Search

As an emerging technology in liquid inactivation, one of the main challenges of pulsed electric fields (PEFs) inactivation lies in quantitatively describing and predicting its lethality to microorganisms. However, due to its cross-scaled complexity and the consequent numerous regulatory factors, there is currently still no unified framework to understand the PEF dose–response relationship and the population dynamics theoretically. In this study, a simple yet powerful model from multiscale coarse-graining method is proposed to simulate the bacterial inactivation in suspensions during PEF processing. The complex dose–response effects at the macroscale are successfully reconstructed from simple evolution rules and several coarse-graining parameters, while considering the damage and death of a single bacterium at the microscale. Our model uncovers the seemingly chaotic and even controversial dose–response relationship of PEF in literatures and systematically explores the regulatory effect of experimental parameters in a unified framework. One of the interesting findings is that PEF with shorter pulsed width enhances lethality and reduces the minimal inhibitory time at a constant energy output per pulse, owing to the phase transitions in three bacterial population dynamics (Bistability mode, Avalanche mode, and Hybrid mode). Our study provides a new insight for numerically modeling PEF lethality in liquid inactivation and could serve as a guide for dosage management in practical applications. [ABSTRACT FROM AUTHOR]

This study investigates novel zinc and indium phthalocyanines with Schiff base and sulphur moieties, focusing on their potential for cancer therapy and antimicrobial applications. It explores the effectiveness of photochemical and sono-photochemical methods to enhance singlet oxygen production, which is crucial for photodynamic therapy. The synthesized complexes in this study demonstrated high singlet oxygen quantum yields, with D3 (ZnPc) and D4 (InPc) showing ΦΔPDT values of 0.71 and 0.75, and ΦΔSPDT values of 0.91 and 0.94, respectively. Furthermore, the evaluation for biological properties revealed that both D3 and D4 exhibit significant antidiabetic properties, DPPH radical scavenging activity, DNA cleavage, antimicrobial activity, biofilm inhibition, and microbial cell viability impacts, both with and without photodynamic therapy. Notably, D3 and D4 achieved antimicrobial cell viability inhibition rates of 84.67 ± 4.67% and 98.32 ± 5.96%, respectively, showcasing their effectiveness in photodynamic antimicrobial therapy. Overall, the study highlights the potential of these phthalocyanine complexes as advanced photosensitizers, with strong singlet oxygen generation and promising biological activities, paving the way for future therapeutic applications. [ABSTRACT FROM AUTHOR]

The use of biocide-loaded hydrogels has recently been exploited for cleaning the biological attacks of cultural heritage and architectural stone materials. However, considering the drawbacks of traditional biocides, and the high costs of synthetic polymers, growing research for innovative and sustainable solutions are taking place. The aim of this work is to explore a bacterial cellulose (BC) hydrogel functionalized with ozone as a renewable, biodegradable, and easy-to-use antimicrobial remedy for stone biodeterioration. The BC microstructure was characterized by Field Emission-Scanning Electron Microscopy observation and high crystallinity was detected by X-ray diffraction analysis. Ozonated BC (OBC) hydrogels were tested against selected biodeteriogenic microorganisms in water suspension abolishing their viability, with its complete suppression after a 10-min and a 24-h treatment with OBC, for bacterial and fungal spores, respectively. Furthermore, the OBC was assessed on contaminated marble, brick, and biocalcarenitic stone specimens for simulating in situ conditions. A 100% reduction of microbial viability after a 24-h treatment was obtained. Successively, the shelf-life of the hydrogel and the antimicrobial activity were also evaluated after 30 days, demonstrating a subsequent cleaning efficiency along time. This research highlights the potential of the new ozonated BC hydrogel as a green and highly effective antimicrobial treatment, with advantages in sustainability. [ABSTRACT FROM AUTHOR]

ABSTRACT Molecular characteristics of emulsifiers such as their molecular weight (MW) and surface charge, not only affect the stability of the emulsion but also can have an impact on its capacity to either inhibit or promote microbial proliferation. These characteristics can affect the behavior of pathogens such as Salmonella Typhimurium in emulsion systems. The growth and thermal resistance of S. Typhimurium were monitored at different oil content levels (20%, 40%, and 60%) in emulsions stabilized by three whey protein‐based emulsifiers: whey protein isolate (WPI), whey protein hydrolysate (WPH), and a modified WPI with an alteration of charge (WPI+). Our study revealed that emulsifier itself with different MW and surface charge had no effect on bacterial growth and inactivation without oil inclusion (p > 0.05). However, it was found that higher bacterial growth rate at 60% oil content emulsion stabilized with WPI+ (0.65 ± 0.03 log CFU/h) than WPI (0.19 ± 0.04 log CFU/h), which showed the charge of emulsifiers has different effects on microbial dynamics in oil‐in‐water emulsion. Interestingly, WPI+ in emulsions also seemed to convey protection against thermal inactivation of bacteria. These data describe a complex interrelationship between the physicochemical characteristics of the emulsifier and its interacting nature with bacterial cells. They throw even more light on the insight about the importance of a strategic approach toward emulsifier selection in food formulations. This is crucial for the food safety and stability of products. [ABSTRACT FROM AUTHOR]

Biohydrogen production by dark fermentation (DF) can be achieved using only indigenous bacteria from substrates or by adding an external inoculum. This study aims to provide new insights on the role of indigenous bacteria in DF process operation by investigating DF performances and microbiological aspects. DF tests are performed with only indigenous bacteria, with indigenous and exogenous bacteria and with only exogenous bacteria by inactivating indigenous bacteria by gamma irradiation. Sorghum irradiation reduces DF performances for both hydrogen (17.8 ± 12.8 versus 45.2 ± 1.7 mLH 2 /gVS added) and total metabolite (0.22 ± 0.01 versus 0.30 ± 0.01 gCOD/gVS added) yields. In contrast, no difference is observed with the organic fraction of municipal solid waste, suggesting a distinct role of indigenous bacteria for both substrates. Indigenous bacteria inactivation strongly modifies the metabolic routes and final bacterial community composition. This study proves the key role of indigenous bacteria in influencing metabolite production and bacterial composition. [Display omitted] • Successful inactivation of indigenous bacteria by gamma irradiation. • Lower performances of dark fermentation for irradiated sorghum. • No impact OFMSW irradiation on hydrogen yield and biomass bioconversion. • Metabolic and microbiological changes after irradiation of both substrates. • Lower reproducibility of DF experiments after indigenous bacteria inactivation. [ABSTRACT FROM AUTHOR]

Antimicrobial photodynamic inactivation (aPDI) offers a promising alternative to combat drug-resistant bacteria. This study explores the potential of lapachol, a natural naphthoquinone derived from Tabebuia avellanedae, as a photosensitizer (PS) for aPDI. Lapachol's photosensitizing properties were evaluated using Staphylococcus aureus and Escherichia coli strains under blue LED light (450 nm). UV-vis spectroscopy confirmed lapachol's absorption peak at 482 nm, aligning with effective excitation wavelengths for phototherapy. Photoinactivation assays demonstrated significant bacterial growth inhibition, achieving complete eradication of S. aureus at 25 µg·mL−1 under light exposure. Scanning electron microscopy (SEM) revealed morphological damage in irradiated bacterial cells, confirming lapachol's bactericidal effect. This research underscores lapachol's potential as a novel photosensitizer in antimicrobial photodynamic therapy, addressing a critical need in combating antibiotic resistance. [ABSTRACT FROM AUTHOR]

The variation in the soil microbial community composition over time was assessed at monthly time steps for 1 year in three neighboring Mollisols spanning a drainage gradient. This was done to distinguish between natural oscillations in the community composition versus lasting adaptations to environmental factors such as soil water availability. To isolate soil water availability as a controlling factor, we selected three soils sharing the same soil order (fine‐silty, superactive Argixerolls/Argialbolls); slope (0%–1%); temperature regime (mesic); moisture regime (xeric); and land use history (continuous grassland for the past 10 years) but differing in drainage class (well‐drained vs. moderately well‐drained vs. poorly drained). Changes in microbial diversity were quantified by monitoring the bacterial community at monthly intervals for 1 year. Within individual soils, α‐diversity varied little with season and drainage classes. Despite the three soils experiencing the same climate regime and vegetation/land use, they exhibited distinct community composition and turnover, which we attribute to differences in moisture availability across drainage and seasons. We posit that a seasonal recurring drop in soil redox potential induced by seasonal water saturation in the poorly drained soil is the most probable cause setting the microbial community of that soil apart from those in the better drained soils. Our investigation suggests that not all indicators of microbial diversity share the same sensitivity to seasonal and drainage‐related soil moisture variations. Core Ideas: Seasonal moisture fluctuations have a small effect on bacterial phylogenetic diversity.Phylogenetic diversity may increase with improved drainage.Impacts of seasonal saturation on the microbial community persist year‐round.Responsiveness to seasonal moisture fluctuations can influence the viability of microbial abundance as a bioindicator. [ABSTRACT FROM AUTHOR]

