Multicellular organisms use chemical messengers to transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids are excellent candidates for this signaling purpose. In mo...Multicellular organisms use chemical messengers to transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids are excellent candidates for this signaling purpose. In most proteins, palmitic acid and other saturated and some unsaturated fatty acids are esterified to the free thiol of cysteines and to the N-amide terminal. This palmitoylation process enhances the surface hydrophobicity and membrane affinity of protein substrates and plays important roles in modulating proteins’ trafficking, stability, and sorting etc. Protein palmitoylation has been involved in numerous cellular processes, including signaling, apoptosis, and neuronal transmission. The palmitoylation process is involved in multiple diseases such as Huntington’s disease, various cardiovascular and T-cell mediated immune disorders, as well as cancer. Protein palmitoylation through the thioester (S-acylation) is unique in that it is the only reversible lipid modification. Our study on lipopolysaccharide (LPS) and deoxynivalenol (DON) treatment to rats provides some insights to the complex role of protein palmitoylation in chemical and microbial toxicity. In contrast, myrisoylated proteins contain the 14-carbon fatty acid myristate attached via amide linkage to the N-terminal glycine residue of protein, and occur cotranslationally. The bacterial outer membrane enzyme lipid A palmitoyltransferase (PagP) confers resistance to host immune defenses by transferring a palmitate chain from a phospholipid to the lipid A component of LPS. PagP is sensitive to cationic antimicrobial peptides (CAMP) which are included among the products of the Toll-like receptor 4 (TLR4) signal transduction pathway. This modification of lipid A with a palmitate appears to both and protects the pathogenic bacteria from host immune defenses and attenuates the activation of those same defenses through the TLR4 signal transduction pathway.展开更多
Parkinson’s disease(PD)is a complicated neurodegenerative disease,characterized by the accumulation ofα-synuclein(α-syn)in Lewy bodies and neurites,and massive loss of midbrain dopamine neurons.Increasing evidence ...Parkinson’s disease(PD)is a complicated neurodegenerative disease,characterized by the accumulation ofα-synuclein(α-syn)in Lewy bodies and neurites,and massive loss of midbrain dopamine neurons.Increasing evidence suggests that gut microbiota and microbial metabolites are involved in the development of PD.Among these,short-chain fatty acids(SCFAs),the most abundant microbial metabolites,have been proven to play a key role in brain-gut communication.In this review,we analyze the role of SCFAs in the pathology of PD from multiple dimensions and summarize the alterations of SCFAs in PD patients as well as their correlation with motor and non-motor symptoms.Future research should focus on further elucidating the role of SCFAs in neuroinflammation,as well as developing novel strategies employing SCFAs and their derivatives to treat PD.展开更多
A mounting body of evidence indicates that dietary fiber(DF)metabolites produced by commensal bacteria play essential roles in balancing the immune system.DF,considered nonessential nutrients in the past,is now consid...A mounting body of evidence indicates that dietary fiber(DF)metabolites produced by commensal bacteria play essential roles in balancing the immune system.DF,considered nonessential nutrients in the past,is now considered to be necessary to maintain adequate levels of immunity and suppress inflammatory and allergic responses.Short-chain fatty acids(SCFAs),such as acetate,propionate,and butyrate,are the major DF metabolites and mostly produced by specialized commensal bacteria that are capable of breaking down DF into simpler saccharides and further metabolizing the saccharides into SCFAs.SCFAs act on many cell types to regulate a number of important biological processes,including host metabolism,intestinal functions,and immunity system.This review specifically highlights the regulatory functions of DF and SCFAs in the immune system with a focus on major innate and adaptive lymphocytes.Current information regarding how SCFAs regulate innate lymphoid cells,T helper cells,cytotoxic T cells,and B cells and how these functions impact immunity,inflammation,and allergic responses are discussed.展开更多
