NovelP450norGene Detection Assay Used To Characterize the Prevalence and Diversity of Soil Fungal Denitrifiers

ABSTRACTDenitrifying fungi produce nitrous oxide (N2O), a potent greenhouse gas, as they generally lack the ability to convert N2O to dinitrogen. Contrary to the case for bacterial denitrifiers, the prevalence and diversity of denitrifying fungi found in the environment are not well characterized. In this study, denitrifying fungi were isolated from various soil ecosystems, and novel PCR primers targeting theP450norgene, encoding the enzyme responsible for the conversion of nitric oxide to N2O, were developed, validated, and used to study the diversity of cultivable fungal denitrifiers. This PCR assay was also used to detectP450norgenes directly from environmental soil samples. Fungal denitrification capabilities were further validated using an N2O gas detection assay and a PCR assay targeting thenirKgene. A collection of 492 facultative anaerobic fungi was isolated from 15 soil ecosystems and taxonomically identified by sequencing the internal transcribed spacer sequence. Twenty-seven fungal denitrifiers belonging to 10 genera had theP450norand thenirKgenes and produced N2O from nitrite. N2O production is reported in strains not commonly known as denitrifiers, such asByssochlamys nivea,Volutella ciliata,Chloridiumspp., andTrichocladiumspp. The prevalence of fungal denitrifiers did not follow a soil ecosystem distribution; however, a higher diversity was observed in compost and agricultural soils. The phylogenetic trees constructed using partialP450norandnirKgene sequences revealed that both genes clustered taxonomically closely related strains together.IMPORTANCEA PCR assay targeting theP450norgene involved in fungal denitrification was developed and validated. The newly developedP450norprimers were used on fungal DNA extracted from a collection of fungi isolated from various soil environments and on DNA directly extracted from soil. The results indicated that approximatively 25% of all isolated fungi possessed this gene and were able to convert nitrite to N2O. All soil samples from which denitrifying fungi were isolated also tested positive for the presence ofP450nor. TheP450norgene detection assay was reliable in detecting a large diversity of fungal denitrifiers. Due to the lack of homology existing betweenP450norand bacterial denitrification genes, it is expected that this assay will become a tool of choice for studying fungal denitrifiers.

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Co-Occurring Anammox, Denitrification, and Codenitrification in Agricultural Soils

Applied and Environmental Microbiology ◽

10.1128/aem.02520-12 ◽

2012 ◽

Vol 79 (1) ◽

pp. 168-176 ◽

Cited By ~ 110

Author(s):

Andrew Long ◽

Joshua Heitman ◽

Craig Tobias ◽

Rebecca Philips ◽

Bongkeun Song

Keyword(s):

Agricultural Soils ◽

The United States ◽

Soil Samples ◽

Soil Incubation ◽

Production Rates ◽

Content Type ◽

The North ◽

Incubation Experiments ◽

Bacteria And Fungi ◽

Isotope Analyses

ABSTRACTAnammox and denitrification mediated by bacteria are known to be the major microbial processes converting fixed N to N2gas in various ecosystems. Codenitrification and denitrification by fungi are additional pathways producing N2in soils. However, fungal codenitrification and denitrification have not been well investigated in agricultural soils. To evaluate bacterial and fungal processes contributing to N2production, molecular and15N isotope analyses were conducted with soil samples collected at six different agricultural fields in the United States. Denitrifying and anammox bacterial abundances were measured based on quantitative PCR (qPCR) of nitrous oxide reductase (nosZ) and hydrazine oxidase (hzo) genes, respectively, while the internal transcribed spacer (ITS) ofFusarium oxysporumwas quantified to estimate the abundance of codenitrifying and denitrifying fungi.15N tracer incubation experiments with15NO3−or15NH4+addition were conducted to measure the N2production rates from anammox, denitrification, and codenitrification. Soil incubation experiments with antibiotic treatments were also used to differentiate between fungal and bacterial N2production rates in soil samples. Denitrifying bacteria were found to be the most abundant, followed byF. oxysporumbased on the qPCR assays. The potential denitrification rates by bacteria and fungi ranged from 4.118 to 42.121 nmol N2-N g−1day−1, while the combined potential rates of anammox and codenitrification ranged from 2.796 to 147.711 nmol N2-N g−1day−1. Soil incubation experiments with antibiotics indicated that fungal codenitrification was the primary process contributing to N2production in the North Carolina soil. This study clearly demonstrates the importance of fungal processes in the agricultural N cycle.

