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The reaction of peracetic acid (PAA) and Fe(II) has recently gained attention due to its utility in wastewater treatment and its role in cloud chemistry. Aerosol-cloud interactions, partly mediated by aqueous hydroxyl radical (OH) chemistry, represent one of the largest uncertainties in the climate system. Ambiguities remain regarding the sources of OH in the cloud droplets. Our research group recently proposed that the dark and light-driven reaction of Fe(II) with peracids may be a key contributor to OH formation, producing a large burst of OH when aerosol particles take up water as they grow to become cloud droplets, in which reactants are consumed within 2 min. In this work, we quantify the OH production from the reaction of Fe(II) and PAA across a range of physical and chemical conditions. We show a strong dependence of OH formation on ultraviolet (UV) wavelength, with maximum OH formation at λ = 304 ± 5 nm, and demonstrate that the OH burst phenomenon is unique to Fe(II) and peracids. Using kinetics modeling and density functional theory calculations, we suggest the reaction proceeds through the formation of an [Fe(II)-(PAA)2(H2O)2] complex, followed by the formation of a Fe(IV) complex, which can also be photoactivated to produce additional OH. Determining the characteristics of OH production from this reaction advances our knowledge of the sources of OH in cloudwater and provides a framework to optimize this reaction for OH output for wastewater treatment purposes.

Peracetic acid (PAA) is efficient for disinfection processes in environmental sanitation and in the presence of transition metals its oxidative performance is enhanced. Thus, the present study aim evaluated the influence of Fe3+ ions during the inactivation process of Escherichia coli and Total Coliforms (TC). The process PAA + Fe3+ ions were also evaluated in relation to the disinfection kinetics, the participation of H2O2 and the influence of the organic load of the treated water. The tests showed an inactivation efficient of 0.5 to 0.9 log in relation to E. coli and 1.3 to 1.5 logs for TC in the concentrations evaluated and complete inactivation of E. coli was achieved within 15 min for both PAA and PAA/Fe3+ There is no damage to the disinfection process in the presence of Fe3+ ions, however, the decomposition of PAA is favored. In this sense, the formation of radicals can justify the maintenance of disinfection efficiency. The decay constants were close both microorganisms: for E. coli with PAA and PAA/Fe3+were 0.0323 and 0.0476 and for TC were 0.0637 and 0.0667. The values of R2 were above 0.95. Computer simulations of peptidoglycans that make up the bacterial cell wall showed that radicals preferentially attacked the carbons from the rings that composes the cell wall peptidoglycan of gram-negative bacteria allowing to break the structure during the disinfection process. [ABSTRACT FROM AUTHOR]

Summary In this research, the effects of washing treatments (potassium carbonate (PC), potassium hydroxide (PH), peracetic acid (PA), alkaline hydrogen peroxide (AHP)), ultrasound (US) and high‐intensity pulsed light (HIPL) technologies on the removal of ochratoxin A (OTA) residues in raisins were investigated. PC at 5 min (66.60%), PH at 10 min (65.25%), alkaline hydrogen peroxide at 5 min (63.30%) and HIPL at 12 J cm−2 (62.50%) were found to be the most successful applications in OTA degradation, respectively. Although the OTA degradation rate was high after chemical washing for 10 min, the raisins had a chemical odour. The results show that HIPL effectively reduces OTA levels in raisins without causing any quality loss. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) has attracted increasing attention in wastewater decontamination for yielding reactive oxygen species (ROS). In this study, mackinawite (FeS) was synthesized and applied as the heterogeneous catalyst for PAA activation. Using sulfamethoxazole (SMX) as the target pollutant, the influences of FeS dosage, PAA dosage and initial pH values on SMX degradation by the FeS/PAA process were investigated. Under optimal conditions, SMX could be completely removed within 5 min with the apparent first-order rate constant (kobs) of 7.71 × 10−4 s−1. Electron spin resonance spectroscopy (ESR) analysis and radical scavenging experiments were modulated to detect the active species. During the activation process of PAA, various active components were evidenced to be hydroxyl radicals (HO•), singlet oxygen (1O2), superoxide radicals (O2•−) and organic radicals (R-O•, e.g., CH3C(O)O• and CH3C(O)OO•), whereas HO• and R-O• were demonstrated as the dominant active species responsible for SMX abatement. Both dissolved Fe(II) ions and active sites on the surface of FeS were proven to be activators for PAA, and SMX abatement was highly promoted as a result. Furthermore, the acidic pH displayed superior efficiency in SMX decomposition compared with alkaline and neutral conditions. Five degradation pathways of SMX were put forward and the toxicity of byproducts was further evaluated. Overall, this study provided an efficient and environmentally friendly PAA activation approach using FeS, which might broaden its applicability in the remediation of micropollutants. [ABSTRACT FROM AUTHOR]

An increase in foodborne illnesses associated with fruits and vegetables has been observed in recent years, with several outbreaks linked to contaminated agricultural water. The effectiveness of peroxyacetic acid (PAA) and chlorine (Cl) at reducing Escherichia coli in rain barrel and creek water was evaluated in this study. Rain barrel and creek water (12 and 32°C overnight) were inoculated with ~5 log CFU/ml of an E. coli cocktail, reequilibrated to 12 and 32°C (30 min), and treated with 25 ± 2 ppm of Cl, 75 ± 5 ppm of PPA, or a water control (W). Samples were collected 0, 5, 10, 60, 1,440, and 2,880 min after treatment, neutralized in Dey-Engley broth, and enumerated using the Food and Drug Administrationapproved IDEXX Colilert method, as well as E. coli/coliform (EC) Petrifilm, and enriched for the presence or absence of E. coli. E. coli was not detected in 12 and 32°C creek and rain barrel water 0 min after treatment with PAA and 60 min after treatment with Cl using Colilert. E. coli was not detected in samples treated with PAA or Cl at any time point using EC Petrifilm. These data allow growers and extension educators to explore the use of these treatments in surface water sources for postharvest uses in produce. [ABSTRACT FROM AUTHOR]

A homogeneous catalyst system consisting of Mn(OAc)2 and 2‐picolinic acid was studied for alcohol oxidation using peracetic acid as the oxidant. Catalyst loadings as low as 0.01 mol% could be utilized and the system compared well to other peroxide based methods. The utilization of continuous flow allowed the fast, exothermic reactions to be carried out in a safe and scalable manner. [ABSTRACT FROM AUTHOR]

