Decontamination Methods Research Articles

Skin decontamination with and without water irrigation.

Rinsing only with water or washing with soap and water are common methods of skin decontamination for skin contaminated during a chemical hazard release. The null hypothesis was that a 15-minute water irrigation (decontamination method 1) would not be superior to decontamination using a microfiber towel, followed by a wet wipe (Signature Select Softly Flushable Tissue Better Living Brands LLC, Pleasanton, CA), followed by using another microfiber towel (decontamination method 2). A simulated contaminant (Magic Fluorescent Glow Paint for Face and Body, iLC Shenzhen Fulimei Technology Co. LTD, Shenzhen, the People's Republic of China) was applied to the dorsal skin of each subject's forearms. Then, photographs of these subject's skin were taken before and after decontamination of the simulated contaminant by using either decontamination method 1 or 2. Each of the subjects underwent both decontamination methods in separate trials, with each subject using one forearm for decontamination method 1 and their other forearm for decontamination method 2. Discrete points of contamination were quantified on the photographs that were taken with the skin illuminated by ambient visible light or ultraviolet light (395nm, Roceei ultraviolet flashlight, China). Under visible light, no residual contamination was seen by inspecting photographs taken after decontaminating with either method. Under ultraviolet light, less visible contamination was seen by inspecting photographs taken after decontaminating with method 1 than after decontaminating with method 2. In this study, skin decontamination with water irrigation was superior to skin decontamination without water irrigation.

Non-thermal plasma decontamination of microbes: a state of the art.

Microbial decontamination is a critical concern in various sectors, from healthcare to food processing. Traditional decontamination methods, while effective to a degree, present limitations in terms of environmental impact, efficiency, and potential harm to the target material. This review investigates the emerging realm of non-thermal plasma (NTP) as a promising alternative for microbial decontamination, emphasizing its mechanisms, reactor designs and applications. The mechanism decomposed into physical, chemical and biological effects of plasma, are elaborated upon to provide a foundational understanding of the intrinsic principles of plasma decontamination. Except for the generation type of NTP, reactors and other parameters by which NTP achieves microbial decontamination, emphasizing the design considerations and parameters that influence its efficacy. Moreover, the latest applications of NTP in decontaminating air, water, and surfaces, supported by the latest research findings in each domain are explored. Additionally, the perspectives on the future research tendencies of NTP decontamination and disinfection are highlighted with potential avenues for exploration and innovation. Through this comprehensive review, the aim is to underscore the potential of NTP, particularly DBD plasma, as a versatile, efficient, and environmentally friendly method for microbial decontamination.

Antibacterial Activity of Ocimum Basilicum L. and Thymus Vulgaris L. Extracts against Escherichia coli as a future method for decontamination and deodorization of compost-like mixtures

Ocimum basilicum L. and Thymus vulgaris L. are natural plant sources of antimicrobial activity, which is essential to determine their qualities as biological agents against pathogenic microorganisms. The aim of the study is the analysis of the antibacterial activity of plant extracts of basil and thyme against Escherichia coli for their subsequent application in agricultural practice as additives for decontamination and deodorization of compost-like mixtures. Plant extracts from roots, stems, leaves and whole plants of basil and thyme were obtained by various methods: decoction, tincture, medicinal vinegar, medicinal wine and medicinal oil. Agar diffusion method was used to determine the antimicrobial activity of the extracts against Escherichia coli. The analyzed essential oil cultures increase the microbiological and enzymatic activity of soils. Basil extracts showed stronger antimicrobial activity against Escherichia coli than thyme extracts, differing for individual plant parts - roots variants showed higher antimicrobial activity compared to variants with leaves, stems and whole plant. In general, a lower antimicrobial activity of the plant extracts was found in the medicated wine and tincture variants (except for roots tincture), compared to the decoction, medicated vinegar and medicated oil variants. The antibacterial activity of the stem extracts depended significantly, and that of the root, leaf and whole plant extracts moderately, on the biogenicity of the soils. The analyzed essential oil cultures can be applied for decontamination (against Escherichia coli) and deodorization of compost-like mixtures. The use of basil and thyme extracts decontaminated composts from E. coli content in a repeated 4-month application.