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Detection and Diversity of Fungal Nitric Oxide Reductase Genes (p450nor) in Agricultural Soils

Applied and Environmental Microbiology ◽

10.1128/aem.00243-16 ◽

2016 ◽

Vol 82 (10) ◽

pp. 2919-2928 ◽

Cited By ~ 27

Author(s):

Steven A. Higgins ◽

Allana Welsh ◽

Luis H. Orellana ◽

Konstantinos T. Konstantinidis ◽

Joanne C. Chee-Sanford ◽

...

Keyword(s):

Nitric Oxide ◽

Agricultural Soils ◽

Agricultural Practices ◽

Environmental Dna ◽

Pcr Primers ◽

Amino Acid Identity ◽

N Loss ◽

Content Type ◽

Denitrification Potential ◽

Fungal Isolates

ABSTRACTMembers of the Fungi convert nitrate (NO3−) and nitrite (NO2−) to gaseous nitrous oxide (N2O) (denitrification), but the fungal contributions to N loss from soil remain uncertain. Cultivation-based methodologies that include antibiotics to selectively assess fungal activities have limitations, and complementary molecular approaches to assign denitrification potential to fungi are desirable. Microcosms established with soils from two representative U.S. Midwest agricultural regions produced N2O from added NO3−or NO2−in the presence of antibiotics to inhibit bacteria. Cultivation efforts yielded 214 fungal isolates belonging to at least 15 distinct morphological groups, 151 of which produced N2O from NO2−. Novel PCR primers targeting thep450norgene, which encodes the nitric oxide (NO) reductase responsible for N2O production in fungi, yielded 26 novelp450noramplicons from DNA of 37 isolates and 23 amplicons from environmental DNA obtained from two agricultural soils. The sequences shared 54 to 98% amino acid identity with reference P450nor sequences within the phylumAscomycotaand expand the known fungal P450nor sequence diversity.p450norwas detected in all fungal isolates that produced N2O from NO2−, whereasnirK(encoding the NO-forming NO2−reductase) was amplified in only 13 to 74% of the N2O-forming isolates using two separatenirKprimer sets. Collectively, our findings demonstrate the value ofp450nor-targeted PCR to complement existing approaches to assess the fungal contributions to denitrification and N2O formation.IMPORTANCEA comprehensive understanding of the microbiota controlling soil N loss and greenhouse gas (N2O) emissions is crucial for sustainable agricultural practices and addressing climate change concerns. We report the design and application of a novel PCR primer set targeting fungalp450nor, a biomarker for fungal N2O production, and demonstrate the utility of the new approach to assess fungal denitrification potential in fungal isolates and agricultural soils. These new PCR primers may find application in a variety of biomes to assess the fungal contributions to N loss and N2O emissions.

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Comparative Clinical Evaluation of NeoPlex RB-8 with Seeplex PneumoBacter ACE for Simultaneous Detection of Eight Respiratory Bacterial Pathogens

Journal of Clinical Microbiology ◽

10.1128/jcm.01500-19 ◽

2019 ◽

Vol 58 (2) ◽

Author(s):

Jeong Woo Kim ◽

Seong Soo Hong ◽

In Seop Lee ◽

Hyun Young Chi ◽

Soo-Ok Kim ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Legionella Pneumophila ◽

