Search Results (17)

Microbial contamination of fresh berries poses a significant public health risk due to their delicate and porous structure. This study evaluated the antimicrobial efficacy of washing and coating with sodium dichloroisocyanurate (SDC) against Escherichia coli, Listeria monocytogenes, and Salmonella enterica on blackberries. Two treatment approaches were tested: washing in SDC solutions (500 ppm and 1000 ppm for 1, 4, and 8 min), and hemicellulose B-based coatings supplemented with SDC (1 and 4 min exposure). Our results demonstrated that microbial reduction was significantly influenced by SDC concentration and exposure duration; longer treatment times and higher SDC concentrations achieved greater reductions. Washing with 1000 ppm SDC for 8 min obtained reductions of 5.0 ± 0.22 Log CFU/mL for E. coli (p < 0.001), 3.6 ± 0.45 Log CFU/mL for L. monocytogenes (p < 0.01), and 4.5 ± 0.30 Log CFU/mL for S. enterica (p < 0.001). Coating treatments at 1000 ppm for 4 min achieved even greater reductions for S. enterica, reaching 6.8 ± 0.35 Log CFU/mL, which was statistically superior to the corresponding washing treatment (p < 0.001). These findings support SDC as a promising antimicrobial agent for blackberry decontamination using a washing or coating method, with potential applications in fresh produce safety. Full article

Staphylococcus aureus is a mastitis pathogen that compromises cow health and causes significant economic losses in the dairy industry. High antimicrobial resistance and biofilm formation by S. aureus limit the efficacy of conventional treatments. This study evaluated the potential of polyhexamethylene biguanide nanoparticles (PHMB NPs) against mastitis-causing S. aureus. PHMB NPs showed low toxicity to bovine mammary epithelial cells (MAC-T cells) at concentrations up to four times higher than the minimum inhibitory concentration (1 µg/mL) against S. aureus. In Experiment 1, PHMB NPs significantly reduced biofilm formation by S. aureus by 50% at concentrations ≥1 µg/mL, though they showed limited efficacy against preformed biofilms. In Experiment 2, using an excised teat model, PHMB NPs reduced S. aureus concentrations by 37.57% compared to conventional disinfectants (chlorhexidine gluconate, povidone–iodine, and sodium dichloroisocyanurate), though limited by short contact time. These findings highlight the potential of PHMB NPs for the control of S. aureus growth and biofilm formation. Full article

The rapid increase in electronic waste emphasizes the urgent need for low-toxicity, highly selective gold recovery methods. This study introduces a novel water-soluble organic leaching system using sodium dichloroisocyanurate (DCCNa) dissolved in water to investigate the gold leaching efficiency from the gold fingers of waste printed circuit boards (WPCBs). The pregnant leach solution (PLS) was processed using stepwise extraction. The gold oxidation states and leaching pathway were confirmed through UV–Vis, XPS, and ESI-MS analyses. Under optimal conditions (pH 2, 3-h leaching time, DCCNa concentration of 40 mmol/L, and 25 °C), the DCCNa leaching system achieved a gold leaching efficiency of 96.4%, significantly outperforming other metals and demonstrating its excellent selectivity. Stepwise extraction of the PLS using Acorga M5640 and dibutyl carbitol (DBC) resulted in a gold extraction efficiency of 95.5%. DCCNa generates the strong oxidant HClO, which reacts with HCl to produce Cl₂. Both HClO and Cl₂ oxidize Au(0) to Au(I) and Au(III), forming [AuCl₂]⁻ and [AuCl₄]⁻ complexes, with Cl⁻ originating from the hydrolysis of HCl. This study presents a safe, economical, and eco-friendly approach for the efficient and selective recovery of gold from WPCB gold fingers under laboratory conditions, which achieves the sustainable utilization of precious metals. Full article

