Paddy soil is frequently flooded,which leads to anaerobic decomposition of soil organic matter(SOM)to produce CO_(2) and CH_(4).Currently,there is limited research about the impact of nanoparticles on anaerobic SOM de...Paddy soil is frequently flooded,which leads to anaerobic decomposition of soil organic matter(SOM)to produce CO_(2) and CH_(4).Currently,there is limited research about the impact of nanoparticles on anaerobic SOM decomposition and CH_(4) production in paddy soil.This study investigates the effects of iron oxide nanoparticles(Fe_(3)O_(4) NPs)and multi-walled carbon nanotubes(MWCNTs)on anaerobic SOM decomposition in two paddy soils.The findings showed that addition of nanoparticles(Fe_(3)O_(4) NPs:0.08%and 0.3%;MWCNTs:0.05%and 0.2%)reduced methane production by 7.48%−31.72%in Guiyang soil and 3.32%−31.24%in Fuyang soil,with decrease in SOM decomposition of 32.19%−47.87%and 19.60%−33.09%,respectively.However,the CH_(4)/TIC(total inorganic carbon)ratio was elevated(by 3.17%to 61.92%)after nanoparticles amendment,suggested that TIC production was more significantly suppressed than CH_(4).The Prolixibacteraceae,which usually involve in organic macromolecule decomposition,decreased in relative abundance with inhibition of CH_(4) production by nanoparticles in both soils,suggesting their sensitivity to nanoparticles.In contrast,the relative abundances of many microbial populations increased with the intensified inhibition of soil mineralization by nanoparticles in both soils.Especially,Sedimentibacter and Melioribacterae increased with inhibition of CH_(4) by nanoparticles,and Clostridiaceae,Minicystis as well as Rhodomicrobium increased with the CH_(4)/TIC ratio in both soils,probably because they might provide substrates for methanogens.These results suggested that nanoparticles not only inhibit the decomposition of SOM but also change the fate of decomposed carbon through modulating microbial populations,leading to a substantial increase in the proportion of CH_(4) produced from SOM decomposition.展开更多
Microorganisms were reported to be the indicators and drivers of metal(loid)s-contaminated soils.Chloroflexota is a widelydistributed phylum in arsenic(As)and antimony(Sb)contaminated soils,but the diversity and funct...Microorganisms were reported to be the indicators and drivers of metal(loid)s-contaminated soils.Chloroflexota is a widelydistributed phylum in arsenic(As)and antimony(Sb)contaminated soils,but the diversity and functional potential of its genomes remain largely unknown.In this study,we collected As and Sb contaminated soils from smelting-affected agricultural soils and mining soils,with the latter exhibiting much higher concentrations of As(mean 19421.2 mg kg^(‒1))and Sb(mean 4953.5 mg kg^(‒1))as well as lower carbon and nitrogen levels.We reconstructed 170 medium-to high-quality metagenome-assembled genomes(MAGs)of Chloroflexota from these soils.A total of 11 MAGs were proposed as novel candidate species,including 3 novel candidate genera affiliated with the classes Ktedonobacteria,Limnocylindria,and Dormibacteria.Functional annotation reveals that many MAGs from Ktedonobacteria and Dormibacteria may have novel potential for carbon fixation through the Calvin-Benson-Bassham cycle.Additionally,many Chloroflexota MAGs harbored essential genes involved in enhancing soil phosphorus(P)availability.In Chloroflexota MAGs,the gene responsible for extracellular oxidation,dldH,rather than the intracellular oxidation gene arsO,was widespread for Sb(III)oxidation.Under heavy As and Sb contamination and nutrient limitation,Chloroflexota MAGs exhibited higher guanine-cytosine contents and smaller genome sizes.Moreover,MAGs derived from these conditions were enriched with a higher proportion of genes related to Sb oxidation,As/P transport,As reduction and methylation,as well as pathways involved in carbohydrate degradation and bioavailable nitrogen biosynthesis.These findings might be helpful for developing bioremediation strategy for Chloroflexota in As/Sb contaminated soils.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42177116)complementary fund from the Guizhou Provincial Department of Science and Technology+1 种基金Guizhou Provincial 2021 Science and Technology Subsidies(Grant No.GZ2021SIG)the Chinese Academy of Sciences“Light of West China”Program.