Simultaneous Detection ◽

Nasopharyngeal Swab ◽

Pcr Assay ◽

Content Type ◽

Bordetella Parapertussis ◽

Molecular Assays ◽

Detection Assay ◽

Higher Sensitivity

ABSTRACT There are several convenient and accurate molecular assays to detect respiratory bacterial infection. The NeoPlex RB-8 detection kit (NeoPlex RB-8) is a new multiplex real-time PCR assay that simultaneously detects Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, Haemophilus influenzae, Bordetella pertussis, Bordetella parapertussis, and Moraxella catarrhalis in a single test. This study compared the clinical concordance of NeoPlex RB-8 with another method, Seeplex PneumoBacter ACE detection assay (Seeplex PB ACE), which simultaneously detects S. pneumoniae, M. pneumoniae, C. pneumoniae, L. pneumophila, H. influenzae, and B. pertussis. We tested 2,137 nasopharyngeal swab and sputum specimens using both assays. For discordant Bordetella parapertussis and M. catarrhalis specimens, we also performed bidirectional sequencing. For S. pneumoniae, M. pneumoniae, C. pneumoniae, L. pneumophila, H. influenzae, and B. pertussis, which are detected by both NeoPlex RB-8 and Seeplex PB ACE, the positive and negative agreement between the two assays ranged from 91.7 to 100% (κ = 0.918 to 1). S. pneumoniae and H. influenzae were the most discordant targets and measured with higher sensitivity and specificity by NeoPlex RB-8 than Seeplex PB ACE. For Bordetella parapertussis and M. catarrhalis, which are not detected by Seeplex PB ACE, NeoPlex RB-8 sensitivity and specificity were >99%. Overall, NeoPlex RB-8 was highly comparable to Seeplex PB ACE, but NeoPlex RB-8 was more clinically accurate, with higher throughput and more convenience.

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Comparison of Assays for Sensitive and Reproducible Detection of Cell Culture-Infectious Cryptosporidium parvum and Cryptosporidium hominis in Drinking Water

Applied and Environmental Microbiology ◽

10.1128/aem.06444-11 ◽

2011 ◽

Vol 78 (1) ◽

pp. 156-162 ◽

Cited By ~ 27

Author(s):

Anne M. Johnson ◽

George D. Di Giovanni ◽

Paul A. Rochelle

Keyword(s):

Cell Culture ◽

Drinking Water ◽

Cryptosporidium Parvum ◽

False Positives ◽

Rt Pcr ◽

Pcr Assay ◽

Cryptosporidium Hominis ◽

Content Type ◽

Detection Assay ◽

Pcr Targeting

ABSTRACTThis study compared the three most commonly used assays for detectingCryptosporidiumsp. infections in cell culture: immunofluorescent antibody and microscopy assay (IFA), PCR targetingCryptosporidiumsp.-specific DNA, and reverse transcriptase PCR (RT-PCR) targetingCryptosporidiumsp.-specific mRNA. Monolayers of HCT-8 cells, grown in 8-well chamber slides or 96-well plates, were inoculated with a variety of viable and inactivated oocysts to assess assay performance. All assays detected infection with low doses of flow cytometry-enumeratedCryptosporidium parvumoocysts, including infection with one oocyst and three oocysts. All methods also detected infection withCryptosporidium hominis. The RT-PCR assay, IFA, and PCR assay detected infection in 23%, 25%, and 51% of monolayers inoculated with threeC. parvumoocysts and 10%, 9%, and 16% of monolayers inoculated with one oocyst, respectively. The PCR assay was the most sensitive, but it had the highest frequency of false positives with mock-infected cells and inactivated oocysts. IFA was the only infection detection assay that did not produce false positives with mock-infected monolayers. IFA was also the only assay that detected infections in all experiments with spiked oocysts recovered from Envirochek capsules following filtration of 1,000 liters of treated water. Consequently, cell culture with IFA detection is the most appropriate method for routine and sensitive detection of infectiousCryptosporidium parvumandCryptosporidium hominisin drinking water.

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Horizontal Dissemination of Antimicrobial Resistance Determinants in Multiple Salmonella Serotypes following Isolation from the Commercial Swine Operation Environment after Manure Application

Applied and Environmental Microbiology ◽

10.1128/aem.01503-17 ◽

2017 ◽

Vol 83 (20) ◽

Cited By ~ 19

Author(s):

Suchawan Pornsukarom ◽

Siddhartha Thakur

Keyword(s):

