Natural Decontamination Research Articles

In-vitro Antimicrobial Study of Non/irradiated Ylang-ylang Essential Oil Against Multi Drug Resistant Pathogens with Reference to Microscopic Morphological Alterations

Essential oils have proven to possess great potential in the field of biomedicine due to their ability to effectively eradicate a diverse range of pathogenic microbes. In this study, the antimicrobial activity of ylang-ylang essential oil (YY-EO) was screened against twelve multidrug-resistant pathogens. The YY-EO was effective up to 536 μg/ml, with the highest inhibition zone in case of S. aureus MMCC21 and Escherichia coli MMCC24. The least effect on both Bacillus cereus MMCC11 and Klebsiella pneumonia MMCC16. The major components of the essential oil were identified using GC–MS analysis. Different gamma irradiation doses against the YY-EO were evaluated as a tool of natural decontamination. Moreover, the antimicrobial assay after irradiation proved no significant changes regarding the antimicrobial activity before and after irradiation of EO at the applied dose. The minimum inhibitory concentration (MIC) for the EO against the tested pathogens was detected. The possible morphological changes in some of the bacterial and yeast cells at the recognized MIC and 2MIC were detected using the scanning electron microscope (SEM). Results revealed a notable change in terms of both the microbial cell population and the morphology of the tested bacterial and yeast cells. The cytotoxicity of ylang-ylang EO was evaluated against normal skin tissue culture and showed a potential cytotoxic effect at concentrated doses. These results refer to the importance of YY-EO as a natural antimicrobial agent and the possible application of YY-EO as a surface decontaminant, but they also draw attention to the importance of the EO concentration used in different applications to avoid possible toxic effects.

Potential of Essential Oils in the Control of Listeria monocytogenes.

Listeria monocytogenes is a foodborne pathogen, the causative agent of listeriosis. Infections typically occur through consumption of foods, such as meats, fisheries, milk, vegetables, and fruits. Today, chemical preservatives are used in foods; however, due to their effects on human health, attention is increasingly turning to natural decontamination practices. One option is the application of essential oils (EOs) with antibacterial features, since EOs are considered by many authorities as being safe. In this review, we aimed to summarize the results of recent research focusing on EOs with antilisterial activity. We review different methods via which the antilisterial effect and the antimicrobial mode of action of EOs or their compounds can be investigated. In the second part of the review, results of those studies from the last 10 years are summarized, in which EOs with antilisterial effects were applied in and on different food matrices. This section only included those studies in which EOs or their pure compounds were tested alone, without combining them with any additional physical or chemical procedure or additive. Tests were performed at different temperatures and, in certain cases, by applying different coating materials. Although certain coatings can enhance the antilisterial effect of an EO, the most effective way is to mix the EO into the food matrix. In conclusion, the application of EOs is justified in the food industry as food preservatives and could help to eliminate this zoonotic bacterium from the food chain.

NEW COMPOSITE MATERIALS AND PROCESSES FOR CHEMICAL, PHYSICO-CHEMICAL AND BIOCHEMICAL TECHNOLOGIES OF WATER PURIFICATION

In traditional methods of water purification, the use of chemical reagents leads to the appearance of toxic by-products and wastes that require complex energy-consumption processing technologies. In accordance with the principles of sustainable development and “green” technologies, a significant revision of existing water treatment methods is required. The review highlights the main trends of innovative development of water purification and disinfection technologies. Modifications of water treatment agents (flocculants, sorbents, membranes) by integration of nanoparticles, environmentally compatible materials and “smart” composites into traditional structures are described. The use of composite nanoparticles is promising, particularly the use of particles with the “magnetic core – shell” structure, in which functional elements are attached to the surface, that provide the selective capture of contaminants, including pathogenic microorganisms. The existence of the magnetic core makes it possible to manipulate particles by the applied magnetic field, which is important for their complete extraction from the water upon completion of their functions. The use of new composite flocculants containing inorganic and organic components capable of ensuring highly effective capture of contaminants from the water, significantly reduces the volumes of flocculants and generated sludges and therefore allows to reduce the cost of the sludges processing and the harm of their disposal in the environment. New carbon nanostructures and natural polymers have an important role to play. In the new generation membranes, the disperse nanoparticles may provide antibacterial and photocatalytic properties, resulting in the high efficiency of disinfection and purification. A novel trend is the development of hybrid structures of coagulants and membranes with the properties which are regulated by the external stimulus, which are temperature, pH, light, electric, magnetic and electromagnetic fields. The use of such «smart» structures will increase the purification efficiency, reduce energy consumption and water purification waste volumes, due to the decrease in membranes fouling. The use of biopolymers and composites based on plant raw materials for the water purification is attractive due to their natural decontamination under the influence of the components of the environment, such as air, soil micro-organisms and sunlight, but also due to the absence of the secondary pollution. Among innovative chemical water treatment technologies Advanced Oxidation Processes play an important role, in particular, by involving electromagnetic fields and ultrasonic activation. By these methods, harmful organic impurities and pathogens are destroyed without the intensive use of chemicals or the production of toxic by-products. The integration of biochemical wastewater treatment with a microalgae growing system can become a promising waste-free, cost-effective "green" technology.