Background Microlab Salmonella is an all-in-one solution for detection of Salmonella O Groups A-E that integrates, in a single disposable device, all elements to perform the analysis: a ready-to-use enrichment broth, a lateral flow immunochromatography test, and a chemical agent for bacterial inactivation. Microlab Salmonella can be easily used on-site and does not require specific laboratory equipment or technical skills. The device is sealed during the analysis, avoiding risks of contamination, and is therefore safe to use in food production environments. Objective This report details the method validation study for raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, deli ham, and pasteurized liquid egg. Methods Matrix studies and inclusivity/exclusivity, product consistency/stability, and robustness testing were conducted to assess the method's performance. Results Inclusivity/exclusivity testing showed that the Microlab Salmonella method was able to detect Salmonella O Group A-E isolates while excluding the non- Salmonella strains. In the matrix studies, the differences between the candidate and reference methods were not statistically significant. Minor variations in test parameters (enrichment time, time to read results, and enrichment temperature) did not affect the performance of the Microlab assay. There were no statistically significant differences between recently manufactured lots and those that were halfway through their expiration period or between those that were close to expiring. Conclusions The reported data confirm that Microlab Salmonella is reliable for detecting Salmonella in raw ground beef, raw turkey (thermal processed, marinated), fresh cheese, pasteurized liquid egg, and deli ham. Highlights Microlab Salmonella is validated to detect Salmonella in select food matrixes. Microlab Salmonella integrates the steps of enrichment, detection, and inactivation in a single device. [ABSTRACT FROM AUTHOR]

Staphyloccocus aureus (S. aureus) is a major bacterial pathogen in orthopedic periprosthetic joint infection (PJI). S. aureus forms biofilms that promote persistent infection by shielding bacteria from immune cells and inducing an antibiotic‐tolerant metabolic state. We developed an in vitro system to study S. aureus biofilm interactions with primary human monocytes in the absence of planktonic bacteria. In line with previous in vivo data, S. aureus biofilm induced expression of inflammatory genes such as TNF and IL1B, and their anti‐inflammatory counter‐regulator IL10. S. aureus biofilm also activated expression of PD‐1 ligands, and IL‐1RA, molecules that have the potential to suppress T cell function or differentiation of protective Th17 cells. Gene induction did not require monocyte:biofilm contact and was mediated by a soluble factor(s) produced by biofilm‐encased bacteria that was heat resistant and >3 kD in size. Activation of suppressive genes by biofilm was sensitive to suppression by Jak kinase inhibition. These results support an evolving paradigm that biofilm plays an active role in modulating immune responses, and suggest this occurs via production of a soluble vita‐pathogen‐associated molecular pattern, a molecule that signals microbial viability. Induction of T cell suppressive genes by S. aureus biofilm provides insights into mechanisms that can suppress T cell immunity in PJI. [ABSTRACT FROM AUTHOR]

Combinations of metal disinfectants (i.e., silver and copper) with chlorine in doses that meet the World Health Organization guidelines for drinking water operate synergistically to provide superior drinking water disinfection across a wide range of pathogens. Moreover, the combination of disinfectants allows for lower chlorine levels and a less objectionable taste and odor to the treated water (some people can taste or smell chlorine at concentrations as low as 300 μg/L). Towards chlorine-releasing materials for combination with silver- or copper-releasing materials in point-of-use water disinfection, N-chloramine containing polymer gels were developed and their potential for E. coli bacteria inactivation was assessed in deionized water that contained salts to simulate groundwater. Following the chlorination of gels containing chloramine precursors, these gels capably inactivated E. coli, achieving log10 reductions—depending on the gel mass—ranging from 1.1 to 4.5. While chlorine released from the gels was not spectroscopically detected, free chlorine solutions inactivated E. coli in a concentration-dependent way, with 5 and 20 μg/L Cl2 yielding log10 reductions of 0.43 and 1.69, respectively, suggesting that low levels of chlorine, below both the limit of detection of spectroscopic assays (ca. 40 μg/L Cl2) and levels known to create adverse taste and smell, are sufficient to inactivate bacteria. Unchlorinated gels or chlorinated control styrene gels (without chloramine precursor) did not inactivate bacteria, suggesting that disinfection did not come from the precursor or from chlorine trapped in the gels after chlorination. In addition, these gels were evaluated together with the MadiDrop (MD, a commercial silver-ceramic tablet) and a copper screen that release silver and copper disinfectants, respectively. Combinations of the gel and MD produced E. coli inactivation close to 2-log10 reduction, with the combination, gels alone, and MD alone achieving 1.86-, 1.10-, and 0.69-log10 reduction, respectively. When the gels were combined with the copper screen, however, neither an increase nor a decrease in bacterial reduction was observed compared to that achieved with the gels alone. The laboratory results in this study are promising and suggest the potential for chloramine-functionalized gels to serve as an alternative to existing commercial chlorine-based POU technologies and in combination with silver-based POU technologies. [ABSTRACT FROM AUTHOR]

The efficacy of ultra-high-pressure homogenisation (UHPH) in inactivating Bacillus pumilus ATCC 27142 and Bacillus subtilis ATCC 6633 spores suspended in sheep and cow milk was investigated. The UHPH treatment was conducted at 200 and 250 MPa with an inlet temperature of 85 °C, resulting in homogenising valve temperatures of 117 °C and 127 °C, respectively. To isolate the role of temperature and pressure in the inactivation of bacterial spores, the UHPH treatment was repeated at 250 MPa with a lower inlet temperature of 70 °C that resulted in a valve temperature of 117 °C. Increasing the pressure and valve temperature resulted in increased inactivation. At 250 MPa with a valve temperature of 127 °C, greater than 5 log CFU/mL reduction was achieved in B. pumilus and B. subtilis spores in both milk types. Reductions of 0.61 ± 0.03 log CFU/mL and 0.62 ± 0.09 log CFU/mL in B. pumilus spores and 1.18 ± 0.04 log CFU/mL and 1.30 ± 0.07 log CFU/mL in B. subtilis spores were obtained at 250 MPa with a valve temperature of 117 °C in sheep and cow milk, respectively. The spore inactivation was influenced by both the pressure and temperature, suggesting a synergistic effect, with the latter playing a critical role in the lethality of the treatment. No significant differences in the inactivation of either strain was observed between sheep and cow milk. [ABSTRACT FROM AUTHOR]

The intricate interplay between the gut microbiome and colorectal cancer (CRC) presents novel avenues for early diagnosis and prognosis, crucial for improving patient outcomes. This comprehensive review synthesizes current findings on the gut microbiome’s contribution to CRC pathogenesis, highlighting its potential as a biomarker for non-invasive CRC screening strategies. We explore the mechanisms through which the microbiome influences CRC, including its roles in inflammation, metabolism, and immune response modulation. Furthermore, we assess the viability of microbial signatures as predictive tools for CRC prognosis, offering insights into personalized treatment approaches. Our analysis underscores the necessity for advanced metagenomic studies to elucidate the complex microbiome-CRC nexus, aiming to refine diagnostic accuracy and prognostic assessment in clinical settings. This review propels forward the understanding of the microbiome’s diagnostic and prognostic capabilities, paving the way for microbiome-based interventions in CRC management. [ABSTRACT FROM AUTHOR]