North Carolina ◽

Gene Transfer ◽

Antimicrobial Resistance ◽

Phylogenetic Trees ◽

Soil Samples ◽

Alkaline Lysis ◽

Manure Application ◽

Content Type ◽

Swine Farms ◽

Resistance Determinants

ABSTRACT The aim of this study was to characterize the plasmids carrying antimicrobial resistance (AMR) determinants in multiple Salmonella serotypes recovered from the commercial swine farm environment after manure application on land. Manure and soil samples were collected on day 0 before and after manure application on six farms in North Carolina, and sequential soil samples were recollected on days 7, 14, and 21 from the same plots. All environmental samples were processed for Salmonella, and their plasmid contents were further characterized. A total of 14 isolates including Salmonella enterica serotypes Johannesburg (n = 2), Ohio (n = 2), Rissen (n = 1), Typhimurium var5− (n = 5), Worthington (n = 3), and 4,12:i:− (n = 1), representing different farms, were selected for plasmid analysis. Antimicrobial susceptibility testing was done by broth microdilution against a panel of 14 antimicrobials on the 14 confirmed transconjugants after conjugation assays. The plasmids were isolated by modified alkaline lysis, and PCRs were performed on purified plasmid DNA to identify the AMR determinants and the plasmid replicon types. The plasmids were sequenced for further analysis and to compare profiles and create phylogenetic trees. A class 1 integron with an ANT(2″)-Ia-aadA2 cassette was detected in the 50-kb IncN plasmids identified in S. Worthington isolates. We identified 100-kb and 90-kb IncI1 plasmids in S. Johannesburg and S. Rissen isolates carrying the bla CMY-2 and tet(A) genes, respectively. An identical 95-kb IncF plasmid was widely disseminated among the different serotypes and across different farms. Our study provides evidence on the importance of horizontal dissemination of resistance determinants through plasmids of multiple Salmonella serotypes distributed across commercial swine farms after manure application. IMPORTANCE The horizontal gene transfer of antimicrobial resistance (AMR) determinants located on plasmids is considered to be the main reason for the rapid proliferation and spread of drug resistance. The deposition of manure generated in swine production systems into the environment is identified as a potential source of AMR dissemination. In this study, AMR gene-carrying plasmids were detected in multiple Salmonella serotypes across different commercial swine farms in North Carolina. The plasmid profiles were characterized based on Salmonella serotype donors and incompatibility (Inc) groups. We found that different Inc plasmids showed evidence of AMR gene transfer in multiple Salmonella serotypes. We detected an identical 95-kb plasmid that was widely distributed across swine farms in North Carolina. These conjugable resistance plasmids were able to persist on land after swine manure application. Our study provides strong evidence of AMR determinant dissemination present in plasmids of multiple Salmonella serotypes in the environment after manure application.

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High Frequency of Virulence Factor Genestdh,trh, andtlhin Vibrio parahaemolyticus Strains Isolated from a Pristine Estuary

Applied and Environmental Microbiology ◽

10.1128/aem.03792-12 ◽

2013 ◽

Vol 79 (7) ◽

pp. 2247-2252 ◽

Cited By ~ 77

Author(s):

Casandra K. Gutierrez West ◽

Savannah L. Klein ◽

Charles R. Lovell

Keyword(s):

Virulence Factor ◽

Dna Sequences ◽

Vibrio Parahaemolyticus ◽

Pcr Primers ◽

North Inlet ◽

Estuarine Ecosystem ◽

Gene Encoding ◽

Content Type ◽

Genes Encoding ◽

Thermostable Direct Hemolysin

ABSTRACTVirulence factor genes encoding the thermostable direct hemolysin (tdh) and the thermostable direct hemolysin-related hemolysin (trh) are strongly correlated with virulence of the emergent human pathogenVibrio parahaemolyticus. The gene encoding the thermolabile hemolysin (tlh) is also considered a signature molecular marker for the species. These genes are typically reported in very low percentages (1 to 2%) of nonclinical strains.V. parahaemolyticusstrains were isolated from various niches within a pristine estuary (North Inlet, SC) and were screened for these genes using both newly designed PCR primers and more commonly used primers. DNA sequences oftdhandtrhwere recovered from 48% and 8.3%, respectively, of these North Inlet strains. The recovery of pathogenicV. parahaemolyticusstrains in such high proportions from an estuarine ecosystem that is virtually free of anthropogenic influences indicates the potential for additional, perhaps environmental roles of thetdhandtrhgenes.

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Detection and differentiation of Burkholderia species with pathogenic potential in environmental soil samples

PLoS ONE ◽

10.1371/journal.pone.0245175 ◽

2021 ◽

Vol 16 (1) ◽

pp. e0245175

Author(s):

Sujintana Janesomboon ◽

Veerachat Muangsombut ◽

Varintip Srinon ◽

Chatruthai Meethai ◽

Chayada S. Tharinjaroen ◽

...

