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The humic-like substances were the main organic components in most wastewater (e.g. domestic sewage, toilet wastewater and landfill leachate). Two types of actual humic-like substances (fulvic acid (FA) and biologically treated landfill leachate (BTLL)) were selected to describe the changes in the properties of humic-like substances (complexation ability, aromaticity and mobility) during electrochemical oxidation. Meanwhile, the acute cytotoxicity of FA and BTLL was also tested by acute toxicological test of luminescent bacteria. The results showed that the consumption of coordinating groups such as phenolic groups and hydrogen bonds reduced the complexation ability of FA and BTLL. The functional groups were degraded with the removal order of quinone group, phenolic group and aromatic group, and finally realized the molecular saturation and aromaticity decrease for humic-like substances. The mobility of FA and BTLL was decreased because of the enhancement of hydrophobicity during electrolysis process. Furthermore, the available chlorine produced during electrochemical oxidation was the main acute cytotoxicity substance, therefore, it is necessary to remove it before discharge in order to reduce ecological risks. This study provides a basis for understanding and evaluating the electrochemical degradation process of humic-like substances in detail.

Organic ligands are commonly believed to decrease the toxicity of metal ions, but there is few experimental evidence, especially for chromium (Cr(III)), which often coexists with organic compounds in industrial effluents. Here, the complexation of Cr(III) with acetate, lactate, l-tartrate, biphthalate and oxalate was tested under the conditions of a toxicity test, with high ion strength, by spectroscopic techniques. The stability constants of the complexes were found to follow the order Cr(III) oxalate > Cr(III) lactate > Cr(III) biphthalate > Cr(III) L-tartrate > Cr(III) acetate. Then, aquatic toxicity of Cr(III) to Photobacterium phosphoreum for a 15-min exposure period was tested in the absence and presence of organic ligands. Results unexpectedly show that the complexation of Cr(III) with acetic, lactate, l-tartrate and biphthalate resulted in enhanced toxicity to luminescent bacteria, whereas the coordination of Cr(III) with oxalate sharply alleviated the toxicity of individual oxalate and inorganic Cr(III), which was further confirmed by the scanning electron microscopy (SEM). Our findings show thus that organics do not always mitigate the toxicity of Cr(III) in acidic water.

This study investigated the degradation of benzophenone-4 (BP-4) in a UV/chlorine disinfection process, with chlorination and UV disinfection as comparisons. With a degradation efficiency of 80% after 10 s, the UV/chlorine process significantly enhanced the degradation of BP-4. However, a rebound of 36% of the initial concentration was observed in the UV/chlorine process ([free active chlorine (FAC)]0:[BP-4]0 = 1:1, pH = 7). The same tendency appeared under the addition of alkalinity, Cl−, and humic acid (HA). This work interpreted this interesting kinetic tendency from the perspective of mechanism. In fact, the transformation between the chlorinated product P1 and BP-4 was reversible under certain conditions. The inhomogeneous charge distribution of the C Cl bond in P1 led to the photolytic dechlorination of P1. This transformation caused an increase in BP-4 concentration. In addition, the increase in the UV light power promoted the photodecomposition of P1 under the experimental condition. In addition, this study evaluated the change in absorbable organic halogens (AOX) and three kinds of toxicity changes in the BP-4 solution after chlorination and the UV/chlorine process, including the acute toxicity of luminescent bacteria, endocrine disrupting effect and cytotoxicity. The UV/chlorine process exhibited lower ecotoxicity than chlorination in water treatment.

