Microorganisms capable of solubilizing and mineralizing phosphorus （P） pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacte...Microorganisms capable of solubilizing and mineralizing phosphorus （P） pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacteria （IPSB） and organic P-mineralizing bacteria （OPMB） in soils taken from subtropical flooded and temperate non-flooded soils, and to compare inorganic P-solubilizing and organic P-solubilizing abilities between IPSB and OPMB. Ten OPMB strains were isolated and identified as Bacillus cereus and Bacillus megaterium, and five IPSB strains as B. megaterium, Burkholderia caryophyUi, Pseudomonas cichorii, and Pseudomonas syringae. P-solubilizing and -mineralizing abilities of the strains were measured using the methods taking cellular P into account. The IPSB strains exhibited inorganic P-solubilizing abilities ranging between 25.4-41.7 μg P mL^-1 and organic P-mineralizing abilities between 8.2-17.8μg P mL^-1. Each of the OPMB strains also exhibited both solubilizing and mineralizing abilities varying from 4.4 to 26.5 μg P mL^-1 and from 13.8 to 62.8 μg P mL^-1, respectively. For both IPSB and OPMB strains, most of the P mineralized from the organic P source was incorporated into the bacterial cells as cellular P. A significantly negative linear correlation （P 〈 0.05） was found between culture pH and P solubilized from inorganic P by OPMB strains. The results suggested that P solubilization and mineralization could coexist in the same bacterial strain.展开更多
Application of phosphate-solubilizing microorganisms (PSMs) has been reported to increase P uptake and plant growth. However, no information is available regarding the ecological consequences of the inoculation with P...Application of phosphate-solubilizing microorganisms (PSMs) has been reported to increase P uptake and plant growth. However, no information is available regarding the ecological consequences of the inoculation with PSMs. The effect of inoculation with phosphate-solubilizing fungal (PSF) isolates Aspergillus niger P39 and Penicillium oxalicum P66 on the bacterial communities in the rhizospheres of maize (Zea mays L. 'Haiyu 6') and soybean (Glycine max Merr. 'Heinong 35') was examined using culture-dependent methods as well as a culture-independent method, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Compared with the control, the number of culturable microbes for soybean was significantly greater with P39, whereas for maize, the same was significantly greater with P66. In addition, a greater number of microbes were found in the rhizosphere of maize compared with soybean. The fingerprint of DGGE for 16S rDNA indicated that inoculation with PSF also increased bacterial communities, with the P66 treatment having higher numbers of DGGE bands and a higher Shannon-Weaver diversity index compared with P39; the composition of the microbial community was also more complex with the P66 treatment. Overall, complex interactions between plant species and exotic PSMs affected the structure of the bacterial community in the rhizosphere, but plant species were more important in determining the bacterial community structure than the introduction of exotic microorganisms.展开更多
The research isolated phosphorus-soluble bacteria from different parts of ryegrasses and selected 7 bacteria performing better in solbilizing capacity. The test results showed that the capacity of phosphorus-solubiliz...The research isolated phosphorus-soluble bacteria from different parts of ryegrasses and selected 7 bacteria performing better in solbilizing capacity. The test results showed that the capacity of phosphorus-solubilizing tended to be volatile in the range from 135.27 to 187.87 μg/ml and the secreting capacity of IAA was in3.47-24.27 μg/ml. It is believed that Lp59, Lp61, Lp65, Lp69, Lp70 and Lp72 are potential for further development.展开更多
With the changing climate and escalating population,there will be extreme pressure on agricultural food production to ensure global food security.Traditional agricultural practices have relied heavily on hazardous pes...With the changing climate and escalating population,there will be extreme pressure on agricultural food production to ensure global food security.Traditional agricultural practices have relied heavily on hazardous pesticides and chemical fertilizers to boost crop yields.However,their continuous and excessive use has caused significant harm to non-target organisms,including humans,while also leading to a severe decline in soil health due to their indiscriminate and unbalanced application.Hence,serious efforts are needed to control this mounting problem of soil and environmental