Comparative Evaluation of the Capacity of Commercial and Autochthonous Saccharomyces cerevisiae Strains to Remove Ochratoxin A from Natural and Synthetic Grape Juices.

In this paper, we assessed the ability of two strains of Saccharomyces cerevisiae, in viable and dead forms, to remove ochratoxin A (OTA) from an artificially contaminated synthetic grape juice medium (SGM) (10 µg OTA/L) and a naturally contaminated grape juice (6.64 µg OTA/L). The first strain, named Levulin FB, is a commercial yeast used in making wine. The second, named SC5, is an autochthonous strain isolated from table grapes. OTA concentrations in juices before and after their contact with yeast cells were assessed. A significant decrease in OTA level (p < 0.05) in the SGM medium and in the natural grape juice was observed after 1 h of adding yeast cells (20 g/L) in viable and heat-treated forms. It was inferred that the dead forms of the two strains were more able to eliminate OTA than their viable forms in both media. This study demonstrates the potential application of an autochthonous yeast for the natural decontamination of grape juice from fungal toxins.

ISOLATION AND CHARACTERIZATION OF MARINE BACTERIA FOR CRUDE OIL DEGRADATION

Environmental spoilage of petroleum hydrocarbons handling is essential to safe our resources and health. The amount of natural crude oil seepage was estimated to be 600,000 metric tons per 2 year with a range of uncertainty of 200,000 metric tons per year. Oil spilled in water tends to spread and form a slick. From the findings wind and wave action, oil-in-water or water-in-oil emulsions may form. So the present study was carried out to isolate and characterize crude oil degrading microbes from crude oil contaminated marine water samples collected from Ennore, Tamil Nadu, India. The gravimetric analysis of degradation shows that two isolates, CDB1 and CDB2 among 5 isolates found to be potential for degradation of crude oil. The effective CDB1 and CDB2 isolates were further characterized morphological, physiological and Biochemical properties. The maximum crude oil degradation of 71.9% was achieved using CDB2 with 1% crude oil after 7 days of reaction. It is concluded that that the CDB2 isolate Such a bacterial species may be useful for preventing natural decontamination process.

Diagnosis of Fungi Associated with Wounds from Lying Patients at Al-Hussein Teaching Hospital in Dhi Qar Governorate

About 30 samples were collected from burn areas from patients attending Al-Hussein TeachingHospital in Dhi Qar governorate for the period between 2-4 for the year 2020. 7 types of fungi andyeasts, represented by the following fungi, have been isolated candida kruzei, candida tropicalis, andRhizopus, candida albican, candida glabrata, Aspirgillus spp, rhodotorella. The results showed thatAspergillus spp. Was dominant over the rest of the fungi, with a rate of 36.36% over the rest of the fungispecies, while candida albican yeast appeared with a frequency of 28.18% compared to the rest of theother fungi, and the rate of appearance of other fungi was about 12-3% compared to the rest of the otherfungi. The fungi were distinguished by the fact that they are all of the opportunistic type, which beginsto infect the body when there is a weakening of immunity or infection with the associated burns andulcers.