Previous studies demonstrated long-term stimulation of some commercial personal care products (PCPs) on freshwater luminescent bacteria Vibrio qinghaiensis sp .-Q67 (Q67). However, whether a certain component can affect mixture's hormetic effect is still unknown. In this paper, two of ingredients in PCPs, 2-phenoxyethanol (PhE) and polyethylene glycol 400 (PEG400), were selected as object compounds to explore the relationship between concentration-response (CR) of mixtures and that of a single component. It was found that PEG400 has monotonic CR (MCR) on Q67 both at the short-term (0.25 h) and long-term (12 h) exposures while PhE has MCR at 0.25 h and hormetic CR (HCR) at 12 h. Here, the concentration-response curves (CRCs) of PEG400 at 0.25 and 12 h are overlapped each other and the CRCs of PEG400 are on the right of PhE. If the pEC 50 is taken as a toxic index, the toxicities of PEG400 at two times are basically the same, and those of PhE are the same, too, but PhE is twice as toxic as PEG400. For the mixtures of PEG400 and PhE, all rays except R1 have MCRs at 0.25 h while all rays have HCRs at 12 h where the higher the mixture ratio of PhE is, the more negative the maximum stimulation effect is. More importantly, the E min values of all rays are more negative (1.79–3.17-fold) than that of PhE worked alone, which implies that the introduction of PEG400 significantly enhances stimulative effect of PhE. At 0.25 h, all binary mixture rays but R1 produce a low-concentration additive action and high-concentration synergism. At 12 h, all rays display additive action, antagonism, additive action, and synergism in turn when the concentration changes from low to high. The overall findings suggested toxicological interactions should be considered in the risk assessment of PCPs and their potential impacts on ecological balances.

Diclofenac was frequently found in various waters, indicating conventional wastewater treatment methods ineffective in its removal. In this study, LaFeO3 (LFO) was synthesized and its catalytic activity of LFO as the activator of different oxidants such as persulfate (PS), hydrogen peroxide and peroxylmonosulfate (PMS) was evaluated in terms of DCF degradation. The influence of calcination temperature was examined on the catalytic activity of LFO. The effects of various parameters including pH levels, PMS concentration, LFO dose and initial DCF concentration were investigated on DCF degradation rate. The marginal effects of PMS concentration and LFO dose were compared. Langmuir-Hinshelwood (LH) model was used to quantitatively describe DCF degradation reaction in LFO/PMS system. The two constants, k (Limiting reaction rate at maximum coverage) and K (Equilibrium adsorption constant), were determined on the basis of LH model. The performance of LFO/PMS process was also estimated in the presence of various inorganic anions. The potential toxicity of LFO and PMS were evaluated using phytoplankton and the toxicity evolution during DCF degradation was also investigated using luminescent bacteria. This contribution provides a basic study regarding the potential application of heterogeneous PMS activation by perovskite LFO for both DCF removal and toxicity elimination.

It has been proven that the raw wastewater, secondary effluent and even reclaimed water may have toxic effects on aquatic organisms. In the present study, fractionation procedures combined with bioassays using luminescent bacteria were conducted to identify the fractions that contributed to the acute and long-term toxicity of municipal wastewater. Solid phase extraction was used to divide dissolved organic matter from the wastewater into three fractions, including non-polar, medium-polar and polar fraction. Among these fractions, although the acute toxicity of municipal wastewater was mainly caused by polar and medium-polar chemicals, the acute toxicity induced by the unit mass of the medium-polar fraction was the greatest. Using three kinds of resins, the organic substances in municipal wastewater were classified into six fractions, and the long-term toxicity of these fractions was further identified. The long-term toxicity of the hydrophobic neutrals, which were the primary toxic substances in raw wastewater, decreased after the conventional secondary biological treatment. Hydrophilic neutrals, which accounted for the majority of organic substances in the secondary effluent, were the main substances with long-term toxicity in the secondary effluent. The identification of fractions with acute and long-term toxicity in municipal wastewater is beneficial for further treatment to attenuate the ecotoxicity of wastewater before discharge into the aquatic environment.

Luminescent bacteria can emit visible light at 450–490 nm, and its luminous intensity decreases with the increase of the concentration of toxic substances in test solution. The method using luminescent bacteria is widely used in acute toxicity analysis of water quality because it is a simple, rapid and low-cost way. In recent years, biosensors based on luminescent bacteria have attracted more and more attention, and the reports of bioluminescence biosensors based on microfluidic systems are increasing day by day. Based on the characteristics and mechanism of luminescent bacteria, this paper introduces their applications in the environmental monitoring, and summarizes several new bioluminescence sensors.