pollution.One effective strategy involves using microorganisms capable of solubilizing nutrients and breaking down pesticides.These microorganisms improve crop nutrient absorption by solubilizing essential nutrients and simultaneously degrade pesticide residues in soil.Utilizing this ability of microorganisms to degrade agrochemicals,microbial remediation offers a dependable and economical method for reducing the effects of such unwarranted contaminants.This review presents an extensive overview of pesticide use as well as microorganisms in soil as pesticide degraders,nutrient mobilizers(phosphate(PO_(4)^(3-)-P),potassium(K),and zinc(Zn)),and plant growth promoters for preventing the unsustainable exploitation of natural reserves.This review aims to highlight the diverse benefits these microorganisms offer across various domains while presenting an exciting opportunity to advance sustainable agriculture and firstly establishes a connection between nutrient solubilization and pesticide degradation mediated by microorganisms.It also offers a comprehensive bibliographic review of the application of plant growth-promoting microorganisms for solubilizing nutrients,such as P,K,and Zn,and degrading pesticides as well.展开更多
Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers ha...Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers has become pervasive in agriculture.Nonetheless,the escalating prices of chemical fertilizers,coupled with new European regulations prohibiting the use of P fertilizers containing cadmium,have highlighted the urgency to identify environmentally friendly products and practices for P fertilization in agricultural soils.This comprehensive review delves into the current landscape of P fertilization from agricultural,political,and economic standpoints.We recognize the potential of microbes in mobilizing P,but emphasize the necessity for more robust research to establish their effectiveness in promoting plant P uptake under real-world conditions.Additionally,we explore the role of agricultural conservation practices,such as optimal tillage,diversified cropping systems,and increased organic carbon input,in conserving P.Furthermore,this review contemplates forthcoming innovations in research.These innovations encompass the development of enhanced formulations for biofertilizers and the undertaking of more comprehensive studies within the realm of conservation agriculture.All these endeavors collectively hold the potential to augment P accessibility to plants in a sustainable manner,thereby advancing agricultural sustainability and productivity.展开更多
INTRODUCTION The insoluble phosphates which can not be directly absorbed by plants are the mai forms of inorganic phosphate in soil. These kinds of phosphates can be solubilized by several species of bacteria which ar...INTRODUCTION The insoluble phosphates which can not be directly absorbed by plants are the mai forms of inorganic phosphate in soil. These kinds of phosphates can be solubilized by several species of bacteria which are widely spread in soil especially in rhizosphere where70% of the bacteria are capable of solubilizing inorganic phosphate. Many researchers re-展开更多
Background:Serratia ureilytica DW2 is a highly efficient phosphate-solubilizing bacteria isolated from Codonopsis pilosula rhizosphere soil that can promote the growth of C.pilosula;nonetheless,until now,no validated ...Background:Serratia ureilytica DW2 is a highly efficient phosphate-solubilizing bacteria isolated from Codonopsis pilosula rhizosphere soil that can promote the growth of C.pilosula;nonetheless,until now,no validated reference genes from the genus Serratia have been reported that can be used for the normalization of quantitative real-time polymerase chain reaction(RT–qPCR)data.Methods:To screen stable reference genes of S.ureilytica DW2,the expression of its eight candidate reference genes(16S rRNA,ftsZ,ftsA,mreB,recA,slyD,thiC,and zipA)under different treatment conditions(pH,temperature,culture time,and salt content)was assayed by RT–qPCR.The expression stability of these genes was analyzed using different algorithms(geNorm,NormFinder,and BestKeeper).To verify the reliability of the data,the expression of the glucose dehydrogenase(gdh)gene under different soluble phosphate levels was quantified using the most stably expressed reference gene.Results:The results showed that the zipA and 16S rRNA genes were the most stable reference genes,and the least stable genes were thiC and recA.The expression of gdh was consistent with the phosphate solubilization ability on plates containing the National Botanical Research Institute phosphate growth medium.Conclusion:Therefore,this study provides a stable and reliable reference gene of Serratia for the accurate quantification of functional gene expression in future studies.展开更多
