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1.
Bioresour Technol ; 367: 128235, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36332857

RESUMO

This study explored the coupling relationships between denitrifiers and N-transformation using multi-level (DNA, RNA and enzyme) and multi-aspect (abundance, diversity, structure, key community, network pattern, and functional module) analyses during cattle-manure (CM) and biochar (CMB) composting. Amino sugar-N (ASN, 0.914) and hydrolysable unknown-N (-0.724) were main organic-N components mediating NH4+-N in CM and CMB, respectively. Biochar lowered nirK, nirS, and nosZ genes copies, up-regulated nir gene transcripts, and inhibited nitrite reductase (NIR) activity. For nirK-denitrifiers, Luteimonas was predominant taxa influencing NO2--N and amino acid-N (AAN). Unclassified_k_norank_d_Bacteria and unclassified_p_Proteobacteria regulated NO3--N and ASN, respectively. These three genera played crucial roles in mediating NIR activity and nosZ/nirK. For nirS-denitrifiers, Paracoccus and Pseudomonas mediated NH4+-N and AAN, respectively, and they were vital genera regulating NO3--N, ASN and NIR activity. Furthermore, nirK-denitrifiers was major contributor to denitrification. Overall, functional denitrifiers might simultaneously participate in multiple N-transformation processes.


Assuntos
Compostagem , Bovinos , Animais , Esterco/microbiologia , Nitrogênio , Desnitrificação/genética , Proteobactérias , Solo/química , Microbiologia do Solo
2.
J Environ Manage ; 325(Pt B): 116694, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36343400

RESUMO

Poor management of crop residues leads to environmental pollution and composting is a sustainable practice for addressing the challenge. However, knowledge about composting with pure crop straw is still limited, which is a novel and feasible composting strategy. In this study, pure corn straw was in-situ composted for better management. Community structure of ß-glucosidase-producing microorganisms during composting was deciphered using high-throughput sequencing. Results showed that the compost was mature with organic matter content of 37.83% and pH value of 7.36 and pure corn straw could be composted successfully. Cooling phase was major period for cellulose degradation with the highest ß-glucosidase activity (476.25 µmol·p-Nitr/kg·dw·min) and microbial diversity (Shannon index, 3.63; Chao1 index, 500.81). Significant compositional succession was observed in the functional communities during composting with Streptomyces (14.32%), Trichoderma (13.85%) and Agromyces (11.68%) as dominant genera. ß-Glucosidase-producing bacteria and fungi worked synergistically as a network to degrade cellulose with Streptomyces (0.3045**) as the key community revealed by multi-interaction analysis. Organic matter (-0.415***) and temperature (-0.327***) were key environmental parameters regulating cellulose degradation via influencing ß-glucosidase-producing communities, and ß-glucosidase played a key role in mediating this process. The above results indicated that responses of ß-glucosidase-producing microorganisms to cellulose degradation were reflected at both network and individual levels and multi-interaction analysis could better explain the relationship between variables concerning composting cellulose degradation. The work is of significance for understanding cellulose degradation microbial communities and process during composting of pure corn straw.


Assuntos
Compostagem , Streptomyces , Trichoderma , beta-Glucosidase/metabolismo , Zea mays/metabolismo , Solo , Celulose/metabolismo , Trichoderma/metabolismo , Streptomyces/metabolismo , Esterco
3.
Artigo em Inglês | MEDLINE | ID: mdl-36251182

RESUMO

Microbes often form complex ecological networks in various habitats. Co-occurrence network analysis allows exploring the complex community interactions beyond the community diversities. This study explores the interspecific relationships within and between bacterial and fungal communities during composting of cow manure using co-occurrence network analysis. Furthermore, the keystone taxa that potentially exert a considerable impact on the microbiome were revealed by network analysis. The networks in the present study harbored more positive links. Specifically, the interactions/coupling within bacterial communities was tighter and the response to changes in external environmental conditions was more quickly during the composting process, while the fungal network had a better buffer capacity for changes in external environmental conditions. Interestingly, this result was authenticated in the bacterial-fungal (BF) network and the Mantel test of major modules and environmental variables. More than that, the Zi-Pi plot revealed that the keystone taxa including "module hubs" and "connectors" were all detected in these networks, which could prevent the dissociation of modules and networks.