The development of a sensitive and reliable method for the detection of bioaccumulated heavy metal toxins is highly desirable for biotoxicity evaluation. However, the conventional biotoxicity evaluation method based on luminescent bacteria suffers from only being able to detect the overall toxicity without selectivity in light-off detection mode. Although various synthetic fluorescent probes have been developed for the selective detection of heavy metal ions, they usually suffer from aggregation-caused quenching after local accumulation in biological systems. To tackle these challenges, we herein develop a dual detection strategy for bioaccumulated Hg2+ based on turn-off of the bioluminescence of P. phosphoreum bacteria by disrupting the quorum sensing system and turn-on of the photoluminescence of an aggregation-induced emission (AIE) probe by forming aggregates with Hg2+ inside the bacteria. It is expected that the dual detection strategy would find broad applications in the evaluation of bioaccumulated toxins.

Background A European inter-laboratory test with 29 participating laboratories investigated whether a battery of four ecotoxicological tests is suitable for assessing the environmental compatibility of construction products. For this purpose, a construction product was investigated with the dynamic surface leaching test (DIN CEN/TS 16637-2) and the percolation test (DIN CEN/TS 16637-3). The eluates were produced centrally by one laboratory and were tested by the participants using the following biotests: algae test (ISO 8692), acute daphnia test (ISO 6341), luminescent bacteria test (DIN EN ISO 11348), and fish egg test (DIN EN ISO 15088). As toxicity measures, EC50 and LID values were calculated. Results Toxic effects of the eluates were detected by all four biotests. The bacteria test was by far the most sensitive, followed by the algae test and the daphnia test; the fish egg test was the least sensitive for eluates of both leaching tests. The toxicity level of the eluates was very high in the bacteria, daphnia, and algae test, with lowest ineffective dilution values of LID = 70 to LID = 13,000 and corresponding EC50 values around or even below 1 volume percent. The reproducibility (approximated by interlaboratory variability) of the biotests was good ( Conclusion It can be confirmed that the combination of leaching and ecotoxicity tests is suitable to characterize with sufficient reproducibility the environmental impact posed by the release of hazardous substances from construction products.

Fifteen native luminescent bacteria were isolated from the Gulf of Thailand, and their sensitivity for the detection of toxicity of crude oil and its aromatic components was investigated. Of these isolates, Vibrio campbellii strain FS5 was one of the two most highly inhibited bacteria at all crude oil concentrations. This bacterium showed a decrease in luminescence intensity of between 10.7 and 80.2% after a 15-min exposure to 0.0001–10 mg/L of crude oil. The degree of bioluminescence inhibition increased with increasing concentrations of crude oil. The presence of crude oil at all concentrations had negative effects on the log bioluminescence per log number of viable cells after 15- to 105-min exposure. About 10 to 100 times, lower half maximal effective concentration (EC50) values were observed for polycyclic aromatic hydrocarbons (PAHs) than those for benzene, toluene, ethylbenzene, and xylene (BTEX). In the presence of each individual BTEX and PAH, the bioluminescence inhibition increased with increasing exposure time (1–32 h). This indigenous bacterium can be used as a simple and general indicator of oil contamination and its impact on coastal waters as well as for assessing potential toxicity during oil bioremediation.

Bioluminescence is the primary source of light by a natural chemical reaction by living organisms thereby emitting visible light. The creation of sustainable light sources which exert less light pollution is increasingly important as illuminating our night times with electrical power is resulting in long term stress on our ecosystem. Bioluminescence emits cold light means it generates less than 20% thermal radiation or heat. These bacteria can be used to produce Biolight, a living lighting system which requires no electricity, whilst producing minimal amount of pollution and CO2 emission. This light provides a non-polluting environmentally friendly source of illumination which is cost effective and since the bacteria used are non-toxic, non-pathogenic, they are harmless as well. These bacterially driven lights can be used in street lights, guiding lights to expel darkness in public places, nighttime’s edge indicators for road and highways, step light for cinemas, theatres and even atmospheric lightning for therapy. This study aimed at developing a novel strategy to produce electricity free Biolight powered by living luminescent bacteria, isolated from marine source and the gene responsible for bioluminescence was targeted.