Rock phosphate (RP) is a low efficient P fertilizer when directly used in the soil. Phosphate-solubilizing microorganisms (PSMs) can solubilize RP in fermentation or soil condition. The effect of different concentrati...Rock phosphate (RP) is a low efficient P fertilizer when directly used in the soil. Phosphate-solubilizing microorganisms (PSMs) can solubilize RP in fermentation or soil condition. The effect of different concentration of lanthanum (La) on the solubilization of RP was investigated by two isolates of phosphate-solubilizing fungi (PSF) Aspergillus niger P39 and Penicillium oxalicum P66 in liquid culture. Experimental results show that relatively higher concentration of La in the culture solution inhibites fungal growth and delays RP solubilizing activity of two isolates. This inhibitory effect of La on RP solubilization varies with PSF (isolate P66 is more sensitive to La than P39 in this experiment). Comparing the pH value of culture media with soluble P content as affected by La application, only within individual isolate not different isolates the negatively significant relationship was observed.展开更多
Phosphorus （P） is a major growth-limiting nutrient, and unlike the case of nitrogen （N）, there is no large atmospheric source that can be made biologically available. Moreover, P governs crucial role in plant as i...Phosphorus （P） is a major growth-limiting nutrient, and unlike the case of nitrogen （N）, there is no large atmospheric source that can be made biologically available. Moreover, P governs crucial role in plant as it stimulates root development and growth, gives plant rapid and vigorous start leading to better tillering and essential for many metabolic processes for seed formation. Soil microbes play very important role in bio-weathering and biodegradation. The microorganisms produce low molecular mass organic acids, which attack the phosphate structure and transform phosphorus from non-utilizable to the utilizable for the plants form. The test of the relative efficiency of isolated strains is carried out by selecting the microorganisms that are capable of producing a halo/clear zone on a plate owing to the production of organic acids into the surrounding medium. It is a well-known fact that as the particle size of rock phosphate decreases, the microbe mediated solubilization of rock phosphate increases in soil. In the present investigation, microbial solubilization of nano rock phosphate （〈 100 nm） particles was studied. Experimental results revealed that Pseudomonas striata solubilized 11.45% of the total P after 24 h of incubation from nano rock phosphate particles while 28.95% and 21.19% of the total P was solubilized by Aspergillus niger （black pigmented） and Aspergillus niger （green pigmented）, respectively. It was also observed that Aspergillus niger has the higher ability to dissolve Udaipur rock phosphate than Pseudomonas striata.展开更多
To alleviate soil phosphorus deficiency,integrating straw-derived biochar with phosphate-solubilizing bacteria(PSB)has been recognized as a promising solution and is gaining growing attention.However,the mechanisms of...To alleviate soil phosphorus deficiency,integrating straw-derived biochar with phosphate-solubilizing bacteria(PSB)has been recognized as a promising solution and is gaining growing attention.However,the mechanisms of bacterial immobilization and the influences of the physicochemical attributes of biochar remain unclear.In this study,we investigated the single-cell interactions of gram-negative Acinetobacter pittii and gram-positive Bacillus subtilis with cotton straw-derived biochars,subjected to progressively increasing pyrolysis temperatures,to understand the attributes of gradually modified biochar properties.The results revealed the correlations between adhesion forces and biochar properties(e.g.,surface area and surface charge),and the strongest adhesion for both strains for the biochar pyrolyzed at 700℃.The extended Derjaguin-Landau-Verwey-Overbeek(XDLVO)model,structured to predict interaction energy,was subsequently compared with experimental observations made using atomic force microscopy(AFM).Discrepancies between the predicted high adhesion barriers and the observed attraction suggested that forces beyond Lifshitz-van der Waals also influenced the immobilization of PSB.Adhesion-distance spectroscopy and XDLVO theory jointly revealed four distinct phases in the immobilization process by biochar:planktonic interaction,secondary minimum entrapment,primary barrier transcendence,and initial reversible adherence,collectively facilitating biofilm formation.Notably,initial reversible adhesion positively correlated with increased protein and polysaccharide levels in extracellular polymeric substances(EPS)(R^(2)>0.67),highlighting its importance in biofilm formation.Unraveling PSB–biochar interactions can improve the effectiveness of soil inoculants,thereby enhancing phosphorus availability in soil,a crucial factor for promoting plant growth and supporting environmental sustainability.展开更多