Effects of sludge age on volatile fatty acids (VFAs) production and Phosphorus (P) release during anaerobic acidification of waste activated sludge (WAS) were investigated.Sequencing batch reactors (SBR) fed with simu...Effects of sludge age on volatile fatty acids (VFAs) production and Phosphorus (P) release during anaerobic acidification of waste activated sludge (WAS) were investigated.Sequencing batch reactors (SBR) fed with simulating domestic sewage were applied to produce WAS of different sludge ages,and batch tests were used for anaerobic acidification.The maximum dissolved total organic carbon,release of PO_(4)^(3+)-P,and accumulation of acetate (C2),propionate (C3),butyrate (C4),and valerate (C5) decreased by 56.2%,55.8%,52.6%,43.7%,82.4%and 84.8%,respectively,as the sludge age of WAS increased from 5 to 40 days.Limited degradation of protein played a dominating role in decreasing DTOC and VFAs production.Moreover,the increase in molecular weight of organics and organic nitrogen content in the supernatant after acidification suggested that the refractory protein in WAS increased as sludge age extended.Although the production of C2,C3,C4,and C5 from WAS decreased as the sludge age increased,the proportions of C2 and C3 in VFAs increased,which might be due to the declined production of C5 from protein and the faded genus Dechlorobacter.Keeping sludge age of WAS at a relatively low level (<10 days) is more appropriate for anaerobic acidification of WAS as internal carbon sources and P resource.展开更多
Chinese hickory(Carya cathayensis Sarg.)is an important economic forest in Southeastern China.A large amount of hickory husk waste is generated every year but with a low proportion of returning.Meanwhile,intensive man...Chinese hickory(Carya cathayensis Sarg.)is an important economic forest in Southeastern China.A large amount of hickory husk waste is generated every year but with a low proportion of returning.Meanwhile,intensive management has resulted in soil degradation of Chinese hickory plantations.This study aims to investigate the effects of three Chinese hickory husk returning modes on soil amendment,including soil acidity,soil nutrition,and microbial community.The field experiment carried out four treatments:control(CK),hickory husk mulching(HM),hickory husk biochar(BC),and hickory husk organic fertilizer(OF).The phospholipid fatty acid(PLFA)biomarker method was employed to determine the soil microbial community.After one year of treatment,the results showed that:(i)HM and BC significantly increased soil pH by 0.33 and 1.71 units,respectively;(ii)HM,BC and OF treatments significantly increased the soil organic carbon,alkaline nitrogen,available phosphorous,and available potassium.The OF treatment demonstrated the most significant improvement in the soil nutrient;(iii)The soil microbial biomass significantly increased in the HM,BC and OF treatments,and all microbial groups showed an increasing trend.HM treatment increased the fungal/bacterial ratio(F/B).The OF treatment significantly decreased the Shannon-Wiener diversity(H’)and evenness index(J)of the microbial community(P<0.05).Considering the treatments effects,costs,and ease of operation,our recommended returning modes of Chinese hickory husk are mulching and organic fertilizer produced by composting with manure.展开更多
Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial c...Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial communities, the soil microbial communities were assessed by plate counts, phospholipid fatty acid （PLFA） and Biolog microplate techniques in five plant communities, i.e., soybean field （SF）, artificial turf （AT）, artificial shrub （AS）, natural shrub （NS）, and maize field （MF） in Jinan, Shandong Province, North China. The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate. Legumes could significantly enhance the number of cultural microorganisms, microbial biomass, and community catabolic diversity. Except for SF dominated by legumes, the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types. These results confirmed that high number of plant species, legumes, and natural vegetation types tend to support soil microbial communities with higher function. The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community. Different research methods led to varied results in this study. The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.展开更多
The prevalence of non-alcoholic fatty liver disease(NAFLD) is rising exponentially worldwide. The spectrum of NAFLD includes non-alcoholic fatty liver, non-alcoholic steatohepatitis, liver cirrhosis, and even hepatoce...The prevalence of non-alcoholic fatty liver disease(NAFLD) is rising exponentially worldwide. The spectrum of NAFLD includes non-alcoholic fatty liver, non-alcoholic steatohepatitis, liver cirrhosis, and even hepatocellular carcinoma. Evidence shows that microbial metabolites play pivotal roles in the onset and progression of NAFLD. In this review, we discuss how microbederived metabolites, such as short-chain fatty acids, endogenous ethanol, bile acids and so forth, contribute to the pathogenesis of NAFLD.展开更多