In many countries’ wastes are considered as a source of raw material, and thus, should be re-used as much as possible. In the European Union, 15 different criteria have been defined for this purpose and one of them, called HP14, addresses the question of whether a specific waste could cause ecotoxicological effects. This criterion is usually addressed by chemical characterization of the waste, which focuses on the concentration of (mainly) heavy metals. Ecotoxicological testing is another possible and broader approach using a test battery consisting of three aquatic (i.e., luminescent bacteria, algae, water fleas) and three soil (Arthrobacter bacteria, higher plants, earthworms) tests. Experiences are available for different solid wastes such as incineration ash, waste wood or potentially contaminated soils, and the corresponding eluates. In this contribution, an overview of the current legislative requirements and examples from testing (e.g., waste wood, contaminated soils, incineration ash), as well as a proposal for a testing strategy were presented. In summary, regular ecotoxicological waste testing is recommended in North Africa and other Mediterranean countries.

Introduction: The light-emitting enzyme complex of luminescent bacteria is a powerful biochemical tool, with a wide variety of applications includ-ing environmental quality monitoring. Objectives: To identify taxonomically two luminescent bacteria from Cuban shelf waters, as well as select the culture media that favor their growth and luminescence. Methods: The taxonomic location of the luminescent bacteria was carried out using traditional and molecular methods. Four culture media (LM, Boss, Chalk, ZoBell) were evaluated as a function of specific growth rate (μ) and lumines-cence, using a Genesys 10UV spectrophotometer and a Shimadzu RF-5301pc spectrofluorometer, respectively.Results: Biochemical and physiological characterization of CBM-976 and CBM-992 isolates showed similari-ties with Vibrio harveyi species. Phylogenetic positioning analysis confirmed a high correspondence with V. harveyi strains isolated from aquatic environments, using partial sequences of 16S rRNA, gyrB and pyrH genes. LM and ZoBell culture media were selected for having a high specific growth rate of CBM-976 and CBM-992 strains, as well as for showing high luminescence values. The results will allow deepening the physiological characterization and are the starting point for the development of contaminant detection methods. Conclusions: The rational combination of physiological and biochemical characteristics, as well as the molecular approach, contributed to determine the taxonomic position of CBM-976 and CBM-992 strains isolated from Cuban marine waters as Vibrio harveyi. Furthermore, LM and ZoBell culture media were selected as the most suitable for growth and luminescence emission for both strains. Introducción: El complejo de enzimas emisoras de luz de bacterias luminiscentes es una poderosa herramienta bioquímica, con una amplia variedad de aplicaciones, incluido el monitoreo de la calidad ambiental. Objetivos: Identificar taxonómicamente dos bacterias luminiscentes de la plataforma de aguas cubanas, así como seleccionar los medios de cultivo que favorezcan su crecimiento y luminiscencia. Métodos: La localización taxonómica de las bacterias luminiscentes se realizó mediante métodos tradicionales y moleculares. Se evaluaron cuatro medios de cultivo (LM, Boss, Chalk, ZoBell) en función de la tasa de crecimiento específico (μ) y luminiscencia, utilizando un espectrofotómetro Genesys 10UV y un espectrofluorómetro Shimadzu RF-5301pc, respectivamente. Resultados: Caracterización bioquímica y fisiológica de los aislados de CBM-976 y CBM-992 mostraron similitudes con las especies de Vibrio harveyi. El análisis de posicionamiento filogenético confirmó una alta correspondencia con las cepas de V. harveyi aisladas de ambientes acuáticos, utilizando secuencias parciales de los genes 16S rRNA, gyrB y pyrH. Los medios de cultivo LM y ZoBell se seleccionaron por tener una alta tasa de crecimiento específico de las cepas CBM-976 y CBM-992, así como por mostrar altos valores de luminiscencia. Los resultados permitirán profundizar en la caracterización fisiológica y son el punto de partida para el desarrollo de métodos de detección de contaminantes. Conclusiones: La combinación racional de características fisiológicas y bioquímicas, así como el enfoque molecular, contribuyeron a determinar la posición taxonómica de cepas CBM-976 y CBM-992 aisladas de aguas marinas cubanas como Vibrio harveyi. Además, los medios de cultivo LM y ZoBell se seleccionaron como los más adecuados para el crecimiento y la emisión de luminiscencia para ambas cepas. Universidad Nacional, Costa Rica Ministerio de Ciencia, Tecnología y Medio Ambiente, Cuba Universidad de La Habana, Cuba Escuela de Ciencias Biológicas