Evaluation of the Effect of the Activity of Gum Arabic Aqueous Solution and Ozonated Water on the Chemical and Organoleptic Properties of Locally Produced Soft Cheese in Baghdad City

Evaluated the effects of Gum Arabic (GA) combined with ozonated water (OW) at refrigeration (4oC)storage temperature on the chemical and organoleptic properties of bovine locally produced Cowsand buffalos’, Fifty Soft cheese (25 for each kinds ) were collected from homemade local producersin the different regions of Abu-Ghraib villages/Baghdad city. Soft cheese samples were analyzed forMoisture percentage %, Total solids, pH levels, Protein, Fat as dry matters and ash contents before andafter immersion in mixture decontamination solution of (GA) at concentration of (3% and 5%) withozonated water (0.5) ppm during (30) minutes of exposure time at refrigeration (4oC) temperature. Theresults showed that the moisture, fat as dry matter and ash content increased, while total solids (TS) andprotein decrease after subjecting to natural decontamination solution. pH value was non significantlyaffected by the washing treatment. In conclusion evaluation of sensory properties showed that localcows soft cheese demonstrates higher values for sensory parameter compared to local buffalo’s softcheese.

PCB mass budget in a perialpine lake undergoing natural decontamination in a context of global change

Despite the fact that PCB contamination of the global environment has been extensively studied in the last decades, the fate of these compounds in freshwater ecosystems is not fully understood and an important knowledge gap remains regarding the understanding of PCB dynamics and fate in perialpine lakes. This study relied on both field sampling performed and modeling to accurately identify the main fluxes involved in the PCB dynamics into the French perialpine Lake Bourget from 2013 to 2017. Our results show that the main inputs responsible for the PCB loading of the water column are tributaries inflows (~90%) rather than atmospheric inputs which could be related to the high catchment area over lake surface area ratio (i.e., 13). The main mechanism responsible for the lake natural decontamination was sediment burial (76%) due to the effect of the biological pump coupled with a high sedimentation rate. Volatilization represented 19% of the loss of PCBs from the water column and was mainly controlled by the high PCB concentration in water. These mechanisms are susceptible to be affected by the impact of the global change (increase of temperature, modification of the primary production rate) in the near future.

Antimicrobial action of octanoic acid against Escherichia coli O157:H7 during washing of baby spinach and grape tomatoes.

We investigated the antimicrobial efficacy of octanoic acid (OA) against Escherichia coli O157:H7 inoculated on the surface of baby spinach and grape tomatoes during simulated washing processes. 3 mM OA at 45 °C achieved >6 log CFU/g reduction from the surface of tomatoes within 2 min. However, washing baby spinach with 6 mM OA at 5 °C resulted in <1 log CFU/g reduction, highlighting the role of surface properties in inactivation efficacy. OA significantly (p < 0.05) reduced the risk of cross-contamination during washing of spinach as well as tomatoes. Also, total mold and yeast population on surface of spinach was significantly reduced immediately after OA wash and inhibited during following 14 days. Baby spinach and grape tomatoes washed with OA did not cause significant (p > 0.05) difference in color compared to the control and no residual OA was detected in most cases following rinsing of produce in water. OA at the concentrations above 2 mM and temperature higher than 25 °C induced severe membrane damage along with release of ATP and other intracellular constituents resulting in bacterial death. OA can be an attractive natural decontamination agent for washing fresh produce.

Distribution and speciation of iodine in drinking waters from geochemically different areas of Bryansk region contaminated after the Chernobyl accident in relation to health and remediation aspects

Chemical composition of drinking water from different sources was studied in private farms distributed in areas of the Bryansk region contaminated by radionuclides after the Chernobyl accident. Concentration of major ions showed clear relation to water-bearing rocks and local anthropogenic contamination (e.g. N, P). Drinking water was in general impoverished in I (Ме=5.76μg/l that is below the lower limit of sanitary standard equal to 10μg/l). Thermodynamic modeling based on chemical composition of the samples showed that the predominant form of iodine is iodide and it forms mineral complexes CaI+, CaI2, MgI+, MgI2, etc. that explains iodine concentration on carbonate barrier in soils and rocks. Complexes' formation may have contributed to radioiodine retention in water during its fallout with further natural decontamination of aqueous phase during water filtration through soils and sediments enriched in carbonates and organic matter. Comparison with distribution of thyroid cancer cases among rural population revealed a tendency of the inverse relation between the number of cases and iodine content in dug well waters; the finding needs further investigation.