The phospholipid fatty acid （PLFA） composition was analyzed in two red soils experimentally contaminated with copper at different concentrations. The total amounts ofphospholipid fatty acids （PLFAs） in both red so...The phospholipid fatty acid （PLFA） composition was analyzed in two red soils experimentally contaminated with copper at different concentrations. The total amounts ofphospholipid fatty acids （PLFAs） in both red soils were significantly correlated with soil microbial biomass C and N, which decreased consistently with increasing levels of copper. The relative quantities of the PLFAs 17：0 （10 Me）, i16：0, il 5：0 and 16：1w5c, decreased with increasing heavy metal concentration, while those of cyl7：0, which is an indicator of gram-negative bacteria, increased. The Shannon index calculated from the PLFA data indicated that Cu addition in the red soils decreased the population diversity of soil microbial communities. Multivariate analysis of PLFA data demonstrated that high levels of Cu application had a significant impact on microbial community structure and there is a threshold metal concentration for PLFA composition. Comparatively higher toxic effect on microbial biomass and community structure were found in the red sandy soil than those in the red clayey soil. The differential effect of Cu addition on microbial communities in the two soils may be due to differences in soil texture and cation exchange capacity.展开更多
To analyze the intrinsic relationship between rhizosphere microbial community structure and variety of rice, the microbial community structures in rhizosphere of different hybrid rice cultivars were determined with ph...To analyze the intrinsic relationship between rhizosphere microbial community structure and variety of rice, the microbial community structures in rhizosphere of different hybrid rice cultivars were determined with phospholipid fatty acids （PLFA） analysis. Three series of new-breeding hybrid rice cultivars in China were tested in the experiment, Ilyouming 86 （II-32A/Minghui 86）, Ilyouhang 1 （II-32A/Hang 1）, and Ilyouhang 2 （II-32A/Hang 2） with H-32A as female parent, XinyouHK02 （XinA/HK02） and YiyouHK02 （YXA/HK02） with HK02 as male parent, Chuanyou 167 （ChuanxiangA/MR167） and 44you167 （Hunan44A/MR167） with MR167 as male parent. The results showed that the microbial community in rhizosphere of the hybrid rice comprised bacteria, fungi, actinomycetes, and protozoa, according to the 40 PLFA biomarkers detected. Bacteria were more abundant than fungi and actinomycetes in rhizosphere of the hybrid rice tested. Both sulfate-reducing and methane-oxidizing bacteria were found to exist in the hybrid rice rhizosphere. It was also found that the characteristics of PLFA biomarkers had correlation with the biological traits of rice. The cluster analysis suggested that microbial community structure and activity in rhizosphere were associated with genetic background of the rice cultivar.展开更多
The relationship between Solidago canadensis L.invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%,80%,and 100...The relationship between Solidago canadensis L.invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%,80%,and 100% coverage of Solidago canadensis L.using sole carbon source utilization profiles analyses,principle component analysis(PCA) and phospholipid fatty acids(PLFA) profiles analyses.The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L.invasion.Solidago canadensis L.invasion tended to result in higher substrate richness,and functional diversity.As compared to the native and ecotones,average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L.monoculture.Soil microbial functional diversity in Solidago canadensis L.monoculture was distinctly separated from the native area and the ecotones.Aerobic bacteria,fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L.monoculture.The ratio of cy19:0 to 18:1ω7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L.became more dominant.The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis,especially 18:1ω7c,16:1ω7t,16:1ω5c and 18:2ω6,9 were present in higher concentrations for exotic soil.In conclusion,Solidago canadensis L.invasion could create better soil conditions by improving soil microbial community structure and functional diversity,which in turn was more conducive to the growth of Solidago canadensis L.展开更多
This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau.The soil microbial community co...This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau.The soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids（PLFAs） of eight croplands abandoned for 1,3,5,10,13,15,20,and 30 yr in the Dunshan watershed,northern Loess Plateau,China.The results showed that soil organic carbon,total nitrogen,soil microbial biomass carbon,and soil microbial biomass nitrogen significantly increased with the abandonment duration,whereas the metabolic quotient significantly decreased.The Shannon richness and Shannon evenness of PLFAs significantly increased after 10 yr of abandonment.Gram-negative,Gram-positive,bacterial,fungal,and total PLFAs linearly increased with increased abandonment duration.Redundancy analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community composition.The soil microbial PLFAs changed from anteiso-to iso-,unsaturated to saturated,and short-to long-chain during natural recovery.Therefore,in the Loess Plateau,cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.展开更多