Due to their widespread use and harmful effects on aquatic environment, sulfonamide antibiotics (SAs) have become an emerging pollutant of great concern around the world. In this study, we investigated the degradation process and mechanism of sulfamerazine (SMR), sulfadiazine (SDZ), and sulfapyridine (SPD) by electron-beam irradiation (EBI). The results showed that the three SAs were well suited to the pseudo-first-order reaction kinetics, and they could be almost completely removed with high efficiency (5 kGy). Among the environmental factors, pH (3.0) and O2 atmosphere can further enhance the removal of the sulfonamides (SAs), while NO2− has the most pronounced degrading inhibitory effects among the many ions, these results illustrate that hydroxyl radicals play a dominant role. Compared with SMR and SDZ, the degree of mineralization of lower molecular weight SPD is obvious (45%). LC-MS and DFT calculations indicate that the concentrations of degradation products of the three SAs show a tendency to increase and then decrease, demonstrating that EBI can achieve efficient removal and further mineralization of SAs. Meanwhile, the results of the common product 4-Aminophenol produced during the degradation process further indicate that HO is the predominant reactive oxygen species (ROS). In addition, acute toxicity experiments with luminescent bacteria and predictions of ECOSAR procedures proved the toxic effects greatly decreased after the degradation. This study provides new ideas for achieving efficient and profound removal of emerging pollutants from the aquatic environment.

This study evaluated the acute effects of nine different production chemicals typically employed in oil exploration on the toxicity of a synthetic produced water (PW). Bioassays with the Microtox® System were performed to monitor changes in the level of light emission of the marine luminescent bacteria Vibrio fischeri during exposure to the samples. The results show that synthetic PW is moderately toxic to these organisms, and the addition of oilfield chemicals significantly increases its toxicity. For most of the additives tested, the toxicity of the aqueous phase following partitioning against crude oil was not strongly altered by the presence of these chemicals. Synergistic effects occurred in the three different mixtures investigated. Among the additives studied, biocide, corrosion inhibitor, H2S scavenger, and surfactant were the most toxic for V. fischeri. Furthermore, the surfactant has been identified as the possible source of the acute toxicity observed.

In this paper, the releasing characteristics and biological toxicity of Tl, Hg, As and Sb in waste of Lanmuchang mercury-thallium mine were studied. The results indicated that strong acidity can significantly promote the release of Tl from waste. With the increase of pH, the release of Sb grew steadily, while Hg and As showed a trend of first increasing and then decreasing. Fe2(SO4)3 contributed less to the release of As and Sb than to that of Hg and Tl. FeCl3 significantly inhibited the release of As, Sb and Tl. In the leaching experiments of litter and root exudates, the lixiviums appeared neutral, and the litter and root exudates solution significantly reduced the release of Tl, and showed less toxicity to luminescent bacteria. However, they promoted the release of Hg, As and Sb at different levels.

Protecting the quality of lake watersheds by preventing and reducing their contamination is an effective approach to ensure the sustainability of the drinking water supply. In this study, acute toxicity assessment was conducted on the basis of acute bioluminescence inhibition assay using the marine bacterium Vibrio fischeri as the test organism and Luoma Lake drinking water source in East China as the research target. The suitable ranges of environmental factors, including pH value, organic matter, turbidity, hardness, and dissolved oxygen of water samples were evaluated for the toxicity testing of bioluminescent bacteria. The physicochemical characteristics of water samples at the selected 43 sites of Luoma Lake watershed were measured. Results showed that the variations in pH value (7.31–8.41), hardness (5–20 °d) and dissolved oxygen (4.44–11.03 mg/L) of Luoma Lake and its main inflow and outflow rivers had negligible impacts on the acute toxicity testing of V. fischeri. The luminescence inhibition rates ranged from −11.21% to 10.80% at the 43 sites. Pearson’s correlation analysis in the experiment revealed that temperature, pH value, hardness, and turbidity had no correlation with luminescence inhibition rate, whereas dissolved oxygen showed a weak statistically positive correlation with a Pearson correlation coefficient of 0.455 (p < 0.05).