4.
Biotechnol Biofuels Bioprod ; 15(1): 3, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35418139

RESUMO

BACKGROUND: ß-Glucosidase is the rate-limiting enzyme of cellulose degradation. It has been stipulated and established that ß-glucosidase-producing microbial communities differentially regulate the expression of glucose/non-glucose tolerant ß-glucosidase genes. However, it is still unknown if this differential expression of functional microbial community happens accidentally or as a general regulatory mechanism, and of what biological significance it has. To investigate the composition and function of microbial communities and how they respond to different carbon metabolism pressures and the transcriptional regulation of functional genes, the different carbon metabolism pressure was constructed by setting up the static chamber during composting. RESULTS: The composition and function of functional microbial communities demonstrated different behaviors under the carbon metabolism pressure. Functional microbial community up-regulated glucose tolerant ß-glucosidase genes expression to maintain the carbon metabolism rate by enhancing the transglycosylation activity of ß-glucosidase to compensate for the decrease of hydrolysis activity under carbon catabolite repression (CCR). Micrococcales play a vital role in the resistance of functional microbial community under CCR. The transcription regulation of GH1 family ß-glucosidase genes from Proteobacteria showed more obvious inhibition than other phyla under CCR. CONCLUSION: Microbial functional communities differentially regulate the expression of glucose/non-glucose tolerant ß-glucosidase genes under CCR, which is a general regulatory mechanism, not accidental. Furthermore, the differentially expressed ß-glucosidase gene exhibited species characteristics at the phylogenetic level.

5.
Arch Microbiol ; 204(4): 236, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35362815

RESUMO

Fungi are reputed to play a significant role in the composting matrix as decomposers of recalcitrant organic materials like cellulose and lignin. However, information on the fungi communities' roles in nitrogen transformation under a compost-biochar mixture is scarce. This study investigated shifts in fungal species mediating N transformation and their network patterns in cattle manure-corn straw (CMCS) and CMCS plus biochar (CMCB) composting using high-throughput sequencing data. The results revealed that the addition of biochar altered fungal richness and diversity and significantly influenced their compositions during composting. Biochar also altered the compost fungal network patterns; CMCS had a more complex network with higher positive links than CMCB, suggesting stable niche overlap. The consistent agreement of multivariate analyses (redundancy, network, regression, Mantel and path analyses) indicated that Ciliophora_sp in CMCS and unclassified_norank_Pleosporales in CMCB were the key fungal species mediating total N transformation, whereas Scedosporium_prolificans in CMCS and unclassified_Microascaceae in CMCB were identified as major predictive indices determining NO3--N transformation. Also, Coprinopsis cinerea and Penicillium oxalicum were the predictive factors for NH4+-N transformation in CMCS and CMCB during composting. These results indicated that the effects of biochar on N conversions in composting could be unraveled using multivariate analyses on fungi community evolution, network patterns, and metabolism.


Assuntos
Compostagem , Animais , Bovinos , Carvão Vegetal , Fungos/genética , Fungos/metabolismo , Esterco , Nitrogênio/metabolismo , Zea mays/metabolismo
6.
Bioresour Technol ; 339: 125515, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34332859

RESUMO

In this study, influence of biochar on nitrification was explored using multi-level (DNA, RNA, protein) and multi-aspect (diversity, structure, key community, co-occurrence pattern and functional modules) analyses (M-LAA) of ammonia-oxidizing microorganisms (AOMs) during cattle manure composting. Biochar addition increased the copy numbers and diversity of AOMs, restricted (36.02%) the amoA gene transcripts of archaea but increased (24.53%) those of bacteria, and reduced (75.86%) ammonooxygenase (AMO) activity. Crenarchaeota and Thaumarcheota mediated NH4+-N, Unclassified_k_norank_d_Archaea and Crenarchaeota regulated AMO activity and potential ammonia oxidation (PAO) rates. Nitrosomonas and Nitrosospira were the predominant microbial taxa influencing NH4+-N variation and PAO rates, respectively. Additionally, both Crenarchaeota and Nitrosospira played crucial roles in mediating NO3--N and NO2--N. Furthermore, biochar altered the network patterns of AOMs community by changing the keystone species and the interactivity among communities. These findings indicated that influence of biochar on nitrification could be better explained using M-LAA of AOMs.


