A LACK OF BACTERICIDAL EFFECT OF SUBSIDENCE-MITIGATING COPPER IN ORGANIC SOILS

1983 ◽  
Vol 63 (3) ◽  
pp. 645-649 ◽  
Author(s):  
SUKHDEV P. MATHUR
Keyword(s):  
Field Experiments ◽  
Organic Soil ◽  
Bactericidal Effect ◽  
Negative Influence ◽  
Organic Soils ◽  
Bacterial Cells ◽  
Old Field ◽  
E Coli ◽  
Rapid Spread ◽  
Mutant Cells

Two poorly humified peat soils, containing 23 or 1207 ppm (wt/wt) Cu, and two well-humified muck soils with 151 or 1264 ppm Cu, obtained from 3-yr-old field experiments on simulated extravagant applications of Cu for mitigation of organic soil degradation and subsidence, were used in this study. The aim was to determine whether the longevity of Escherichia coli (K12 JE 2517-a nonmotile mutant) cells inoculated into the soils would be affected by the soil Cu concentrations. The rapid spread plate method was used for counting viable cells of the coliform. Both microbially active and bromomethane-sterilized soils were aerobically incubated with the bacterium normally alien to the soils for 48 and 168 h, respectively, with or without further additions of 10 ppm Cu to the soils with the bacterial cells. A pulverized quartz sand was included in the experiments to provide comparison. Unlike the immediate and sustained lethality of Cu revealed in sand suspensions, neither the previously nor the newly added Cu had any negative influence on the survival or proliferation of the added E. coli cells. The results thus showed that the soil Cu had no direct bactericidal or bacteriostatic effect. These data were therefore in accord with earlier suggestions that the Cu mitigates decomposition and resultant subsidence by inactivating degradative and accumulated soil enzymes that contribute substantially to the dissipation of their substrate-rich milieux. Key words: Copper, bacteria, organic soils, subsidence

scholarly journals A new method for performing smouldering combustion field experiments in peatlands and rich-organic soils

2017 ◽  
Vol 26 (12) ◽  
pp. 1040 ◽  
Author(s):  
E. Pastor ◽  
I. Oliveras ◽  
E. Urquiaga-Flores ◽  
J. A. Quintano-Loayza ◽  
M. I. Manta ◽  
...  
Keyword(s):  
Field Experiments ◽  
Organic Soil ◽  
Ecological Effects ◽  
Organic Soils ◽  
Rating Systems ◽  
Environmental Implications ◽  
Combustion Dynamics ◽  
Peruvian Andes ◽  
Undisturbed Soils ◽  
Smouldering Combustion

Smouldering ground fires have severe environmental implications. Their main effects are the release of large amounts of carbon to the atmosphere with loses of organic soil and its biota. Quantitative data on the behaviour of smouldering wildfires are very scarce and are needed to understand its ecological effects, to validate fuel consumption and smouldering propagation models and to develop danger-rating systems. We present, for the first time, a methodology for conducting smouldering experiments in field conditions. This method provides key data to investigate smouldering combustion dynamics, acquire fire behaviour metrics and obtain indicators for ecological effects of smouldering fires. It is to be applied in all types of undisturbed soils. The experimental protocol is based on a non-electric ignition source and the monitoring system relies on combining both point and surface specific temperature measurements. The methodology has been developed and applied by means of large series of replicate experiments in highly organic soils at the forest–grassland treeline of the Peruvian Andes. The soil tested exhibited weak ignition conditions. However, transition to oxidation phase was observed, with smouldering combustion during 9 h at 15-cm depth and residence times at temperatures above dehydration of ~22 h.