Biosurfactants: Chemical Properties, Ecofriendly Environmental Applications, and Uses in the Industrial Energy Sector

The exploitation of nature and the increase in manufacturing production are the cause of major environmental concerns, and considerable efforts are needed to resolve such issues. Oil and petroleum derivatives constitute the primary energy sources used in industries. However, the transportation and use of these products have huge environmental impacts. A significant issue with oil-related pollution is that hydrocarbons are highly toxic and have low biodegradability, posing a risk to ecosystems and biodiversity. Thus, there has been growing interest in the use of renewable compounds from natural sources. Biosurfactants are amphipathic microbial biomolecules emerging as sustainable alternatives with beneficial characteristics, including biodegradability and low toxicity. Biosurfactants and biosurfactant-producing microorganisms serve as an ecologically correct bioremediation strategy for ecosystems polluted by hydrocarbons. Moreover, synthetic surfactants can constitute additional recalcitrant contaminants introduced into the environment, leading to undesirable outcomes. The replacement of synthetic surfactants with biosurfactants can help solve such problems. Thus, there has been growing interest in the use of biosurfactants in a broad gamut of industrial sectors. The purpose of this review was to furnish a comprehensive view of biosurfactants, classifications, properties, and applications in the environmental and energy fields. In particular, practical applications of biosurfactants in environmental remediation are discussed, with special focus on bioremediation, removal of heavy metals, phytoremediation, microbial enhanced oil recovery, metal corrosion inhibition, and improvements in agriculture. The review also describes innovating decontamination methods, including nanobioremediation, use of genetically modified microorganisms, enzymatic bioremediation, modeling and prototyping, biotechnology, and process engineering. Research patents and market prospects are also discussed to illustrate trends in environmental and industrial applications of biosurfactants.

Cloning of Three Aflatoxin B1 Oxidases of the Dipeptidyl Peptidase III Family and Evaluation of Their Potential for Practical Applications as Decontamination Enzymes.

Aflatoxin B1 (AFB1) produced by some Aspergillus species belongs to the most dangerous contaminants of animal feeds. Development of safe and cost efficient decontamination methods saving feed quality and nutritional value are of paramount importance. The use of recombinant AFB1-detoxifying microbial enzymes represents a promising biotechnological approach meeting the aforementioned requirements. In this study, three AFB1-degrading oxidases (AFOs) from edible basidiomycetes Cantharellus cibarius, Lentinula edodes and Pleurotus eryngii as well as AFO from Armillaria tabescens were expressed in E. coli Rosetta (DE3) and purified by immobilized metal-chelate chromatography. The stabilizing effect of the addition of glycerol and β-mercaptoethanol during protein extraction is shown. The catalytic constants of the recombinant AFOs (rAFOs) and other characteristics, which might be important for their practical application (and optimal temperature and pH, thermolability, regulation of the activity by metal ions and chelating agents, storage stability) were investigated. Among the obtained enzymes, rAFO from P. eryngii (Pe-AFO), which was characterized by the highest specific activity, thermostability and pH stability (especially at acidic pH range), the lowest Km, and relative resistance to the inhibition by phytate, showed the best AFB1-degrading efficacy. However, Pe-AFO and all other rAFOs significantly decreased the target activity during heating above 45 °C, storage frozen or lyophilization.

Mycoplasma: Properties, Detection, and Decontamination Methods of Cell Cultures and Viral Strains (Review)

Mycoplasma: Properties, Detection, and Decontamination Methods of Cell Cultures and Viral Strains (Review)

Qualitative Comparison of Hydrogen Peroxide Decontamination Systems: Vapor vs. Aerosol