Assuntos
Compostagem , Esterco , Amônia , Animais , Archaea/genética , Bovinos , Carvão Vegetal , Nitrificação , Oxirredução , Filogenia , Microbiologia do Solo
7.
Sci Total Environ ; 775: 145672, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-33618307

RESUMO

A few researchers have reported enhancing soil physicochemical properties and reducing greenhouse gas emission using biochar-compost mixture as an alternative method to address soil fertility, soil degradation and climate change. However, information about its effects on soil microbiome has rarely been studied. This investigation was on the impact of a combined biochar-compost application on soil physicochemical variables, fungal community composition, function and network patterns in maize at seedling stage (SS), reproductive stage (RS), and maturity stage (MS). The experimental design consists of five treatments: control (CNT), compost (CMP), composted biochar (CMB), compost fortified with biochar (CFWB), biochar (BCH). The results showed that CFWB, CMB, and CMP increased fungal diversity indices (Shannon, Sobs, and Chao) at the RS and MS stages respectively, compared to BCH and CNT. Distance-based redundancy analysis (db-RDA) at genus level indicated that the pH, available nitrogen, and soil organic matter at SS; available phosphorus at RS; Mg, Mn, Fe, and Zn at MS significantly and positively affected the fungi community. Based on the Linear discriminant analysis (LDA) and effect size (LEfSe) analysis, the results revealed that only Cystofilobasidiaceae and Guehomyces were the MS biomarkers; and significantly enriched in CFWB. FUNGuild analysis indicated that organic amendments (CFWB, CMB, CMP, and BCH) suppressed the abundance of plant pathogenic fungi (Edenia and Waitea) compared to CNT. Network analysis showed that CFWB and CMB had a high niche overlap and cross-feeding in their networks compared to other treatments. However, CMP network had more positive links with Saprotroph, Pathotroph-Saprotroph-Symbiotroph, Pathotroph and Pathotroph-Symbiotroph compared with other treatments. This study showed that applying biochar, compost and a mixture of both, positively affected soil fungal communities plus co-occurrence network pattern in a single cropping season. Thus, their application as soil amendments may improve the soil fungi ecosystem, soil health and quality and mitigate climate change.


Assuntos
Compostagem , Micobioma , Carvão Vegetal , Fungos , Solo , Microbiologia do Solo
8.
Sci Total Environ ; 765: 142738, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33097264

RESUMO

Increasing salinity and sodicity have been recognized as threats to soil fertility and crop yield worldwide. In recent years, salt-affected soils have received great attentions due to the shortage of arable land. This study therefore aims to characterize soil bacterial community, assembly process and co-occurrence network along natural saline-sodic gradients across Songnen Plain, Northeast China. As revealed by Miseq sequencing, 8482 bacterial OTUs were annotated at 97% identity across 120 soil samples. Our results indicated that soil salinity-sodicity not only significantly decreased bacterial richness and but also impacted bacterial community composition. The dominant bacterial phyla included Proteobacteria (28.89%), Actinobacteria (19.96%) and Gemmatimonadetes (16.71%). By applying threshold indicator species analysis (TITAN), OTUs from Gemmatimonadetes were found to be the taxa with the most prevalent and strongest preference for high salinity-sodicity. Null model analysis revealed that the majority (76.4%) of ßNTI values were below -2 or above 2, indicating deterministic process was dominant across all samples. Notably, deterministic process contributed to a greater extent in higher saline-sodic soils. The bacterial co-occurrence network was more complex in slightly saline-sodic soils than in moderately and extremely saline-sodic soils, reflected by more nodes, more hubs and stronger connections, which was mainly driven by soil pH. These results provide strong evidence that salinity-sodicity was a key determinant in shaping soil bacterial community, assembly process and co-occurrence network pattern.