Keyword(s):

Multiplex Pcr ◽

Capsular Polysaccharide ◽

High Sensitivity ◽

Pcr Primers ◽

Soil Samples ◽

Pcr Assay ◽

Pathogenic Potential ◽

Specific Pcr ◽

Phylogenetic Cluster ◽

Multiplex Pcr Assay

The Burkholderia pseudomallei phylogenetic cluster includes B. pseudomallei, B. mallei, B. thailandensis, B. oklahomensis, B. humptydooensis and B. singularis. Regarded as the only pathogenic members of this group, B. pseudomallei and B. mallei cause the diseases melioidosis and glanders, respectively. Additionally, variant strains of B. pseudomallei and B. thailandensis exist that include the geographically restricted B. pseudomallei that express a B. mallei-like BimA protein (BPBM), and B. thailandensis that express a B. pseudomallei-like capsular polysaccharide (BTCV). To establish a PCR-based assay for the detection of pathogenic Burkholderia species or their variants, five PCR primers were designed to amplify species-specific sequences within the bimA (Burkholderia intracellular motility A) gene. Our multiplex PCR assay could distinguish pathogenic B. pseudomallei and BPBM from the non-pathogenic B. thailandensis and the BTCV strains. A second singleplex PCR successfully discriminated the BTCV from B. thailandensis. Apart from B. humptydooensis, specificity testing against other Burkholderia spp., as well as other Gram-negative and Gram-positive bacteria produced a negative result. The detection limit of the multiplex PCR in soil samples artificially spiked with known quantities of B. pseudomallei and B. thailandensis were 5 and 6 CFU/g soil, respectively. Furthermore, comparison between standard bacterial culture and the multiplex PCR to detect B. pseudomallei from 34 soil samples, collected from an endemic area of melioidosis, showed high sensitivity and specificity. This robust, sensitive, and specific PCR assay will be a useful tool for epidemiological study of B. pseudomallei and closely related members with pathogenic potential in soil.

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Denitrification byAnaeromyxobacter dehalogenans, a Common Soil Bacterium Lacking the Nitrite Reductase GenesnirSandnirK

Applied and Environmental Microbiology ◽

10.1128/aem.01985-17 ◽

2017 ◽

Vol 84 (4) ◽

Cited By ~ 17

Author(s):

Jenny R. Onley ◽

Samiha Ahsan ◽

Robert A. Sanford ◽

Frank E. Löffler

Keyword(s):

Soil Bacterium ◽

Reference Sequence ◽

Bacterial Genomes ◽

N Loss ◽

Content Type ◽

Denitrification Potential ◽

Soil Ecosystems ◽

New Findings ◽

Soils And Sediments ◽

Denitrification Genes

ABSTRACTThe versatile soil bacteriumAnaeromyxobacter dehalogenanslacks the hallmark denitrification genesnirSandnirK(encoding NO2−→NO reductases) and couples growth to NO3−reduction to NH4+(respiratory ammonification) and to N2O reduction to N2.A. dehalogenansalso grows by reducing Fe(III) to Fe(II), which chemically reacts with NO2−to form N2O (i.e., chemodenitrification). Following the addition of 100 μmol of NO3−or NO2−to Fe(III)-grown axenic cultures ofA. dehalogenans, 54 (±7) μmol and 113 (±2) μmol N2O-N, respectively, were produced and subsequently consumed. The conversion of NO3−to N2in the presence of Fe(II) through linked biotic-abiotic reactions represents an unrecognized ecophysiology ofA. dehalogenans. The new findings demonstrate that the assessment of gene content alone is insufficient to predict microbial denitrification potential and N loss (i.e., the formation of gaseous N products). A survey of complete bacterial genomes in the NCBI Reference Sequence database coupled with available physiological information revealed that organisms lackingnirSornirKbut with Fe(III) reduction potential and genes for NO3−and N2O reduction are not rare, indicating that NO3−reduction to N2through linked biotic-abiotic reactions is not limited toA. dehalogenans. Considering the ubiquity of iron in soils and sediments and the broad distribution of dissimilatory Fe(III) and NO3−reducers, denitrification independent of NO-forming NO2−reductases (through combined biotic-abiotic reactions) may have substantial contributions to N loss and N2O flux.IMPORTANCECurrent attempts to gauge N loss from soils rely on the quantitative measurement ofnirKandnirSgenes and/or transcripts. In the presence of iron, the common soil bacteriumAnaeromyxobacter dehalogenansis capable of denitrification and the production of N2without the key denitrification genesnirKandnirS. Such chemodenitrifiers denitrify through combined biotic and abiotic reactions and have potentially large contributions to N loss to the atmosphere and fill a heretofore unrecognized ecological niche in soil ecosystems. The findings emphasize that the comprehensive understanding of N flux and the accurate assessment of denitrification potential can be achieved only when integrated studies of interlinked biogeochemical cycles are performed.