This work demonstrates facile synthesis of Tb-doped ZnO nanoparticles and investigates their structural, optical, electrochemical, photocatalytic, and antibacterial performance. XRD patterns of undoped and doped ZnO nanoparticles confirm a hexagonal wurtzite structure. TEM and SAED reveals that the particle size is 14–38 nm. SEM images show that ZnO and Tb-doped ZnO nanoparticles have smooth surfaces, and elemental composition was confirmed by EDX analysis. UV–Visible spectrophotometry studies, reveals that the band gap narrows with increasing Tb concentration. Photoluminescence spectra at room temperature showed a band at 538 nm, indicating zinc vacancies and green emission. Tb-doped ZnO with x = 0.075 exhibited the highest photocatalytic activity for degrading Rose Bengal dye compared to other photocatalysts. The electrochemical behaviour of Catechol (CC), Hydroquinone (HQ), and Bisphenol-A (BPA) at Tb–ZnO/MCPE was studied. The modified electrode process for CC and BPA was adsorption-controlled, and simultaneous recognition of CC, HQ, and BPA was achieved, showing an increase in current. Electro polymerization of poly (Congo red) on Tb–ZnO/MCPE confirmed clean deposition on the surface, enhancing electrocatalytic activity. The antibacterial efficacy was tested using the traditional disc diffusion method, showing effective inactivation of bacterial strains, including pathogens such as S. aureus (G+) and E. coli (G-). [Display omitted] • This work demonstrates the facile synthesis of ZnO and Tb doped nanoparticles via chemical co-precipitation process. • The XRD pattern appearance hexagonal wurtzite structure. TEM and SAED reveal particle sizes of 14–38 nm. SEM and EDX confirm morphology and elemental composition. • Higher Tb doping exhibit the highest photocatalytic activity in degrading Rose Bengal dye. And the antibacterial activity, tested via disc diffusion, effectively inactivates S. aureus (G+) and E. coli (G−) bacterium. • The sweep rate confirms that the modified electrode process of CC and BPA at the PCRTZO/MCPE was adsorption controlled. Tb–ZnO/MCPE electrode simultaneously detects CC, HQ and BPA with distinct current increases. • Electro polymerization of poly (Congo red) on Tb–ZnO/MCPE confirms Congo red deposition on the electrode surface. [ABSTRACT FROM AUTHOR]

Essential genes are crucial for microbial viability, playing key roles in both the primary and secondary metabolism. Since mutations in these genes can threaten organism viability, identifying them is challenging. Conditionally essential genes are required only under specific conditions and are important for functions such as virulence, immunity, stress survival, and antibiotic resistance. Transposon-directed sequencing (Tn-Seq) has emerged as a powerful method for identifying both essential and conditionally essential genes. In this review, we explored Tn-Seq workflows, focusing on eubacterial species and some yeast species. A comparison of 14 eubacteria species revealed 133 conserved essential genes, including those involved in cell division (e.g., ftsA, ftsZ), DNA replication (e.g., dnaA, dnaE), ribosomal function, cell wall synthesis (e.g., murB, murC), and amino acid synthesis (e.g., alaS, argS). Many other essential genes lack clear orthologues across different microorganisms, making them specific to each organism studied. Conditionally essential genes were identified in 18 bacterial species grown under various conditions, but their conservation was low, reflecting dependence on specific environments and microorganisms. Advances in Tn-Seq are expected to reveal more essential genes in the near future, deepening our understanding of microbial biology and enhancing our ability to manipulate microbial growth, as well as both the primary and secondary metabolism. [ABSTRACT FROM AUTHOR]

In this study, new peripherally substituted symmetric zinc and magnesium phthalocyanines (4 and 5) were successfully prepared by cyclotetramerization of the tetrahydropyrimidone (THPM)-linked phthalonitrile 3. The identity of the compounds were confirmed primarily through spectroscopic analysis including NMR, FT-IR, UV-Vis and MALDI-TOF mass spectroscopy. The photophysical and photochemical properties of the synthesized phthalocyanines (Pcs) were examined using UV–Vis absorption and fluorescence emission spectroscopy techniques. The quantum yields of singlet oxygen were found to be 0.50 and 0.33 for compounds 4 and 5 in DMSO, respectively. In addition to photo-physicochemical properties, the enhanced biological activities of compounds 4 and 5 were investigated using a range of biological assays, namely, antibiofilm, microbial cell viability, antioxidant, DNA cleavage, antimicrobial and photodynamic antimicrobial assays. The maximum DPPH inhibition of 4 and 5 was detected as 40.46% and 25.76% at 100 mg L−1, respectively. Fragmentation of the DNA molecule was observed at concentrations of 25 mg L−1, 50 mg L−1 and 100 mg L−1 for 4 and 5. Additionally, effective inhibition of microbial cell viability was observed with the targeted Pcs. The antibiofilm properties of these compounds were found to be concentration-dependent. The biofilm inhibition activities of 4 and 5 were found to be 96.01% and 92.04% for S. aureus, while they were 95.42% and 91.27%, for P. aeruginosa, respectively. The antimicrobial activities of 4 and 5 on different microorganisms were evaluated using the microdilution assay. In the case of photodynamic antimicrobial treatment, the newly synthesized Pcs showed more effective antimicrobial inhibition compared to the control. These findings suggest that compounds 4 and 5 can be used as promising photodynamic antimicrobial agents for the treatment of many diseases, particularly infectious diseases. [ABSTRACT FROM AUTHOR]

The present research aimed to explore the durability of MMO electrodes through electro-oxidation (EO) in purifying secondary treated actual sewage wastewater using batch and pilot-scale setups. The main aim is to inactivate bacteria in sewage treatment plants before they are released into the environment, thus contaminating water and soil. Process parameters such as current density (j), NaCl dose (n), and treatment time (t) were optimized using response surface methodology in a lab-scale EO reactor under batch conditions. The results showed that optimization of current density at 5.90 mA/cm2 and NaCl concentration at 1.31 g/L led to 93.90% of bacterial inactivation (Q1) within 8 min of treatment and 0.48 kWh/m3 energy consumption (Q2). Biological analysis was conducted to validate bacterial cell destruction and count coliform bacteria in the EO-treated sewage wastewater. XRD, cyclic voltammetry studies, and FE-SEM/EDS analysis were done to confirm the MMO anode's durability and stability after 100 recycles. The study prioritized bacterial inactivation along with organic matter degradation. Besides that, a small pilot-scale study on the actual sewage wastewater with a volume of 10–50 L was done in batch mode under previously optimized conditions to analyze the efficacy of the MMO anodes in terms of bacterial inactivation. [ABSTRACT FROM AUTHOR]

Poorly-treated wastewater harbors harmful microorganisms, posing risks to both the environment and public health. To mitigate this, it is essential to implement robust disinfection techniques in wastewater treatment plants. The use of performic acid (PFA) oxidation has emerged as a promising alternative, due to its powerful disinfection properties and minimal environmental footprint. While PFA has been used to inactivate certain microbial indicators, its potential to tackle the entire microbial community in effluents, particularly resistant bacterial strains, remains largely unexplored. The present study evaluates the efficacy of PFA disinfection on the microbial communities of a WWTP effluent, through microbial resistance mechanisms due to their membrane structure. The effluent microbiome was quantified and identified. The results showed that the number of damaged cells increases with CT, reaching a maximum for CT = 240 mg/L•min and plateauing around 60 mg/L•min, highlighting the optimal conditions for PFA-disinfection against microbial viability. A low PFA level with a 10-min contact time significantly affected the microbial composition. It is worth noting the sensitivity of several bacterial genera such as Flavobacterium, Pedobacter, Massilia, Exiguobacterium, and Sphingorhabdus to PFA, while others, Acinetobacter, Leucobacter, Thiothrix, Paracoccus, and Cloacibacterium, showed resistance. The results detail the resistance and sensitivity of bacterial groups to PFA, correlated with their Gram-positive or Gram-negative membrane structure. These results underline PFA effectiveness in reducing microbial levels and remodeling bacterial composition, even with minimal concentrations and short contact times, demonstrating its suitability for widespread application in WWTPs. [ABSTRACT FROM AUTHOR]