Assuntos
Microbiota , Solo , China , Salinidade , Cloreto de Sódio
9.
Bioresour Technol ; 323: 124572, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33370679

RESUMO

This study investigated nitrification process during cattle manure-maize straw (CM) and biochar (CMB) composting in terms of multi-variable interaction (MVI) among environmental parameters, ammonia-oxidizing archaea (AOA) and bacteria (AOB) community structure, nitrogen-related enzymes as well as substrates using structural equation model (SEM). Results showed that adding biochar significantly reduced potential ammonia oxidation rates. SEM analysis revealed that AOB was affected by temperature and pH, which stimulated the release of urease, increased NH4+-N concentration and finally exerted influence on nitrification in CM. Temperature (0.755) and NO2--N (-0.994) were identified as the main factors mediating nitrification in CM and CMB, respectively. Moreover, MVI analysis indicated that nitrification and denitrification occurred simultaneously. Mutual verification of SEM and quantitative analyses (RNA level) confirmed that AOB predominated nitrification. The above results indicated that nitrification could be better explained by MVI using SEM during composting.


Assuntos
Compostagem , Esterco , Amônia , Animais , Archaea , Bovinos , Carvão Vegetal , Nitrificação , Oxirredução , Solo , Microbiologia do Solo , Zea mays
10.
PeerJ ; 8: e8844, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32341890

RESUMO

Organic fertilizer application could have an impact on the nitrogen cycle mediated by microorganisms in arable soils. However, the dynamics of soil ammonia oxidizers and denitrifiers in response to compost addition are less understood. In this study, we examined the effect of four compost application rates (0, 11.25, 22.5 and 45 t/ha) on soil ammonia oxidizers and denitrifiers at soybean seedling, flowering and mature stage in a field experiment in Northeast China. As revealed by quantitative PCR, compost addition significantly enhanced the abundance of ammonia oxidizing bacteria (AOB) at seedling stage, while the abundance of ammonia oxidizing archaea was unaffected across the growing season. The abundance of genes involved in denitrification (nirS, nirK and nosZ) were generally increased along with compost rate at seedling and flowering stages, but not in mature stage. The non-metric multidimensional scaling analysis revealed that moderate and high level of compost addition consistently induced shift in AOB and nirS containing denitrifers community composition across the growing season. Among AOB lineages, Nitrosospira cluster 3a gradually decreased along with the compost rate across the growing season, while Nitrosomonas exhibited an opposite trend. Network analysis indicated that the complexity of AOB and nirS containing denitrifiers network gradually increased along with the compost rate. Our findings highlighted the positive effect of compost addition on the abundance of ammonia oxidizers and denitrifiers and emphasized that compost addition play crucial roles in shaping their community compositions and co-occurrence networks in black soil of Northeast China.

11.
Sci Total Environ ; 721: 137759, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32172117

RESUMO

A better understanding of the microbial group influencing nitrogen (N) dynamics and cycling in composting matrix is critical in achieving good management to alleviate N loss and improve final compost quality. This study investigated the bacterial composition, structure, co-occurrence network patterns and topological roles of N transformation in cattle manure-maize straw composting using high-throughput sequencing. The two treatments used in this experiment were cattle manure and maize straw mixture (CM) and CM with 10% biochar addition (CMB). In both treatments, the bacterial community composition varied during composting and the major phyla included Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes and Chloroflexi. The phyla Actinobacteria and Proteobacteria were more abundant in CMB treatment while Firmicutes was abundant in CM piles. The metabolic functional profiles of bacteria was predicted using the "phylogenetic investigation of communities by reconstruction of unobserved states" (PICRUSt) which revealed that except for cellular processes pathway, CMB had slight higher abundance in metabolism, genetic information processing and environmental information processing than the CM. Pearson correlation revealed more significant relationship between the important bacteria communities and N transformation in CMB piles compared with CM. Furthermore, network pattern analysis revealed that the bacterial networks in biochar amended piles are more complex and harbored more positive links than that of no biochar piles. Corresponding agreement of multivariate analyses (correlation heatmap, stepwise regression, Path and network analyses) revealed that Psychrobacter, Thermopolyspora and Thermobifida in CM while Corynebacterium_1, Thermomonospora and Streptomyces in CMB were key bacterial genera affecting NH4+-N, NO3--N and total nitrogen (TN) transformation respectively during composting process. These results provide insight into nitrogen transformation and co-occurrence patterns mediating microbes and bacterial metabolism which could be useful in enhancing compost quality and mitigating N loss during composting.