The persistence of Listeria monocytogenes biofilms on equipment surfaces poses a significant risk of cross-contamination, necessitating effective surface decontamination strategies. This study assessed the effectiveness of hurdle treatments combining peroxyacetic acid (PAA) and saturated steam against 7-day-old L. innocua (a non-pathogenic surrogate for L. monocytogenes) biofilms on stainless steel (SS), polyester (PET), and rubber surfaces. Results demonstrated >6 log10 CFU/coupon L. innocua reductions on SS and PET surfaces after PAA (40 ppm, 1 min) followed by steam treatment (100 °C, 6 s). On rubber surfaces, PAA (80 ppm, 1 min) followed by steam treatment (100 °C, 6 s) resulted in ~5 log10 CFU/coupon L. innocua reduction. The presence of apple juice soil reduced the efficacy of hurdle treatments, with PAA (40 ppm, 1 min) and steam exposure (6 s) resulting in 5.6, 5.8, and 4.2 log10 CFU/coupon reductions of L. innocua on SS, PET, and rubber, respectively. The efficacy of this antimicrobial combination was further reduced by surface defects, especially in the presence of organic matter. Nevertheless, the treatment still achieved >5 log10 CFU/coupon reductions of L. innocua on worn SS and PET soiled with apple juice and ~4.5 log10 CFU/coupon reduction on worn, soiled rubber surfaces. These findings highlight that PAA treatments followed by a brief steam exposure are effective strategies for controlling Listeria on food-contact surfaces. [ABSTRACT FROM AUTHOR]

One of the main threats to aquaculture is represented by microbial pathogens, causing mass mortality episodes in hatcheries, which result in huge economic losses. Among the many disinfection methods applied to reduce this issue, the use of chemicals and beneficial microorganisms (probiotics) seems to be the most efficient. The aim of this study is to test the efficacy of two of them: a chemical, peracetic acid (PAA), and a probiotic, Phaeobacter inhibens. Tests were run on microalgae of the species Isochrysis galbana (var T-ISO). For both remedies, the microalgae survival rate and final cell concentration (cell/mL) were monitored. PAA analysis tested six different concentrations of the chemical: 7.5 µg, 10 µg/L, 20 µg/L, 30 µg/L, 40 µg/L, and 60 µg/L. Meanwhile, P. inhibens was tested with a concentration of 104 CFU/mL. Analysis for both the remedies was conducted on a laboratory scale using glass flasks, and on an industrial scale inside photobioreactors (PBRs). Among all the treatments, the one with PAA dosed with a concentration of 60 µg/L gave the best results, as the culture reached a final density of 8.61 × 106 cell/mL. However, none of the remedies involved in the experiment harmed microalgae or their growth. The results match perfectly with the condition requested for the tested remedies: to obtain an optimal breakdown of pathogens without interfering with culture growth. These features make PAA and P. inhibens good candidates for disinfection methods in aquaculture facilities. [ABSTRACT FROM AUTHOR]

The tolerance of 17 isolates of enterobacteria isolated from raw goat milk was evaluated against three sanitisers. All isolates were tolerant to sodium hypochlorite (1250 to >5000 ppm) and eight isolates were tolerant to peracetic acid (up to 1000 ppm). Two isolates were tolerant to all tested concentrations of quaternary ammonium with biguanide (>150/100 ppm). Although not all isolates are considered pathogens, they exert an important influence on the milk production chain. Sanitisers based on quaternary ammonium and biguanide seem to be more suitable for sanitisation in goat milk chain than sodium hypochlorite. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) shows potential for use in drinking water treatment as an alternative to prechlorination, such as for mussel control and disinfection by-product precursor destruction, though its impact as a preoxidant during cyanobacterial blooms remains underexplored. Here, Microcystis aeruginosa inactivation and microcystin-LR and -RR release and degradation using PAA were explored. The toxin degradation rates were found to be higher in alkaline conditions than in neutral and acidic conditions. However, all rates were significantly smaller than comparable rates when using free chlorine. The inactivation of M. aeruginosa cells using PAA was faster at acidic pH, showing immediate cell damage and subsequent cell death after 15–60 min of exposure to 10 mg/L PAA. In neutral and alkaline conditions, cell death occurred after a longer lag phase (3–6 h). During cell inactivation, microcystin-LR was released slowly, with <35% of the initial intracellular toxins measured in solution after 12 h of exposure to 10 mg/L PAA. Overall, PAA appears impractically slow for M. aeruginosa cell inactivation or microcystin-LR and -RR destruction in drinking water treatment, but this slow reactivity may also allow it to continue to be applied as a preoxidant for other purposes during cyanobacterial blooms without the risk of toxin release. [ABSTRACT FROM AUTHOR]

Foodborne pathogens pose a persistent threat in broiler chicken production, particularly during the slaughter process, where contamination with zoonotic pathogens remains a concern. This study focuses on the potential of organic acids, such as formic and lactic acid, and the oxidizing agent peracetic acid, to decontaminate scalding water and enhance the hygiene of chicken carcasses. We conducted suspension tests introducing various organic loads to mirror the conditions of practical scalding water. Additionally, the surface tests were performed on chicken skin. Both methods were further tested in an experimental slaughtering facility. In suspension tests, the organic acids achieved impressive decontamination, with a 5‐log10 reduction of the test organisms Enterococcus hirae, Salmonella Typhimurium and Campylobacter jejuni at minimal concentrations (between 0.04% and 2% for formic acid; between 0.1% and 4.5% for lactic acid). Peracetic acid also effectively sanitized model water and chicken skin, even when used in low concentrations (between 0.001% and 0.1%), both in the laboratory‐based testing and in the experimental slaughtering facility. These results suggest that the tested disinfectants can effectively sanitize process water, even under conditions mimicking practical scalding water with organic matter. Peracetic acid, in particular, proved highly effective in improving chicken skin hygiene even at low concentrations. [ABSTRACT FROM AUTHOR]

The activated sludge process plays a crucial role in modern wastewater treatment plants. During the treatment of daily sewage, a large amount of residual sludge is generated, which, if improperly managed, can pose burdens on the environment and human health. Additionally, the highly hydrated colloidal structure of biopolymers limits the rate and degree of dewatering, making mechanical dewatering challenging. This study investigates the impact and mechanism of microwave irradiation (MW) in conjunction with peracetic acid (PAA) on the dewatering efficiency of sludge. Sludge dewatering effectiveness was assessed through capillary suction time (CST) and specific resistance to filtration (SRF). Examination of the impact of MW-PAA treatment on sludge dewatering performance involved assessing the levels of extracellular polymeric substances (EPS), employing three-dimensional excitation-emission matrix (3D-EEM), Fourier transform–infrared spectroscopy (FT-IR), and scanning electron microscopy. Findings reveal that optimal dewatering performance, with respective reductions of 91.22% for SRF and 84.22% for CST, was attained under the following conditions: microwave power of 600 W, reaction time of 120 s, and PAA dosage of 0.25 g/g MLSS. Additionally, alterations in both sludge EPS composition and floc morphology pre- and post-MW-PAA treatment underwent examination. The findings demonstrate that microwaves additionally boost the breakdown of PAA into •OH radicals, suggesting a synergistic effect upon combining MW-PAA treatment. These pertinent research findings offer insights into employing MW-PAA technology for residual sludge treatment. [ABSTRACT FROM AUTHOR]

