scholarly journals Degradation of boscalid, pyraclostrobin, fenbuconazole, and glyphosate residues by an advanced oxidative process utilizing ultraviolet light and hydrogen peroxide

2020 ◽  
Author(s):  
Blake Skanes ◽  
Jordan Ho ◽  
Keith Warriner ◽  
Ryan S. Prosser
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Ultraviolet Light ◽  
Pesticide Residues ◽  
Individual Treatment ◽  
Oxidative Process ◽  
Uv C ◽  
Advanced Oxidative Process

AbstractRecently an advanced oxidative process (AOP) combining H2O2 and UV-C light was observed to be effective at controlling Listeria monocytogens (Murray et al., 2018) and Escherichia coli O157:H7 and degrading chlorpyrifos residues on the surface of apples (Ho et al., 2020). Little is known about the application of AOP for the degradation of other pesticide residues. This study examined degradation of boscalid, pyraclostrobin, fenbuconazole and glyphosate by 3% (w/v) H2O2, UV-C (254 nm) irradiation and their combination on apple skin and glass. The extent of degradation was not significantly different between the AOP and optimal individual treatment. However, treatment susceptibility was different with glyphosate most effectively degraded by H2O2 exposure (up to 98% on apple, 3% (w/v) H2O2 at 30□C for 15 min) while boscalid, pyraclostrobin and fenbuconazole were more effectively degraded by UV-C (up to 88%, 100% and 70% degradation after ~11,000 mJ/cm2). Suggestions for possible causes of degradation are proposed.

Inactivation of Listeria monocytogenes on and within Apples Destined for Caramel Apple Production by Using Sequential Forced Air Ozone Gas Followed by a Continuous Advanced Oxidative Process Treatment

2018 ◽  
Vol 81 (3) ◽  
pp. 357-364 ◽  
Author(s):  
K. Murray ◽  
P. Moyer ◽  
F. Wu ◽  
J. B. Goyette ◽  
K. Warriner
Keyword(s):  
Hydrogen Peroxide ◽  
Listeria Monocytogenes ◽  
Continuous Process ◽  
Scar Tissue ◽  
Ozone Treatment ◽  
Oxidative Process ◽  
Chamber Temperature ◽  
Forced Air ◽  
Uv C ◽  
Advanced Oxidative Process

ABSTRACT This study evaluated the efficacy of using sequential forced air ozone followed by an advanced oxidative process (AOP) treatment to inactivate Listeria monocytogenes on and within Empire apples. The forced air ozone treatment consisted of a reactor that introduced ozone (6 g/h) into an airstream that flowed through an apple bed (ca. 30 cm in depth). Before treatment, the apples were conditioned at 4°C to ensure that condensate had formed before the apples were transferred to the reactor. The condensate ensured sufficient relative humidity to enhance the antimicrobial action of ozone. Air was passed through the apple bed at 9.3 m/s, and the ozone was introduced after 10 min. The ozone concentration measured after exiting the apple bed reached a steady state of 23 ppm. A 20-min ozone treatment supported a 2.12- to 3.07-log CFU reduction of L. monocytogenes, with no significant effect of apple position within the bed. The AOP-based method was a continuous process whereby hydrogen peroxide was introduced as a vapor into a reactor illuminated by UV-C and ozone-emitting lamps that collectively generated hydroxyl radicals. Operating the AOP reactor with UV-C light (54-mJ cm2 dose), 6% (v/v) hydrogen peroxide, 2 g/h ozone, and a chamber temperature of 48°C resulted in a 3-log CFU reduction of L. monocytogenes on the surface of the apples and internally within the scar tissue. Applying a caramel coating, from a molten solution (at 80°C), resulted in a 0.5-log CFU reduction of L. monocytogenes on the apple surface. In apples treated with the sequential process, L. monocytogenes could only be recovered sporadically by enrichment and did not undergo outgrowth when the caramel apples were stored at 22°C for 19 days. However, growth of L. monocytogenes within the core, but not the surface, was observed from caramel apples prepared from nontreated control fruit.