Toxicity monitoring of harmful radiation is an indispensable issue in modern radioecology. As bioluminescent bacteria have the simplest structure to epitomize the biosphere, their bioluminescence can also act as an indicator of the conditions, therefore assay systems based on luminous bacteria can be used to monitor environmental radiotoxicity. The present investigation explored the measurement of bacterial luminescence, which can be easily computed. Bioluminescent bacterial strains were used to evaluate the effect of ultraviolet (UV) and gamma irradiation. A random amplified polymorphic DNA (RAPD) assay was carried out to observe alterations under exposure. Using a phylogenetic tree, a comparative study of the effect of UV and gamma rays was carried out. The isolated strains showed marked sensitivity towards radiation exposure present in the environment and therefore they could be used as potential biosensing elements for developing an on-site pollution monitoring biosensor.

Although luminescent bacteria-based bioluminescence inhibition assay has been widely used in the toxicity assessment of environmental pollutants, the response of a luminescent bacterium usually lacks specificity to a target analyte. Recently, some specific analyte inductive promoters were fused to the lux genes for the purpose of selective bioluminescent sensing, and suits of specific promoters were fused to lux genes to compose a bioluminescent array sensor for simultaneous identification of multiple analytes. However, specific promoter-based methods still suffer from drawbacks including limited selectivity, slow responding time, expensive to construct different promoters involved plasmids, and laborious to find new promoters. Herein, we proposed a novel strategy to construct a lux reporter array sensor by directly transforming the natural lux genes in different bacterial hosts without the involvement of any specific promoters. Due to the distinct pathways of signal production, the responding time of the current different bacterial host (DBH)-based lux reporter array has nearly an order of magnitude faster than with specific promoter-based methods. The DBH-based lux reporter array was successfully used for simultaneous identification, quantification, and toxicity/bioactivity assessment of multiple metal ions. Obviously, all the chemical synthetic material-based metal ion sensing methods cannot simultaneously achieve analysis and toxicity evaluation. This approach possessed additional advantages of facile construction, easy operation, high selectivity, fast response, and strong adaptability to other analytes. A different bacterial host-based lux reporter array was established for simultaneous analysis and toxicity assessment of multiple metal ions.

Trans-resveratrol becomes more and more popular all over the world as a powerful antioxidant. Since its positive properties, including antioxidant, anti-inflammatory, anti-tumor are indisputable, nowadays trans-resveratrol is used as a component of various products from nutriceutics to body care formulations, where it is supposed to behave as natural antioxidant and anti-aging compound. It is also added to food packaging materials to increase their stability or/and prevent oxidation. Nevertheless, being released to the environment resveratrol easily forms various transformation products with potentially negative environmental and health effects. The present paper deals with transformation of pure resveratrol and its formulation used as UV-protectors in conditions of aquatic chlorination. Over 80 transformation products were tentatively identified using gas chromatography-high resolution mass spectrometry (GC-HRMS) and ultra pressure liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). Chlorinated phenols and biphenyls are the most relevant among them. Estimation of toxicity of resveratrol products was carried out using luminescent bacteria V. fischeri tests.

Doxazosin (DOX), a selective alpha blocker, is widely used in medical therapy as an effective antihypertensive agent. It is a frequently prescribed drug and for this reason, environmental and ecotoxicological research is of great importance in terms of exposure and risk for both aquatic species and humans. In this study we focused on photolytic and TiO2 photocatalytic degradation processes of doxazosin under different simulated conditions, with the emphasis on identification of degradation products. Photolytic (without TiO2) experiments were performed in the presence and absence of oxygen, while photocatalytic degradation of doxazosin aqueous solution has been carried out under constant oxygen flow. DOX degradation was more efficient in the TiO2/UVA photocatalytic experiment than during photolytic processes (UVA and UVC, UVC-N2). LC-HRMS analyses with electrospray ionization allowed observing the formation of several major degradation products depending on the reaction conditions (presence or absence of oxygen, photocatalysis). The transformation products were identified based on exact mass measurements, isotopic distribution, and fragmentation pattern. Among them, dominated C17H21N5O3 and C17H23N5O4 (cleavage of the dioxane cycle), and C23H25N5O7 (hydroxylation). The detailed degradation pathway has been proposed. Toxicity testing with V. fischeri luminescent bacteria revealed higher toxicity of samples in photolytic rather than photocatalytic experiments which might be attributed to the formation of different products.