During field conditions and storage, onion bulbs are often severely affected by Aspergillus niger L., which leads to substantial yield and quality loss due to black mold. In the El-Minia region of Egypt, we isolated several strains of A. niger from different onion bulbs. To combat the black mold rot disease caused by A. niger, we tested the individual and combined effects of acetic acid and hydrogen peroxide against the most virulent strain under both in vitro and storage (180 days) conditions. Additionally, we measured the levels of antioxidant compounds such as phenolic acids, polyphenols, and ascorbic acid. Our pathogenicity tests helped us identify the most virulent isolate. We found that the environmentally friendly compound peroxyacetic acid, derived from the combination of hydrogen peroxide and acetic acid, reduced black mold infection in both, in vitro and storage conditions. Treating postharvest onion bulbs with 0.2 g L−1 acetic acid and 0.4 g L−1 hydrogen peroxide promised to mitigate the development of black mold rot for 180 days of storage. Furthermore, our results indicated that these treatments increased bioactive antioxidant compounds such as ascorbic acid, phenolic compounds, and polyphenols. These compounds, as secondary metabolites, served as the first line of defense against onion rot disease during storage. In conclusion, applying peroxyacetic acid proved a practical approach to controlling black mold rot disease development in onion bulbs during storage. [ABSTRACT FROM AUTHOR]

Chick performance and hatchability are adversely affected by microbial contamination of hatching eggs. Egg disinfection is therefore crucial to limiting bacterial numbers and optimizing production. The present study was applied to detect the effect of hatching eggs spraying (nest and floor) with two commercial disinfectants: A (H2O2, peracetic and acetic acid) and B (glutraldehyde and Benzalkonium chloride) on hatching parameters and eggshell microbial counts. Hatching eggs were collected from broiler breeder flocks at different ages (37, 47 and 57 weeks). The obtained results indicated that both disinfectants reduced the levels of bacteria in similar ways, but there were no significant differences between them. Concerning the hatching parameters; hatchability percentages (total and true) were lower than standard in both nest and floor eggs, and higher hatchability percentages were found in eggs sanitized with disinfectant A. However, the lowest values were reported in eggs of 57 weeks old breeders with both disinfectants. Conclusively, disinfectants A and B reduced the microbial load of hatching eggs of different ages, and some hatchability parameters were affected with flock age and the used disinfectants. [ABSTRACT FROM AUTHOR]

Objective: The antiparasitic effect of peracetic acid (PAA) was evaluated against an infestation of the protozoan Trichodina spp. in naturally infected juvenile domestic seventh‐generation (F7) Striped Bass Morone saxatilis. Methods: Replicated treatments (n = 3) consisted of 1 and 2 mg/L PAA and a control; treatments were applied every other day for three treatments (30‐min static exposure). Infestation intensity was enumerated 20–24 h after each treatment by counting the number of Trichodina present in a wet mount of excised gill tissue. Result: Neither treatment rate was able to completely eradicate the parasite; however, 2 mg/L PAA resulted in a statistically significant reduction, which equated to 75% reduction of observed parasites. Conclusion: The 2‐mg/L PAA treatment regimen in the present study is proposed as a safe, environmentally friendly, and effective method for reducing the intensity of Trichodina infestations in Striped Bass. Impact statementDefining new treatment regimens for common aquaculture parasites is beneficial to the industry. Emphasis on environmentally friendly chemicals is also good for the industry. Improving animal welfare can be achieved by reducing parasites in fish. [ABSTRACT FROM AUTHOR]

Copper-containing materials are attracting attention as self-disinfecting surfaces, suitable for helping healthcare settings in reducing healthcare-associated infections. However, the impact of repeated exposure to disinfectants frequently used in biocleaning protocols on their antibacterial activity remains insufficiently characterized. This study aimed at evaluating the antibacterial efficiency of copper (positive control), a brass alloy (AB+®) and stainless steel (negative control) after repeated exposure to a quaternary ammonium compound and/or a mix of peracetic acid/hydrogen peroxide routinely used in healthcare settings. A panel of six antibiotic-resistant strains (clinical isolates) was selected for this assessment. After a short (5 min) exposure time, the copper and brass materials retained significantly better antibacterial efficiencies than stainless steel, regardless of the bacterial strain or disinfectant treatment considered. Moreover, post treatment with both disinfectant products, copper-containing materials still reached similar levels of antibacterial efficiency to those obtained before treatment. Antibiotic resistance mechanisms such as efflux pump overexpression did not impair the antibacterial efficiency of copper-containing materials, nor did the presence of one or several genes related to copper homeostasis/resistance. In light of these results, surfaces made out of copper and brass remain interesting tools in the fight against the dissemination of antibiotic-resistant strains that might cause healthcare-associated infections. [ABSTRACT FROM AUTHOR]

The P450 enzyme CYP121 from Mycobacterium tuberculosis catalyzes a carbon-carbon (C-C) bond coupling cyclization of the dityrosine substrate containing a diketopiperazine ring, cyclo(l-tyrosine-l-tyrosine) (cYY). An unusual high-spin (S = 5/2) ferric intermediate maximizes its population in less than 5 ms in the rapid freeze-quenching study of CYP121 during the shunt reaction with peracetic acid or hydrogen peroxide in acetic acid solution. We show that this intermediate can also be observed in the crystalline state by EPR spectroscopy. By developing an on-demand-rapid-mixing method for time-resolved serial femtosecond crystallography with X-ray free-electron laser (tr-SFX-XFEL) technology covering the millisecond time domain and without freezing, we structurally monitored the reaction in situ at room temperature. After a 200 ms peracetic acid reaction with the cocrystallized enzyme-substrate microcrystal slurry, a ferric-hydroperoxo intermediate is observed, and its structure is determined at 1.85 Å resolution. The structure shows a hydroperoxyl ligand between the heme and the native substrate, cYY. The oxygen atoms of the hydroperoxo are 2.5 and 3.2 Å from the iron ion. The end-on binding ligand adopts a near-side-on geometry and is weakly associated with the iron ion, causing the unusual high-spin state. This compound 0 intermediate, spectroscopically and structurally observed during the catalytic shunt pathway, reveals a unique binding mode that deviates from the end-on compound 0 intermediates in other heme enzymes. The hydroperoxyl ligand is only 2.9 Å from the bound cYY, suggesting an active oxidant role of the intermediate for direct substrate oxidation in the nonhydroxylation C-C bond coupling chemistry.