Application of agricultural waste such as rapeseed meal(RM)is regarded as a sustainable way to improve soil phosphorus(P)availability by direct nutrient supply and stimulation of native phosphate‐solubilizing microor...Application of agricultural waste such as rapeseed meal(RM)is regarded as a sustainable way to improve soil phosphorus(P)availability by direct nutrient supply and stimulation of native phosphate‐solubilizing microorganisms(PSMs)in soils.However,exploration of the in situ microbial P solubilizing function in soils remains a challenge.Here,by applying both phenotype‐based single‐cell Raman with D_(2)O labeling(Raman‐D_(2)O)and genotype‐based high‐throughput chips targeting carbon,nitrogen and P(CNP)functional genes,the effect of RM application on microbial P solubilization in three typical farmland soils was investigated.The abundances of PSMs increased in two alkaline soils after RM application identified by single‐cell Raman D_(2)O.RM application reduced the diversity of bacterial communities and increased the abundance of a few bacteria with reported P solubilization function.Genotypic analysis indicated that RM addition generally increased the relative abundance of CNP functional genes.A correlation analysis of the abundance of active PSMs with the abundance of soil microbes or functional genes was carried out to decipher the linkage between the phenotype and genotype of PSMs.Myxococcota and C degradation genes were found to potentially contribute to the enhanced microbial P release following RM application.This work provides important new insights into the in situ function of soil PSMs.It will lead to better harnessing of agricultural waste to mobilize soil legacy P and mitigate the P crisis.展开更多
Biocontrol by inoculation with beneficial microbes is a proven strategy for reducing the negative effect of soil-borne pathogens.The effects of Trichoderma harzianum LTR-2 and Arthrobacter ureafaciens DnL1-1 on reduci...Biocontrol by inoculation with beneficial microbes is a proven strategy for reducing the negative effect of soil-borne pathogens.The effects of Trichoderma harzianum LTR-2 and Arthrobacter ureafaciens DnL1-1 on reducing Fusarium crown rot(FCR)disease and influencing microbial community structure in wheat root-zone were evaluated by a plot experiment.The experimental design consisted of four treatments:(1)control,(2)Fusarium pseudograminearum Fp(FP),(3)F.pseudograminearum+LTR-2(LFP),and(4)F.pseudograminearum+LTR-2+DnL1-1(HFP).The results showed that wheat seeds coated with LTR-2 spore suspension and combination of LTR-2 and DnL1-1 had relative control efficacies of 50.77%and 67.73%on FCR disease,and increased wheat yield by 58.32%and 64.19%,respectively.Illumina MiSeq sequencing revealed that bacterial and fungal abundance and diversity were significantly higher(P<0.05)in both treatment groups(HFP and LFP)than in FP and control groups.Principal coordinates analyses revealed that fungal and bacterial communities were distinctly separated among the treatment and control groups.Fungal community composition analysis demonstrated that the relative abundance of phytopathogenic fungi Alternaria,Fusarium,and Cladosporium decreased and that of beneficial fungi Mortierella and Gamsia was more enriched in HFP and LFP than in FP group.Bacterial community composition analysis revealed that the beneficial microbes,such as Bacillus and Streptomyces were more abundant in HFP and LFP than in FP group.LEfSe analysis indicated that the key different genera,e.g.Tetracladium(fungus),Sphingomonas and Ramlibacter(bacteria),which were significantly negatively correlated with TP in HFP treatment.It was concluded that application of LTR-2 and DnL1-1 may recruit a variety of phosphate-solubilizing microbes to promote wheat growth.Overall,these results confirm that the relative abundance of phytopathogenic fungi decreased significantly following application of LTR-2 alone and combined with DnL1-1 and beneficial microbes accumulated more easily in the wheat root-zone compared with that in FP and control groups.展开更多
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars, the Ministry of Education of the P.R. China.