This study aimed to compare the efficiency of two methods for airborne surface decontamination: hydrogen peroxide vapor (HPV) and aerosolized hydrogen peroxide (aHP). Spores of G. stearothermophilus and B. atrophaeus were exposed to a 35% hydrogen peroxide solution under controlled laboratory conditions, including specific concentrations, exposure durations, humidity levels, and temperatures. Following each decontamination procedure, the spores were incubated for 7 days to evaluate bacterial growth and assess the efficacy of each method. The results indicate that the aHP method achieved biocidal rates of 84.76% for G. stearothermophilus and 89.52% for B. atrophaeus, while the HPV method demonstrated respective rates of 90.95% and 90.48%. These findings suggest that both the aHP and HPV methods are highly effective for microbial decontamination, with HPV showing a slight edge in overall efficacy. However, despite its comparable effectiveness, the HPV method has raised concerns regarding technical and economic factors. Observations highlighted issues such as fluctuations in humidity levels causing surface damage, a problem not encountered with the aHP method. Economically, HPV requires specific devices that can cost up to EUR 50,000, whereas aHP equipment costs do not exceed EUR 10,000. These observations emphasize the importance of critically evaluating the pros and cons of each decontamination method, taking into account factors such as biocidal efficacy, technical feasibility, and the associated costs.

Comparison of Air Abrasion and Mechanical Decontamination for Managing Inflammatory Reactions around Dental Implants: A Systematic Review and Meta-Analysis

Background: A number of mechanical decontamination methods have been proposed, however, there is no agreed-upon gold standard among them. This study aims to conduct a meta-analysis to assess the differences in the management of an inflammatory reaction around dental implants between air abrasion and mechanical decontamination. Methods: A comprehensive search strategy was employed, incorporating controlled vocabulary (MeSH) and free-text terms. This search was conducted by two reviewers to identify published systematic reviews. Three major electronic databases, namely, Medline via PubMed, the Cochrane database, and Embase, were searched up to May 2024. Results: Initially, 300 articles were identified. After conducting a comprehensive search and applying strict inclusion criteria, a total of 13 studies were deemed eligible for inclusion in the meta-analysis. The results showed that the mean difference in probing depth between air abrasion and other mechanical decontamination was 0.28 (95% confidence interval, −0.20 to 0.76). The mean difference in probing depth of air abrasion compared with other mechanical decontamination in maintenance purposes was 1.05 (95% confidence interval, 0.18 to 1.91). The mean difference in bleeding on probing between air abrasion and other mechanical decontamination was 0.51 (95% confidence interval, 0.07 to 0.95). The mean difference in alveolar bone loss between air abrasion and other mechanical decontamination was −0.14 (95% confidence interval, −0.77 to 0.48). The mean difference in alveolar bone loss for surgical approaches of air abrasion compared with other mechanical decontamination was 0.32 (95% confidence interval, 0.03 to 0.61). Conclusions: The findings of the study indicate that the use of air abrasion was just as effective as other mechanical decontamination methods in reducing probing depth and alveolar bone loss. The subgroup analysis showed that air abrasion was less effective in reducing probing depth in maintenance purposes. Additionally, air abrasion was less effective in reducing alveolar bone loss in surgical approaches.

Effects of chemical & biological warfare agent decontaminants on trace survival: Impact on DNA profiling from blood and saliva

Forensic investigations following incidents involving chemical or biological agents present considerable challenges. Understanding the possibilities and limitations can aid in determining the most suitable procedures and enhancing the recovery of useful traces in these complex situations. This work complements previously published results on the effects of decontaminants on fingermarks deposited on glass. Identifying the perpetrators can be crucial, and DNA analysis remains a cornerstone in this regard. In this study, we investigated the ability to obtain usable DNA profiles from blood and saliva (pure and diluted) exposed to 16 different decontamination methods. Both DNA quantitation and DNA profiling were considered to assess the outcomes. The results revealed considerable variability but indicated that biological agents' decontaminants hindered DNA profiling post-decontamination to a greater extent than decontaminants aimed for chemical agents. Chlorine-based decontaminants also globally had a deleterious impact on DNA profiling. Powder decontaminants such as Fast-Act, CHpowder, and the liquid decontaminants GDS2000 did not affect DNA profiling.