Reduction of Escherichia coli bacteria from contaminated water by combining hydrogen peroxide, ozone and ultraviolet light

2013 ◽  
Vol 13 (3) ◽  
pp. 782-789 ◽  
Author(s):  
Bassam Tawabini ◽  
Amjad Khalil ◽  
Basim Abussaud
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Ultraviolet Light ◽  
Water Samples ◽  
Organic Contaminants ◽  
Inactivation Rate ◽  
Contaminated Water ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Escherichia Coli Bacteria

This study demonstrates the reduction of Escherichia coli bacteria from contaminated water when the water is treated with advanced oxidation processes utilising the following combinations: hydrogen peroxide (H2O2) and ozone (O3), ultraviolet light (UV) and hydrogen peroxide (H2O2), and ultraviolet light (UV) and ozone (O3). Approximately 1 × 108cell/mL of E. coli were spiked into water samples contaminated with 500 ppb of methyl tertiary butyl ether (MTBE) and benzene. Water samples were then treated in a bench-scale photoreactor using 15 W low pressure (LP) and 150 W medium pressure (MP) UV lamps. Hydrogen peroxide at 20, 50 and 100 ppm and ozone at 1, 2 and 5 ppm were used along with the UV irradiation to generate the hydroxyl radicals (.OH) needed to degrade organic contaminants such as MTBE and benzene and most likely destroy bacteria. The results of the study showed that, under the study conditions, no effect of benzene or MTBE was observed on the inactivation rate of the bacteria. Moreover, results showed that the combined effect of the LP 15 W UV lamp with 2 ppm O3 or with 50 ppm H2O2 showed the highest inactivation rate of bacteria within 5 min. The H2O2/O3 process showed high disinfection capability at high dosages of peroxide (50 ppm) and O3 (2 and 5 ppm).

scholarly journals Escherichia coli MutM Suppresses Illegitimate Recombination Induced by Oxidative Stress

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Masaaki Onda ◽  
Katsuhiro Hanada ◽  
Hirokazu Kawachi ◽  
Hideo Ikeda
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Double Strand Breaks ◽  
Illegitimate Recombination ◽  
Recombination Analysis ◽  
Wild Type ◽  
Strand Breaks ◽  
In The Wild

Abstract DNA damage by oxidative stress is one of the causes of mutagenesis. However, whether or not DNA damage induces illegitimate recombination has not been determined. To study the effect of oxidative stress on illegitimate recombination, we examined the frequency of λbio transducing phage in the presence of hydrogen peroxide and found that this reagent enhances illegitimate recombination. To clarify the types of illegitimate recombination, we examined the effect of mutations in mutM and related genes on the process. The frequency of λbio transducing phage was 5- to 12-fold higher in the mutM mutant than in the wild type, while the frequency in the mutY and mutT mutants was comparable to that of the wild type. Because 7,8-dihydro-8-oxoguanine (8-oxoG) and formamido pyrimidine (Fapy) lesions can be removed from DNA by MutM protein, these lesions are thought to induce illegitimate recombination. Analysis of recombination junctions showed that the recombination at Hotspot I accounts for 22 or 4% of total λbio transducing phages in the wild type or in the mutM mutant, respectively. The preferential increase of recombination at nonhotspot sites with hydrogen peroxide in the mutM mutant was discussed on the basis of a new model, in which 8-oxoG and/or Fapy residues may introduce double-strand breaks into DNA.

scholarly journals The use of germicidal ultraviolet light, vaporised hydrogen peroxide and dry heat to decontaminate face masks and filtering respirators contaminated with an infectious norovirus

2020 ◽  
pp. 100111
Author(s):  
Constance Wielick ◽  
Louisa F. Ludwig-Begall ◽  
Lorène Dams ◽  
Ravo M. Razafimahefa ◽  
Pierre-Francois Demeuldre ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ultraviolet Light ◽  
Dry Heat
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