Developments in industrial applications inevitably accelerate the discharge of enormous substances into the environment, whereas multi-component mixtures commonly cause joint toxicity which is distinct from the simple sum of independent effect. Thus, ecotoxicological assessment, by luminescent bioassays has recently brought increasing attention to overcome the environmental risks. Based on the above viewpoint, this review included a brief introduction to the occurrence and characteristics of toxic bioassay based on the luminescent bacteria. In order to assess the environmental risk of mixtures, a series of models for the prediction of the joint effect of multi-component mixtures have been summarized and discussed in-depth. Among them, Quantitative Structure-Activity Relationship (QSAR) method which was widely applied in silico has been described in detail. Furthermore, the reported potential mechanisms of joint toxicity on the luminescent bacteria were also overviewed, including the Trojan-horse type mechanism, funnel hypothesis, and fishing hypothesis. The future perspectives toward the development and application of toxicity assessment based on luminescent bacteria were proposed.

In this study, a biosensor is designed to remove mercury as a toxic metal contaminant from the soil. The rhamnolipid biosurfactant was used to extract the mercury sorbed to soil to the aqueous phase. An immobilized bioluminescent bacterium (Escherichia coli MC106) with pmerRBPmerlux plasmid is assisted for mercury detection. A significant decrease in luminescence level was observed in a biosensor system containing contaminated soil sample extract. The concentrations of extracting mercury are well correlated with the mercury toxicity data obtained from experimental biosensor systems according to the RBL value. The optimum aeration rate of 20 ml/min was obtained for the biosensor systems. The advantage of such a biosensor is the in situ quantification of mercury as a heavy metal contaminant in soils. Therefore, this system could be proposed as a good biosensor-based alternative for future detection of heavy toxic metals in soils.

The production of biodegradable plastics is considered to be a way to reduce plastic waste issue. Among others, oxo-degradant additives enable a faster degradation of plastics in the environment. However, the introduction of these new materials could provoke the release of substances potentially toxic in the environment. This work determined and compared the toxicity of leachates from various additivated polymers (polyethylene, PE; polypropylene, PP; polystyrene, PS) upon different test organisms: plants (Sorghum saccharatum, Lepidium sativum, Sinapis alba, and Vicia faba), crustacean (Daphnia magna), and luminescent bacteria (Vibrio fischeri). Daphnia magna survival was mainly affected by PS and PP leachates (72% and 61% effect, respectively) while PS notably reduced the reproduction rate. On plants, only PP exerted a negative effect (S. saccharatum IG% 32.4), while V. fischeri always showed values around 50%. The data integration, through the Toxicity Test Battery Integrated Index (TBI) approach, allowed to rank the leachates toxicity as PE > PS > PP. This result could be mainly ascribable to the highest metals content in PE since no difference with organic compounds analysis was evidenced. In conclusion, since the polymers exerted dissimilar toxicity, the additive could not be considered the sole responsible of the measured toxicity, but its role in the enhancement of the virgin polymers leachates effects can be solidly hypothesized.