Abstract Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising candidates for research and industry. Nevertheless, information about pathogens and diseases that may affect squid aquaculture remains sparse. In this study, we identify new parasitic copepod species that causes squid mortality and decreases squid hatching rates, and we also offer a solution to eliminate the pathogen during incubation of squid eggs. The newly discovered copepod Ikanecator primus gen. et sp. nov. was identified on oval squid eggs for the first time using both morphological and molecular diagnostic markers. In the genomes of the copepod and associated microbiome, we identified multiple genes for enzymes involved in cephalopod eggshell degradation in genomes of the copepod and associated microbiome. Furthermore, we conducted experiments to assess efficacy of peracetic acid in inhibiting the I. primus gen. et sp. nov. both in vitro and in vivo using immersion treatment. We established that a 2-min exposure to a concentration of 250 μl/L of peracetic acid containing product (PAA-product; 35 mg/L PAA and 15 mg/L H2O2) inhibited the development of nauplii in vitro. All parasites exposed to a concentration of 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) were eliminated within two minutes. On top of this, the immersion treatment with 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) improved survival of squid embryos and increased size of squid hatchlings compared with control and the immersion treatment with 125 μl/L of PAA-product (17.5 mg/L PAA and 7.5 mg/L H2O2) and the immersion treatment with 250 μl/L of PAA-product (35 mg/L PAA and 15 mg/L H2O2). These findings suggest that PAA holds a great potential as inhibitor and controller of parasitic copepod infections and for overall health management in cephalopod culture.

Reasonable regulation of electronic structures of heterogeneous composite catalysts can enhance the charge separation and transfer at the interface of materials, thus further promoting the catalytic performance of catalysts. Recently, peracetic acid〔CH3C(O)OOH, PAA〕 based on heterogeneous advanced oxidation process with biochar(BC) materials has attacked much interests due to various reactive oxygen species(ROS) generated in the process. In this study, biochar modified with Co(OH)2 nanoparticles(h-Co/BC) was successfully synthesized by a simple co-precipitation method, which was applied to activate PAA for tetracycline(TC) degradation. The results showed that h-Co/BC could completely degrade TC with an initial concentration of 10 µmol/L within 7 min at pH 7. The scavenger quenching tests and electron paramagnetic resonance(EPR) analysis further indicated that the produced primary ROS were alkoxy radical, which mainly including CH3COO·, CH3COOO·, ·OH and 1O2. In addition, materials characterizations combined with density functional theory calculation showed that biochar was successfully modified with Co(OH)2 nanoparticles. Thus, the Co 3d-band in h-Co/BC was closer to Fermi level compared with that in pure Co(OH)2, benefiting to directional electron transfer, which could then be easily captured by PAA for cleavage to ROS. This study provided a new method for synthesis of functional materials applied in PAA-based AOPs.

Metronidazole(MNZ), prone to accumulate in the environment, is a nitroimidazole antibiotic and its metabolites have potential carcinogenicity and mutagenicity. In this paper, the degradation characteristics of MNZ by coupled ferrate/peroxyacetic acid〔Fe(Ⅵ)/PAA〕technology, as well as the simulation of MNZ degradation and reaction mechanism, were investigated. When the dosages of Fe(Ⅵ) as 500 μmol/L and PAA as 100 μmol/L, the degradation of MNZ reached 94.85% at pH of 8 in 60 min, and the degradation process followed pseudo-first-order kinetics. Variable experiments showed that the degradation of MNZ was positively correlated with the dosage of Fe(Ⅵ) and PAA, and the best effect was achieved at pH=8. Chloride (Cl-) and nitrate (NO3-) in the water matrix had little effect on the degradation of MNZ. Ammonium salt (NH4+) could promote the degradation of MNZ,while bicarbonate (HCO3-) and humic acid (HA) inhibited the degradation. The removal of MNZ in simulated medical wastewater by Fe(Ⅳ)/PAA was similar to that in ultra-pure water, which could achieve better removal effect. Probe experiments and quenching experiments showed that PAA accelerated the removal of MNZ from active species. H2O2 coexisting with PAA was the main activator of Fe(Ⅵ) while the main active species of Fe(Ⅵ)/PAA system were Fe(V) and Fe(Ⅳ). The results were expected to provide theoretical reference and data support for the application of Fe(Ⅵ)/PAA system in the deep treatment of MNZ in medical wastewater.

Having been successfully bred in semi-intensive and intensive aquaculture systems, oval squids of the Sepioteuthis lessoniana species complex are emerging as promising candidates for research and industry. Nevertheless, information about pathogens and diseases that may affect squid aquaculture remains sparse. In this study, we identify new parasitic copepod species that causes squid mortality and decreases squid hatching rates, and we also offer a solution to eliminate the pathogen during incubation of squid eggs. The newly discovered copepod Ikanecator primus gen. et sp. nov. was identified on oval squid eggs for the first time using both morphological and molecular diagnostic markers. In the genomes of the copepod and associated microbiome, we identified multiple genes for enzymes involved in cephalopod eggshell degradation in genomes of the copepod and associated microbiome. Furthermore, we conducted experiments to assess efficacy of peracetic acid in inhibiting the I. primus gen. et sp. nov. both in vitro and in vivo using immersion treatment. We established that a 2-min exposure to a concentration of 250 μl/L of peracetic acid containing product (PAA-product; 35 mg/L PAA and 15 mg/L H2O2) inhibited the development of nauplii in vitro. All parasites exposed to a concentration of 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) were eliminated within two minutes. On top of this, the immersion treatment with 500 μl/L of PAA-product (70 mg/L PAA and 30 mg/L H2O2) improved survival of squid embryos and increased size of squid hatchlings compared with control and the immersion treatment with 125 μl/L of PAA-product (17.5 mg/L PAA and 7.5 mg/L H2O2) and the immersion treatment with 250 μl/L of PAA-product (35 mg/L PAA and 15 mg/L H2O2). These findings suggest that PAA holds a great potential as inhibitor and controller of parasitic copepod infections and for overall health management in cephalopod culture. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing demand for environmentally friendly epoxides made from vegetable oils, including castor oil. This study aims to produce epoxidized castor oil derived ricinoleic acid (ECORA) with applied synergistic sulfate-impregnated zeolite ZM-5 as catalyst. To date, there is no published work on production of ECORA by peracetic acids mechanism using hybrid homogenous–heterogenous catalyst. Peracetic acid produced in situ was used to produce ECORA. By combining acetic acid, which acts as an oxygen carrier, with hydrogen peroxide, which acts as an oxygen donor, peracetic acid was formed. The ratio of ricinoleic acid to acetic acid was used at a ratio of 1:1, while a 1:1 molar ratio of hydrogen peroxide to castor oil was introduced. The epoxidation process has been conducted at a temperature of 55 °C. The mixture was then stirred continuously at a fixed speed of 200 rpm. The maximum conversion to oxirane was achieved at 58%. Overall, ECORA was successfully produced via in situ epoxidation of castor oil with applied hybrid catalyst. [ABSTRACT FROM AUTHOR]

