The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of China.Two common mulching methods to conserve soil moisture,ridge furrows with plastic film mulching (RP) and flat soil surf...The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of China.Two common mulching methods to conserve soil moisture,ridge furrows with plastic film mulching (RP) and flat soil surfaces with plastic film mulching (FP) are helpful for wheat production.Our previous study indicated that FP could improve wheat yield more effectively than RP,but the reason remains unclear.The effect of mulching method on functional bacteria also needs to be further studied.In this study,winter wheat was employed to evaluate the impacts of mulching method on soil temperature,moisture content,microorganisms and grain yield.The results showed that FP had a warming effect when the soil temperature was low and a cooling effect when the temperature was too high.However,the ability to regulate soil temperature in the RP method was unstable and varied with year.The lowest negative accumulated soil temperature was found in the FP treatment,which was 20–89 and 43–99%lower than that of the RP and flat sowing with non-film mulching control (NP) treatments,respectively.Deep soil moisture was better transferred to topsoil for wheat growth in the FP and RP treatments than the NP treatment,which made the topsoil moisture in the two treatments (especially FP) more sufficient than that in the NP treatment during the early growing stage of wheat.However,due to the limited water resources in the study area,there was almost no difference between treatments in topsoil water storage during the later stage.The wheat yield in the FP treatment was significantly higher,by 12–16and 23–56%,respectively,than in the RP and NP treatments.Significant positive correlations were observed among the negative accumulated soil temperature,spike number and wheat yield.The Chao1 and Shannon indices in the RP treatment were 17 and 3.9%higher than those in the NP treatment,respectively.However,according to network relationship analysis,the interspecific relationships of bacteria were weakened in the RP treatment.Phosphorus solubilizing,ammonification and nitrification bacteria were more active in the RP than in the FP treatment,and microbes with nitrate reduction ability and plant pathogens were inhibited in the RP treatment,which improved nutrient availability and habitat for wheat.展开更多
In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in de...In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in degrading organic pollutants at the bottom of shrimp ponds, were studied. The results showed that the favorable fermentation medium (per L) was 25 g of peptone, 5 g of yeast extract, and 0.2 g of ferric phosphate, and the initial pH value of the medium was 8.0. The optimum fermentation time was 20 h. The optimum stirring way was stirring one hour after one hour. Iso-electric point sedimentation collecting method was the most efficient and economic method to collect the bacteria cells after fermentation, with the optimum sediment pH of 3.67, 4.02, and 3.40 for the strains Lt7222, Gy7018 and Lt7511,respectively. It was also indicated that the survival and reproducing ability of the bacterial cells were not affected by the sedimentation process.展开更多
Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater sa...Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater samples in outer coral reef flats and semi-closed inner lagoons from the surface,middle and bottom layers in the pristine coral-reef system of Xisha Islands,South China Sea.We detected the abundance,composition and distribution of bacteria and microeukaryotes using flow cytometry,qPCR and high throughput sequencing techniques,and profiled the potential ecological roles based on the information of 16S and 18S rDNA sequencing.In terms of flow cytometry,Prochlorococcus dominated the autotrophs with cell abundance ranging from 5.8×10^(2)to 5.44×10^(3)cells mL−1 seawater.Based on qPCR,the 16S rDNA copies were much higher in coral reef flats than in lagoons(P=0.003).The bacterial communities held significantly lower diversity in bottom waters compared with surface and middle waters(P<0.05),which were dominated by SAR11,Flavobacteriales,and Synechococcus.Alveolata represented most of the microeukaryotic communities with Dinophyceae and Syndiniales well represented in all samples.Neither bacterial nor microeukaryotic community exhibited distinct layer or niche pattern,however,Haptophyta and Picozoa decreased with depth and SAR 86,MAST-3 and Picozoa were enriched in lagoons(P<0.05).To adapt the nutrient-poor and organic matter-rich environment,bacterial nitrogen fixation and assimilatory/dissimilatory nitrate reduction were active in the system,and mixotrophy was the most important trophic strategy among microeukaryotes.The study highlighted the ecological adaptability of seawater microbes to the unique coral-reef environments.展开更多
After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different...After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single -strain groups. Three-strain groups are better than two-strain groups, and four-strain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1 % in 114 h. It is suggested that multi-species bacteria be used as functional bacteria in bioremediation of mariculture environment.展开更多
Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clos...Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.展开更多
AIM: To investigate the protective effects of combinations of probiotic (Bifico) on interleukin (IL)-10-gene-deficient (IL-10 KO) mice and Caco-2 cell monolayers.