Assuntos
Compostagem , Microbiota , Animais , Bovinos , Carvão Vegetal , Esterco , Nitrogênio , Filogenia , Solo , Zea mays
12.
Waste Manag ; 105: 190-197, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32078983

RESUMO

Analyzing diazotrophic community may help to understand nitrogen transformation in composting and improves the final compost quality. In this study, diazotrophic community dynamics were investigated in terms of nifH gene during dairy manure and corn straw composting with biochar addition using high-throughput sequencing. Biochar decreased the diversity of diazotrophic community and altered diazotroph community structure during composting. At phylum level, Proteobacteria, Actinobacteria and Firmicutes were dominant diazotrophic communities throughout composting process. Biochar addition registered higher correlation coefficient (R) between physicochemical factors (temperature, ammonium (NH4+-N) and nitrate (NO3--N)) and diazotroph community composition. Rhodopseudomonas and Pseudoxanthomonas was the key diazotrophic communities influencing NH4+-N transformation in control (CK) and biochar compost (BC), respectively, while for NO3--N transformation Clostridium and Bradyrhizobium in CK, Azospira and Methylocystis in BC served as predominant factors. These results indicated that addition of biochar altered the key diazotroph communities influencing nitrogen transformation. Furthermore, some diazotrophs (e.g. Rhodopseudomonas, Bradyrhizobium and Azospira) affecting NH4+-N and NO3--N transformation were also observed to be mediating total nitrogen (TN). Interestingly, interactions between diazotrophic communities were observed and these interactions could also influence nitrogen transformation.


Assuntos
Compostagem , Carvão Vegetal , Esterco , Nitrogênio , Solo
13.
Ecotoxicol Environ Saf ; 191: 110161, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954219

RESUMO

Denitrification and nitrification processes are the two prominent pathways of nitrogen (N) transformation in composting matrix. This study explored the dynamics of denitrifying and nitrifying bacteria at different composting stages of cow manure and corn straw using functional gene sequencing at DNA and cDNA levels. Corresponding agreement among OTUs, NMDS, mental test and network analyses revealed that functional bacteria community compositions and responses to physicochemical factors were different at DNA and cDNA levels. Specifically, some OTUs were detected at the DNA level but were not observed at cDNA level, differences were also found in the distribution patterns of nitrifying and denitrifying bacteria communities at both levels. Furthermore, co-occurrence network analysis indicated that Pseudomonas, Paracoccus and Nitrosomonas were identified as the keystone OTUs at the DNA level, while Paracoccus, Agrobacterium and Nitrosospira were keystone OTUs at the cDNA level. Mantel test revealed that TN, C/N and moisture content significantly influenced both the denitrifying bacteria and ammonia-oxidizing bacteria (AOB) communities at the DNA level. NO3--N, NH4+-N, TN, C/N, and moisture content only registered significant correlation with the nosZ-type denitrifiers and ammonia-oxidizing bacteria (AOB) communities at the cDNA level. Structural equation model (SEM) showed that TN, NH4+-N, and pH were direct and significantly influenced the gene abundance of denitrifying bacteria. Howbeit, TN, NH4+-N, and NO3--N had significant direct effects on amoA gene abundance.