Enhancing bioethanol yield from food waste: Integrating decontamination strategies and enzyme dosage optimization for sustainable biofuel production

Amidst the global surge in energy demand, the public’s focus has shifted from fossil fuels to more sustainable and eco-friendly fuels like bioethanol. Thus, the prospect of producing bioethanol from food waste (FW) is gaining traction, offering a sustainable solution to both waste management and energy needs. However, increasing bioethanol yields during food waste fermentation requires an approach that addresses the variability of these heterogeneous feedstocks in terms of chemical composition, microbial contamination, enzyme dosage requirements, and high moisture content. Hence, this study evaluated thermal and chemical decontamination strategies for pre- and post-consumer food waste and minimised the exogenous enzyme dosage by applying an engineered, amylase-producing strain (Saccharomyces cerevisiae ERT12). Results show that thermal sterilisation at an elevated liquefaction temperature significantly improved ethanol yields (from pre-and post-consumer food waste) more than chemical decontamination methods. Also, key findings show that applying the amylase-secreting yeast reduced enzyme dosages by up to 33 %. During fed-batch fermentation with strain ER T12, the highest possible solids loading increased the final ethanol concentrations by 96 % (for pre-consumer FW) and 85 % (for post-consumer FW) compared to batch fermentation. Also, the pre-consumer to post-consumer FW fed-batch fermentation maintained acceptable volumetric production rates of 2.35 to 1.57 g/l.h and yielded 87.6 to 61.2 % of the theoretical maximum. Although the maximum solids loadings, ethanol titres and yields achievable in food waste fermentations were still limited by the inherent moisture contents of the feed, they demonstrated performances that may be appropriate for industrial implementation, considering the negative feedstock costs.

Effect of IONIZING radiation on the stereochemical composition of dihydroquercetin sample

Introduction. Microbiological quality is one of the key criteria for active pharmaceutical ingredients. To ensure it, a set of preventive measures and various decontamination methods are used. A relatively new approach is ionizing radiation, characterized by high efficiency. However, according to the literature, during ionizing sterilization, a change in the chemical composition of the drug may occur, which requires studying the effect of the radiation factor on each individual compound. Objective. To investigate the effect of ionizing radiation on the stereoisomeric composition of the dihydroquercetin (DHQ), a natural flavananol and a promising object for the development of chiral remedies. Material and methods. The object of the study is a sample of DHQ exposed to ionizing radiation of 9.5 MeV (DHQrad), while the reference sample is a native substance of DHQ from the same manufacturer and batch (DHQref). Analysis was conducted using polarimetry and reversed-phase HPLC with diode array and mass spectrometric detection. Results. Taking into account the moisture content of the samples, the average values of the specific optical rotation for acetone solutions of DHQrad and DHQref were 20.85±1.54° and 19.65±1.93°, respectively. Chromatograms showed two peaks with retention times of 10.18±0.03 and 11.63±0.01 min, which, based on UV and mass spectra profiles, were identified as trans- and cis-diastereomers of DHQ. The total content of flavananol in the analyzed samples was 93.25±0.01% for DHQrad and 94.92±0.01% for DHQref, with the amount of the cis-isomer being 0.59±0.13% and 1.27±0.70%, respectively. Conclusion. The study did not establish a significant effect of ionizing radiation on the specific optical rotation value and the stereoisomeric composition of the DHQ substance. The findings support the recommendation of this sterilization method for remedies containing the studied flavananol.

Effective Decontamination Methods for Shiga Toxin-producing Escherichia coli on Beef Surfaces for Application in Beef Carcass Hygiene

Effective methods for decontamination of Shiga toxin-producing Escherichia coli (STEC) on beef were evaluated by 48 mL spraying, 100 mL, and 500 mL flushing with ethanol, hydrogen peroxide, peracetic acid, acidified sodium chlorite, and sodium hypochlorite in this study. The flushing with 500 mL of 1,000 ppm peracetic acid was most effective, reducing pathogens by 2.8 log CFU/cm2, followed by 1,200 ppm acidified sodium chlorite. The spraying with 1,000 ppm peracetic acid reduced pathogens by 1.6 log CFU/cm2. The flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite, and 50, 100, 200, and 500 ppm peracetic acid significantly reduced the STEC population compared with those treated with distilled water (p < 0.05), reducing pathogens by 2.1, 2.4, 1.6, 1.8, 2.1 and 2.4 log CFU/cm2, respectively. Additionally, the flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite significantly changed the color of beef samples (p < 0.05), whereas 100–500 ppm peracetic acid did not significantly change the color (p > 0.05). The flushing with 500 mL of 200 and 500 ppm acidified sodium chlorite and 200 and 500 ppm peracetic acid significantly changed the odor of beef samples compared with those treated with distilled water (p < 0.05). There was no difference in the reduction of STEC population between peracetic acid treatment at 25 °C and 55 °C, with or without washing with sterilized distilled water after decontamination. Washing with distilled water after flushing with peracetic acid tended to reduce the odor of the samples. These results suggest that treatment with 100, 200, and 500 ppm peracetic acid, followed by washing with distilled water, might reduce the STEC population without retaining the odor of the sanitizer.