文摘Multicellular organisms use chemical messengers to transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids are excellent candidates for this signaling purpose. In most proteins, palmitic acid and other saturated and some unsaturated fatty acids are esterified to the free thiol of cysteines and to the N-amide terminal. This palmitoylation process enhances the surface hydrophobicity and membrane affinity of protein substrates and plays important roles in modulating proteins’ trafficking, stability, and sorting etc. Protein palmitoylation has been involved in numerous cellular processes, including signaling, apoptosis, and neuronal transmission. The palmitoylation process is involved in multiple diseases such as Huntington’s disease, various cardiovascular and T-cell mediated immune disorders, as well as cancer. Protein palmitoylation through the thioester (S-acylation) is unique in that it is the only reversible lipid modification. Our study on lipopolysaccharide (LPS) and deoxynivalenol (DON) treatment to rats provides some insights to the complex role of protein palmitoylation in chemical and microbial toxicity. In contrast, myrisoylated proteins contain the 14-carbon fatty acid myristate attached via amide linkage to the N-terminal glycine residue of protein, and occur cotranslationally. The bacterial outer membrane enzyme lipid A palmitoyltransferase (PagP) confers resistance to host immune defenses by transferring a palmitate chain from a phospholipid to the lipid A component of LPS. PagP is sensitive to cationic antimicrobial peptides (CAMP) which are included among the products of the Toll-like receptor 4 (TLR4) signal transduction pathway. This modification of lipid A with a palmitate appears to both and protects the pathogenic bacteria from host immune defenses and attenuates the activation of those same defenses through the TLR4 signal transduction pathway.
基金supported by the Jiangsu Provincial Key R&D Program(BE2018658)Jiangsu Provincial Medical Key Discipline(ZDXK202217)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Parkinson’s disease(PD)is a complicated neurodegenerative disease,characterized by the accumulation ofα-synuclein(α-syn)in Lewy bodies and neurites,and massive loss of midbrain dopamine neurons.Increasing evidence suggests that gut microbiota and microbial metabolites are involved in the development of PD.Among these,short-chain fatty acids(SCFAs),the most abundant microbial metabolites,have been proven to play a key role in brain-gut communication.In this review,we analyze the role of SCFAs in the pathology of PD from multiple dimensions and summarize the alterations of SCFAs in PD patients as well as their correlation with motor and non-motor symptoms.Future research should focus on further elucidating the role of SCFAs in neuroinflammation,as well as developing novel strategies employing SCFAs and their derivatives to treat PD.
基金supported,in part,by the NIH(R01AI121302,R21AI14889801,R01AI074745,and R01AI080769)Kenneth and Judy Betz Professorship at the Mary H.Weiser Food Allergy Center at the University of Michigan to C.H.K.
文摘A mounting body of evidence indicates that dietary fiber(DF)metabolites produced by commensal bacteria play essential roles in balancing the immune system.DF,considered nonessential nutrients in the past,is now considered to be necessary to maintain adequate levels of immunity and suppress inflammatory and allergic responses.Short-chain fatty acids(SCFAs),such as acetate,propionate,and butyrate,are the major DF metabolites and mostly produced by specialized commensal bacteria that are capable of breaking down DF into simpler saccharides and further metabolizing the saccharides into SCFAs.SCFAs act on many cell types to regulate a number of important biological processes,including host metabolism,intestinal functions,and immunity system.This review specifically highlights the regulatory functions of DF and SCFAs in the immune system with a focus on major innate and adaptive lymphocytes.Current information regarding how SCFAs regulate innate lymphoid cells,T helper cells,cytotoxic T cells,and B cells and how these functions impact immunity,inflammation,and allergic responses are discussed.
基金supported by the National Natural Science Foundation of China(Grant No.52000139)the China Post-doctoral Science Foundation(Grant number 2020M680058).