Peracetic acid (PAA) is emerging as a versatile agent for generating long-lived and selectively oxidative organic radicals (R-O•). Currently, the conventional transition metal-based activation strategies still suffer from metal ion leaching, undesirable by-products formation, and uncontrolled reactive species production. To address these challenges, we present a method employing BiOI with a unique electron structure as a PAA activator, thereby predominantly generating CH3C(O)O• radicals. The specificity of CH3C(O) O• generation ensured the superior performance of the BiOI/PAA system across a wide pH range (2.0 to 11.0), even in the presence of complex interfering substances such as humic acids, chloride ions, bicarbonate ions, and real-world water matrices. Unlike conventional catalytic oxidative methods, the BiOI/PAA system degrades sulfonamides without producing any toxic by-products. Our findings demonstrate the advantages of CH3C(O)O• in water decontamination and pave the way for the development of eco-friendly water decontaminations based on organic peroxides. [ABSTRACT FROM AUTHOR]

Canola oil can serve as a substitute for polyol in the production of eco-friendly polyurethane. The aim of this study is to investigate the optimal conditions for the epoxidation of canola oil via the Taguchi optimization method. To date, there is no published work on optimization of process parameters for epoxidized canola oil production using the Taguchi method. In this study, the epoxidation of canola oil was performed using in situ-generated peracetic acid. Peracetic acid was formed by the reaction between acetic acid and hydrogen peroxide in the presence of a catalyst. The highest conversion to oxirane of 85% was achieved at a ratio of 2:1 of hydrogen peroxide to canola oil, a temperature of 65°C, and a stirring speed of 400 rpm. The Fourier-transform infrared spectroscopy (FTIR) characterization reveals the presence of the oxirane ring group, identified at a wavenumber of 1150 cm−1. Employing particle swarm numerical simulations, the results exhibit excellent agreement with the experimental data, thereby confirming the accuracy and validity of the kinetic model. [ABSTRACT FROM AUTHOR]

Effective disinfection methods are crucial in the cold chain transportation process of food due to the specificity of temperature and the diversity of contaminated flora. The objective of this study was to investigate the sanitizing effect of different disinfectants on various fungi at – 20 °C to achieve accurate disinfection of diverse bacterial populations. Peracetic acid, hydrogen peroxide, and potassium bisulfate were selected as low-temperature disinfectants and were combined with antifreeze. The sanitizing effect of these cryogenic disinfectants on pathogens such as Bacillus subtilis black variant spores (ATCC9372), Staphylococcus aureus (ATCC 6538), Candida albicans (ATCC 10231), Escherichia coli (8099), and poliovirus (PV-1) was sequentially verified by bactericidal and virus inactivation experiments. After a specified time of disinfection, a neutralizing agent was used to halt the sanitizing process. The study demonstrates that different disinfectants exhibit selective effects during the low-temperature disinfection process. Peracetic acid, hydrogen peroxide, and potassium monopersulfate are suitable for the low-temperature environmental disinfection of bacterial propagules, viruses, and fungal contaminants. However, for microorganisms with strong resistance to spores, a low-temperature disinfectant based on peracetic acid should be chosen for effective disinfection treatment. Our results provide a valuable reference for selecting appropriate disinfectants to sanitize various potential pathogens in the future. [ABSTRACT FROM AUTHOR]