Evaluation of two household decontamination methods on protective mask materials and disinfection effects

Abstract In order to find affective disinfection methods for general public to reuse protective mask, which could address supply shortages in the period of epidemic, household ovens and household ultraviolet disinfection cabinets were used as decontamination tools, and the influence of decontamination process on the protective performance of masks including PFE and TIL, as well as virus (PV I and MHV) inactivation effect were completely evaluated. It was found that the dry heat and UVGI decontamination with household devices had a little impact on PFE or TIL of masks, which indicated that two process had little effect on mask material and face seal fit. The virus inactivation results showed that dry heat decontamination could effectively inactivate the virus on the masks, and UVGI decontamination could not completely inactivate the virus caused by the special shape of masks, which could be concluded that dry heat decontamination with household oven was a feasible method to reuse the mask, and UVGI decontamination was not recommended. This study had guiding significance for the decontamination and reuse of masks by the general public.

Pulsed light technology for fresh‐cut produce: A review on mechanism and inactivation kinetics of microbes and enzymes

AbstractConsumers are becoming more aware of the benefits of eating healthy foods like fresh‐cut produce without compromising the quality of sensory and nutritional aspects. Emerging non‐thermal technology like pulsed light (PL) is one of the most potential surface decontamination methods for fresh‐cut produce. Unlike conventional methods, PL does not cause unwanted changes in finished products like nutritional losses, color, textural changes, production of off‐flavors, etc. Its application is confined to not only surface disinfection but also enzyme inactivation. The death of microbes is due to PL's photochemical and photothermal effects. The photochemical effect is also responsible for enzyme inactivation, and Weibull or log‐linear models can explain their inactivation kinetics. Despite several advantages, PL has limitations of less effectiveness in eliminating microorganisms due to low penetration into the tissue of fresh‐cut produce, which can be overcome by applying different absorption‐enhancing agents to improve absorption capacity. Moreover, in‐package treatment can avoid the problem of recontamination of the treated products. This review provides an overview of the mechanisms and kinetics involved in the inactivation of microbes and enzymes in PL treatment. Additionally, this paper reviews the advantages and limitations of utilizing PL technology for shelf‐life enhancement of fresh‐cut produce and compiles the recent works done to enhance the efficacy of PL treatment. Furthermore, future scope and remedies to solve the existing problems of PL and for commercialization of this technique in the field of fresh produce are discussed.

Comparison of Power Ultrasound and NALC-NaOH Decontamination Methods for Stool Mycobacterial Culture: A Prospective Study.

Stool samples have been reported to be useful for the diagnosis of pulmonary tuberculosis (PTB), especially in patients who are unable to produce sputum. However, contamination limits the usefulness of stool specimens in mycobacterial culture. In this study, a novel decontamination method of power ultrasound (PU) was evaluated for mycobacterial isolation from suspected PTB cases. Stool samples (n = 650) were collected, and each sample was divided into approximately three equal groups. In addition to an AFB smear (Auramine O method), the stool samples were treated using different decontamination methods (NaOH-NALC vs. PU methods). The sensitivity (calculated against CRS) and contamination rates between the two methods were compared using McNemar's test. Of the 650 samples, 32 (4.92%) stool samples treated with the NaOH-NALC method were culture-positive, including Mycobacterium tuberculosis (M.TB; n = 21, 3.23%) and nontuberculous mycobacteria (NTM; n = 11, 1.69%). Sixty-one (9.38%) stool samples treated with the PU method were culture-positive, including M.TB (n = 37, 5.69%) and NTM (n = 24, 3.69%). Statistical analysis showed that a significant difference was found in the isolation rate of M.TB and NTM between the two methods (p < 0.05). Additionally, compared with the NALC-NaOH method (19.07%), stool samples treated with the PU method (13.23%) had a significantly lower contamination rate (p < 0.05). In conclusion, our findings suggest that the utilization of the PU method as a novel decontamination technique could significantly enhance the isolation rates of both NTM and M.TB when stool specimens are employed for culture. Compared to the NaOH-NALC method, this approach proves to be more effective in facilitating stool mycobacterial culture.