文摘Effects of sludge age on volatile fatty acids (VFAs) production and Phosphorus (P) release during anaerobic acidification of waste activated sludge (WAS) were investigated.Sequencing batch reactors (SBR) fed with simulating domestic sewage were applied to produce WAS of different sludge ages,and batch tests were used for anaerobic acidification.The maximum dissolved total organic carbon,release of PO_(4)^(3+)-P,and accumulation of acetate (C2),propionate (C3),butyrate (C4),and valerate (C5) decreased by 56.2%,55.8%,52.6%,43.7%,82.4%and 84.8%,respectively,as the sludge age of WAS increased from 5 to 40 days.Limited degradation of protein played a dominating role in decreasing DTOC and VFAs production.Moreover,the increase in molecular weight of organics and organic nitrogen content in the supernatant after acidification suggested that the refractory protein in WAS increased as sludge age extended.Although the production of C2,C3,C4,and C5 from WAS decreased as the sludge age increased,the proportions of C2 and C3 in VFAs increased,which might be due to the declined production of C5 from protein and the faded genus Dechlorobacter.Keeping sludge age of WAS at a relatively low level (<10 days) is more appropriate for anaerobic acidification of WAS as internal carbon sources and P resource.
基金financially supported by Natural Science Foundation of Zhejiang Province(LY20C160003)the National College Students’Innovation and Entrepreneurship Training Program(202110341063).
文摘Chinese hickory(Carya cathayensis Sarg.)is an important economic forest in Southeastern China.A large amount of hickory husk waste is generated every year but with a low proportion of returning.Meanwhile,intensive management has resulted in soil degradation of Chinese hickory plantations.This study aims to investigate the effects of three Chinese hickory husk returning modes on soil amendment,including soil acidity,soil nutrition,and microbial community.The field experiment carried out four treatments:control(CK),hickory husk mulching(HM),hickory husk biochar(BC),and hickory husk organic fertilizer(OF).The phospholipid fatty acid(PLFA)biomarker method was employed to determine the soil microbial community.After one year of treatment,the results showed that:(i)HM and BC significantly increased soil pH by 0.33 and 1.71 units,respectively;(ii)HM,BC and OF treatments significantly increased the soil organic carbon,alkaline nitrogen,available phosphorous,and available potassium.The OF treatment demonstrated the most significant improvement in the soil nutrient;(iii)The soil microbial biomass significantly increased in the HM,BC and OF treatments,and all microbial groups showed an increasing trend.HM treatment increased the fungal/bacterial ratio(F/B).The OF treatment significantly decreased the Shannon-Wiener diversity(H’)and evenness index(J)of the microbial community(P<0.05).Considering the treatments effects,costs,and ease of operation,our recommended returning modes of Chinese hickory husk are mulching and organic fertilizer produced by composting with manure.
基金Project supported by the Outstanding Young Scientists Foundation Grant of Shandong Province (No.2005BS08010)China Geological Survey Project (No.1212010310306)Key Project of Natural Science Foundation of Shandong Province (No.Z2006D04).
文摘Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial communities, the soil microbial communities were assessed by plate counts, phospholipid fatty acid （PLFA） and Biolog microplate techniques in five plant communities, i.e., soybean field （SF）, artificial turf （AT）, artificial shrub （AS）, natural shrub （NS）, and maize field （MF） in Jinan, Shandong Province, North China. The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate. Legumes could significantly enhance the number of cultural microorganisms, microbial biomass, and community catabolic diversity. Except for SF dominated by legumes, the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types. These results confirmed that high number of plant species, legumes, and natural vegetation types tend to support soil microbial communities with higher function. The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community. Different research methods led to varied results in this study. The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.
基金Supported by National Key Research and Development Plan ‘Precision Medicine Research’,No.2017YFSF090203the National Natural Science Foundation of China,No.81470840,No.81873565,and No.81800510Shanghai Sailing Program,No.18YF1415900
文摘The prevalence of non-alcoholic fatty liver disease(NAFLD) is rising exponentially worldwide. The spectrum of NAFLD includes non-alcoholic fatty liver, non-alcoholic steatohepatitis, liver cirrhosis, and even hepatocellular carcinoma. Evidence shows that microbial metabolites play pivotal roles in the onset and progression of NAFLD. In this review, we discuss how microbederived metabolites, such as short-chain fatty acids, endogenous ethanol, bile acids and so forth, contribute to the pathogenesis of NAFLD.