Lithium-ion portable batteries (LiPBs) contain valuable elements such as cobalt (Co), nickel (Ni), copper (Cu), lithium (Li) and manganese (Mn), which can be recovered through solid–liquid extraction using choline chloride-based Deep Eutectic Solvents (DESs) and bi-functional ionic liquids (ILs). This study was carried out to investigate the extraction of metals from solid powder, black mass (BM), obtained from LiPBs, with various solvents used: six choline chloride-based DESs in combination with organic acids: lactic acid (1:2, DES 1), malonic acid (1:1, DES 2), succinic acid (1:1, DES 3), glutaric acid (1:1, DES 4) and citric acid (1:1, DES 5 and 2:1, DES 6). Various additives, such as didecyldimethylammonium chloride (DDACl) surfactant, hydrogen peroxide (H₂O₂), trichloroisocyanuric acid (TCCA), sodium dichloroisocyanurate (NaDCC), pentapotassium bis(peroxymonosulphate) bis(sulphate) (PHM), (glycine + H₂O₂) or (glutaric acid + H₂O₂) were used. The best efficiency of metal extraction was obtained with the mixture of {DES 2 + 15 g of glycine + H₂O₂} in two-stage extraction at pH = 3, T = 333 K, 2 h. In order to obtain better extraction efficiency towards Co, Ni, Li and Mn (100%) and for Cu (75%), the addition of glycine was used. The obtained extraction results using choline chloride-based DESs were compared with those obtained with three bi-functional ILs: didecyldimethylammonium bis(2,4,4-trimethylpentyl) phosphinate, [N_10,10,1,1][Cyanex272], didecyldimethylammonium bis(2-ethylhexyl) phosphate, [N_10,10,1,1][D2EHPA], and trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate, [P_6,6,6,14][Cyanex272]/toluene. The results of the extraction of all metal ions with these bi-functional ILs were only at the level of 35–50 wt%. The content of metal ions in aqueous and stripped organic solutions was determined by ICP-OES. In this work, we propose an alternative and highly efficient concept for the extraction of valuable metals from BM of LiPBs using DESs and ILs at low temperatures instead of acid leaching at high temperatures. Full article

Environmental decontamination and water disinfection practices are hallmarks of disease prevention and control in agricultural and public health settings. Informed fit-to-purpose biocontainment is thus dependent on methodologies accurately assessing microbial burden and viability. Also, rigorous evaluation of the efficacy of biocontrol measures implies monitoring microbial inactivation after decontamination/disinfection procedures. In this study, we used flow cytometry coupled with a resuscitation protocol to monitor the metabolic inactivation of bacteria capable of entering non-cultivable states, after the application of a chlorine-based water disinfectant. For this purpose, we used Mycobacterium bovis BCG as a model of slow-growing bacteria able to enter dormancy and representing a multi-host pathogen in a zoonotic disease system—animal tuberculosis—thriving both across temperate and semi-arid regions and involving environmental contamination. The biocide activity of a commercial sodium dichloroisocyanurate (NaDCC) disinfectant against M. bovis BCG was evaluated through mock environmental matrix tests. Using the manufacturer-recommended dosage of NaDCC, BCG cells were apparently inactivated after 24 h upon exposure. However, we show via flow cytometry that, upon exposure to optimal growth conditions, mycobacterial cells were able to regain metabolic activity shortly after, highlighting a sublethal effect of NaDCC at the recommended commercial dosage due to reversible BCG cell damage. In contrast, increasing twice the disinfectant dosage completely inactivated BCG cells after 24 h of exposure, with full irreversible loss of metabolic activity. Methodological workflows based on conventional culture or PCR would have missed the detection of these dormant subpopulations that were in fact able to resume growth when following the recommendations of a commercial disinfectant. This study highlights the superior, high-resolution value of single-cell approaches, such as flow cytometry, to accurately assess the activity of biocides against metabolically heterogeneous and dormant pathogenic bacteria with environmental cycles, supporting data-driven prioritization of environmental management and disinfection options in contaminated vulnerable settings. Full article