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AFLP-derived, Codominant Markers for Locus-specific Applications

HortScience ◽

10.21273/hortsci.33.3.514e ◽

1998 ◽

Vol 33 (3) ◽

pp. 514e-514

Author(s):

James M. Bradeen ◽

Philipp W. Simon

Keyword(s):

Linkage Mapping ◽

Large Scale ◽

Pcr Primers ◽

Inverse Pcr ◽

Sequence Information ◽

Pcr Assay ◽

Specific Primers ◽

Simultaneous Evaluation ◽

Feral Populations ◽

Diversity Assessment

The amplified fragment length polymorphism (AFLP) is a powerful marker, allowing rapid and simultaneous evaluation of multiple potentially polymorphic sites. Although well-adapted to linkage mapping and diversity assessment, AFLPs are primarily dominant in nature. Dominance, relatively high cost, and technological difficulty limit use of AFLPs for marker-aided selection and other locus-specific applications. In carrot the Y2 locus conditions carotene accumulation in the root xylem. We identified AFLP fragments linked to the dominant Y2 allele and pursued conversion of those fragments to codominant, PCR-based forms useful for locus-specific applications. The short length of AFLPs (≈60 to 500 bp) precludes development of longer, more specific primers as in SCAR development. Instead, using sequence information from cloned AFLP fragments for primer design, regions outside of the original fragment were amplified by inverse PCR or ligation-mediated PCR, cloned, and sequenced. Differences in sequences associated with Y2 vs. y2 allowed development of simple PCR assays differentiating those alleles. PCR primers flanking an insertion associated with the recessive allele amplified differently sized products for the two Y2 alleles in one assay. This assay is rapid, technologically simple (requiring no radioactivity and little advanced training or equipment), reliable, inexpensive, and codominant. Our PCR assay has a variety of large scale, locus-specific applications including genotyping diverse carrot cultivars and wild and feral populations. Efforts are underway to improve upon conversion technology and to more extensively test the techniques we have developed.

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Describing Phosphorus Sorption Processes on Volcanic Soil in the Presence of Copper or Silver Engineered Nanoparticles

Minerals ◽

10.3390/min11040373 ◽

2021 ◽

Vol 11 (4) ◽

pp. 373

Author(s):

Jonathan Suazo-Hernández ◽

Erwin Klumpp ◽

Nicolás Arancibia-Miranda ◽

Patricia Poblete-Grant ◽

Alejandra Jara ◽

...

Keyword(s):

Organic Matter ◽

Crop Production ◽

Agricultural Soils ◽

Ph Value ◽

Consumer Products ◽

Soil Samples ◽

Engineered Nanoparticles ◽

P Availability ◽

Agricultural Crop ◽

Phosphorus Sorption

Engineered nanoparticles (ENPs) present in consumer products are being released into the agricultural systems. There is little information about the direct effect of ENPs on phosphorus (P) availability, which is an essential nutrient for crop growthnaturally occurring in agricultural soils. The present study examined the effect of 1, 3, and 5% doses of Cu0 or Ag0 ENPs stabilized with L-ascorbic acid (suspension pH 2–3) on P ad- and desorption in an agricultural Andisol with total organic matter (T-OM) and with partial removal of organic matter (R-OM) by performing batch experiments. Our results showed that the adsorption kinetics data of H2PO4− on T-OM and R-OM soil samples with and without ENPs were adequately described by the pseudo-second-order (PSO) and Elovich models. The adsorption isotherm data of H2PO4− from T-OM and R-OM soil samples following ENPs addition were better fitted by the Langmuir model than the Freundlich model. When the Cu0 or Ag0 ENPs doses were increased, the pH value decreased and H2PO4− adsorption increased on T-OM and R-OM. The H2PO4− desorption (%) was lower with Cu0 ENPs than Ag0 ENPs. Overall, the incorporation of ENPs into Andisols generated an increase in P retention, which may affect agricultural crop production.

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