基金The National Natural Science Foundation of China (No. 30200164 40371063) and the Foundation for the Retuned Scholars ofZhejiang Province
文摘The phospholipid fatty acid （PLFA） composition was analyzed in two red soils experimentally contaminated with copper at different concentrations. The total amounts ofphospholipid fatty acids （PLFAs） in both red soils were significantly correlated with soil microbial biomass C and N, which decreased consistently with increasing levels of copper. The relative quantities of the PLFAs 17：0 （10 Me）, i16：0, il 5：0 and 16：1w5c, decreased with increasing heavy metal concentration, while those of cyl7：0, which is an indicator of gram-negative bacteria, increased. The Shannon index calculated from the PLFA data indicated that Cu addition in the red soils decreased the population diversity of soil microbial communities. Multivariate analysis of PLFA data demonstrated that high levels of Cu application had a significant impact on microbial community structure and there is a threshold metal concentration for PLFA composition. Comparatively higher toxic effect on microbial biomass and community structure were found in the red sandy soil than those in the red clayey soil. The differential effect of Cu addition on microbial communities in the two soils may be due to differences in soil texture and cation exchange capacity.
基金supported by the National Basic Research Program of China (2011CB111607)the Fujian Funds for Distinguished Young Scientists,China (2009J06010)
文摘To analyze the intrinsic relationship between rhizosphere microbial community structure and variety of rice, the microbial community structures in rhizosphere of different hybrid rice cultivars were determined with phospholipid fatty acids （PLFA） analysis. Three series of new-breeding hybrid rice cultivars in China were tested in the experiment, Ilyouming 86 （II-32A/Minghui 86）, Ilyouhang 1 （II-32A/Hang 1）, and Ilyouhang 2 （II-32A/Hang 2） with H-32A as female parent, XinyouHK02 （XinA/HK02） and YiyouHK02 （YXA/HK02） with HK02 as male parent, Chuanyou 167 （ChuanxiangA/MR167） and 44you167 （Hunan44A/MR167） with MR167 as male parent. The results showed that the microbial community in rhizosphere of the hybrid rice comprised bacteria, fungi, actinomycetes, and protozoa, according to the 40 PLFA biomarkers detected. Bacteria were more abundant than fungi and actinomycetes in rhizosphere of the hybrid rice tested. Both sulfate-reducing and methane-oxidizing bacteria were found to exist in the hybrid rice rhizosphere. It was also found that the characteristics of PLFA biomarkers had correlation with the biological traits of rice. The cluster analysis suggested that microbial community structure and activity in rhizosphere were associated with genetic background of the rice cultivar.
基金Project(2009QNA6015) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(Y3110055)supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(Y200803219) supported by the Foundation of Zhejiang Educational Committee of China
文摘The relationship between Solidago canadensis L.invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%,80%,and 100% coverage of Solidago canadensis L.using sole carbon source utilization profiles analyses,principle component analysis(PCA) and phospholipid fatty acids(PLFA) profiles analyses.The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L.invasion.Solidago canadensis L.invasion tended to result in higher substrate richness,and functional diversity.As compared to the native and ecotones,average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L.monoculture.Soil microbial functional diversity in Solidago canadensis L.monoculture was distinctly separated from the native area and the ecotones.Aerobic bacteria,fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L.monoculture.The ratio of cy19:0 to 18:1ω7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L.became more dominant.The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis,especially 18:1ω7c,16:1ω7t,16:1ω5c and 18:2ω6,9 were present in higher concentrations for exotic soil.In conclusion,Solidago canadensis L.invasion could create better soil conditions by improving soil microbial community structure and functional diversity,which in turn was more conducive to the growth of Solidago canadensis L.
基金funded by the Strategic Technology Project of Chinese Academy of Sciences (XDA05060300)the Science and Technology Research and Development Program of Shaanxi Province, China (2011KJXX63)
文摘This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau.The soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids（PLFAs） of eight croplands abandoned for 1,3,5,10,13,15,20,and 30 yr in the Dunshan watershed,northern Loess Plateau,China.The results showed that soil organic carbon,total nitrogen,soil microbial biomass carbon,and soil microbial biomass nitrogen significantly increased with the abandonment duration,whereas the metabolic quotient significantly decreased.The Shannon richness and Shannon evenness of PLFAs significantly increased after 10 yr of abandonment.Gram-negative,Gram-positive,bacterial,fungal,and total PLFAs linearly increased with increased abandonment duration.Redundancy analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community composition.The soil microbial PLFAs changed from anteiso-to iso-,unsaturated to saturated,and short-to long-chain during natural recovery.Therefore,in the Loess Plateau,cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.