Seed germination requires the relaxation of endosperm cap and radicle cell walls, with cell wall hydrolases playing a significant role in this process. Our study revealed that a type of cell wall hydrolase, xyloglucan endotransglucosylase, may significantly contribute to endosperm weakening during lettuce seed germination. Through bioinformatics analysis, the XTH gene family in lettuce was divided into five subfamilies localized on nine chromosomes. Notably, there were significant differences in gene structure among the members of the LsXTHs family containing 1–4 exons and 20 conserved motifs. Among these motifs, motif1, motif2, and motif3 encoded the XTH structural domain. The promoter regions of LsXTHs contained a large number of cis-acting elements responsive to various abiotic stresses, such as drought, anaerobiosis, low temperature, high temperature, and salt stress. Germination experiments showed that seeds imbibed in water and 5 μmol/L abscisic acid (ABA) were able to achieve typical germination with radicle protrusion from the endosperm cap, achieving germination of 100% and 36%, respectively. Conversely, in 0.3% sodium dichloroisocyanurate (SDIC), the swollen seeds were unable to germinate or complete atypical germination, resulting in a germination rate of 30%. Compared to the control, the mechanical strength of the endosperm cap of seeds imbibed in 0.3% SDIC for 8 h increased by 14%, indicating that SDIC may inhibit seed germination by enhancing the mechanical strength of the endosperm cap. Enzyme activity analysis revealed that during lettuce seed germination, XTH enzyme activity in the endosperm cap was significantly higher than in other tissues and increased gradually with imbibition. Transcriptome analysis of the endosperm cap detected the expression of 10 LsXTH genes. Among these, LsXTH43 exhibited the highest expression during germination and was significantly upregulated two-fold by high temperatures, suggesting a potential role in the high-temperature germination of lettuce seeds. Additionally, SDIC downregulated the expression of LsXTHs to varying degrees, with the expression of LsXTH15 reduced to only 6% of its original level. Low temperature, high temperature, drought, and salt stress all reduced the expression of most LsXTHs to different degrees; when seeds germinated under waterlogging and cadmium stress, LsXTH6, LsXTH7, LsXTH8, LsXTH32, and LsXTH33 were all upregulated to some extent. Full article

Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L⁻¹) and NaDCC (1.5 mg L⁻¹) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time. Full article

This study was based on similar physicochemical characteristics of pseudorabies virus (PRV) and African swine fever virus (ASFV). A cellular model for evaluation of disinfectants was established with PRV as an alternative marker strain. In the present study, we evaluated the disinfection performance of commonly used commercialized disinfectants on PRV to provide a reference for the selection of good ASFV disinfectants. In addition, the disinfection (anti-virus) performances for four disinfectants were investigated based on the minimum effective concentration, onset time, action time, and operating temperature. Our results demonstrated that glutaraldehyde decamethylammonium bromide solution, peracetic acid solution, sodium dichloroisocyanurate, and povidone-iodine solution effectively inactivated PRV at concentrations 0.1, 0.5, 0.5, and 2.5 g/L on different time points 30, 5, 10, and 10 min, respectively. Specifically, peracetic acid exhibits optimized overall performance. Glutaraldehyde decamethylammonium bromide is cost effective but requires a long action time and the disinfectant activity is severely affected by low temperatures. Furthermore, povidone-iodine rapidly inactivates the virus and is not affected by environmental temperature, but its application is limited by a poor dilution ratio such as for local disinfection of the skin. This study provides a reference for the selection of disinfectants for ASFV. Full article

In this work, we present an efficient one-pot method for the synthesis of three new azo-isoxazoline derivatives (4a–c) from aromatic aldehydes, hydroxylamine hydrochloride and 4-(allyloxy)azobenzene. Thus, the azo-isoxazoline derivatives (4a–c) were synthesized via 1,3-dipolar cycloaddition using sodium dichloroisocyanurate (SDIC) as an eco-friendly and inexpensive oxidizing agent under ultrasound cavitation in water as a green solvent. The desired compounds 4a–c were obtained in high to excellent yields of 75–90%. Full article

