Bacterial counts of free-living bacteria by DAPI staining ranged from 0.2×10 6 to 3.2×10 6 cells·mL -1, decreasing with depth, whereas aggregated bacterial numbers dramatically increased with depth, ranging from 0.4×10 4 to 3.3×10 4 cells·mL -1. Ratios of EUB probe binding cells to DAPI counts ranged from 52.3 to 74.1% in free-living bacteria and from 39.6 to 66.7% in aggregated bacteria, respectively. Community composition of aggregated bacteria was very different from free-living bacteria, especially at 25m depth where highest phytoplankton numbers were observed. The vertical profile of aggregated bacteria community was very characteristic. Beta-Proteobacteria increased with depth down to 100m. At 250m, gamma-Proteobacteria was 44% of DAPI bound cells, while other groups were less than 1%. We conclude that community structures of free-living and aggregated bacteria were different, and they may sustain the ecosystem in independent ways.
文摘【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact of this soaking method on the fungal and bacterial community structures using next-generation sequencing technology(NGS).【Methods】Lily bulbs were soaked in a seed treating agent containing beneficial microbes(SP treatment)for 4 hours.Subsequently,they were planted in soil in July and sampled in September to assess plant growth,rhizosphere soil physicochemical properties,and microorganism community structures.In addition,we employed the software PICRUSt and FUNGuild to predict bacterial pathways and fungal functions.【Results】Under SP treatment,there were significant alterations in fungi and bacteria community structures,accompanied by improved soil nutrient status.Notably,the relative abundance of dominant microorganism groups,such as the fungi Basidiomycota,Pseudeurotium,Cladophialophora,Microascus,and Dactylonectria,as well as the bacteria Proteobacteria,Chloroflexi,Ochrobactrium,Lysobacter,and RB41,underwent notable changes.Microorganism function prediction results indicated a reduction in pathotrophic fungi(including plant pathogens)and an increase in endophytic and saprotrophic fungi under SP treatment.Among the top 20 metabolism pathways,80%were upregulated in SP treatment compared to the CK.【Conclusions】Seed soaking with beneficial microbial strain promotes the growth of Lanzhou lily bulbs.The beneficial microorganisms play a crucial role in regulating soil microbial structures,enhancing the accumulation of endophytic fungi,reducing the abundance of pathogens,and improving soil functions.Furthermore,specific microbial groups are found to be involved in maintaining soil health.
文摘[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of fish resources and the characteristics of their diversity is crucial for the ecological management of the Pinglu Canal.[Methods]During the spring and autumn in 2021 and 2022,a survey of fish resources and species diversity in the Pinglu Canal was conducted using multi-mesh gill nets.A total of 125 fish species were collected,belonging to 10 orders,34 families,and 89 genera.[Results]The result showed that the Pinglu Canal contained three nationally protected Class II species,two endemic species of the Qinjiang River,three anadromous/migratory species,and eight invasive species,accounting for 2.4%,1.6%,2.4%,and 6.4%of the total species,respectively.The fish community primarily consisted of mid-and bottom-dwelling,adhesive-egg-laying,and omnivorous species.The Shannon-Wiener,Simpson,Margalef,and Pielou indices of the fish community in the Pinglu Canal ranged from 2.347 to 2.757,0.081 to 0.151,3.493 to 4.382,and 0.812 to 0.892,respectively.These indices showed relatively uniform distribution across different river reaches.[Conclusion]The result indicate that the fish community structure in the Pinglu Canal is relatively uniform.The reach from the Yujiang River to the Shaping River shows higher stability,while other river reaches experience moderate or severe disturbances.This study provides supplementary baseline data on the fish community structure in the Pinglu Canal and explores the potential impact of inter-basin connectivity on fish resources,aiming to provide a scientific basis for habitat restoration assessments after the channel straightening project.
基金Project(2010CB630901) supported by the National Basic Research Program of ChinaProject(50621063) supported by Creative Research Group of China+2 种基金Projects(51104189, 50321402, 50774102) supported by the National Natural Science Foundation of ChinaProject (1343-77341) supported by the Graduate Education Innovative Program of Central South University, ChinaProject(DOE-ER64125) supported by the Department of Energy, Office of Science under the Environmental Remediation Science Program of USA
文摘Eleven acid mine drainage （AMD） samples were obtained from southeast of China for the analysis of the microbial communities diversity, and the relationship with geochemical variables and spatial distance by using a culture-independent 16S rDNA gene phylogenetic analysis approach and multivariate analysis respectively. The principle component analysis （PCA） of geochemical variables shows that eleven AMDs can be clustered into two groups, relative high and low metal rich （RHMR and RLMR） AMDs. Total 1691 clone sequences are obtained and the detrended correspondence analysis （DCA） of operational taxonomic units （OTUs） shows that, ~,-Proteobacteria, Acidobacteria, Actinobacteria, Cyanobacteria, Firmicutes and Nitrospirae are dominant species in RHMR AMDs. In contrast, a-Proteobacteria, fl-Proteobacteria, Planctomycetes and Bacteriodetes are dominant species in RLMR AMD. Results also show that high-abundance putative iron-oxidizing and only putative sulfur-oxidizing microorganisms are found in RHMR AMD. Multivariate analysis shows that both geochemical variables （r=0.429 3, P=-0.037 7） and spatial distance （r=0.321 3, P=-0.018 1） are significantly positively correlated with microbial community and pH, Mg, Fe, S, Cu and Ca are key geochemistry factors in shaping microbial community. Variance partitioning analysis shows that geochemical variables and spatial distance can explain most （92%） of the variation.