Background: The balance between antioxidants and pro-oxidants plays a significant role in the context of oxidative stress, influenced by both physiological and non-physiological factors. Objectives: In this study, 18 prescribed antibiotics (including doxycycline hydrochloride, tigecycline, rifampicin, tebipenem, cefuroxime, cefixime, potassium clavulanate, colistin, ampicillin, amoxicillin, amikacin, nalidixic acid, azithromycin, pipemidic acid trihydrate, pivmecillinam, aztreonam, fosfomycin sodium, and ciprofloxacin) were subjected to simultaneous determination of antioxidant and pro-oxidant potential to assess if pro-oxidant activity is a dominant co-mechanism of antibacterial activity or if any antibiotic exhibits a balanced effect. Methods: This study presents a recently developed approach for the simultaneous assessment of antioxidant and pro-oxidant potential on a single microplate in situ, applied to prescribed antibiotics. Results: Ten antibiotics from eighteen showed lower antioxidant or pro-oxidant potential, while five exhibited only mild potential with DPPH50 values over 0.5 mM. The pro-oxidant antioxidant balance index (PABI) was also calculated to determine whether antioxidant or pro-oxidant activity was dominant for each antibiotic. Surprisingly, three antibiotics—doxycycline hydrochloride, tigecycline, and rifampicin—showed significant measures of both antioxidant and pro-oxidant activities. Especially notable was tebipenem, a broad-spectrum, orally administered carbapenem, showed a positive PABI index ratio, indicating a dominant antioxidant over pro-oxidant effect. Conclusions: These findings could be significant for both therapy, where the antibacterial effect is enhanced by radical scavenging activity, and biotechnology, where substantial pro-oxidant activity might limit microbial viability in cultures and consequently affect yield. [ABSTRACT FROM AUTHOR]

Aquatic mobile robots are gaining attention for their potential to revolutionize marine monitoring and exploration within the Ocean Internet of Things. A significant challenge for these untethered robots, especially in remote areas, is achieving energy autonomy. This work presents an innovative self‐sustaining energy system for compact aquatic robots, inspired by biological digestion. Utilizing microbial fuel cell (MFC) technology, organic materials found in aquatic environments are converted into electricity through catalytic redox reactions. To extend the MFC's lifespan, spore‐forming Bacillus subtilis is used as the anodic biocatalyst, leveraging its ability to endure harsh conditions and reactivate in favorable environments, thus enhancing the MFC's longevity. To ensure a steady supply of organic substrates for microbial viability, a biomimetic Janus membrane with asymmetric surface wettability is integrated, enabling selective substrate intake. Additionally, stability mechanisms inspired by water striders allow the robot to move efficiently across water surfaces. The robot mimics the water strider's movement using a motor powered by microbial metabolism, fueled by organic nutrients via the Janus membrane. This study demonstrates the feasibility of using natural processes for technological advancement, setting new benchmarks in the design of autonomous systems. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of poly (diallyldimethylammonium chloride) (PDADMAC) and crystalline nanocellulose (CNC) on cassava starch-based film (CS), focusing on their structural, physicochemical, and antimicrobial properties. Three film types were analyzed: a control film (CS), a film with CS and PDADMAC (CS/PDADMAC), and films containing CS, CNC, and PDADMAC simultaneously (CS/CNC/PDADMAC). The opacity values were influenced (p < 0.05) by incorporating PDADMAC and CNC, decreasing film transparency. Furthermore, due to its hydrophilic characteristics, an increase in water vapor permeability (WVP) values of 86.57–111.6% was observed by incorporating PDADMAC and CNC compared to CS film, respectively. SEM revealed that all films had smooth surfaces without cracks. Furthermore, FTIR analysis confirmed chemical interactions between the film's constituent polymers. Notably, the tensile strength (TS) improved significantly with the addition of CNC, with a notable increase of 82.1% compared to the other films. Furthermore, the CS/CNC/PDADMAC film exhibited antiviral activity, inactivating 90–99.9% of the MHV-3 coronavirus within 1 and 1440 min of direct contact. This film also demonstrated effective inhibition against Staphylococcus aureus and Escherichia coli bacteria. The film attains its antimicrobial effect through electrostatic interaction involving the quaternary ammonium groups of PDADMAC and the phospholipid membrane of the microorganism. Therefore, this study promotes an innovative approach to reduce the spread of pathogens through potential contamination on plastic film surfaces. [ABSTRACT FROM AUTHOR]

Consumption of beverages with caffeine has increased in last decade and has led to increase in the concentration of caffeine in various water bodies, placing it in the category of emerging contaminants (ECs). Sewage treatment plants are incapable of completely removing ECs and therefore use of photocatalysis as tertiary treatment is the need of the hour. Reported is a visible light active Copper doped Zirconium oxide loaded Graphene oxide based (Cu–ZrO 2 @GO) composite using co-precipitation method for photocatalytic degradation of caffeine. The composite was characterized using physiochemical techniques such as FTIR, XPS, XRD, FE-SEM, HR-TEM, UV-DRS, PL, and BET for its successful synthesis confirming distribution of Cu–ZrO 2 (5–40 nm) over GO matrix. With the band gap energy of 2.5 eV, Cu–ZrO 2 @GO could effectively degrade 81.18% for caffeine in 240 min (min) under optimum conditions (pH 3, dose 70 mg) due to its high surface area (80.57 m2 g−1) with pore diameter of 37.4 A o mainly by the hydroxyl radical as reactive oxygen species (ROS). Proposed degradation mechanism for caffeine is supported by LC /MS analysis. Cu–ZrO 2 @GO could degrade 78% of caffeine in tea extract (real sample) as confirmed by HPLC studies. Reported composite also depicted antibacterial activity against Gram-positive staphylococcus aureus (S. Aureus) and Gram-negative Escherichia Coli (E. coli) bacteria and could be recycled upto four cycles. Cu–ZrO 2 @GO can effectively be used for wastewater remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology 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 variation in the population of pathogenic microorganisms in wastewater over time can be predicted by single-spectral analysis, which outperforms conventional multivariate methods. This type of information is important for the performance of sewage treatment plants. The objective of this study was to monitor the variability of the population of microorganisms and the removal of microbiological attributes of sanitary wastewater in a treatment plant equipped with a septic tank and solar reactor. Effluent samples were collected monthly upstream of the septic tank and inside the solar reactor, and the effluent was exposed to solar radiation. Total coliforms and Escherichia coli were analyzed by means of descriptive analysis and singular spectrum analysis. Solar disinfection obtained bacterial inactivation levels of 99.94%, equivalent to 4 log units for the Escherichia coli population, and 99.45%, equivalent to 3 log units for the total coliform population. For the inlet effluent, the prediction showed a trend of growth alternating with periods of stability. For the outlet effluent, the prediction was able to provide regular data up to the first six months, showing error and overestimation of the data for the final six months of the study. [ABSTRACT FROM AUTHOR]

Recent research has highlighted the effectiveness of starter inocula in fermentation processes. In this sense, this study examines the use of an inoculum composed of coffee pulp, mucilage broth, and microorganisms such as Saccharomyces cerevisiae, L. delbrueckii ssp. bulgaricus, and S. thermophilus in fermenting Castillo variety coffee. An inoculum was prepared, measuring variables such as the pH, acidity, °Brix, lactic acid bacteria, and yeast viability. Following optimization, the inoculum was evaluated in a fermentation process, evaluating the pH, °Brix, acidity, microbiological analysis, ochratoxin A, and cup quality post-drying and roasting. The findings demonstrated a significant reduction in the pH from 4.47 to 4.05 and in the °Brix from 15.8 to 8.45, indicating efficient organic acid production and sugar degradation. Acidity levels increased from 20.02 mg/g to 42.69 mg/g, while microbial viabilities remained above 107 CFUs/g, suggesting effective biomass production. The process effectively reduced the microbial load without detecting ochratoxin A. Sensory evaluations confirmed the enhanced cup quality, validating the positive impact of inoculum use in coffee fermentation. The results support the use of coffee pulp and mucilage broth as effective substrates for the growth of the evaluated microorganisms, and the application of starter cultures containing lactic acid bacteria and yeast can elevate the coffee to a specialty grade. [ABSTRACT FROM AUTHOR]

The increasing resistance of bacterial pathogens to antibiotics poses serious threats to public health, exacerbating the challenge of treating infectious diseases. Antibacterial materials that integrate two or more therapeutic modalities concurrently have emerged as a viable alternative strategy to combat pathogenic bacteria. In this study, a postmethylation approach was employed to significantly enhance the photothermal and photodynamic activity of a photoactive antibacterial agent simultaneously. Using this method, a cationic covalent organic framework (COF) nanostructure, named IPB-COF, was easily fabricated through the postmethylation of a BODIPY-based COF obtained via the polycondensation of piperazine and dialdehyde-BODIPY through an aminal linkage. Besides improving the photothermal and photodynamic activities, the postmethylation also led to the formation of built-in quaternary ammonium cations, enhancing the adhesion capacity with bacteria. The resulting IPB-COF nanostructures exhibited enhanced synergistic photothermal and photodynamic therapeutic capabilities against both Gram-positive and Gram-negative bacteria upon visible light irradiation. It achieved rapid sterilization with an approximately 100% bactericidal ratio at a low dosage, significantly higher than that of the unmethylated sample (PB-COF). Additionally, in vivo assays demonstrated that IPB-COF nanostructures also possessed high efficiency and safe wound disinfection capacities, significantly accelerating the healing of infected wounds. Overall, this study proposes a simple yet robust method for the tunable preparation of COF-based antibacterial agents that can rapidly, safely, and synergistically combat pathogenic bacteria infections, circumventing antibiotic resistance. [ABSTRACT FROM AUTHOR]