In South Korea, testing disinfectants against foot-and-mouth disease virus (FMDV) that are contagious in livestock or that require special attention with respect to public hygiene can be manipulated only in high-level containment laboratories, which are not easily available. This causes difficulties in the approval procedure for disinfectants, such as a prolonged testing period. Additionally, the required biosafety level (BSL) in the case of FMDV has hindered its extensive studies. However, this drawback can be circumvented by using a surrogate virus to improve the performance of the efficacy testing procedure for disinfectants. Therefore, we studied bacteriophage MS2 (MS2) and bovine enterovirus type 1 (ECBO) with respect to disinfectant susceptibility for selecting a surrogate for FMDV according to the Animal and Plant Quarantine Agency (APQA) guidelines for efficacy testing of veterinary disinfectants. Effective concentrations of the active substances in disinfectants (potassium peroxymonosulfate, sodium dichloroisocyanurate, malic acid, citric acid, glutaraldehyde, and benzalkonium chloride) against FMDV, MS2, and ECBO were compared and, efficacies of eight APQA-listed commercial disinfectants used against FMDV were examined. The infectivity of FMDV and ECBO were confirmed by examination of cytopathic effects, and MS2 by plaque assay. The results reveal that the disinfectants are effective against MS2 and ECBO at higher concentrations than in FMDV, confirming their applicability as potential surrogates for FMDV in efficacy testing of veterinary disinfectants. Full article

Chlorinated compounds are usually applied in vegetable sanitization, but there are concerns about their application. Thus, this study aimed to evaluate ultrasound (50 kHz), acetic acid (1000; 2000 mg/L), and peracetic acid (20 mg/L) and their combination as alternative treatments to 200 mg/L sodium dichloroisocyanurate. The overall microbial, physicochemical, and nutritional quality of kale stored at 7 °C were assessed. The impact on Salmonella enterica Typhimurium was verified by plate-counting and scanning electron microscopy. Ultrasound combined with peracetic acid exhibited higher reductions in aerobic mesophiles, molds and yeasts, and coliforms at 35 °C (2.6; 2.4; 2.6 log CFU/g, respectively). Microbial counts remained stable during storage. The highest reduction in Salmonella occurred with the combination of ultrasound and acetic acid at 1000 mg/L and acetic acid at 2000 mg/L (2.8; 3.8 log CFU/g, respectively). No synergistic effect was observed with the combination of treatments. The cellular morphology of the pathogen altered after combinations of ultrasound and acetic acid at 2000 mg/L and peracetic acid. No changes in titratable total acidity, mass loss, vitamin C, or total phenolic compounds occurred. Alternative treatments presented equal to or greater efficacies than chlorinated compounds, so they could potentially be used for the decontamination of kale. Full article

In South Korea, despite the increase in emerging viral pathogens in the veterinary industry, only efficacy-tested, virus-specific disinfectants are allowed to be used. Moreover, domestic testing of disinfectants for their virucidal efficacies against foreign, malignant, infectious pathogens that are unreported within the country and/or contagious livestock diseases that require special attention regarding public hygiene are legally restricted. Therefore, the Animal and Plant Quarantine Agency (APQA) designed a study to select a potential biosafety level 2 surrogate of African swine fever virus (ASFV) for efficacy testing to improve the disinfectant approval procedures. For this, the modified vaccinia virus Ankara (MVA) was compared to ASFV in terms of its susceptibility to disinfectants. Effective concentrations of active substances of disinfectants (potassium peroxymonosulfate, sodium dichloroisocyanurate, malic acid, citric acid, glutaraldehyde, and benzalkonium chloride) against ASFV and MVA were compared; similarly, efficacies of APQA-listed commercial disinfectants were examined. Tests were performed according to APQA guidelines, and infectivities of ASFV and MVA were confirmed by hemadsorption and cytopathic effect, respectively. The results reveal that the disinfectants are effective against MVA at similar or higher concentrations than those against ASFV, validating the use of MVA as a potential biosafety level 2 surrogate for ASFV in efficacy testing of veterinary disinfectants. Full article

