Effect of biosynthesized silver nanoparticles on native soil microflora via plant transport during plant–pathogen–nanoparticles interaction

The persistence of Enterococcus faecalis, fecal enterococci from swine waste, and Tn916-like elements was determined following inoculation into autoclaved and native soil microcosms. When cells of E. faecalis CG110 (Tn916) were inoculated into native microcosms, enterococcal viability in the soil decreased approximately 5 orders of magnitude (4.8 × 105CFU/g soil to < 10 CFU/g) after 5 weeks. In autoclaved microcosms, the viability of E. faecalis decreased by only 20% in 5 weeks. In contrast, the content of Tn916, based on PCR of DNA extracts from soil microcosms, decreased by about 20% in both native and autoclaved microcosms. Similar results were obtained when the source of fecal enterococci and Tn916-like elements was swine waste. Because the concentration of Tn916-independent E. faecalis DNA (the D-alanine D-alanine ligase gene), based on PCR, decreased to nearly undetectable levels (at least 3 orders of magnitude) after 5 weeks in the native microcosms, the evidence suggests Tn916 stability in the soil results from en masse transfer of the transposon to the normal soil microflora and not survival of E. faecalis DNA in the soil system. Results from denaturing gradient gel electrophoresis suggest that multiple forms of Tn916 occur in swine waste, but only forms most like Tn916 exhibit stability in the soil.Key words: Tn916, Enterococcus faecalis, soil, antibiotic resistance, conjugation, transposon.

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Long-term effects of sulfidized silver nanoparticles in sewage sludge on soil microflora

Environmental Toxicology and Chemistry ◽

10.1002/etc.3904 ◽

2017 ◽

Vol 36 (12) ◽

pp. 3305-3313 ◽

Cited By ~ 34

Author(s):

Marco Kraas ◽

Karsten Schlich ◽

Burkhard Knopf ◽

Franziska Wege ◽

Ralf Kägi ◽

...

Keyword(s):

Silver Nanoparticles ◽

Sewage Sludge ◽

Soil Microflora ◽

Long Term Effects

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Potential of biochar after the biological activation by native soil microflora

Revista Mvz Córdoba ◽

10.21897/rmvz.2219 ◽

2021 ◽

Vol 26 (3) ◽

pp. e2219

Author(s):

Helena Dvorackova ◽

Jaroslav Záhora ◽

Lubica Pospíšilová ◽

Vítězslav Vlček

Keyword(s):

Dehydrogenase Activity ◽

Soil Microorganisms ◽

Mineral Fertilizer ◽

Statistical Test ◽

Soil Microflora ◽

Mineral Fertilizers ◽

Activated Biochar ◽

Native Soil ◽

Negative Effect ◽

And Control

Objective. Dehydrogenase activity after the biological activation of biochar by the native soil microorganisms was studied. The main aim was to improve biochar properties by activation and make it more friendly for the soil microflora. Materials and methods. The activation was reached by aerating with the soil solution for two weeks. No special inoculum of microorganisms was applied. The following treatments in four replicates were prepared: conventional raw biochar (BR), activated biochar (BA), mineral fertilizer DAM 390 (NF), and control (C). A statistical test for comparing treatments means (Fisher p≤0.05; program STATISTICA 12.0; StatSoft software Inc., Tulsa, Oklahoma, USA) was used. Results. Statistically significant differences in the dehydrogenase activity between the treatments BR, BA, and C were found. Application of mineral fertilizers had a negative effect and increasing of nitrogen leaching was observed. Conclusions. Activating of biochar is suitable metods for impove soil biota conition compared with convention biochar.

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Formation of Bound Residues during Microbial Degradation of [14C]Anthracene in Soil

Applied and Environmental Microbiology ◽

10.1128/aem.65.5.1834-1842.1999 ◽

1999 ◽

Vol 65 (5) ◽

pp. 1834-1842 ◽

Cited By ~ 102

Author(s):

M. Kästner ◽

S. Streibich ◽

M. Beyrer ◽

H. H. Richnow ◽

W. Fritsche

Keyword(s):

Microbial Degradation ◽

Soil Microflora ◽

Minor Role ◽

Second Phase ◽

Organic Carbon Content ◽

Native Soil ◽

Bound Residues ◽

Polycyclic Aromatic ◽

Two Phases ◽

A Minor

ABSTRACT Carbon partitioning and residue formation during microbial degradation of polycyclic aromatic hydrocarbons (PAH) in soil and soil-compost mixtures were examined by using [14C]anthracenes labeled at different positions. In native soil 43.8% of [9-14C]anthracene was mineralized by the autochthonous microflora and 45.4% was transformed into bound residues within 176 days. Addition of compost increased the metabolism (67.2% of the anthracene was mineralized) and decreased the residue formation (20.7% of the anthracene was transformed). Thus, the higher organic carbon content after compost was added did not increase the level of residue formation. [14C]anthracene labeled at position 1,2,3,4,4a,5a was metabolized more rapidly and resulted in formation of higher levels of residues (28.5%) by the soil-compost mixture than [14C]anthracene radiolabeled at position C-9 (20.7%). Two phases of residue formation were observed in the experiments. In the first phase the original compound was sequestered in the soil, as indicated by its limited extractability. In the second phase metabolites were incorporated into humic substances after microbial degradation of the PAH (biogenic residue formation). PAH metabolites undergo oxidative coupling to phenolic compounds to form nonhydrolyzable humic substance-like macromolecules. We found indications that monomeric educts are coupled by C-C- or either bonds. Hydrolyzable ester bonds or sorption of the parent compounds plays a minor role in residue formation. Moreover, experiments performed with14CO2 revealed that residues may arise from CO2 in the soil in amounts typical for anthracene biodegradation. The extent of residue formation depends on the metabolic capacity of the soil microflora and the characteristics of the soil. The position of the 14C label is another important factor which controls mineralization and residue formation from metabolized compounds.

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Evolutionary Dynamics of Plant-Pathogen Interactions

10.1017/9781108625517 ◽

2019 ◽

Cited By ~ 13

Author(s):

Jeremy J. Burdon ◽

Anna-Liisa Laine

Keyword(s):

Plant Pathogen ◽

Evolutionary Dynamics ◽

Plant Pathogen Interactions

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Genome sequence of the plant pathogen Ralstonia solanacearum

Nature ◽

10.1038/news020128-8 ◽

2002 ◽

Keyword(s):

Genome Sequence ◽

Plant Pathogen ◽

Ralstonia Solanacearum

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Synthesis, performance and growth mechanism of silver nanoparticle coated SERS fiber probe

Matériaux & Techniques ◽

10.1051/mattech/2018061 ◽

2019 ◽

Vol 107 (3) ◽

pp. 305

Author(s):

Mengmei Geng ◽

Yuting Long ◽

Tongqing Liu ◽

Zijuan Du ◽

Hong Li ◽

...

Keyword(s):

Silver Nanoparticles ◽

Absorption Spectrum ◽

Reaction Time ◽

Growth Mechanism ◽

Fiber Optic ◽

Fiber Optic Probe ◽

Visible Absorption ◽

Fiber Probe ◽

Surface Enhanced Raman ◽

Optic Probe

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.

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