A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic anal...A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus(47.8% of the total number of endophytic isolates). These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid(IAA) on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia's(PKO) liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.展开更多
Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modu...Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.展开更多
Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing act...Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.展开更多
Biological desilication process is an effective way to remove silicate from rutile so that high purity rutile could be obtained. However, little is known about the molecular mechanism of this process. In this work, a ...Biological desilication process is an effective way to remove silicate from rutile so that high purity rutile could be obtained. However, little is known about the molecular mechanism of this process. In this work, a newly developed rutile bio-desilication reactor was applied to enrich rutile from rough rutile concentrate obtained from Nanzhao rutile mine and a comprehensive high through-put functional gene array(Geo Chip 4.0) was used to analyze the functional gene diversity, structure and metabolic potential of microbial communities in the biological desilication reactor. The results show that TiO2 grade of the rutile concentrate could increase from 78.21% to above 90% and the recovery rate could reach to 96% or more in 8-12 d. The results also show that almost all the key functional genes involved in the geochemical cycling process, totally 4324 and 4983 functional microorganism genes, are detected in the liquid and ore surface, respectively. There are totally 712 and 831 functional genes involved in nitrogen cycling for liquid and ore surface samples, respectively. The relative abundance of functional genes involved in the phosphorus and sulfur cycling is higher in the ore surface than liquid. These results indicate that nitrogen, phosphorus and sulfur cycling are also present in the desiliconization process of rutile. Acetogenesis genes are detected in the liquid and ore surface, which indicates that the desiliconizing process mainly depends on the function of acetic acid and other organic acids. Four silicon transporting genes are also detected in the sample, which proves that the bacteria have the potential to transfer silicon in the molecule level. It is shown that bio-desilication is an effective and environmental-friendly way for enrichment of rough rutile concentrate and presents an overview of functional diversity and structure of desilication microbial communities, which also provides insights into our understanding of metabolic potential in biological desilication reactor ecosystems.展开更多
BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive...BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.展开更多
Magnetotactic bacteria is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. A magnetotactic bacteria optimization algori...Magnetotactic bacteria is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. A magnetotactic bacteria optimization algorithm(MBOA) inspired by the characteristics of magnetotactic bacteria is researched in the paper. Experiment results show that the MBOA is effective in function optimization problems and has good and competitive performance compared with the other classical optimization algorithms.展开更多
构建光序批式反应器(PSBR)处理模拟生活污水,考察光合细菌投加量、pH值、光照强度和溶解氧(DO)对反应器污染物去除性能影响,通过16S r RNA测序技术揭示光合细菌对活性污泥微生物群落结构、功能和氮代谢通路的影响.结果表明:10%光合细菌...构建光序批式反应器(PSBR)处理模拟生活污水,考察光合细菌投加量、pH值、光照强度和溶解氧(DO)对反应器污染物去除性能影响,通过16S r RNA测序技术揭示光合细菌对活性污泥微生物群落结构、功能和氮代谢通路的影响.结果表明:10%光合细菌投加通过促进微生物种间协调功能使PSBR系统CODCr、NH_(4)^(+)-N和TN去除率提高,pH值、光照强度和DO分别为7、5000lux和3mg/L时,PSBR脱氮性能最好.光合细菌提高了活性污泥微生物多样性和丰富度,Proteobacteria菌门和norank_f__Saprospiraceae菌属相对丰度增多.光合细菌促进部分参与硝化过程和反硝化过程的功能基因(amo、hao和nap)和酶(AMO、HAO和NAP)丰度增加,活性污泥的整体氮代谢潜力得到提升.展开更多
基金supported by the State Key Laboratory of Integrative Sustainable Dryland Agriculture (in preparation)Shanxi Agricultural University, China (202105D121008)+1 种基金the National Natural Science Foundation of China (42007121)the National Key R&D Program of China (2021YFD1900700)。
文摘The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of China.Two common mulching methods to conserve soil moisture,ridge furrows with plastic film mulching (RP) and flat soil surfaces with plastic film mulching (FP) are helpful for wheat production.Our previous study indicated that FP could improve wheat yield more effectively than RP,but the reason remains unclear.The effect of mulching method on functional bacteria also needs to be further studied.In this study,winter wheat was employed to evaluate the impacts of mulching method on soil temperature,moisture content,microorganisms and grain yield.The results showed that FP had a warming effect when the soil temperature was low and a cooling effect when the temperature was too high.However,the ability to regulate soil temperature in the RP method was unstable and varied with year.The lowest negative accumulated soil temperature was found in the FP treatment,which was 20–89 and 43–99%lower than that of the RP and flat sowing with non-film mulching control (NP) treatments,respectively.Deep soil moisture was better transferred to topsoil for wheat growth in the FP and RP treatments than the NP treatment,which made the topsoil moisture in the two treatments (especially FP) more sufficient than that in the NP treatment during the early growing stage of wheat.However,due to the limited water resources in the study area,there was almost no difference between treatments in topsoil water storage during the later stage.The wheat yield in the FP treatment was significantly higher,by 12–16and 23–56%,respectively,than in the RP and NP treatments.Significant positive correlations were observed among the negative accumulated soil temperature,spike number and wheat yield.The Chao1 and Shannon indices in the RP treatment were 17 and 3.9%higher than those in the NP treatment,respectively.However,according to network relationship analysis,the interspecific relationships of bacteria were weakened in the RP treatment.Phosphorus solubilizing,ammonification and nitrification bacteria were more active in the RP than in the FP treatment,and microbes with nitrate reduction ability and plant pathogens were inhibited in the RP treatment,which improved nutrient availability and habitat for wheat.