文摘Paddy soil is frequently flooded,which leads to anaerobic decomposition of soil organic matter(SOM)to produce CO_(2) and CH_(4).Currently,there is limited research about the impact of nanoparticles on anaerobic SOM decomposition and CH_(4) production in paddy soil.This study investigates the effects of iron oxide nanoparticles(Fe_(3)O_(4) NPs)and multi-walled carbon nanotubes(MWCNTs)on anaerobic SOM decomposition in two paddy soils.The findings showed that addition of nanoparticles(Fe_(3)O_(4) NPs:0.08%and 0.3%;MWCNTs:0.05%and 0.2%)reduced methane production by 7.48%−31.72%in Guiyang soil and 3.32%−31.24%in Fuyang soil,with decrease in SOM decomposition of 32.19%−47.87%and 19.60%−33.09%,respectively.However,the CH_(4)/TIC(total inorganic carbon)ratio was elevated(by 3.17%to 61.92%)after nanoparticles amendment,suggested that TIC production was more significantly suppressed than CH_(4).The Prolixibacteraceae,which usually involve in organic macromolecule decomposition,decreased in relative abundance with inhibition of CH_(4) production by nanoparticles in both soils,suggesting their sensitivity to nanoparticles.In contrast,the relative abundances of many microbial populations increased with the intensified inhibition of soil mineralization by nanoparticles in both soils.Especially,Sedimentibacter and Melioribacterae increased with inhibition of CH_(4) by nanoparticles,and Clostridiaceae,Minicystis as well as Rhodomicrobium increased with the CH_(4)/TIC ratio in both soils,probably because they might provide substrates for methanogens.These results suggested that nanoparticles not only inhibit the decomposition of SOM but also change the fate of decomposed carbon through modulating microbial populations,leading to a substantial increase in the proportion of CH_(4) produced from SOM decomposition.
基金financially supported by the National Key Research and Development Program of China(Grant No.2020YFC1807700)by complementary fund from the Guizhou Provincial Department of Science and Technology+2 种基金by Guizhou Provincial 2021 Science and Technology Subsidies(Grant No.GZ2021SIG)by the Chinese Academy of Sciences"Light of West China"Programby Guizhou Provincial Science and Technology Projects(Grant No.ZK[2022]328).
文摘Microorganisms were reported to be the indicators and drivers of metal(loid)s-contaminated soils.Chloroflexota is a widelydistributed phylum in arsenic(As)and antimony(Sb)contaminated soils,but the diversity and functional potential of its genomes remain largely unknown.In this study,we collected As and Sb contaminated soils from smelting-affected agricultural soils and mining soils,with the latter exhibiting much higher concentrations of As(mean 19421.2 mg kg^(‒1))and Sb(mean 4953.5 mg kg^(‒1))as well as lower carbon and nitrogen levels.We reconstructed 170 medium-to high-quality metagenome-assembled genomes(MAGs)of Chloroflexota from these soils.A total of 11 MAGs were proposed as novel candidate species,including 3 novel candidate genera affiliated with the classes Ktedonobacteria,Limnocylindria,and Dormibacteria.Functional annotation reveals that many MAGs from Ktedonobacteria and Dormibacteria may have novel potential for carbon fixation through the Calvin-Benson-Bassham cycle.Additionally,many Chloroflexota MAGs harbored essential genes involved in enhancing soil phosphorus(P)availability.In Chloroflexota MAGs,the gene responsible for extracellular oxidation,dldH,rather than the intracellular oxidation gene arsO,was widespread for Sb(III)oxidation.Under heavy As and Sb contamination and nutrient limitation,Chloroflexota MAGs exhibited higher guanine-cytosine contents and smaller genome sizes.Moreover,MAGs derived from these conditions were enriched with a higher proportion of genes related to Sb oxidation,As/P transport,As reduction and methylation,as well as pathways involved in carbohydrate degradation and bioavailable nitrogen biosynthesis.These findings might be helpful for developing bioremediation strategy for Chloroflexota in As/Sb contaminated soils.