Assuntos
Betaproteobacteria/isolamento & purificação , Compostagem , DNA Bacteriano/genética , DNA Complementar/genética , Esterco/microbiologia , Amônia/metabolismo , Animais , Betaproteobacteria/genética , Betaproteobacteria/metabolismo , Bovinos , China , Desnitrificação , Feminino , Microbiota/genética , Nitrificação , Nitrogênio/metabolismo , Oxirredução
14.
Biotechnol Appl Biochem ; 67(5): 799-811, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31746033

RESUMO

In this study, nutrient loss, the direct and indirect relationship between period, compost types, temperature, total nitrogen (TN), nitrate nitrogen (NO3 - -N), ammonium nitrogen (NH4 + -N), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) were investigated during composting of cattle manure-maize straw mixture. This study findings revealed that biochar addition lowered NH4 + -N but did not increase NO3 - -N concentrations unlike no biochar piles during composting. The first-order kinetic models showed that biochar accelerated organic matter (OM) degradation and improved nitrogen mineralization, consequently reducing TN losses by 13.6% and OM losses by 12.66%. Transformation ratio of MBC/MBN, coupled with other chemical components of the entire microbial community, suggested a shift in the microbial succession and diversity during composting from the dominant bacteria and actinomycetes to fungi. The structural equation model and path coefficient revealed temperature to be the main factor mediating the evolution of MBC and MBN in composting. The physicochemical variables, phytotoxicity, and final product quality revealed that biochar incorporation to the composting feedstock is an ideal material for mitigating problems of TN and OM losses in composting and ultimately enhancing the fertility potential of the final compost product.


Assuntos
Carvão Vegetal/metabolismo , Compostagem/métodos , Esterco , Microbiota , Nitrogênio/metabolismo , Zea mays/metabolismo , Compostos de Amônio/metabolismo , Animais , Biomassa , Bovinos , Esterco/análise , Esterco/microbiologia , Nitratos/metabolismo , Zea mays/microbiologia
15.
Bioresour Technol ; 291: 121815, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31344636

RESUMO

In this study, mechanism of nitrogen transformation was investigated in terms of genetic associations (nitrogen-related gene groups) in co-composting of cattle manure and rice straw. Mutual validation among KEGG, Pearson correlation, stepwise regression, and Path analyses indicated that the functional genes synergistically affected on nitrogen transformation in composting process. NxrA/qnorB (0.9419 ±â€¯0.0334) and (amoA + anammox)/Bacteria (0.7187 ±â€¯0.0334) were the key functional gene groups mediating NH4+-N transformation. AmoA/(narG + napA) (-0.8400 ±â€¯0.0129), amoA/bacteria (0.8692 ±â€¯0.0273), and (nirK + nirS)/nosZ (1.1652 ±â€¯0.0089) determined NO3--N, NO2--N and N2O transformation, respectively. AmoA/(napA + narG) mediated both NO3--N and NO2--N transformation. AmoA/anammox (-0.7172 ±â€¯0.0591) and (nirK + nirS)/nosZ (-0.6626 ±â€¯0.0825) served as predominant factors for total nitrogen removal. These results provided a molecular-level insight that nitrification, anaerobic ammonia oxidation and denitrification (SNAD) might simultaneously contribute to nitrogen transformation during composting, rather than sequentially.


Assuntos
Compostagem , Oryza , Animais , Bovinos , Desnitrificação , Esterco , Nitrificação , Nitrogênio
16.
Waste Manag ; 92: 59-67, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31160027

RESUMO

Insight to nitrogen transformation and cycling during composting is vital in developing management strategies that improve nitrogen content and quality of the end product. In this study, a positive ventilation device was constructed and used to elucidate nitrogen transformation and microbial community structures during the composting of cow manure and rice straw. Bacterial community successions were analyzed during the composting process by examining the change in their structural dynamics using high-throughput sequencing technique. The results revealed that dominant phyla, included Acidobacter, Proteobacteria, Firmicutes, Bacteroidetes, Chloroflexi, and Actinobacteria. Furthermore, a positive strong correlation was observed between the key bacterial communities and nitrogen transformation. Analyses of functional genera, Spearman correlation and Path showed that Thermomonospora_curvata_DSM_43183 followed by Luteimonas and Simiduia, Brevundimonas and Tamlana, Pseudomonas followed by Brevundimonas and Flavobacterium were the key bacterial communities affecting NH4+-N, NO3--N, and NO2--N transformation, respectively. Thauera followed by Pseudomonas_putida_NBRC_14164 played a dominant role in N2O transformation.