Decontamination of E scherichia coli O157:H7 and S taphylococcus aureus from Fresh-Cut Parsley with Natural Plant Hydrosols

The inhibitory effects of sage, rosemary, oregano and thyme hydrosols were evaluated against Escherichia coli O157:H7 and Staphylococcus aureus inoculated on parsley at high and low concentrations. Following the pathogen inoculations, parsley samples were washed with the hydrosols and sterile tap water as a control for 0, 20, 40 and 60 min, and reductions on pathogen counts were determined. Sterile tap water was ineffective on all conditions tested. After 20 min of application, oregano and thyme hydrosols were able to significantly (P < 0.05) reduce E. coli O157:H7 counts on low inoculum level, while all hydrosols showed significant reductions (P < 0.05) on high inoculum levels at this period. Additional reductions on E. coli O157:H7 counts were observed with the increasing time. S. aureus was more sensitive to hydrosol treatments, and oregano hydrosol was able to completely eliminate S. aureus after 40 min. In conclusion, decontamination of foodborne pathogens from fresh-cut vegetables can be achieved by hydrosol treatments. Practical Applications Recent trends in consumer perceptions have led to increased consumption of ready to eat food products and fresh fruits and vegetables. Leafy vegetables such as parsley are one of the most important ingredients of freshly consumed food products including salads. The main concern on leafy vegetables is their high contamination risk with pathogenic microorganisms including Escherichia coli O157:H7 and Staphylococcus aureus and new strategies based on natural preservatives to control these pathogens on leafy vegetables are of particular interest. Plant hydrosols originated from Lamiaceae family which have antimicrobial effects can be important sources of natural preservatives against certain pathogens. Similarly their simple and cheap production method and their safe recognition for human consumption increase their potential usage as natural decontamination agents. In this study the antimicrobial activities of sage, rosemary, oregano and thyme hydrosols against E.coli O157:H7 and S. aureus on parsley samples were evaluated and their efficiencies were determined.

Movement of radiocaesium fallout released by the 2011 Fukushima nuclear accident

The moment magnitude (Mw) 9.0 Tohoku-Oki Earthquake occurred on March 11, 2011, generating an unusually large tsunami. The seismic shocks and tsunami inundation severely damaged the Fukushima Daiichi Nuclear Power Plant. Radionuclide emission due to reactor breakdown contaminated wide areas of Fukushima and its surroundings. Heavy rainfall causes runoff across surface soil, and fine soil particles are susceptible to uptake by the flowing water. The high radioactivity of grains suspended in floodwater indicates that radioactive fallout was streamed into rivers in particulate form and transported downstream under high-flow conditions. Here, we investigated the diachronic mode of 134Cs and 137Cs in central Fukushima, through which the contaminated air mass drifted and caused wet deposition of radionuclides. Stratigraphic measurements of radioactivity in sediment cores is the method employed in this study to determine the basin-wide movement of 134Cs and 137Cs, to evaluate the significance of the erosion–transportation–accumulation processes on natural decontamination in terrain characterized by steep slopes and high precipitation. Stratigraphic results illustrate the process of fluvial sediment discharge, and the massive deposition of radiocaesium suggests basin-wide movement of fallout during concentrated rainfall. Grain suspension in torrential currents is an important pathway for transportation of radionuclides from land to sea, and the appearance of hotspots on floodplains and the offshore sea floor is the consequence of erosion and transportation under seasonal heavy precipitation. Radioactive horizons occur in offshore sediment columns and thus radiocaesium discharged from the estuary will persist forever under the sea floor if no artificial disturbance occurs.