Antibacterial Activity of the Silver Nanoparticles against Escherichia coli and Enterobacter sp

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Kathirvel Maruthai ◽  
Kommoju Vallayyachari ◽  
Thirumurugan Ravibalan ◽  
Sheryl Ann Philip ◽  
Antony V. Samrot ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chemical Method ◽  
Reduction Method ◽  
Clinical Importance ◽  
Bactericidal Effect ◽  
Bacterial Cells ◽  
E Coli ◽  
Protein Leakage ◽  
Glucose Reduction ◽  
Membrane Destabilization

In this study, spherical silver nanoparticle (AgNP) was produced by sustainable chemical method i.e. glucose reduction method and it was utilized to analyse the bactericidal effect against the pathogens of clinical importance - E. coli (ATCC 10536) and Enterobacter sp., KL46 by membrane destabilization and protein leakage analyses. Minimum inhibitory/bactericidal and antibiogram analyses reported that 20ng/ml was enough to inhibit/kill bacterial cells. Even 20ng/ml concentration of AgNPs was found to destabilize membrane and lead to protein leakage from bacterial cells. 

scholarly journals SUPRESSION OF BIOFILMS OF OPPORTUNISTIC BACTERIA IN URINARY CATHETERS

2017 ◽  
pp. 3-11
Author(s):  
O. V. Rybalchenko ◽  
M. V. Erman ◽  
O. G. Orlova ◽  
T. M. Pervunina ◽  
V. V. Kapustina ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bactericidal Effect ◽  
Bacterial Biofilms ◽  
Bacterial Cells ◽  
Plant Origin ◽  
Urinary Catheters ◽  
E Coli ◽  
Opportunistic Bacteria ◽  
And Staphylococcus Aureus

Aim. Study regularities of development of bacterial biofilms in opportunistic bacteria in urinary catheters, as well as a possibility of their suppression by an officinal preparation of plant origin - Kanefron and nitrofuran class preparation - Furamag. Materials and methods. Escherichia coli Ml7 and Staphylococcus aureus 193 cultures were cultivated as biofilms on an inner surface of Foley latex catheter. Effect of Kanefron and Furamag on the ability of these strain to form biofilms was evaluated, as well as suppression of already developed biofilm of E. coli M17 and S. aureus 193 on urine catheters. Determination of bactericidal effect of preparations during incubation of microorganisms on the surface of urine caterers was carried out by Koch method. Morphologic and i ultrastructure changes in bacterial cells and biofilms were studied by transmission and scanning j electron microscopy. Results. A pronounced bactericidal effect of Kanefron and Furamag on the formed bacterial biofilms was detected. Inhibiting effect on growth and development of biofilms of the strains was noted. Destructive changes in cells and biofilms during the effect of the studied preparations are shown on electron microscopy level. Conclusion. The detected bactericidal effect of officinal preparation of plant origin - Kanefron and nitrofuran class preparation - Furamag on opportunistic bacteria on Foley urine catheters allows not only to suppress biofilm formation process of E. coli M17 и S. aureus 193 compared with classic antiseptic methods, but also effectively destroy already formed biofilms that must prevent development of catheter-associated infections and result in enhancement of recuperation of patients with diseases of the urinary tract.

scholarly journals Antimicrobial activity of Lippia sidoides Cham. (Verbenaceae) essential oil against Staphylococcus aureus and Escherichia coli

2011 ◽  
Vol 13 (3) ◽  
pp. 293-297 ◽  
Author(s):  
C.E Castro ◽  
J.M Ribeiro ◽  
T.T Diniz ◽  
A.C Almeida ◽  
L.C Ferreira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Antibacterial Effect ◽  
Bactericidal Effect ◽  
Bacterial Cells ◽  
E Coli ◽  
Lippia Sidoides

The antibacterial effect of Lippia sidoides (rosemary pepper) essential oil was tested against the bacteria Staphylococcus aureus and Escherichia coli isolated from homemade Minas cheese produced in Brazil. The Minimum Inhibitory Concentration (MIC) determined in the Dilution Test was 13 µL oil mL-1 for both bacteria, which characterizes inhibitory action in broth for a 24-hour interaction period. The Minimum Bactericidal Concentration (MBC) determined in the Suspension Test, with one minute of contact, was 25 µL oil mL-1 for both tested bacteria, obtaining at this concentration a bactericidal effect of 99.9% on the viable bacterial cells from each sample. Results demonstrated the bacterial activity of Lippia sidoides essential oil against S. aureus and E. coli, suggesting its use as an antibacterial agent in foods.