Technologies to decontaminate aflatoxins in foods: a review

SummaryAflatoxins are toxic secondary metabolites produced by Aspergillus spp., found in staple food commodities. Aflatoxins are carcinogenic, teratogenic, and mutagenic and pose a serious threat to the health of humans. The identification and quantification of aflatoxins in foods is a major challenge to guarantee food safety. Therefore, developing feasible, sensitive, and robust methods for decontamination is paramount, with short processing time and negligible impact on quality. This review evaluates recent novel technologies for aflatoxins decontamination by physical methods (microwave heating, Gama and electron beam irradiation, pulse light and ultraviolet), chemical methods (ozone, natural plant extracts, and organic acids), and biological methods (atoxigenic Aspergillus strains, Trichoderma spp., and bacteria and yeast). The study highlights on the cutting‐edge technologies of smart packaging and artificial intelligence (AI). To achieve more efficiency and adaptability to different food matrices in aflatoxins decontamination, the study suggests integrating multiple strategies. The study also recommends integrating Partnership for Delivery (P4D) to share the responsibility to increase the chance for success and control aflatoxins in foods.

Dissipation kinetics and decontamination of chlorantraniliprole and thiamethoxam residues in curry leaves

ABSTRACT Herein, using liquid chromatography – tandem mass spectrometry, we validated a modified QuEChERS method to analyse thiamethoxam and chlorantraniliprole residues in curry leaves. These insecticides are part of a pest management module against the major curry leaf insect pests, psyllid and leaf roller. Based on the SANTE guideline, the method exhibited satisfactory recovery and precision. For both insecticides, the R2 value was 0.99. Furthermore, the determined limit of detection and limit of quantification were 0.008 and 0.025 mg/kg, respectively. The field persistence of both insecticides was longer, and below quantification limit was achieved within 30 and 40 days for chlorantraniliprole and 35 and 40 days for thiamethoxam. Residue degradation followed first-order kinetics, with longer half-lives of 5.08 and 5.28 days for chlorantraniliprole and 3.50 and 3.96 days for thiamethoxam at single (x) and double (2×) doses, respectively. For both insecticides, the hazard index (HI), calculated based on the highest residue on the day of insecticide treatment in the field study, was less than 1 at x and 2× doses, indicating an acceptable level of risk. Seasoning or quick frying of curry leaves in oil reduced maximum of thiamethoxam and chlorantraniliprole residues followed by treatment with NaCl (2%)/tamarind water (2%)/lemon water (2%) solutions. Analysis of 85 farm-gate samples revealed detectable residues of thiamethoxam in 25 samples (0.03–0.49 mg kg−1) and chlorantraniliprole in 1 sample (0.18 mg kg−1). The HI for the maximum quantity of insecticide residues detected in monitoring study was <1. Therefore, the research backs the idea of ensuring safe harvested produce, considering the field persistence of chlorantraniliprole and thiamethoxam in curry leaf and simple decontamination methods to satisfy consumer need for clean food commodity, if properly adopted.