Background Peracetic acid and irradiation are common sterilization methods for allograft tendons; however, under some conditions, both methods adversely affect the fiber arrangement and ultimate load of the tendon. An in vitro study showed that low-dose peracetic acid combined with irradiation may be less detrimental to allograft tendon structure and properties, possibly because the breakdown of peracetic acid can lead to an enlargement of the interstitial spaces and an increase in porosity. Questions/purposes Using a rabbit Achilles tendon model, we asked: What is the effect of peracetic acid-ethanol combined irradiation on (1) the histopathology and fiber diameter of the allograft tendon, (2) tensile creep and load-to-failure biomechanical properties of allograft tendons, and (3) healing of the treated tendon in vivo compared with fresh-frozen allograft and peracetic acid-ethanol sterilization at 4 and 8 weeks? Methods The Achilles tendons used in this study were sourced from euthanized 10-week-old male New Zealand White rabbits previously used for ophthalmic experiments. All allografts were divided into three groups: fresh-frozen group (control group, n = 20), peracetic acid-ethanol sterilization group (n =20), and peracetic acid-ethanol combined irradiation group (n = 20). The sterilization protocols were performed per a predetermined plan. In the peracetic acid-ethanol sterilization group, the tendon tissues were covered with the peracetic acid-ethanol sterilization solution (1% peracetic acid for 30 minutes). In the peracetic acid-ethanol combined irradiation group, the tendon tissues were covered with the peracetic acid-ethanol sterilization solution (0.2% peracetic acid for 30 minutes) and were subjected to 15 kGy gamma irradiation. Thirty 10-week-old male New Zealand White rabbits received bilateral Achilles tendon allografts surgically. Tendon samples from each group were harvested at 4 weeks (n = 30) and 8 weeks (n = 30) postoperatively. For each timepoint, eight tissues were used for histologic staining and electron microscopy, 15 tissues were used for biomechanical testing, and seven tissues were used for hydroxyproline assay and quantitative polymerase chain reaction. Histopathology was determined qualitatively by hematoxylin and eosin and Masson staining, while fiber diameter was measured quantitatively by transmission electron microscopy. Biomechanical properties were measured using cyclic loading tests and load-to-failure tests. The healing outcome was quantitatively judged through healing-related genes and proteins. Results At 4 weeks and 8 weeks postoperatively, the peracetic acid-ethanol combined irradiation group visually demonstrated the best continuity and minimal peripheral adhesions. Histologic staining showed that tendon fibers in the peracetic acid-ethanol combined irradiation group maintained consistent alignment without notable disruptions or discontinuities, and there was a qualitatively observed increase in the number of infiltrating cells compared with the control group at the 4-week timepoint (444 ± 49 /mm² versus 256 ± 43 /mm², mean difference 188 /mm² [95% confidence interval 96 to 281]; p < 0.001). At 8 weeks postoperatively, the tendon fiber diameter in the peracetic acid-ethanol combined irradiation groups was similar to that of the control group (0.23 ± 0.04 μm versus 0.21 ± 0.03 μm, mean difference 0.02 μm [95% CI -0.04 to 0.08]; p = 0.56). At 8 weeks postoperatively, the peracetic acid-ethanol combined irradiation group exhibited better properties in terms of both ultimate load (129 ± 15 N versus 89 ± 20 N, mean difference 40 N [95% CI 7 to 73]; p = 0.02) and energy absorption density (17 ± 6 kJ/m² versus 8 ± 4 kJ/m², mean difference 8 kJ/m² [95% CI 0.7 to 16]; p = 0.004) compared with the control group. Gene expression analysis revealed higher expression levels of COL1A1 (2.1 ± 0.8 versus 1.0 ± 0, mean difference 1.1 [95% CI 0.1 to 2.1]; p = 0.003) and MMP13 (2.0 ± 0.8 versus 1.0 ± 0, mean difference 1.0 [95% CI 0.4 to 1.6]; p = 0.03) in the peracetic acid-ethanol combined irradiation group than in the control group. There was a higher amount of collagen Type I in tendons treated with peracetic acid-ethanol combined irradiation than in the control group (0.36 ± 0.03 versus 0.31 ± 0.04, mean difference 0.05 [95% CI 0.01 to 0.09]; p = 0.02). Conclusion Treatment with peracetic acid-ethanol combined irradiation did not have any discernible adverse effect on the histology, fiber diameter, enzymatic resistance, collagen content, or biomechanical strength of the allograft tendons compared with the control group. Peracetic acid-ethanol combined irradiation treatment had a positive impact on remodeling of the extracellular matrix and realignment of collagen fibers. Clinical Relevance This sterilization method could be helpful to expand the scope and frequency with which allogeneic materials are applied. The long-term healing effect and strength of allograft tendons must be tested before clinical use, and it is necessary to conduct comparative studies on autografts and synthetic materials that are currently widely used clinically. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Holocellulose fibers exhibit excellent recycling performance and are increasingly gaining attention for addressing the hornification effect that occurs during the recycling of waste paper products. However, the mechanism by which hemicellulose components in holocellulose fibers impact fiber reuse remains unknown. In this study, birch holocellulose was prepared through peracetic acid delignification. The hemicellulose content was adjusted using alkali treatment and xylanase treatment, both based on holocellulose. The removal of hemicellulose resulted in an increase in hornification and porosity growth rate during the recycling process due to these pretreatments. Consequently, fibers subjected to alkali treatment and xylanase treatment exhibited diminished mechanical performance with each recycling cycle. In particular, after five recycling runs, alkali treatment paper experienced a significant reduction in ultimate strength, dropping from 48 to 11 MPa, representing a 77% decrease. In contrast, hemicellulose-rich holocellulose paper retained an ultimate strength as high as 56 MPa (reduced from 81 MPa), marking a 33% decrease. The high hemicellulose content in holocellulose fibers proved advantageous for preserving the network structure of fibers and impeding the co-crystallization and aggregation of fibers during the recycling process, ultimately ensuring the maintenance of mechanical performance, including tensile, tearing, and bursting strength. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) combined with n-hydroxysuccinimide (NHS) can repair tendon damage caused by peracetic acid–ethanol and gamma irradiation sterilization. The semitendinosus tendons of 15 New Zealand white rabbits were selected as experimental materials, and the tendons were sterilized in a solution containing 1% (v/w) peracetic acid and 24% (v/w) ethanol. After 15 kGy gamma irradiation sterilization, the tendons were randomly divided into three groups (n = 10). The tendons were repaired with EDCs of 0, 2.5 and 5 mM combined with 5 mM NHS for 6 h, the tendons were temporarily stored at − 80 ± °C. The arrangement and spatial structure of collagen fibers were observed by light microscopy and scanning electron microscopy, the collagen type and collagen crimp period were observed under a polarizing microscope, and the collagen fibril diameter and its distribution were measured by transmission electron microscopy, from which the collagen fibril index and mass average diameter were calculated. The resistance of collagen to enzymolysis was detected by the free hydroxyproline test, and tensile fracture and cyclic loading tests of each group of tendons were carried out, from which the elastic modulus, maximum stress, maximum strain, strain energy density and cyclic creep strain were calculated. The obtained results showed that the gap between loose collagen fibers in the 0 mM control group was wider, the parallel arrangement of tendons in the 2.5 and 5 mM groups was more uniform and regular and the fiber space decreased, the crimp period in the 5 mM group was lower than that in the 0 mM group (P < 0.05), and the concentration of hydroxyproline in the 5 mM group (711.64 ± 77.95 μg/g) was better than that in the control group (1150.57 ± 158.75 μg/g). The elastic modulus of the 5 mM group (424.73 ± 150.96 MPa) was better than that of the 0 mM group (179.09 ± 37.14 MPa). Our results show that EDC combined with NHS can repair damaged tendons after peracetic acid–ethanol and gamma radiation treatment, and 5 mM EDC has better morphological performance, anti-enzymolysis ability and biomechanical properties than 2.5 mM EDC. [ABSTRACT FROM AUTHOR]

Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study investigates the impact of chemical treatments on the properties of Brazilian jute woven fabric/polyester resin composites. Sodium hydroxide, hydrogen peroxide, and peracetic acid were utilized to treat the jute fabrics, followed by resin transfer molding (RTM) to form the composites. Evaluation included water absorption, flexural strength, tensile strength, and short-beam strength. The alkaline treatment induced changes in the chemical composition of the fibers' surface. Chemical treatments resulted in increased flexural and short-beam strength of the composites, with no significant alterations in tensile properties. The hydrogen peroxide treatment exhibited lower water absorption, suggesting its potential as a viable option for enhancing the performance of these composites. [ABSTRACT FROM AUTHOR]

This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets (Oreochromis niloticus) by fogging (15 min) or by immersion (2 s) in a pool of Escherichia coli (NEWP 0022, ATCC 25922, and a field-isolated strain), Staphylococcus aureus (ATCC 25923 and a field-isolated strain), and Salmonella Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control S. Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding E. coli, there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For S. aureus, only immersion in PA showed no significant difference (p < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing S. Typhimurium, E. coli, and S. aureus in tilapia fillets. [ABSTRACT FROM AUTHOR]

Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant. Numerous recent incidents involving ricin have occurred, many in the form of mailed letters resulting in both building and mail sorting facility contamination. The goal of this study was to assess the decontamination efficacy of several commercial off-the-shelf (COTS) cleaners and decontaminants (solutions of sodium hypochlorite [bleach], quaternary ammonium, sodium percarbonate, peracetic acid, and hydrogen peroxide) against a crude preparation of ricin toxin. The ricin was inoculated onto four common building materials (pine wood, drywall joint tape, countertop laminate, and industrial carpet), and the decontaminants were applied to the test coupons using a handheld sprayer. Decontamination efficacy was quantified using an in-vitro cytotoxicity assay to measure the quantity of bioactive ricin toxin extracted from test coupons as compared to the corresponding positive controls (not sprayed with decontaminant). Results showed that decontamination efficacy varied by decontaminant and substrate material, and that efficacy generally improved as the number of spray applications or contact time increased. The solutions of 0.45% peracetic acid and the 20,000-parts per million (ppm) sodium hypochlorite provided the overall best decontamination efficacy. The 0.45% peracetic acid solution achieved 97.8 to 99.8% reduction with a 30-min contact time. [ABSTRACT FROM AUTHOR]