Response by sugar beet to various amounts and times of application of sodium chloride fertilizer in relation to soil type

1982 ◽  
Vol 98 (3) ◽  
pp. 579-592 ◽  
Author(s):  
A. P. Draycott ◽  
Susan M. Bugg
Keyword(s):  
Sodium Chloride ◽  
Sugar Beet ◽  
Field Experiments ◽  
Sodium Concentration ◽  
Organic Soil ◽  
Organic Soils ◽  
Predictive Test ◽  
Mineral Soils ◽  
Sugar Beet Crop ◽  
Sodium And Potassium

SUMMARYTwo-thirds of the sugar-beet crop in the U.K. receives sodium chloride as part of the fertilizer programme. It is well known that the crop responds profitably on sandy soils which contain relatively little sodium and potassium, and most of these fields now receive sodium chloride. Few crops on clays, silts and organic soils are treated because the value of sodium chloride has never been clearly defined. Thus 36 field experiments were made over the 5 years 1975–9 on contrasting soil types testing five amounts of sodium chloride, 0, 100, 200, 400 and 800 kg/ha, and at two times, either autumn or spring. All the fields chosen were in continuous arable rotations where potassium chloride was applied regularly and nearly all the soils contained more than 120 mg exchangeable K/l.Sodium chloride (400 kg/ha costing £12) increased sugar yield on average by about 0·2 t/ha (worth £40) on the mineral soils but no crop responded on organic soil. Exchangeable soil sodium concentration was not a good predictive test of which fields would respond but all the large increases in yield were on fields with less than 20 mg Na/1. A few crops responded on soils with 20–40 mg Na/1 but no crop responded on soil with more than 40 mg Na/1. A survey of sodium concentrations in 800 soils showed that most mineral soils contained less than 40 mg Na/1 so it is suggested that all mineral soils regardless of texture should receive 400 kg sodium chloride/ha. Crops on organic soils did not respond to sodium chloride because the soils already contained sufficient.Autumn and spring applications of sodium chloride on mineral soils gave similar increases in yield provided the fertilizer was not applied just before sowing, when in 2 years it decreased plant establishment. This effect was particularly damaging on clays and silts where it is frequently difficult for other reasons to obtain good seed beds and full establishment. It is concluded that sodium-containing fertilizers should always be applied well ahead of sowing to allow rainfall and cultivations to incorporate them into the soil. On clays and silts it is suggested that they should be applied before ploughing to avoid soil compaction but on sands there may be advantages in post-ploughing application.

scholarly journals relA Inactivation Converts Sulfonamides Into Bactericidal Compounds

2021 ◽  
Vol 12 ◽  
Author(s):  
Lizhen Si ◽  
Jing Gu ◽  
Mi Wen ◽  
Ruiqi Wang ◽  
Joy Fleming ◽  
...  
Keyword(s):  
De Novo ◽  
Excision Repair ◽  
Bacterial Species ◽  
Pantothenic Acid ◽  
Bactericidal Effect ◽  
Bacterial Cells ◽  
Dna Double Strand Breaks ◽  
E Coli ◽  
Folate Biosynthesis ◽  
Base Excision