Role of nitrogen and silver compounds in photocatalytic properties of carbon nanoparticle

To develop the photocatalytic method of water decontamination in an industrial scale, the structure of the photocatalyst should be modified in order to work under visible light irradiation. This paper is a report on a comparison of the efficiency of the photocatalytic activity of carbon, carbon nitride (CN) and carbon-silver (CAg) nanostructures for the degradation of Methylthioninium chloride in water. Carbon nanoparticles were synthesized by pulsed laser ablation (PLA) of a graphite target in distilled water. To synthesize CN nanocomposite, carbon nanoparticles were placed in normal pressure nitrogen-filled oven at 700 °C for 5 h. And to synthesize the CAg nanocomposite, bulk silver was ablated in the carbon nanoparticles solution by pulsed laser. Degradation was examined in dark condition and under the UV and visible light irradiations. Results show that the efficiency of photocatalytic activity of carbon dots as an abundant nanomaterial was increased, by their modification through atomic substitution (carbon nitride) and alloying (carbon-silver). Results show that the chemical properties of CN made this nanocomposite have the best performance among the 3 nanomaterials in dark and UV irradiated conditions, while the plasmonic absorption of silver nanoparticles made this material to have the best photocatalytic performance under visible light irradiation.

Potential of bacteriophage phT4A as a biocontrol agent against Escherichia coli in food matrices

Escherichia coli is one of the most prevalent foodborne pathogens, frequently found in meat and dairy products. Current decontamination methods are often associated with changes in organoleptic characteristics, nutrient loss, and potentially harmful side effects. Furthermore, despite the array of available methods, foodborne outbreaks still frequently occur. For this reason, bacteriophages (or simply phages) emerged as a natural alternative for the biocontrol of bacterial contamination in food without altering their organoleptic properties. In this study, the potential of phage phT4A was assessed in the biocontrol of E. coli in liquid (milk) and solid (ham) food matrices. Firstly, as foods have different pH and temperature values, the influence of these parameters on phage phT4A viability was also assessed to develop an effective protocol. Phage phT4A proved to be stable for long storage periods at pH 7–8 (56 days) and temperatures of 4–37 °C (21 days). Before application of phages to inactivate pathogenic bacteria in food, previous assays were carried out in Tryptic Soy Broth (TSB) to study the dynamics of phage-bacteria interaction. Then, the antibacterial potential of phage phT4A was evaluated in the two food matrices at different temperatures (4, 10 and 25 °C). This phage was more efficient at 25 °C in all tested matrices (maximum inactivation of 6.6, 3.9 and 1.8 log CFU/mL in TSB, milk and ham, respectively) than at 10 °C (maximum decrease of 4.7, 2.1 and 1.0 log CFU/mL in TSB, milk and ham, respectively) and 4 °C (maximum reduction of 2.6 and 0.7 log CFU/mL in TSB and milk, respectively). However, the decrease of temperature from 25 °C to 10 and 4 °C prevented bacterial regrowth. The results suggest that during phage treatment, a balance between an incubation temperature that provide effective results in terms of bacterial inactivation by the phages and at the same time prevents or delays bacterial regrowth, is needed. The application of phage phT4A at a temperature of 10 °C can be an effective strategy in terms of bacterial inactivation, delaying bacterial regrowth and also reducing energy costs.

Environmental Implications of Energy Sources: A Review on Technologies for Cleaning Oil-Contaminated Ecosystems

This review analyzes the main methods for cleaning up oil pollution in natural ecosystems, with a particular focus on the synergy between chemical and microbiological techniques for environmental remediation. While biological methods are a green and inexpensive soil remediation technique, they have a major limitation in their inability to clean up high concentrations of toxic contaminants. The poor performance of chemical methods stems from the high cost of chemicals and concerns over their negative and toxic effects on the environment. Physical methods also have high costs due to energy consumption and the need for additional treatment of gases generated during decontamination, making them ineffective for soil remediation. The main principle of bioremediation is based on microorganisms’ ability to degrade complex organic compounds, such as petroleum. This process is described in this review. This combination of methods allows for a higher level of decontamination of soil and water ecosystems, even against pollutants that are usually resistant to degradation, such as oil derivatives. While existing methods for cleaning oil-contaminated ecosystems are highly effective, they require significant material costs to implement. Additionally, the review discusses how the joint use of current and future biotechnology techniques can lead to the development of an effective set of strategies to protect soil and water systems from oil pollution. The reviewed studies show that a hybrid biotechnological approach is the most effective remediation method. When biological decontamination methods are adopted, the optimized combination of different remediation strategies can overcome the limitations of each technique, allowing efficiencies of even more than 70% to be achieved, given that the choice still depends on the type of contaminant, its concentration, and the properties of the receiving substrate.