文摘Microorganisms capable of solubilizing and mineralizing phosphorus （P） pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacteria （IPSB） and organic P-mineralizing bacteria （OPMB） in soils taken from subtropical flooded and temperate non-flooded soils, and to compare inorganic P-solubilizing and organic P-solubilizing abilities between IPSB and OPMB. Ten OPMB strains were isolated and identified as Bacillus cereus and Bacillus megaterium, and five IPSB strains as B. megaterium, Burkholderia caryophyUi, Pseudomonas cichorii, and Pseudomonas syringae. P-solubilizing and -mineralizing abilities of the strains were measured using the methods taking cellular P into account. The IPSB strains exhibited inorganic P-solubilizing abilities ranging between 25.4-41.7 μg P mL^-1 and organic P-mineralizing abilities between 8.2-17.8μg P mL^-1. Each of the OPMB strains also exhibited both solubilizing and mineralizing abilities varying from 4.4 to 26.5 μg P mL^-1 and from 13.8 to 62.8 μg P mL^-1, respectively. For both IPSB and OPMB strains, most of the P mineralized from the organic P source was incorporated into the bacterial cells as cellular P. A significantly negative linear correlation （P 〈 0.05） was found between culture pH and P solubilized from inorganic P by OPMB strains. The results suggested that P solubilization and mineralization could coexist in the same bacterial strain.
基金Project supported by the Director Fund of Northeast Institute of Geography and Agroecology, Chinese Academy of Sciencesthe National High Technology Research and Development Program (863 Program) of China (No. 2006AA10Z424).
文摘Application of phosphate-solubilizing microorganisms (PSMs) has been reported to increase P uptake and plant growth. However, no information is available regarding the ecological consequences of the inoculation with PSMs. The effect of inoculation with phosphate-solubilizing fungal (PSF) isolates Aspergillus niger P39 and Penicillium oxalicum P66 on the bacterial communities in the rhizospheres of maize (Zea mays L. 'Haiyu 6') and soybean (Glycine max Merr. 'Heinong 35') was examined using culture-dependent methods as well as a culture-independent method, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Compared with the control, the number of culturable microbes for soybean was significantly greater with P39, whereas for maize, the same was significantly greater with P66. In addition, a greater number of microbes were found in the rhizosphere of maize compared with soybean. The fingerprint of DGGE for 16S rDNA indicated that inoculation with PSF also increased bacterial communities, with the P66 treatment having higher numbers of DGGE bands and a higher Shannon-Weaver diversity index compared with P39; the composition of the microbial community was also more complex with the P66 treatment. Overall, complex interactions between plant species and exotic PSMs affected the structure of the bacterial community in the rhizosphere, but plant species were more important in determining the bacterial community structure than the introduction of exotic microorganisms.
基金Supported by Social Development Projects in Guizhou Province(NY[2011]3104)System Reform Program of Guizhou Province(Z[2012]4005)~~
文摘The research isolated phosphorus-soluble bacteria from different parts of ryegrasses and selected 7 bacteria performing better in solbilizing capacity. The test results showed that the capacity of phosphorus-solubilizing tended to be volatile in the range from 135.27 to 187.87 μg/ml and the secreting capacity of IAA was in3.47-24.27 μg/ml. It is believed that Lp59, Lp61, Lp65, Lp69, Lp70 and Lp72 are potential for further development.