Folates are required for the de novo biosynthesis of purines, thymine, methionine, glycine, and pantothenic acid, key metabolites that bacterial cells cannot survive without. Sulfonamides, which inhibit bacterial folate biosynthesis and are generally considered as bacteriostats, have been extensively used as broad-spectrum antimicrobials for decades. Here we show that, deleting relA in Escherichia coli and other bacterial species converted sulfamethoxazole from a bacteriostat into a bactericide. Not as previously assumed, the bactericidal effect of SMX was not caused by thymine deficiency. When E. coli ∆relA was treated with SMX, reactive oxygen species and ferrous ion accumulated inside the bacterial cells, which caused extensive DNA double-strand breaks without the involvement of incomplete base excision repair. In addition, sulfamethoxazole showed bactericidal effect against E. coli O157 ∆relA in mice, suggesting the possibility of designing new potentiators for sulfonamides targeting RelA. Thus, our study uncovered the previously unknown bactericidal effects of sulfonamides, which advances our understanding of their mechanisms of action, and will facilitate the designing of new potentiators for them.

scholarly journals Weed Control and Radish (Raphanus sativus) Response to S-metolachlor on Organic Soils

HortScience ◽  
2016 ◽  
Vol 51 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Dennis C. Odero ◽  
Jose V. Fernandez ◽  
Nikol Havranek
Keyword(s):  
Weed Control ◽  
Raphanus Sativus ◽  
Logistic Model ◽  
Field Experiments ◽  
Organic Soil ◽  
Effective Control ◽  
Yield Reduction ◽  
Organic Soils ◽  
Common Lambsquarters ◽  
Root Crops

Field experiments were conducted to determine weed control and radish (Raphanus sativus) response to S-metolachlor on organic soil in the Everglades Agricultural Area (EAA) using a dose–response bioassay. S-metolachlor was applied preemergence at 0.35, 0.7, 1.4, 2.8, 5.6, and 11.2 kg·ha−1. The rate of S-metolachlor required to provide 90% weed control (ED90) and result in 5% and 10% radish injury were determined by fitting a three-parameter log-logistic model. The ED90 values for common lambsquarters, spiny amaranth, and fall panicum control were 2.7, 1.6, and 1.2 kg·ha−1 of S-metolachlor, respectively, at 14 days after treatment (DAT). At 28 DAT, the ED90 values were 3.8, 1.9, and 1.5 kg·ha−1 of S-metolachlor, respectively. Injury on radish increased as S-metolachlor rates increased with maximum injury of 24% and 19% at 14 and 28 DAT, respectively. S-metolachlor at 2.1 and 3.1 kg·ha−1 at 14 DAT and 2.6 and 3.7 kg·ha−1 at 28 DAT would result in 5% and 10% radish injury, respectively. Radish yield decreased with increasing rates of S-metolachlor. At the proposed S-metolachlor use rate of 1.4 kg·ha−1 for root crops, radish yield was 80% of the weed-free yield probably resulting from competition from common lambsquarters, which was controlled 74%. These results show that preemergence S-metolachlor would provide effective control of spiny amaranth and fall panicum in radish on organic soils of the EAA at the proposed use rate for root crops while about three times the proposed use rate would be required to provide effective common lambsquarters control. This implies that infestation of common lambsquarters on radish fields on organic soils will not be effectively controlled by S-metolachlor at the proposed use rate resulting in yield reduction.

Toxic Effect of 2-ethyl (bicyclo[2.2.1] heptane) on Bacterial Cells

2019 ◽  
Vol 35 (6) ◽  
pp. 67-72 ◽  
Author(s):  
I.V. Manukhov ◽  
L.S. Yaguzhinsky ◽  
M.V. Bermeshev ◽  
M.A. Zisman ◽  
V.G. Pevgov ◽  
...  
Keyword(s):  
Toxic Effect ◽  
Atmospheric Oxygen ◽  
Inducible Promoter ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Unique Identifier ◽  
E Coli ◽  
Lux Biosensors ◽  
High Level ◽  
Ministry Of Higher Education

Toxic effect of 2-ethylnorbornane (2-ethyl(bicyclo[2.2.1]heptane) (EBH)) on bacteria has been studied using the E. coli pRecA-lux and E. coli pKatG- lux cells as lux-biosensors. It was shown that the addition of EBH to the incubation medium leads to death and growth retardation, high level oxidative stress and DNA damage in E. coli cells. It is assumed that the oxidation of EBH with atmospheric oxygen causes the formation of reactive oxygen species in the medium, which makes a major contribution to the toxicity of this substance. biosensor, luciferase, bioluminescence, inducible promoter, PrecA, PkatG The authors are grateful to Stanislav Filippovich Chalkin for the development of interdisciplinary ties in the scientific community. The work was financially supported by the Ministry of Higher Education and Science of Russia (Project Unique Identifier RFMEFI60417X0181, Agreement No. 14.604.21.0181 of 26.09.2017).