Consuming microbiologically‐contaminated water is the primary cause of many water‐borne diseases and deaths worldwide. Governments aim at providing drinking water for vulnerable populations, especially through low‐cost interventions. Therefore, the solar disinfection (SODIS) of such pathogens provides a simple and cost‐effective way to obtain good quality water. In this procedure, PET bottles are filled with contaminated water and exposed to sunlight for 1–2 days. To accelerate decontamination, methylene blue (MB) dye added as a photocatalyst, boosts singlet oxygen generation upon absorbing red‐band sunlight. This study explores the use of a Sunlight Simulator (SSL) device to research and standardize the SODIS method with a vital dye as MB. PET bottles were filled with artificially‐contaminated water with Streptococcus epidermidis and Deinococcus radiodurans Gram‐positive bacteria, Escherichia coli and Salmonella typhimurium Gram‐negative bacteria, or bacteriophage λ as well. In all experiments, 50 ng/mL MB ensued a synergistic lethal effect after SSL exposure. The results indicate that bacterial and bacteriophage inactivation can be achieved in shorter times with MB‐SSL treatment compared to SSL without MB. In this sense, when compared to previous sunlight‐SODIS results, the SSL source is a reliable tool to study the parameters of both SODIS and MB‐SODIS protocols, and also a feasible tool to afford assays whenever there are unfavorable climate conditions. [ABSTRACT FROM AUTHOR]

Formation of bacterial films on structural surfaces often leads to severe contamination of medical devices, hospital equipment, implant materials, etc., and antimicrobial resistance of microorganisms has indeed become a global health issue. Therefore, effective therapies for controlling infectious and pathogenic bacteria are urgently needed. Being a promising active method for this purpose, surface acoustic waves (SAWs) have merits such as nanoscale earthquake-like vibration/agitation/radiation, acoustic streaming induced circulations, and localised acoustic heating effect in liquids. However, only a few studies have explored controlling bacterial growth and inactivation behaviour using SAWs. In this study, we proposed utilising piezoelectric thin film-based SAW devices on a silicon substrate for controlling bacterial growth and inactivation with and without using ZnO micro/nanostructures. Effects of SAW powers on bacterial growth for two types of bacteria, i.e., E. coli and S. aureus, were evaluated. Varied concentrations of ZnO tetrapods were also added into the bacterial culture to study their effects and the combined antimicrobial effects along with SAW agitation. Our results showed that when the SAW power was below a threshold (e.g., about 2.55 W in this study), the bacterial growth was apparently enhanced, whereas the further increase of SAW power to a high power caused inactivation of bacteria. Combination of thin film SAWs with ZnO tetrapods led to significantly decreased growth or inactivation for both E. coli and S. aureus, revealing their effectiveness for antimicrobial treatment. Mechanisms and effects of SAW interactions with bacterial solutions and ZnO tetrapods have been systematically discussed. [ABSTRACT FROM AUTHOR]

Pigmented rice grass juice (RGJ) is a good source of bioactive compounds, but fresh juice has a relatively short shelf life of only 7 days at 4 °C. The objectives of this study were to determine the optimal growth stage of pigmented rice grass, investigate the optimal condition of high-pressure processing (HPP) for bacterial inactivation in inoculated RGJ using response surface methodology (RSM), and evaluate quality changes in uninoculated HPP-treated juice during storage at 4 °C compared with heat-treated (85 °C/10 min) and untreated samples. Results revealed that the optimal growth stage of rice grass was 9 days with the highest total anthocyanin content of 158.92 mg/L. The optimal condition of HPP was determined to be 612 MPa, 11 min, and 36 °C, and inactivated Escherichia coli K12 and Listeria innocua with 6.43 and 5.02 log reductions, respectively, meeting FDA regulations. The lethality of bacteria after HPP treatment can be explained by damage to the cell membrane and the leakage of intracellular constituents such as protein and nucleic acid. During 12 weeks of storage at 4 °C, total plate counts and yeast and mold counts in uninoculated HPP-treated juice were not detected. Moreover, HPP did not significantly change phytochemical properties (p < 0.05), caused a minor impact on physicochemical properties of RGJ, and maintained the durability of juice samples during storage. Analysis of the phytochemical profile revealed that HPP treatment could preserve most of the phenolic compounds in RGJ and especially increase the contents of protocatechuic acid, 4-hydroxybenzoic acid, syringic acid, transcinnamic acid, isorhamnetin-3-o-glucoside, quercetin, and cyanidin-3-glucoside (p < 0.05). Overall, HPP is a potential pasteurization technique for microbial inactivation and nutritional preservation for rice grass juice. [ABSTRACT FROM AUTHOR]

Normal and damaged microorganisms are related to food safety. The colony-forming unit (CFU) assay and viability of microorganisms have broad applications in food. Traditionally, the CFU assay has been the benchmark for assessing microbial viability across various fields. However, the normal and damaged microorganisms cannot be distinguished. Here, we introduce an improved technology for foods that uses a visible absorbance microplate reader platform for high-throughput quantitative analysis of microbial lag time, doubling time, and CFU. This platform utilizes a 96-well plate and a microplate reader to accurately determine the viable cell number from a five-microliter sample. It boasts the capability to measure a dynamic range spanning from five to seven orders of magnitude, significantly reducing the time required by over 20-fold in comparison to traditional spread plate methods. Additionally, it demonstrates a remarkable ability to detect a single cell within a well. A mild temperature treatment for cell viability detection was implemented and was able to reflect the real microbial quality. Consequently, the high-throughput method as an improved technology provides essential technical support for microbial detection. [ABSTRACT FROM AUTHOR]

Hierarchical nanostructures fabricate by electrospinning in combination with light‐responsive agents offer promising scenarios for developing novel activable antibacterial interfaces. This study introduces an innovative antibacterial face mask developed from poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) nanofibers integrated with indocyanine green (ICG), targeting the urgent need for effective antimicrobial protection for community health workers. The research focuses on fabricating and characterizing this nanofibrous material, evaluating the mask's mechanical and chemical properties, investigating its particle filtration, and assessing antibacterial efficacy under photothermal conditions for reactive oxygen species (ROS) generation. The PHBV/ICG nanofibers are produced using an electrospinning process, and the nanofibrous construct's morphology, structure, and photothermal response are investigated. The antibacterial efficacy of the nanofibers is tested, and substantial bacterial inactivation under both near‐infrared (NIR) and solar irradiation is demonstrated due to the photothermal response of the nanofibers. The material's photothermal response is further analyzed under cyclic irradiation to simulate real‐world conditions, confirming its durability and consistency. This study highlights the synergistic impact of PHBV and ICG in enhancing antibacterial activity, presenting a biocompatible and environmentally friendly solution. These findings offer a promising path for developing innovative face masks that contribute significantly to the field of antibacterial materials and solve critical public health challenges. [ABSTRACT FROM AUTHOR]