基金the University Grant Commission(UGC),New Delhi,India,for supporting this work by providing a fellowship under the scheme of National Eligibility Test for Junior Research Fellowship(NET-JRF),India(No.210510284434)Financial support from the Core Research Grant by Science and Engineering Research Board,India(No.SERB-CRG/2022/002534)is appreciated。
文摘With the changing climate and escalating population,there will be extreme pressure on agricultural food production to ensure global food security.Traditional agricultural practices have relied heavily on hazardous pesticides and chemical fertilizers to boost crop yields.However,their continuous and excessive use has caused significant harm to non-target organisms,including humans,while also leading to a severe decline in soil health due to their indiscriminate and unbalanced application.Hence,serious efforts are needed to control this mounting problem of soil and environmental pollution.One effective strategy involves using microorganisms capable of solubilizing nutrients and breaking down pesticides.These microorganisms improve crop nutrient absorption by solubilizing essential nutrients and simultaneously degrade pesticide residues in soil.Utilizing this ability of microorganisms to degrade agrochemicals,microbial remediation offers a dependable and economical method for reducing the effects of such unwarranted contaminants.This review presents an extensive overview of pesticide use as well as microorganisms in soil as pesticide degraders,nutrient mobilizers(phosphate(PO_(4)^(3-)-P),potassium(K),and zinc(Zn)),and plant growth promoters for preventing the unsustainable exploitation of natural reserves.This review aims to highlight the diverse benefits these microorganisms offer across various domains while presenting an exciting opportunity to advance sustainable agriculture and firstly establishes a connection between nutrient solubilization and pesticide degradation mediated by microorganisms.It also offers a comprehensive bibliographic review of the application of plant growth-promoting microorganisms for solubilizing nutrients,such as P,K,and Zn,and degrading pesticides as well.
基金financed by the Spanish Ministry of Science and Innovation and the European Regional Development Fund(ERDF)(No.PID20211234690BI00)the European Joint Program EJP_Soil(TRACE-Soils)(No.862695)+1 种基金the Spanish Ministry of Science and Innovation(RED2018-102624TMCIN/AEI/10.13039/501100011033)the Project PREPSOIL European Union(No.101070045,HORIZON CSA)。
文摘Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers has become pervasive in agriculture.Nonetheless,the escalating prices of chemical fertilizers,coupled with new European regulations prohibiting the use of P fertilizers containing cadmium,have highlighted the urgency to identify environmentally friendly products and practices for P fertilization in agricultural soils.This comprehensive review delves into the current landscape of P fertilization from agricultural,political,and economic standpoints.We recognize the potential of microbes in mobilizing P,but emphasize the necessity for more robust research to establish their effectiveness in promoting plant P uptake under real-world conditions.Additionally,we explore the role of agricultural conservation practices,such as optimal tillage,diversified cropping systems,and increased organic carbon input,in conserving P.Furthermore,this review contemplates forthcoming innovations in research.These innovations encompass the development of enhanced formulations for biofertilizers and the undertaking of more comprehensive studies within the realm of conservation agriculture.All these endeavors collectively hold the potential to augment P accessibility to plants in a sustainable manner,thereby advancing agricultural sustainability and productivity.
基金Projcct supponcd by the National Natural science Foundation of China.
文摘INTRODUCTION The insoluble phosphates which can not be directly absorbed by plants are the mai forms of inorganic phosphate in soil. These kinds of phosphates can be solubilized by several species of bacteria which are widely spread in soil especially in rhizosphere where70% of the bacteria are capable of solubilizing inorganic phosphate. Many researchers re-
基金supported by the General Program of Natural Science Foundation of China(32071770)the Fundamental Research Program of Shanxi Province(Award No.202103021223380)the Fund for Shanxi“1331 Project”Key Subjects Construction(1331KSC).
文摘Background:Serratia ureilytica DW2 is a highly efficient phosphate-solubilizing bacteria isolated from Codonopsis pilosula rhizosphere soil that can promote the growth of C.pilosula;nonetheless,until now,no validated reference genes from the genus Serratia have been reported that can be used for the normalization of quantitative real-time polymerase chain reaction(RT–qPCR)data.Methods:To screen stable reference genes of S.ureilytica DW2,the expression of its eight candidate reference genes(16S rRNA,ftsZ,ftsA,mreB,recA,slyD,thiC,and zipA)under different treatment conditions(pH,temperature,culture time,and salt content)was assayed by RT–qPCR.The expression stability of these genes was analyzed using different algorithms(geNorm,NormFinder,and BestKeeper).To verify the reliability of the data,the expression of the glucose dehydrogenase(gdh)gene under different soluble phosphate levels was quantified using the most stably expressed reference gene.Results:The results showed that the zipA and 16S rRNA genes were the most stable reference genes,and the least stable genes were thiC and recA.The expression of gdh was consistent with the phosphate solubilization ability on plates containing the National Botanical Research Institute phosphate growth medium.Conclusion:Therefore,this study provides a stable and reliable reference gene of Serratia for the accurate quantification of functional gene expression in future studies.