Meta-aramid fibrids (MAF) have attracted much attention. However, it is difficult for this high mechanical performance fiber to form sufficient interface adhesion between the MAF and polyurethane (PU) matrix due to the chemical inertness of its surface. Thus, the surface activity of MAF should be improved to obtain a high-performance MAF/PU composite. A novel methodology to modify the surface of MAF with a sodium dichloroisocyanurate solution (DCCNa) was developed to obtain chlorinated MAF (MAFC) in this study. A series of MAFC/PU composites was prepared by in situ polymerization processes. The results of Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) demonstrated that the chlorine-contained chemical groups were introduced onto the MAF surfaces after chlorination. Dynamic contact angle analysis (DCAA) revealed that the surface wettability and the surface free energy of the MAFC were significantly improved, which allowed for strong chemical bonding to PU. Scanning electron microscopy (SEM) showed a uniform distribution of MAFC and good interfacing bonding between the MAFC and PU. With the incorporation of 1.5 wt% MAFC into the polyurethane matrix, the tensile and tear strength values of MAFC/PU were 36.4 MPa and 80.1 kN·m⁻¹ respectively, corresponding to improvements of approximately 43.3% and 21.1%, as compared to those of virgin PU as 25.4 MPa and 66.1 kN·m⁻¹, respectively. Full article

Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) are commonly used for household water treatment (HWT); chlorine dioxide (ClO₂) is a potential new HWT option. We compared the residual maintenance of NaOCl, NaDCC, and ClO₂ over 24 hours using recommended dosages (2 and 4 mg/L) in waters of varying turbidity (0–300 NTU, from kaolin clay or creek-bottom sediments) and total organic carbon (TOC) concentrations (0–100 mg/L), for a total of 324 reactors. NaOCl and NaDCC had similar free chlorine decay rates, and ClO₂ decayed more rapidly across all of the tested conditions. Little variability was observed across clay-based turbidity levels and TOC concentrations. With a dosage of 2 mg/L, a residual ≥0.2 mg/L was maintained at 30 NTU for NaOCl and 100 NTU for NaDCC; for ClO₂, 4 mg/L were required to maintain ≥0.2 mg/L under all conditions except at zero turbidity. Comparisons with data from the literature suggest that the three compounds would inactivate E. coli, rotavirus, and Giardia cysts within 1 hour under all conditions, except 300 NTU for NaOCl and NaDCC. All three disinfectants are similarly efficacious for this usage; however, differences are seen in decay rates that may influence disinfectant selection depending on water storage time. Full article

Candida auris is an emerging pathogen that needs to be controlled effectively due to its association with a high mortality rate. The presence of biofilms on dry surfaces has been shown to be widespread in healthcare settings. We produced a C. auris dry surface biofilm (DSB) on stainless steel surfaces following sequential hydration and desiccation cycles for 12 days. The ASTM2967-15 was used to measure the reduction in viability of 12 commercially wipe-based disinfectants and sodium hypochlorite (1000 ppm) against C. auris DSB. We also evaluated C. auris transferability and biofilm regrowth post-treatment. A peracetic acid (3500 ppm) product and two chlorine-based products (1000 ppm available chlorine) were successful in reducing C. auris viability and delaying DSB regrowth. However, 50% of the products tested failed to decrease C. auris viability, 58% failed to prevent its transferability, and 75% did not delay biofilm regrowth. Using three different parameters to measure product efficacy provided a practical evaluation of product effectiveness against C. auris DSB. Although log₁₀ reduction in viability is traditionally measured, transferability is an important factor to consider from an infection control and prevention point of view as it allows for determination of whether the surface is safe to touch by patients and hospital staff post-treatment. Full article