Postconsumer household food residues can act as useful substrates for other industries, but transporting high‐moisture material corresponds to high fuel use and associated greenhouse gas production. Drying food residues at the household level reduces transportation weight, increases stability, and preserves the nutritional quality of recovered material. Mitigating foodborne microbiological safety risks is crucial to encourage the development of novel methods to rapidly dry and stabilize food residues. The objective of this study was to improve the prediction of bacterial pathogen inactivation under various thermal and drying processes in a synthetic mixture of residual food material (RFM). The log reduction rate was measured for Escherichia coli, Enterococcus faecium, and Listeria innocua (surrogates of common foodborne pathogens) in RFM under different moisture contents (12% and 25% by fresh weight) and temperatures (50, 55, and 60°C). Inactivation data were used to determine D‐ and z‐values and to fit a multiple regression model to predict log(D‐values) in response to temperature and moisture content. Across conditions, D‐values were measured to be 5.1–120, 4.6–123, and 32–545 min for E. coli, L. innocua, and E. faecium, respectively. Temperature sensitivities were significantly higher in lower moisture RFM for E. coli and L. innocua. Applying E. coli inactivation models during RFM at 55°C yielded inactivation rates that aligned with experimental values after 5 min (0.1 vs. 0–0.1 logs), 30 min (2.1 vs. 1.3–2.3 logs), and 90 min (7.2 vs. 7.1–8.9 logs). These results can inform the design of RFM drying and stabilization processes to promote pathogen inactivation and safety in downstream applications of dried material. [ABSTRACT FROM AUTHOR]

Aims This study aims to assess the potential bacterial inactivation pathway triggered by argon (Ar) cold atmospheric pressure plasma jet (CAPJ) discharge using spectroscopic and imaging techniques. Methods and results Electrical and reactive species of the Ar CAPJ discharge was characterized. The chemical composition and morphology of bacteria pre- and post-CAPJ exposure were assessed using Fourier transform infrared (FTIR), Raman micro-spectroscopy, and transmission electron microscopy (TEM). A greater than 6 log reduction of Escherichia coli and Staphylococcus aureus was achieved within 60 and 120 s of CAPJ exposure, respectively. Extremely low D- values (<20 s) were recorded for both the isolates. The alterations in the FTIR spectra and Raman micro-spectra signals of post-CAPJ exposed bacteria revealed the degree of destruction at the molecular level, such as lipid peroxidation, protein oxidation, bond breakages, etc. Further, TEM images of exposed bacteria indicated the incurred damages on cell morphology by CAPJ reactive species. Also, the inactivation process varied for both isolates, as evidenced by the correlation between the inactivation curve and FTIR spectra. It was observed that the identified gas-phase reactive species, such as Ar I, O I, OH•, NO+, OH+, NO2−, NO3−, etc. played a significant role in bacterial inactivation. Conclusions This study clearly demonstrated the effect of CAPJ exposure on bacterial cell morphology and molecular composition, illuminating potential bacterial inactivation mechanisms. [ABSTRACT FROM AUTHOR]

In this study, La2O3 and CeO2 nanopowders were prepared using a simple and cost-effective precipitation method. Wide-angle X-ray diffraction (WAXD), UV-Visible reflectance diffuses (UV-Vis DRS), Raman spectroscopy, and specific surface area were used to characterize the photocatalysts, evidencing that the used preparation method was effective in the generation of crystalline CeO2 and La2O3. In particular, WAXD results showed that the average crystallite size of the achieved La2O3 and CeO2 samples were about 22 nm and 28 nm, respectively. The photocatalytic performances of the prepared catalysts were investigated in the degradation of levofloxacin (LEV) and the inactivation of a waterborne pathogen levofloxacin resistant (Enterococcus faecalis ATCC 29212) by using a photoreactor equipped with a solar simulator (SS). After 120 min, the CeO2 and La2O3 photocatalytic treatments allowed us to achieve between 75% and 83% of levofloxacin removal, respectively. A complete removal of 106 CFU/mL Enterococcus faecalis ATCC 29212 was achieved after 5 and 60 min of La2O3 and CeO2 photocatalytic processes, respectively. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of polyphenol-rich Strobilanthes crispus extract (SCE) fortification at various concentrations on yogurt. Proximate data revealed that the moisture, carbohydrate, and protein content decreased as the SCE concentration increased while fat and ash content remained unaffected. A significant decrease in pH, color (L*, a*, b*), and viscosity was noticed across all SCE-fortified yogurts. With an increasing concentration of SCE, a concomitant increment in the total phenolic content (TPC) and antioxidant activity of yogurts was observed albeit statistically insignificant. A weak, positive correlation was found between TPC and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The starter culture (L. bulgaricus and S. thermophilus) remained viable above log 7 CFU/mL for fortified concentrations. The consumer acceptance of SCE-fortified yogurt and the control was similar. Overall, this study suggested that SCE could serve as a potential functional ingredient in yogurt and fortification of SCE at 20% is deemed optimal. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) and plant extracts, rich in beneficial chemical compounds, have diverse applications in medicine, food, cosmetics, and agriculture. This study investigates the antibacterial activity of nine essential oil constituents (EOCs) against Escherichia coli, focusing on the effects of treatment pH and biosynthetic requirements. The impact of EOCs on bacterial inactivation in E. coli strains was examined using both nonselective and selective culture media. Computer-assisted drug design (CADD) methods were employed to identify critical binding sites and predict the main binding modes of ligands to proteins. The EOCs, including citral, α-terpinyl acetate, α-terpineol, and linalool, demonstrated significant bacterial inactivation, particularly under acidic conditions. This study revealed that EOCs have an effect on the presence of sublethal damage to both the cytoplasmic membrane and the outer membrane in Gram-negative bacteria. Adding penicillin G to the repair medium prevents the recovery of sublethal injuries in E. coli treated with α-terpinyl acetate, α-terpineol, linalool, and citral, indicating that peptidoglycan synthesis is essential for recovering from these injuries. However, penicillin G did not hinder the recovery process of most sublethally injured cells treated with the other assessed EOCs. Molecular docking studies revealed the favorable binding interactions of α-terpinyl acetate, α-terpineol, linalool, and citral with the β-lactamase enzyme Toho-1, indicating their potential as effective antibacterial agents. The findings suggest that EOCs could serve as viable alternatives to synthetic preservatives, offering new strategies for combating antibiotic-resistant bacteria. [ABSTRACT FROM AUTHOR]

Customer requests are addressed to safe products that best express their characteristics of "naturalness" and "freshness" for their entire shelf life; therefore, scientific research has been exploring the use of "non-thermal technologies". Thermosonication using low-frequency focused ultrasound determines bacterial inactivation through the phenomenon of "cavitation", guaranteeing high-quality standards of safety, nutrition, and freshness of the products. The present work aims to evaluate the effectiveness of the inactivation of Salmonella typhimurium in culture broth by low-frequency focused thermosonication with two different operational parameters: sublethal temperature (40°C, 50°C) and treatment time (5, 10, and 15 minutes). Treatment determined a bacterial load reduction compared to the negative control (untreated inoculum), which was statistically significant at the t-test (p<0.05). Average decreases of 1.5 log and 3.5 CFU/mL were observed, respectively, after treatment and after 24 hours of storage at +4°C. Treatment at 50°C for 15 minutes was the most effective (average value: 3.06 log CFU/mL; minimum value: 2.13 log CFU/mL; maximum value: 4.59 log CFU/mL). However, strains have shown markable variability: one of them even showed an increase in the microbial load 24 hours after treatment at 40°C for 5 minutes (-0.20 log CFU/mL); however, the same treatment showed a reduction of bacterial charge in all the other strains (average value: 1.05 log CFU/mL; minimum value: -0.20 log CFU/mL; maximum value: 2.28 log CFU/mL). This study poses numerous perspectives on the use of low-frequency focused thermosonication treatment in the food industry as a sustainable and safe alternative to classic thermal treatments. [ABSTRACT FROM AUTHOR]

Bentonite is an integral part of the engineered barrier system (EBS) in deep geological repositories (DGR) for nuclear waste, but its indigenous microorganisms may jeopardize long-term EBS integrity. To predict microbial activity in DGRs, it is essential to understand microbial reactions to the early hot phase of DGR evolution. Two bentonites (BCV and MX-80) with varied bentonite/water ratios and saturation levels (compacted to 1600 kg.m− 3 dry density/powder/suspension), were subjected to heat (90–150 °C) and irradiation (0.4 Gy.h− 1) in the long-term experiments (up to 18 months). Molecular-genetic, microscopic, and cultivation-based techniques assessed microbial survivability. Exposure to 90 °C and 150 °C notably diminished microbial viability, irrespective of bentonite form, with negligible impacts from irradiation or sample type compared to temperature. Bentonite powder samples exhibited microbial recovery after 90 °C heating for up to 6 months but not 12 months in most cases; exposure to 150 °C had an even stronger effect. Further long-term experiments at additional temperatures combined with the mathematical prediction of temperature evolution in DGR are recommended to validate the possible evolution and spatial distribution of microbially depleted zones in bentonite buffer around the waste canisters and refine predictions of microbial effects over time in the DGR. [ABSTRACT FROM AUTHOR]