文摘In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in degrading organic pollutants at the bottom of shrimp ponds, were studied. The results showed that the favorable fermentation medium (per L) was 25 g of peptone, 5 g of yeast extract, and 0.2 g of ferric phosphate, and the initial pH value of the medium was 8.0. The optimum fermentation time was 20 h. The optimum stirring way was stirring one hour after one hour. Iso-electric point sedimentation collecting method was the most efficient and economic method to collect the bacteria cells after fermentation, with the optimum sediment pH of 3.67, 4.02, and 3.40 for the strains Lt7222, Gy7018 and Lt7511,respectively. It was also indicated that the survival and reproducing ability of the bacterial cells were not affected by the sedimentation process.
基金the National Key Research and Development Program of China(No.2018YF C1406501)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050303)+1 种基金the National Natural Science Foundation of China(Nos.41676154,41976115)the Key Research Program of Frontier Sciences of CAS(Nos.QYZDB-SSW-DQC013,QYZ DB-SSW-DQC041)。
文摘Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater samples in outer coral reef flats and semi-closed inner lagoons from the surface,middle and bottom layers in the pristine coral-reef system of Xisha Islands,South China Sea.We detected the abundance,composition and distribution of bacteria and microeukaryotes using flow cytometry,qPCR and high throughput sequencing techniques,and profiled the potential ecological roles based on the information of 16S and 18S rDNA sequencing.In terms of flow cytometry,Prochlorococcus dominated the autotrophs with cell abundance ranging from 5.8×10^(2)to 5.44×10^(3)cells mL−1 seawater.Based on qPCR,the 16S rDNA copies were much higher in coral reef flats than in lagoons(P=0.003).The bacterial communities held significantly lower diversity in bottom waters compared with surface and middle waters(P<0.05),which were dominated by SAR11,Flavobacteriales,and Synechococcus.Alveolata represented most of the microeukaryotic communities with Dinophyceae and Syndiniales well represented in all samples.Neither bacterial nor microeukaryotic community exhibited distinct layer or niche pattern,however,Haptophyta and Picozoa decreased with depth and SAR 86,MAST-3 and Picozoa were enriched in lagoons(P<0.05).To adapt the nutrient-poor and organic matter-rich environment,bacterial nitrogen fixation and assimilatory/dissimilatory nitrate reduction were active in the system,and mixotrophy was the most important trophic strategy among microeukaryotes.The study highlighted the ecological adaptability of seawater microbes to the unique coral-reef environments.
基金The paper is supported by the national high-technology development project (819-02-07) and the project of NSFC (30200209).
文摘After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single -strain groups. Three-strain groups are better than two-strain groups, and four-strain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1 % in 114 h. It is suggested that multi-species bacteria be used as functional bacteria in bioremediation of mariculture environment.
文摘Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.
基金Supported by The National Natural Science Foundation Key Projects of China,No.81230057National Natural Science Foundation of China,No.81172325The Major Basic Research Program of Shanghai,No.12DZ1930502
文摘AIM: To investigate the protective effects of combinations of probiotic (Bifico) on interleukin (IL)-10-gene-deficient (IL-10 KO) mice and Caco-2 cell monolayers.