Assuntos
Compostagem , Microbiota , Animais , Bovinos , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Esterco , Nitrogênio , Solo
17.
Front Microbiol ; 10: 529, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30936861

RESUMO

In composting system, the composition of microbial communities is determined by the constant change in the physicochemical parameters. This study explored the dynamics of bacterial and fungal communities during cow manure and corn straw composting using high throughput sequencing technology. The relationships between physicochemical parameters and microbial community composition and abundance were also evaluated. The sequencing results revealed the major phyla included Proteobacteria, Bacteroidetes, Firmicutes, Chloroflexi and Actinobacteria, Ascomycota, and Basidiomycota. Linear discriminant analysis effect size (LEfSe) illustrated that Actinomycetales and Sordariomycetes were the indicators of bacteria and fungi in the maturation phase, respectively. Mantel test showed that NO3 --N, NH4 +-N, TN, C/N, temperature and moisture content significantly influenced bacterial community composition while only TN and moisture content had a significant effect on fungal community structure. Structural equation model (SEM) indicated that TN, NH4 +-N, NO3 --N and pH had a significant effect on fungal abundance while TN and temperature significantly affected bacterial abundance. Our finding increases the understanding of microbial community succession in cow manure and corn straw composting under natural conditions.

18.
Can J Microbiol ; 65(6): 436-449, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30861347

RESUMO

This study applied high-throughput sequencing technology and PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved state) to examine the microbial population dynamics during the composting of dairy manure and rice straw in a static (without turning) composting system. The results showed that the composition of the bacterial community varied significantly during the composting process. The dominant phyla included Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi. Biodiversity indices showed that bacterial community diversity had the peak value during the mesophilic phase. Redundancy analysis indicated that nitrogen was the most important factor in the distribution of genera during the composting process. Finally, the Pearson correlation results suggested that Thermomonospora and Thermopolyspora could be the biomarkers of the composting maturation phase. The metabolic characteristics of the bacterial communities were predicted by PICRUSt. The result showed that metabolism of amino acids, lipids, and most of the carbohydrates increased during the whole composting treatment. However, methane metabolism, carbon fixation pathways in prokaryotes, and nucleotide metabolism decreased after the thermophilic phase. The present study provides a better understanding for bacterial community composition and function succession in dairy manure composting.


Assuntos
Bactérias/isolamento & purificação , Compostagem , Esterco/microbiologia , Microbiologia do Solo , Animais , Bactérias/classificação , Biodiversidade , Bovinos , Nitrogênio , Oryza/microbiologia , Filogenia
19.
Front Microbiol ; 9: 169, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29467752

RESUMO

Arbuscular mycorrhizal (AM) fungi form symbiotic associations with most crop plant species in agricultural ecosystems, and are conspicuously influenced by various agricultural practices. To understand the impact of compost addition on AM fungi, we examined effect of four compost rates (0, 11.25, 22.5, and 45 Mg/ha) on the abundance and community composition of AM fungi in seedling, flowering, and mature stage of soybean in a 1-year compost addition experiment system in Northeast China. Soybean [Glycine max (L.) Merrill] was used as test plant. Moderate (22.5 Mg/ha) and high (45 Mg/ha) levels of compost addition significantly increased AM root colonization and extraradical hyphal (ERH) density compared with control, whereas low (11.5 Mg/ha) level of compost addition did not cause significant increase in AM root colonization and ERH density. AM fungal spore density was significantly enhanced by all the compost rates compared with control. The temporal variations analysis revealed that, AM root colonization in seedling stage was significantly lower than in flowering and mature stage. Although AM fungal operational taxonomic unit richness and community composition was unaffected by compost addition, some abundant AM fungal species showed significantly different response to compost addition. In mature stage, Rhizophagus fasciculatum showed increasing trend along with compost addition gradient, whereas the opposite was observed with Paraglomus sp. In addition, AM fungal community composition exhibited significant temporal variation during growing season. Further analysis indicated that the temporal variation in AM fungal community only occurred in control treatment, but not in low, moderate, and high level of compost addition treatments. Our findings highlighted the significant effects of compost addition on AM growth and sporulation, and emphasized that growth stage is a stronger determinant than 1-year compost addition in shaping AM fungal community in black soil of Northeast China.

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