Modeling of the fate of radionuclides in urban sewer systems after contamination due to nuclear or radiological incidents

After an accidental radioactive contamination by aerosols in inhabited areas, the radiation exposure to man is determined by complex interactions between different factors such as dry or wet deposition, different types of ground surfaces, chemical properties of the radionuclides involved and building development as well as dependence on bomb construction e.g. design and geometry. At short-term, the first rainfall is an important way of natural decontamination: deposited radionuclides are washed off from surfaces and in urban areas the resulting contaminated runoff enters the sewer system and is collected in a sewage plant. Up to now the potential exposure caused by this process has received little attention and is estimated here with simulation models. The commercial rainfall-runoff model for urban sewer systems KANAL++ has been extended to include transport of radionuclides from surfaces through the drainage to various discharge facilities. The flow from surfaces is modeled by unit hydrographs, which produce boundary conditions for a system of 1d coupled flow and transport equations in a tube system. Initial conditions are provided by a map of surface contamination which is produced by geo-statistical interpolation of γ-dose rate measurements taking into account the detector environment. The corresponding methodology is implemented in the Inhabited Area Monitoring Module (IAMM) software module as part of the European decision system JRODOS. A hypothetical scenario is considered where a Radiation Dispersal Device (RDD) with Cs-137 is detonated in a small inhabited area whose drainage system is realistically modeled. The transition of deposited radionuclides due to rainfall into the surface runoff is accounted for by different nuclide-specific entrainment coefficients for paved and unpaved surfaces. The concentration of Cs-137 in water is calculated at the nodes of the drainage system and at the sewage treatment plant. The external exposure to staff of the treatment plant is estimated. For Cs-137 radiation levels in the plant are low since wash-off of cesium from surfaces is an ineffective process.

Isolation and Identification of hydrocarbon degrading bacteria from Ennore creek.

The widespread problem caused due to petroleum products, is their discharge and accidental spillage in marine environment proving to be hazardous to the surroundings as well as life forms. Thus remediation of these hydrocarbons by natural decontamination process is of utmost importance. Bioremediation is a non-invasive and cost effective technique for the clean-up of these petroleum hydrocarbons. In this study we have investigated the ability of microorganisms present in the sediment sample to degrade these hydrocarbons, crude oil in particular, so that contaminated soils and water can be treated using microbes. Sediments samples were collected once in a month for a period of twelve months from area surrounding Ennore creek and screened for hydrocarbon degrading bacteria. Of the 113 crude oil degrading isolates 15 isolates were selected and cultivated in BH media with 1% crude oil as a sole carbon and energy source. 3 efficient crude oil bacterial isolates Bacillus subtilis I1, Pseudomonas aeruginosa I5 and Pseudomonas putida I8 were identified both biochemically and phylogenetically. The quantitative analysis of biodegradation is carried out gravimetrically and highest degradation rate, 55% was recorded by Pseudomonas aeruginosa I5 isolate.

Natural decontamination of water of large rivers of Russian north from global 90Sr

Regional differences in the 90Sr transfer from catchment areas to rivers of the European Russian North and Eastern Siberia and in the rates of natural water clearance were revealed. The annual 90Sr transfer was 0.5–0.6 and 0.2–0.3%, respectively, of the total inventory in the catchment area. The half-times T of natural decontamination of Onega, Northern Dvina, Pechora, Lena, and Indigirka from global 90Sr are estimated at 15.0, 15.4, 13.9, 10.0, and 7.5 years, respectively.

Retrospective estimation of the contamination of Lake Onega with global 90Sr and of natural decontamination of its water

The dynamics of the concentration of global 90Sr in Lake Onega water for a 40-year period was reconstructed. The natural decontamination of Lake Onega water was characterized by a decrease in the 90Sr content with the half-clearance time T = 16.5 years. By the end of formation of the major part of cumulative 90Sr inventory in the lake ecosystem (1965), the 90Sr inventories in water and bottom media were in 1: 1.2 ratio. By that time, only 55% of the 90Sr ingress passed from the lake water to bottom sediments. The water exchange in the lake occurred two times faster than the 90Sr clearance. Decelerated natural decontamination of the lake water from 90Sr was attributed to buffer properties of the system catchment area-deep lake-river drainage. The annual removal of 90Sr from the lake with water of the Svir River was partially compensated by the 90Sr supply to the lake from the catchment areas of rivers flowing into the lake. The cumulative inventory of global 90Sr in the volume of Lake Onega water during the period from 1964 to 2005 decreased by a factor of ∼5, from 10 to 1.9 TBq.