基金the National Natural Science Foundation of China(31160122)the Key Laboratory of Grassland Ecosystem(Gansu Agricultural University),Ministry of Education(CYzs-2011011)for financial support
文摘A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus(47.8% of the total number of endophytic isolates). These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid(IAA) on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia's(PKO) liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.
基金supported by the National Natural Science Foundation of China(31972636,31672508,31790411 and 31802103)the National Key Research and Development Program of China(2017YFD0500501)+1 种基金the Guangdong Key Areas Research and Development Project(2019B020218001)the Provincial Agricultural Science and Technology Innovation Promotion and Agricultural Resources and Ecological Environmental Protection Construction Project(2021KJ266).
文摘Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.
基金Supported by the Scientifi c Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(MNR)(Nos.JB1906,JG1616,JG1910)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)+4 种基金the Key Projects of Philosophy and Social Sciences Research,Ministry of Education(No.18JZD059)the National Key Technology Research and Development Program of the Ministry of Science and Technology of the China(No.2015BAD08B01)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the National Natural Science Foundation of China(No.41806136)the Project of Long Term Observation and Research Plan in the Changjiang Estuary and the Adjacent East China Sea(LORCE,14282)。
文摘Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.
基金Project(2011-622-40) supported by the Mineral Exploration Foundation of Henan Province,ChinaProject(51104189) supported by the National Natural Science Foundation of ChinaProject(2013M531814) supported by the Postdoctoral Science Foundation of China
文摘Biological desilication process is an effective way to remove silicate from rutile so that high purity rutile could be obtained. However, little is known about the molecular mechanism of this process. In this work, a newly developed rutile bio-desilication reactor was applied to enrich rutile from rough rutile concentrate obtained from Nanzhao rutile mine and a comprehensive high through-put functional gene array(Geo Chip 4.0) was used to analyze the functional gene diversity, structure and metabolic potential of microbial communities in the biological desilication reactor. The results show that TiO2 grade of the rutile concentrate could increase from 78.21% to above 90% and the recovery rate could reach to 96% or more in 8-12 d. The results also show that almost all the key functional genes involved in the geochemical cycling process, totally 4324 and 4983 functional microorganism genes, are detected in the liquid and ore surface, respectively. There are totally 712 and 831 functional genes involved in nitrogen cycling for liquid and ore surface samples, respectively. The relative abundance of functional genes involved in the phosphorus and sulfur cycling is higher in the ore surface than liquid. These results indicate that nitrogen, phosphorus and sulfur cycling are also present in the desiliconization process of rutile. Acetogenesis genes are detected in the liquid and ore surface, which indicates that the desiliconizing process mainly depends on the function of acetic acid and other organic acids. Four silicon transporting genes are also detected in the sample, which proves that the bacteria have the potential to transfer silicon in the molecule level. It is shown that bio-desilication is an effective and environmental-friendly way for enrichment of rough rutile concentrate and presents an overview of functional diversity and structure of desilication microbial communities, which also provides insights into our understanding of metabolic potential in biological desilication reactor ecosystems.
基金Supported by the Key-Area Research and Development Program of Guangdong Province,No.2022B1111070006the Guangdong Innovation Research Team for Higher Education,No.2021KCXTD025.
文摘BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.
文摘Magnetotactic bacteria is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. A magnetotactic bacteria optimization algorithm(MBOA) inspired by the characteristics of magnetotactic bacteria is researched in the paper. Experiment results show that the MBOA is effective in function optimization problems and has good and competitive performance compared with the other classical optimization algorithms.
文摘构建光序批式反应器(PSBR)处理模拟生活污水,考察光合细菌投加量、pH值、光照强度和溶解氧(DO)对反应器污染物去除性能影响,通过16S r RNA测序技术揭示光合细菌对活性污泥微生物群落结构、功能和氮代谢通路的影响.结果表明:10%光合细菌投加通过促进微生物种间协调功能使PSBR系统CODCr、NH_(4)^(+)-N和TN去除率提高,pH值、光照强度和DO分别为7、5000lux和3mg/L时,PSBR脱氮性能最好.光合细菌提高了活性污泥微生物多样性和丰富度,Proteobacteria菌门和norank_f__Saprospiraceae菌属相对丰度增多.光合细菌促进部分参与硝化过程和反硝化过程的功能基因(amo、hao和nap)和酶(AMO、HAO和NAP)丰度增加,活性污泥的整体氮代谢潜力得到提升.