Background: Implementing Hazard Analysis and Critical Control Point (HACCP) management across the supply chain is promoted globally to ensure the safety of marine food products due to their rapid quality deterioration. However, many seafood retail stores deviate from adopting these practices. Therefore, in this study, we aimed to create a flowchart based on HACCP and validate it in retail stores. Methods: Chub mackerel (Scomber japonicus), scallops (Patinopecten yessoensis), and whiteleg shrimp (Litopenaeus vannamei) specimens were purchased from a supermarket from August to December 2020. The handling information of these products from receipt to sales was obtained to prepare an HACCP plan for retail stores. Groups adhering to and deviating from flowchart conditions were categorized as Critical Control Point (CCP)- compliant and CCP-deviant, respectively. Four samples of each product for each condition were analyzed. Bacterial viability was evaluated using the flat agar culture method. Escherichia coli and Vibrio parahaemolyticus were detected using the Brilliant Green-Lactose-Bile and material point methods, respectively. Product freshness was assessed by determining K-values using High-Performance Liquid Chromatography. Results were compared using Student's t-test. Results: At elevated storage temperatures, bacterial growth rates were higher in chub mackerel and whiteleg shrimp than those in scallops. E. coli was not detected in any sample, whereas V. parahaemolyticus was detected in scallops and whiteleg shrimp but not in chub mackerel. CCP-deviant refrigerated scallops had increased V. parahaemolyticus counts; however, it did not differ between the frozen scallop and whiteleg shrimp. K-values increased more rapidly in CCP-deviant chub mackerel, whiteleg shrimp, and refrigerated scallops, but not in frozen scallops. Inadequate temperature control during display and sale markedly deteriorated the quality of marine products. Conclusion: Setting CCPs for marine food product display and sale while controlling temperature can preserve product quality. The flowchart created in this study can be broadly used for marine retail stores. [ABSTRACT FROM AUTHOR]

Effective disinfection processes have been investigated to provide pathogen-free drinking water. Due to growing concern about the potential negative effects of cyanobacteria in portable water, their treatment has gained more attention recently. This study aims to compare the inhibition efficiencies of Gram-negative bacteria (Escherichia coli; E. coli), Gram-positive bacteria (Bacillus subtilis; B. subtilis), and cyanobacteria (Microcystis aeruginosa; M. aeruginosa) using UV-C and solar irradiation, and their combination process with H2O2. Over 6 log removal value (LRV) of E. coli and B. subtilis was achieved within 1 min of UV-C irradiation (0.76 ± 0.02 mW/cm2). The solar and solar/H2O2 (50 mg/L) processes effectively reduced (>99%) both bacteria after 20 min. E. coli was more sensitive to hydroxyl radicals (•OH) compared to the B. subtilis due to a different cell wall structure, resulting in a 0.18–0.62 higher LRV than B. subtilis. However, solar-based processes did not effectively inhibit M. aeruginosa (>52.23%). The UV-C/H2O2 (50 mg/L) process showed the highest inhibition rate for M. aeruginosa (77.83%) due to the generation of •OH, leading to oxidative damage to cells. Additionally, chlorophyll-a (Chl-a) was measured to indicate cell lysis of M. aeruginosa. The removal rate of Chl-a extracted by viable M. aeruginosa was higher using the UV-C process (93.03%) rather than the UV-C/H2O2 process (80.95%), because UV-C irradiation could be most effective in damaging Chl-a. [ABSTRACT FROM AUTHOR]

Pathogen contamination is a severe problem in maintaining food safety in the cold chain. Cold plasma (CP) is a novel non-thermal disinfection method that can be applied for the bacterial inactivation of food in appropriate contexts. Currently, research on CP used on food at cold chain temperatures is rare. This work investigated the bacterial inactivation effect of CP on beef at typical cold storage temperatures of 4 and −18 °C and room temperature (25 °C). The reactive species in CP were indirectly tested by evaluating O3, NO3− and NO2− in cold plasma-activated water (PAW), which indicated the highest concentrations of reactive species in CP at 25 °C and the lowest at −18 °C. The bactericidal efficacy of CP treatment against beef inoculated with Escherichia coli at −18 °C, 4 °C, and 25 °C was 30.5%, 60.1%, and 59.5%, respectively. The 4 °C environment was the most appropriate treatment for CP against beef, with the highest bactericidal efficacy and a minor influence on beef quality. The indirect CP treatment had no significant effect on the texture, color, pH, or cooking loss of beef at −18 °C. CP shows significant potential for the efficient decontamination of food at cold chain temperatures. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a common cause of hospital-acquired infections and exhibits a strong resistance to antibiotics. An alternative treatment option for bacterial infections is the use of bacteriophages (or phages). In this study, two distinct phages, VB_PaD_phPA-G (phPA-G) and VB_PaN_phPA-Intesti (phPA-Intesti), were used as single suspensions or in a phage cocktail to inactivate the planktonic cells and biofilms of P. aeruginosa. Preliminary experiments in culture medium showed that phage phPA-Intesti (reductions of 4.5–4.9 log CFU/mL) outperformed phPA-G (reductions of 0.6–2.6 log CFU/mL) and the phage cocktail (reduction of 4.2 log CFU/mL). Phage phPA-Intesti caused a maximum reduction of 5.5 log CFU/cm2 in the P. aeruginosa biofilm in urine after 4 h of incubation. The combination of phage phPA-Intesti and ciprofloxacin did not improve the efficacy of bacterial inactivation nor reduce the development of resistant mutants. However, the development of resistant bacteria was lower in the combined treatment with the phage and the antibiotic compared to treatment with the antibiotic alone. This phage lacks known toxins, virulence, antibiotic resistance, and integrase genes. Overall, the results suggest that the use of phage phPA-Intesti could be a potential approach to control urinary tract infections (UTIs), namely those caused by biofilm-producing and multidrug-resistant strains of P. aeruginosa. [ABSTRACT FROM AUTHOR]

KrCl* excilamp treatment has emerged as a potential method to replace conventional 254 nm low-pressure mercury UV-C lamps to ensure the microbiological safety of food items. In this study, we demonstrated a dielectric barrier discharge (DBD) based mercury-free 222 nm exciplex source to investigate the microbial and physicochemical properties of raw milk and compared it with 253 nm and pasteurization methods. The UV dose delivered to the milk samples was estimated using the chemical actinometry method and found to be 10.9 J/ml. The methylene blue reduction test (MBRT) of milk was increased for more than 5 h, with just 2.5 min of far UV-C (222 nm) treatment. Approximately 2.58 log and 2.11 log decrease in the E. coli and S. aureus were achieved after 2.5 min of 222 nm treatment of whole milk. We inferred that 222 nm UV light is more efficacious vis-à-vis 253 nm and pasteurization in increasing milk quality without altering its physicochemical properties, indicating its potential use as a more efficient UV source for enhancing milk safety, quality, and shelf life. This widens the scope for the use of mercury-free far UV-C irradiation as a viable and non-thermal technology in the dairy industry, food sector, and overall sterilization applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The serious combination of abundant electrons/holes in bulk primarily hinders the efficiency in the photocatalytic reaction. It is crucial to control the spatial charge dynamics through delicately designing the crystal configuration of photocatalyst. In this work, a modified tungsten trioxide nanosheet colloid (M-WO 3) was synthesized by an ion exchange method. Compared to pristine WO 3 (P-WO 3), the crystal lattice vibration frequency of M-WO 3 increases from 2.8 meV to 4.3 meV, which effectively prohibits electron–phonon coupling and powerfully accelerates the separation and transfer of photoinduced charge carriers. Irradiated by visible-light, M-WO 3 shows much higher photocatalytic bacterial inactivation performance than P-WO 3. In addition, this regulation method increases the surface charges of the WO 3 colloid to improve its stability, which endows this colloid photocatalyst with broad prospects in practical photocatalytic antibacterial applications. This work offers guidance to construct efficiently separated photoinduced electron/hole pairs of the colloid photocatalyst by designing its crystal structure. [ABSTRACT FROM AUTHOR]