Antibacterial silver-diatomite nanocomposite ceramic with low silver release

2019 ◽  
Vol 20 (2) ◽  
pp. 633-643
Author(s):  
Xiaopeng Qi ◽  
Junwei Chen ◽  
Qian Li ◽  
Hui Yang ◽  
Honghui Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Treatment ◽  
Photoelectron Spectroscopy ◽  
Bactericidal Effect ◽  
Ceramic Filter ◽  
Ceramic Filters ◽  
X Ray ◽  
E Coli ◽  
Point Of Use ◽  
Silver Release

Abstract There is an urgent need for an effective and long-lasting ceramic filter for point-of-use water treatment. In this study, silver-diatomite nanocomposite ceramic filters were developed by an easy and effective method. The ceramic filters have a three-dimensional interconnected pore structure and porosity of 50.85%. Characterizations of the silver-diatomite nanocomposite ceramic filters were performed using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Silver nanoparticles were confirmed to be formed in situ in the ceramic filter. The highest silver concentration in water was 0.24 μg/L and 2.1 μg/L in short- and long-term experiments, indicating very low silver-release properties of silver-diatomite nanocomposite ceramic filter. The nanocomposite ceramics show strong bactericidal activity. When contact time with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of 105 colony forming units (CFU)/mL exceeded 3 h, the bactericidal rates of the four different silver content ceramics against E. coli and S. aureus were all 100%. Strong bactericidal effect against E. coli with initial concentration of 109 CFU/mL were also observed in ceramic newly obtained and ceramic immersed in water for 270 days, demonstrating its high stability. The silver-diatomite nanocomposite ceramic filters could be a promising candidate for point-of-use water treatment.

scholarly journals Evaluation of the Antimicrobial Activity of Some Components of the Essential Oils of Plants Used in the Traditional Medicine of the Tehuacán-Cuicatlán Valley, Puebla, México

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 295
Author(s):  
Sebastián Candelaria-Dueñas ◽  
Rocío Serrano-Parrales ◽  
Marisol Ávila-Romero ◽  
Samuel Meraz-Martínez ◽  
Julieta Orozco-Martínez ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Qualitative Evaluation ◽  
Bactericidal Effect ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Diffusion Technique ◽  
Agar Dilution

In Tehuacán-Cuicatlán valley (Mexico), studies have been carried out on the essential oils of medicinal plants with antimicrobial activity and it was found that they present compounds in common such as: α-pinene, β-pinene, carvacrol, eugenol, limonene, myrcene, ocimene, cineole, methyl salicylate, farnesene, and thymol. The goal of this study was to assess the antimicrobial activity of essential oils’ compounds. The qualitative evaluation was carried out by the Kirby Baüer agar diffusion technique in Gram-positive bacteria (11 strains), Gram-negative bacteria (18 strains), and yeasts (8 strains). For the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), the agar dilution method was used. All the evaluated compounds presented antimicrobial activity. The compounds eugenol and carvacrol showed the largest inhibition zones. Regarding yeasts, the compounds ocimene, cineole, and farnesene did not show any activity. The compounds eugenol, carvacrol, and thymol presented the lowest MIC; bactericidal effect was observed at MIC level for S. aureus 75MR, E. coli 128 MR, and C albicans CUSI, for different compounds, eugenol, carvacrol, and thymol. Finally, this study shows that the essential oils of plants used by the population of Tehuacán-Cuicatlán valley share compounds and some of them have antibacterial and fungicidal activity.

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