This study aimed at evaluating the efficacy of a blend of citric acid and hydrochloric acid (CP), peroxyacetic acid (PAA), and sulfuric acid (SA) against Salmonella and mesophilic aerobic plate counts (APC) on chicken hearts and livers. Samples were inoculated with a five‐serovar cocktail of Salmonella at ca. 4.8 log CFU/g and treated by immersion with a water control (90 s), CP (5% v/v, 30 s), PAA (0.05% v/v or 500 ppm, 90 s), or SA (2% v/v, 30 s), all at 4°C and with mechanical agitation. Samples were vacuum packed and stored for up to 3 days at 4°C. Three independent replications were performed for each product, treatment, and time combination. The average Salmonella reductions in chicken hearts after 3 days were 1.33 ± 0.25, 1.40 ± 0.04, and 1.32 ± 0.12 log CFU/g for PAA, SA, and CP, respectively. For chicken livers, the values were 1.10 ± 0.12, 1.09 ± 0.19, and 0.96 ± 0.27 for PAA, SA, and CP, respectively. All antimicrobials reduced Salmonella counts in both chicken hearts and livers by more than one log, in contrast to the water control. All treatments effectively minimized the growth of APC for up to 3 days of refrigerated storage, and no differences in objective color values (L, a, or b) were observed. The poultry industry may use these antimicrobials as components of a multifaceted approach to mitigate Salmonella in nonconventional chicken parts. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The postharvest life of strawberries is short, and disinfection processes for fresh-cut and frozen strawberries are needed to address the risk posed by foodborne pathogens in this kind of product. For this, a process involving immersion in a 40 mg L−1 peracetic acid (PA) solution accompanied by the use of an emerging technology, ultraviolet-C for 2 min, was studied for its impact on strawberry quality and microbial load as a novel alternative method to chlorine sanitation. The shelf life of the washed strawberries was evaluated in fresh (whole or fresh-cut) product for 11 days at 4 °C and in product that had been frozen for 12 months at –20 °C (air or modified atmosphere, 20% CO2, 5% O2, and 75% N2). After washing, total aerobic mesophylls, yeast, and mold decreased by 0.5–1.0 log units and these counts remained low during storage. The fresh and fresh-cut fruits' firmness (2.3 ± 0.5 N at day 11) and lightness (expressed by L*, averaging 31.0 ± 0.1) were maintained. Although antioxidant activity, expressed by the amount of radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), decreased during storage in fresh-cut samples, total ferric reducing antioxidant power (FRAP), total phenolic content, and total anthocyanin content were maintained in all the formats during storage (averaging 1.33 ± 0.04 g kg−1 ascorbic acid equivalents, 0.212 ± 0.01 g kg−1 gallic acid equivalents, and 0.03 ± 0.01 g kg−1 pelargonidine-3-glucoside). An increase in red color (from 32.1 to 39.3 a* values) and a loss of firmness of up to 46.8% was observed after the first month of frozen storage with no changes in the nutritional quality. Considering the sanitizing effect of water UV-C with peracetic acid (WUVPA) and the results obtained in the present study, the addition of this process in the production chain of strawberries could be an effective method to maintain the shelf life of the fruits, especially for fresh-cut strawberries. [ABSTRACT FROM AUTHOR]

The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of −10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop efficient and environmentally friendly decontaminants for poultry products. In this study, we aimed to evaluate the practical application of peroxyacetic acid (PAA) as a replacement for sodium hypochlorite (SH) to sterilize fresh chicken carcasses, using microbial, color, and electronic-nose analyses. We evaluated the decontamination effects of different concentrations of PAA and SH on chicken carcasses. The bactericidal effects of PAA at pH 3, 7, and 9, and SH at pH 10, at concentrations ranging from 100 to 500 ppm on coliform bacteria, total bacteria, and Salmonella spp. were evaluated. PAA induced a similar bactericidal effect at lower concentrations than SH. Therefore, at the same concentration and treatment time, PAA showed better bactericidal effects than SH. Although treatment with PAA (pH 3) and SH (pH 10) resulted in considerable discoloration, the degree of discoloration decreased when the pH of PAA was increased to 7 and 9. Therefore, by increasing the pH of PAA, the discoloration effect on chicken carcasses can be reduced without altering the microbial-reduction effect. Electronic-nose analysis showed that the flavor of the chicken was almost unaffected by volatile components at a treatment time < 30 min. Therefore, this study experimentally identified the optimal PAA concentration for the decontamination of chicken carcasses. The study findings provide a theoretical basis for the replacement of traditional bactericides, such as SH, with PAA for the production of poultry products. [ABSTRACT FROM AUTHOR]

Using banana peel as raw material, the composite material CuFe2O4@BC was synthesised and used it to activate peracetic acid (PAA) to remove tetracycline (TC) in water. The crystal phase, morphology, and chemical bonding of the composite were analysed by XRD, SEM, FTIR, XPS, and other characterisation techniques. In the degradation experiments, CuFe2O4@BC showed high catalytic activity and found that the best dosage ratio of CuFe2O4@BC and PAA is 300 mg/L: 3 mmol/L, and under this condition, the removal rate of TC in 60 min reached 85%. CuFe2O4@BC showed degradation effect in a wide pH range, and the catalytic activity was found to be the best under acidic conditions. At the same time, after five cycles of test, the composite still maintained more than 80% of TC removal rate. The free radical quenching experiments proved that the main active species in the reaction were •OH, CH3COO• and CH3COOO•. [ABSTRACT FROM AUTHOR]

Due to the need for environmental protection and sustainability, there has been a rising need to replace the traditionally harsh oxidative functionalization process, which is essential for syntheses of various organic compounds, by biocatalysis. However, the investigated alternative processes are still challenged with enzyme instability and/or low specific reaction rate. Due to these still existing challenges and the recognition of Pickering emulsions as an efficient platform for continuous biphasic biocatalysis, the first, enzymatic step of the lipase catalyzed oxidative functionalization was investigated in bioactive Pickering emulsions. The study focused on the impact of Pickering emulsion composition such as the volume phase fraction, type and concentration of the nanoparticles and enzymes on continuous peroxyacetic acids synthesis. The type of nanoparticles used and Candida antarctica lipase B concentration significantly impacted the process while the other named parameters only had a marginal influence. [ABSTRACT FROM AUTHOR]

Immunocompromised patients are at an increased risk of severe legionella infections. We present the results of an outbreak investigation initiated following a fatal case of hospital-acquired legionellosis linked to contaminated water from a toilet-flushing cistern. Additionally, we provide experimental data on the growth of Legionella spp. in flushing cisterns and propose a straightforward protocol for prevention. We monitored the growth of Legionella spp. in the building's hot- and cold-water systems using quantitative bacterial culture on selective agar. Molecular typing of Legionella pneumophila isolates from the infected patient and the water system was conducted through core-genome multi-locus sequence typing (cgMLST). Legionella contamination in the hospital building's cold-water system was significantly higher than in the hot-water system and significantly higher in toilet flushing cistern's water compared with cold water from bathroom sinks and showers. Isolates from the patient and from the flushing cistern of the patient's bathroom were identical by cgMLST. In an experimental setting, daily toilet flushing for a period of 21 days resulted in a 67% reduction in the growth of Legionella spp. in the water of toilet flushing cisterns. Moreover, a one-time disinfection of cisterns with peracetic acid, followed by daily flushing, decreased legionella growth to less than 1% over a period of at least seven weeks in these setting. One-time disinfection of highly contaminated cisterns with peracetic acid and daily toilet flushing as short-term measure can significantly reduce legionella contamination in flushing cisterns. These measures may aid in preventing legionella infection among immunocompromised patients. [ABSTRACT FROM AUTHOR]