A novel S-scheme photocatalyst InVO 4 /Bi 5 O 7 I with a compact heterojunction structure was prepared by hydrothermal combined calcination method, which exhibited excellent photocatalytic performance at low dose and low energy consumption. The antimicrobial and degradation properties of the photocatalysts were evaluated by inactivating E. coli and S. aureus and degrading pollutants (TC and BPA) under LED light irradiation. The best sample was able to completely inactivate E. coli and S. aureus in 30 min, and the degradation rate of TC reached 76.0% in 60 min and that of BPA reached 93.0% in 90 min, and the active species produced in this process were e−, h+, O 2 − and OH. The synergistic effect of S-scheme heterojunction makes it possess excellent photocatalytic activity. [Display omitted] The low efficiency of charge carrier separation is a major limitation hindering the application of photocatalytic technology. Constructing S-scheme heterojunction photocatalysts not only effectively promotes the separation of charge carriers, but also maximizes the oxidative and reductive capabilities of the two monomers. In this study S-scheme heterogeneous InVO 4 /Bi 5 O 7 I photocatalyst was synthesized by hydrothermal method combined with calcination. The optimal sample 20 % InVO 4 /Bi 5 O 7 I can completely deactivate Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in 30 min, remove 20 mg/L TC 76.0 % in 60 min and 20 mg/L BPA 93.0 % in 90 min. Intermediate products of TC and BPA degradation were detected using LC-MS, and possible degradation pathways were proposed. The photocurrent and electrochemical impedance spectroscopy (EIS) tests confirm that InVO 4 /Bi 5 O 7 I exhibits excellent photocurrent intensity and photocarrier migration ability, which are crucial reasons for the enhancement of the photocatalytic performance of the InVO 4 /Bi 5 O 7 I composite. Capture experiments indicate that OH, O 2 −, h+ and e−are reactive species. EPR further confirms the generation of OH and O 2 −. Combined with Kelvin probe force microscopy (KPFM) and band structure analysis, it is proposed that InVO 4 /Bi 5 O 7 I has an S-scheme charge transfer mechanism. [ABSTRACT FROM AUTHOR]

A facile carbon‐doping process is proposed to enhance the photocatalytic activity of anatase/rutile‐mixed phase TiO2 nanoparticles using polyethylene glycol (PEG). The TiO2‐PEG composite is loaded into a boat and covered tightly with Al foil to increase the pressure inside that boat during annealing. The boat is annealed for 1 h at different temperatures and PEG ratios. The annealing with 30% PEG at 300 °C enhances the decomposition of organic pollutants and bacterial inactivation under 405 nm light compared to the annealing without Al films. This annealing causes 2.5–3% carbon doping, introduces more oxygen vacancies, and converts PEG into organic compounds rich in CC bond components. These modifications of TiO2 can be attributed to carbon‐centered radicals produced from PEG during annealing. The modifications change the band structure to enhance the photogenerated carrier concentration responsible for the photocatalytic activity. The carbon doping narrows the anatase and rutile bandgaps, allowing the anatase phase to absorb 405 nm light. The introduced oxygen vacancies increase the electron‐trapping sites and raise the adsorbed oxygen groups enhancing the upward band bending and the depletion layer depth at the surface. The PEG‐converted compounds can transfer photogenerated electrons within the compounds to the TiO2 conduction band. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is an increasing challenge in semen preservation of breeding animals, especially in the porcine species. Bacteria are a natural component of semen, and their growth should be inhibited to protect sperm fertilizing capacity and the female's health. In pig breeding, where semen is routinely stored at 17°C in the liquid state, alternatives to conventional antibiotics are urgently needed. Photodynamic inactivation (PDI) of bacteria is a well-established tool in medicine and the food industry but this technology has not been widely adopted in semen preservation. The specific challenge in this setting is to selectively inactivate bacteria while maintaining sperm integrity and functionality. The aim of this study was to test the principle of PDI in liquid stored boar semen using the photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) and a white light LED-setup. In the first step, photophysical experiments comprising singlet oxygen phosphorescence kinetics of TMPyP and determination of the photosensitizer triplet time revealed a sufficiently high production of reactive singlet oxygen in the Androstar Premium semen extender, whereas seminal plasma acted as strong quencher. In vitro experiments with extended boar semen showed that the established PDI protocol preserves sperm motility, membrane integrity, DNA integrity, and mitochondrial activity while efficiently reducing the bacteria below the detection limit. A proof-of-concept insemination study confirmed the in vivo fertility of semen after photodynamic treatment. In conclusion, using the PDI approach, an innovative tool was established that efficiently controls bacteria growth in extended boar and maintains sperm fertility. This could be a promising contribution to the One Health concept with the potential to reduce antimicrobial resistance in animal husbandry. [ABSTRACT FROM AUTHOR]

Metal-free photocatalysis that produces reactive oxygen species (ROS) shows significant promising applications for environmental remediation. Herein, we constructed iodine-doped carbon nitride (I-CN) for applications in the photocatalytic inactivation of bacteria and the heterogeneous Fenton reaction. Our findings revealed that I-CN demonstrates superior photocatalytic activity compared to pure CN, due to enhanced light adsorption and a narrowed band gap. Antibacterial tests confirmed that I-CN exhibits exceptional antibacterial activity against both Escherichia coli and Staphylococcus aureus. The results showed that I-CN effectively generates superoxide radicals and hydroxyl radicals under light irradiation, resulting in enhanced antibacterial activity. In addition, I-CN can also be applied for a heterogeneous photo-Fenton-like reaction, achieving a high performance for the degradation of sulfamethoxazole (SMX), a typical antibiotic, via the photocatalytic activation of peroxymonosulfate (PMS). These results shed new light on the fabrication of metal-free nanozymes and their applications for disinfection and water decontamination. [ABSTRACT FROM AUTHOR]

Bacterial wound infections are a significant socioeconomic concern in the modern healthcare industry owing to increased morbidity, prolonged hospital stay, and mortality. Bacterial infectious agents that colonize the wound bed develop biofilms, acting as a physical barrier that prevents the effective penetration of topical antimicrobials. Further, bacteria in such infectious wounds express a wide range of virulence factors promoting intercellular transmigration and host cell invasion complicating the treatment regimen. To address this need, a water‐dissolvable poly‐vinyl pyrrolidine (PVP), calcium peroxide (CPO) infused microneedle structure (denoted as PVP/CPO MN) for effective transdermal delivery of antimicrobial payload deep into the tissues is developed. Fluid exudate from the wound bed dissolves the PVP/CPO MN enabling the release of CPO deep into the infected wound bed. A slow catalytic decomposition of CPO results in the sustained release of reactive oxygen species (ROS) deep within the infected wound inhibiting the inter‐ and intracellular pathogens. Here, a systematic study of microneedle fabrication and sterilization after complete packaging is conducted to ensure scalability and safe applicability while maintaining mechanical and antibacterial properties. In vitro, antibacterial efficacy of the microneedles is validated against two common wound pathogens, Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). Moreover, the PVP/CPO MN exhibited significant efficacy in eradicating both extracellular and intracellular bacterial populations within an in vivo porcine wound model. Additionally, the microneedle technology facilitated a faster wound healing, with ≈30% increase compared to control and a 15% improvement over conventional silver dressing. [ABSTRACT FROM AUTHOR]

Wearing face masks is an effective non‐pharmaceutical strategy to inhibit the transmission of airborne diseases. Nonetheless, most commercial face masks lack disinfecting capabilities, posing risks of secondary transmission, while those with antimicrobial coatings are incapable of instant pathogen inactivation. Herein, a proof‐of‐concept instant disinfecting face mask is demonstrated consisting of a Cu(OH)2‐nanowire electroporation filter powered by a respiration‐driven triboelectric nanogenerator (R‐TENG). The R‐TENG comprises electrospun polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) membranes. A dome‐shaped PVA membrane is specifically designed to maximize the effective contact area. Coupling the novel dome‐shape design with maximized β‐phase crystallites of PVDF, the enhanced R‐TENG generates an open‐circuit voltage of 120 V under the normal breathing rate of an adult, resulting in an amplified electric field of 19 MV m−1 at the nanowire tips of the electroporation filter. Under this high localized electric field, effective inactivation of bacteria (>99.9%) is achieved via a synergy of electroporation and physical penetration. Conversely, when the R‐TENG is disconnected, only partial inactivation (90%–99%) via physical penetration is realized. For the first time, it shows that R‐TENG powered electroporation is a viable solution to achieve instant, effective disinfection, paving the way for next‐generation face masks. [ABSTRACT FROM AUTHOR]