文摘Rock phosphate (RP) is a low efficient P fertilizer when directly used in the soil. Phosphate-solubilizing microorganisms (PSMs) can solubilize RP in fermentation or soil condition. The effect of different concentration of lanthanum (La) on the solubilization of RP was investigated by two isolates of phosphate-solubilizing fungi (PSF) Aspergillus niger P39 and Penicillium oxalicum P66 in liquid culture. Experimental results show that relatively higher concentration of La in the culture solution inhibites fungal growth and delays RP solubilizing activity of two isolates. This inhibitory effect of La on RP solubilization varies with PSF (isolate P66 is more sensitive to La than P39 in this experiment). Comparing the pH value of culture media with soluble P content as affected by La application, only within individual isolate not different isolates the negatively significant relationship was observed.
文摘Phosphorus （P） is a major growth-limiting nutrient, and unlike the case of nitrogen （N）, there is no large atmospheric source that can be made biologically available. Moreover, P governs crucial role in plant as it stimulates root development and growth, gives plant rapid and vigorous start leading to better tillering and essential for many metabolic processes for seed formation. Soil microbes play very important role in bio-weathering and biodegradation. The microorganisms produce low molecular mass organic acids, which attack the phosphate structure and transform phosphorus from non-utilizable to the utilizable for the plants form. The test of the relative efficiency of isolated strains is carried out by selecting the microorganisms that are capable of producing a halo/clear zone on a plate owing to the production of organic acids into the surrounding medium. It is a well-known fact that as the particle size of rock phosphate decreases, the microbe mediated solubilization of rock phosphate increases in soil. In the present investigation, microbial solubilization of nano rock phosphate （〈 100 nm） particles was studied. Experimental results revealed that Pseudomonas striata solubilized 11.45% of the total P after 24 h of incubation from nano rock phosphate particles while 28.95% and 21.19% of the total P was solubilized by Aspergillus niger （black pigmented） and Aspergillus niger （green pigmented）, respectively. It was also observed that Aspergillus niger has the higher ability to dissolve Udaipur rock phosphate than Pseudomonas striata.
基金supported by the National Natural Science Foundation of China(Grant No.52200198)Taishan Scholars Project of Shandong Province(NO.tstp20230604)Natural Science Foundation of Shandong Province(Grant No.ZR2021QB186).
文摘To alleviate soil phosphorus deficiency,integrating straw-derived biochar with phosphate-solubilizing bacteria(PSB)has been recognized as a promising solution and is gaining growing attention.However,the mechanisms of bacterial immobilization and the influences of the physicochemical attributes of biochar remain unclear.In this study,we investigated the single-cell interactions of gram-negative Acinetobacter pittii and gram-positive Bacillus subtilis with cotton straw-derived biochars,subjected to progressively increasing pyrolysis temperatures,to understand the attributes of gradually modified biochar properties.The results revealed the correlations between adhesion forces and biochar properties(e.g.,surface area and surface charge),and the strongest adhesion for both strains for the biochar pyrolyzed at 700℃.The extended Derjaguin-Landau-Verwey-Overbeek(XDLVO)model,structured to predict interaction energy,was subsequently compared with experimental observations made using atomic force microscopy(AFM).Discrepancies between the predicted high adhesion barriers and the observed attraction suggested that forces beyond Lifshitz-van der Waals also influenced the immobilization of PSB.Adhesion-distance spectroscopy and XDLVO theory jointly revealed four distinct phases in the immobilization process by biochar:planktonic interaction,secondary minimum entrapment,primary barrier transcendence,and initial reversible adherence,collectively facilitating biofilm formation.Notably,initial reversible adhesion positively correlated with increased protein and polysaccharide levels in extracellular polymeric substances(EPS)(R^(2)>0.67),highlighting its importance in biofilm formation.Unraveling PSB–biochar interactions can improve the effectiveness of soil inoculants,thereby enhancing phosphorus availability in soil,a crucial factor for promoting plant growth and supporting environmental sustainability.