The alkali/urea system is an economical and environmentally friendly solvent system for dissolving cellulose. However, the mechanical performance of cellulose derived materials (such as fibres or films) treated with alkali/urea must be improved. The capacity of this system for cellulose dissolution is limited and the mechanical properties of the regenerated cellulose fibres are still unsatisfactory. Here, cotton linter pretreated with peracetic acid (PAA) was dissolved in a LiOH/urea aqueous suspension in which Zn–Al layered double hydroxide (Zn–Al LDH) nanosheets (NS thickness = 3 nm) were exfoliated in situ. After wet spinning, the strength and toughness of the regenerated cellulose fibres reached 290 ± 7.66 MPa and 23.5 ± 4.40 MJ/m3 respectively, which were 66.7% and 150% higher than those without the LDH NS treatment. It is interesting to note that the synergistic effect of Zn2+ and Al3+ distributed on the surface of the LDH host layer significantly improved the solubility of cellulose at low temperature and the interaction between the cellulose and LDH NSs also improved the mechanical performance. This work provides a strategy for improving both the solubility of cellulose in the alkali/urea system and the mechanical properties of regenerated cellulose fibres. [ABSTRACT FROM AUTHOR]

Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls due to contamination with Salmonella. A study was conducted to determine the fate of Salmonella on apple slices, following immersion in three antimicrobial solutions (viz., ε-polylysine [epsilon-polylysine or EP], sodium bisulfate [SBS], or peracetic acid [PAA]), and subsequent hot air dehydration. Gala apples were aseptically cored and sliced into 0.4 cm thick rings, bisected, and inoculated with a five-strain composite of desiccation-resistant Salmonella, to a population of 8.28 log CFU/slice. Slices were then immersed for 2 min in various concentrations of antimicrobial solutions, including EP (0.005, 0.02, 0.05, and 0.1%), SBS (0.05, 0.1, 0.2, and 0.3%), PAA (18 or 42 ppm), or varying concentrations of PAA + EP, and then dehydrated at 60°C for 5 h. Salmonella populations in positive control samples (inoculated apple slices washed in sterile water) declined by 2.64 log after drying. In the present study, the inactivation of Salmonella, following EP and SBS treatments, increased with increasing concentrations, with maximum reductions of 3.87 and 6.20 log (with 0.1 and 0.3% of the two compounds, respectively). Based on preliminary studies, EP concentrations greater than 0.1% did not result in lower populations of Salmonella. Pretreatment washes with either 18 or 42 ppm of PAA inactivated Salmonella populations by 4.62 and 5.63 log, respectively, following desiccation. Combining PAA with up to 0.1% EP induced no greater population reductions of Salmonella than washing with PAA alone. The addition of EP to PAA solutions appeared to destabilize PAA concentrations, reducing its biocidal efficacy. These results may provide antimicrobial predrying treatment alternatives to promote the reduction of Salmonella during commercial or consumer hot air drying of apple slices.

Introduction: Targeted amplicon sequencing of the 16S rRNA delineates the complex microbial interactions that occur during food spoilage, providing a tool to intensively screen microbiota response to antimicrobial processing aids and interventions. The current research determines the microbiota and spoilage indicator (total aerobes and lactic acid bacteria; LAB) response to inorganic and organic antimicrobial intervention use on the shelf-life of fresh, never-frozen, skin-on, bone-in chicken wings. Methods: Wings (n=200) were sourced from local processor and either not treated (NT) or treated with 15-s dips of tap water (TW), organic (peracetic acid; PAA), inorganic acids (sodium bisulfate; SBS), and their combination (SBS + PAA). Wings were stored (4°C) and rinsed in neutralizing Buffered Peptone Water (BPW) for 1 min on d 0, 7, 14, and 21 post-treatment. Spoilage indicators, aerobic mesophiles and LAB, were quantified from rinsates. Genomic DNA of d 14 and 21 rinsates were extracted, and V4 of 16S rRNA gene was sequenced. Sequences were analyzed using QIIME2.2019.7. APC and LAB counts were reported as Log10 CFU/g of chicken and analyzed in R Studio as a General Linear Model using ANOVA. Pairwise differences were determined using Tukey’s HSD (P£0.05). Results: Spoilage was indicated for all products by day 21 according to APC counts (>7 Log10 CFU/g); however, wings treated with SBS and SBS + PAA demonstrated a 7-day extended shelf-life compared to those treated with NT, TW, or PAA. The interaction of treatment and time impacted the microbial diversity and composition (p < 0.05), with those treated with SBS having a lower richness and evenness compared to those treated with the controls (NT and TW; p < 0.05, Q < 0.05). On d 14, those treated with SBS and SBS + PAA had lower relative abundance of typical spoilage population while having a greater relative abundance of Bacillus spp. (~70 and 50% of population; ANCOM p < 0.05). By d 21, the Bacillus spp. populations decreased below 10% of the population among those treated with SBS and SBS + PAA. Discussion: Therefore, there are differential effects on the microbial community depending on the chemical intervention used with organic and inorganic acids, impacting the microbial ecology differently. [ABSTRACT FROM AUTHOR]

Aims This study investigated the antimicrobial efficacy of ultrasound technology (US) in combination with two different disinfectants (Disinfectant A and Disinfectant B), containing peracetic acid (PAA) and quaternary ammonium compounds (QACs), respectively, against two sporigenic pathogens, Aspergillus brasiliensis and Bacillus subtilis. Methods and results The microbicidal activity of the coupled treatment was compared with the use of the disinfectants alone, and the efficacy of the disinfection strategies was evaluated by the log reduction of the population of the microorganism inoculated onto stainless-steel surface. The combination treatment resulted in a log reduction of 5.40 and 3.88 (Disinfectant A + US) against A. brasiliensis and B. subtilis , at 850 and 500 ppm PAA, compared to 265 and 122 (Disinfectant A only). For Disinfectant B, in combination with US, showed a logarithmic reduction of 5.04 and 4.79 against A. brasiliensis and B. subtilis at 078% v v−1 and 392% v v−1 QACs, respectively, vs. 1.58 and 1.64 (Disinfectant B only). Moreover, no colonies or not statistically significant growth was observed within the US bath containing the disinfectant. Conclusions The antimicrobial efficacy of the two disinfectants was greatly enhanced when used in combination with US, and this also makes it possible to avoid the overuse of chemicals for disinfection. [ABSTRACT FROM AUTHOR]