Aeromonas veronii, a tributyltin (TBT)-degrading bacterium isolated from an estuarine environment, Ria de Aveiro in Portugal

Organotin compounds are used in a variety of industrial processes therefore their subsequent discharge into the environment is widespread. Bacteria play an important role in biogeochemical transformations acting as natural decontamination agents. Therefore, screening for tributyltin (TBT)-resistant and -degrading bacteria is relevant for the selection of isolates with decontamination ability of these polluted areas. With this purpose, 50 strains were isolated from sediment and water from Ria de Aveiro and their tolerance to TBT, up to 3mM, was evaluated. Generally, occurrence of highly TBT-resistant bacteria was observed, and Gram negative bacteria exhibited more tolerance to TBT than Gram positive bacteria. A memory response was observed when bacteria were progressively exposed to increasingly higher TBT concentrations. One isolate, Aeromonas veronii Av27, highly resistant to TBT (3mM) uses this compound as carbon source and degrades it to less toxic compounds.

Leaching of nickel and copper from soil contaminated by metallurgical dust

The paper presents the results of the laboratory percolation experiment simulated soil contamination by emissions from a Ni–Cu smelter. Humus (Ao horizon) columns were transferred to lysimeters from an illuvial, humic, ferriferous forest podzol site. Fine metallurgical dust containing Ni and Cu was layered on the columns and irrigated with sulphuric acid solutions at pH 3, 4, 5, and 6. Irrigation for 19 months indicated that the leaching of metals down the humus column was greatest at pH 6. Calculations indicated that it would take 160–270 years for complete leaching of Ni from the Ao layer, and 100–200 years for Cu, depending on the dust composition. Natural decontamination of affected soils will take centuries.

Lessons from Minamata mercury pollution, Japan - after a continuous 22 years of observation

One of the most visible tragedies by industrial water pollution is Minamata disease, methylmercury poisoning caused by eating contaminated fish, which has killed more than 100 people and paralyzed several thousand people around Minamata Bay, Japan and the adjacent Yatsushiro Sea since 1956. The cause of Minamata disease was confirmed, not by analyzing environmental samples such as sediments (containing more than 600 ppm of Hg) or fish (at least 20 ppm) at the bay, but by symptoms of Minamata disease patients that resembled previous mercury poisoning reported in a European medical journal. Mercury dispersion was traced for 22 years to collect mercury concentration measurements in Yatsushiro Sea surface sediments at 24 fixed stations. The analytical results of mercury revealed four trends of mercury movement from the bay: 1) a rapid increase in Hg concentrations up to 1984; 2) a dramatic decrease in mercury concentrations after an artificial mercury decontamination project began in 1984; 3) a strange drop in mercury contents due to an historical rainfall in the region in 1982 and; 4) natural decontamination, which has been underway since 1985. The tragedy at Minamata has provided many lessons which have shaped the scientific field in environmental research, especially in the area of water quality.

Lessons from Minamata mercury pollution, Japan — After a continuous 22 years of observation

One of the most visible tragedies by industrial water pollution is Minamata disease, methylmercury poisoning caused by eating contaminated fish, which has killed more than 100 people and paralyzed several thousand people around Minamata Bay, Japan and the adjacent Yatsushiro Sea since 1956. The cause of Minamata disease was confirmed, not by analyzing environmental samples such as sediments (containing more than 600 ppm of Hg) or fish (at least 20 ppm) at the bay, but by symptoms of Minamata disease patients that resembled previous mercury poisoning reported in a European medical journal. Mercury dispersion was traced for 22 years to collect mercury concentration measurements in Yatsushiro Sea surface sediments at 24 fixed stations. The analytical results of mercury revealed four trends of mercury movement from the bay: 1) a rapid increase in Hg concentrations up to 1984; 2) a dramatic decrease in mercury concentrations after an artificial mercury decontamination project began in 1984; 3) a strange drop in mercury contents due to an historical rainfall in the region in 1982 and; 4) natural decontamination, which has been underway since 1985. The tragedy at Minamata has provided many lessons which have shaped the scientific field in environmental research, especially in the area of water quality.