基金funded by the National Natural Science Foundation of China(42021005,22241603)the Chinese Academy of Sciences(ZDBS‐LY‐DQC027).
文摘Application of agricultural waste such as rapeseed meal(RM)is regarded as a sustainable way to improve soil phosphorus(P)availability by direct nutrient supply and stimulation of native phosphate‐solubilizing microorganisms(PSMs)in soils.However,exploration of the in situ microbial P solubilizing function in soils remains a challenge.Here,by applying both phenotype‐based single‐cell Raman with D_(2)O labeling(Raman‐D_(2)O)and genotype‐based high‐throughput chips targeting carbon,nitrogen and P(CNP)functional genes,the effect of RM application on microbial P solubilization in three typical farmland soils was investigated.The abundances of PSMs increased in two alkaline soils after RM application identified by single‐cell Raman D_(2)O.RM application reduced the diversity of bacterial communities and increased the abundance of a few bacteria with reported P solubilization function.Genotypic analysis indicated that RM addition generally increased the relative abundance of CNP functional genes.A correlation analysis of the abundance of active PSMs with the abundance of soil microbes or functional genes was carried out to decipher the linkage between the phenotype and genotype of PSMs.Myxococcota and C degradation genes were found to potentially contribute to the enhanced microbial P release following RM application.This work provides important new insights into the in situ function of soil PSMs.It will lead to better harnessing of agricultural waste to mobilize soil legacy P and mitigate the P crisis.
基金supported by the Shandong Provincial Natural Science Foundation of China(ZR2022MC215 and ZR2023MC045)the Innovation Pilot Project of Integration of Science,Education and Industry of Shandong Academy of Sciences(International Scientific and Technology Cooperation)(2024GH21 and 2024GH15).
文摘Biocontrol by inoculation with beneficial microbes is a proven strategy for reducing the negative effect of soil-borne pathogens.The effects of Trichoderma harzianum LTR-2 and Arthrobacter ureafaciens DnL1-1 on reducing Fusarium crown rot(FCR)disease and influencing microbial community structure in wheat root-zone were evaluated by a plot experiment.The experimental design consisted of four treatments:(1)control,(2)Fusarium pseudograminearum Fp(FP),(3)F.pseudograminearum+LTR-2(LFP),and(4)F.pseudograminearum+LTR-2+DnL1-1(HFP).The results showed that wheat seeds coated with LTR-2 spore suspension and combination of LTR-2 and DnL1-1 had relative control efficacies of 50.77%and 67.73%on FCR disease,and increased wheat yield by 58.32%and 64.19%,respectively.Illumina MiSeq sequencing revealed that bacterial and fungal abundance and diversity were significantly higher(P<0.05)in both treatment groups(HFP and LFP)than in FP and control groups.Principal coordinates analyses revealed that fungal and bacterial communities were distinctly separated among the treatment and control groups.Fungal community composition analysis demonstrated that the relative abundance of phytopathogenic fungi Alternaria,Fusarium,and Cladosporium decreased and that of beneficial fungi Mortierella and Gamsia was more enriched in HFP and LFP than in FP group.Bacterial community composition analysis revealed that the beneficial microbes,such as Bacillus and Streptomyces were more abundant in HFP and LFP than in FP group.LEfSe analysis indicated that the key different genera,e.g.Tetracladium(fungus),Sphingomonas and Ramlibacter(bacteria),which were significantly negatively correlated with TP in HFP treatment.It was concluded that application of LTR-2 and DnL1-1 may recruit a variety of phosphate-solubilizing microbes to promote wheat growth.Overall,these results confirm that the relative abundance of phytopathogenic fungi decreased significantly following application of LTR-2 alone and combined with DnL1-1 and beneficial microbes accumulated more easily in the wheat root-zone compared with that in FP and control groups.