Проблематика. Сучасною проблемою є визначення особливостей характеристик різних мікроорганізмів для біоіндикації активності стану геофізичних параметрів середовища.Мета. Виявлення кореляційних залежностей між значеннями інтенсивності світіння бактерій Photobacterium phosphoreum та факторами, що визначають геомагнітну активність.Методика реалізації. Визначались оптимальні параметри суспензії для досліджень інтенсивності біолюмінісценції як біоіндикатора стану геомагнітного поля. Протягом 2 місяців проводили моніторинг питомої інтенсивності світіння бактерій і порівнювали її зі щоденними значеннями активності геомагнітного поля в умовах м. Києва в години проведення досліджень біолюмінесценції. Визначення варіацій геомагнітного поля проводилось за даними Центру прогнозу космічної погоди Національного управління океанічних і атмосферних досліджень США. Опис сонячної активності проводили для “чисел Вольфа” та потоку сонячного радіовипромінювання на довжині хвилі 10,7 см.Результати. Було розраховано коефіцієнти кореляції змін щоденних значень інтенсивності біолюмінесценції бактерій та порівняно їх зі значенням К-індексу та Ар-індексу, “чисел Вольфа” і потоку сонячного радіовипромінювання. Визначено обернено пропорційний достовірний середній кореляційний зв’язок R = -0,41 між значеннями питомої бактеріальної люмінесценції та К-індексами геомагнітного поля, а зі значеннями потоку сонячного радіовипромінювання встановлено достовірний прямо пропорційний зв’язок. Показано, що при збільшенні інтенсивності варіацій геомагнітного поля відбувається зменшення значень питомої інтенсивності біолюмінесценції бактерій.Висновки. Показано наявність достовірної оберненої залежності між К-індексами геомагнітного поля та питомою інтенсивністю люмінесценції P. рhosphoreum, коефіцієнт кореляції у місяці з підвищеною геомагнітною активністю дорівнював R = -0,51. Використання автоматизованої системи моніторингу інтенсивності світіння люмінесцентних бактерій дає можливість краще прогнозувати в часі наявність збурень магнітного поля Землі., Background. An actual problem is determination of features of different micro-organisms for the activity bioindication of environment geophysical parameter state.Objective. The aim of the paper is to determine correlation dependences between values of luminescence intensity of bacteria Photobacterium phosphoreum and factors determining geomagnetic activity.Methods. The optimum parameters of suspension were determined for research of bioluminescence intensity as a bioindicator of the geomagnetic field state. The monitoring of specific intensity of bacteria luminescence has been carried out for 2 months and it was compared to the daily values of activity of the geomagnetic field in the conditions of Kiev, during the research of bioluminescence. Vari­ation determination of the geomagnetic field was conducted from data of Space Environment Center, NOAA & U.S. Air Force. Description of sun activity was conducted with the use of the "Wolf numbers" and flux of sun radio radiation at a wavelength 10,7 сm.Results. The correlation coefficients of changes of bacteria bioluminescence intensity daily values were calculated and compared to the K-index and Ap-index values, "Wolf numbers", and flux of sun radio radiation. The inverse proportional reliable average correlation was defined R = -0,41 between the values of specific bacterial luminescence and the K-indexes of the geomagnetical field, and with the values of flux of sun radio radiation – reliable directly proportional correlation. It is shown, that at the geomagnetic field variation intensity increase there is reduction of values of bacteria bioluminescence specific intensity.Conclusions. The presence of reliable inverse dependence between K-indexes of geomagnetic field is shown and specific intensity of the P. rhosphoreum luminescence, the correlation coefficient in months with increased geomagnetic activity was R = -0,51. The use of the automated system of the luminescent bacteria luminescence intensity monitoring allows better forecasting in time the manifestations of indignations of the Earth’s magnetic field., Проблематика. Современной проблемой является определение особенностей характеристик разных микроорганизмов для биоиндикации активности состояния геофизических параметров среды.Цель. Определение корреляционных зависимостей между значениями интенсивности свечения бактерий Photobacterium phosphoreum и факторами, определяющими геомагнитную активность.Методика реализации. Определяли оптимальные параметры суспензии для исследований интенсивности биолюминесценции в качестве биоиндикатора состояния геомагнитного поля. На протяжении 2 месяцев проводили мониторинг удельной интенсивности свечения бактерий и сравнивали ее с ежедневными значениями активности геомагнитного поля в условиях г. Киева во время проведения исследований биолюминесценции. Определения вариаций геомагнитного поля проводились по данным Центра прогноза космической погоды Национального управления океанических и атмосферных исследований США. Описание солнечной активности проводили для “чисел Вольфа” и потока солнечного радиоизлучения на длине волны 10,7 см.Результаты. Были рассчитаны коэффициенты корреляции изменений ежедневных значений интенсивности биолюминесценции бактерий и сравнены со значениями К-индекса и Ар-индекса, “чисел Вольфа” и потока солнечного радиоизлучения. Определена обратно пропорциональная достоверная средняя корреляционная связь R = -0,41 между значениями удельной бактериальной люминесценции и К-индексами геомагнитного поля, а со значениями потока солнечного радиоизлучения установлена достоверная прямо пропорциональная связь. Показано, что при увеличении интенсивности вариаций геомагнитного поля происходит уменьшение значений удельной интенсивности биолюминесценции бактерий.Выводы. Показано наличие достоверной обратной зависимости между К-индексами геомагнитного поля и удельной интенсивностью люминесценции P. рhosphoreum, коэффициент корреляции в месяцы с повышенной геомагнитной активностью равнялся R = -0,51. Использование автоматизированной системы мониторинга интенсивности свечения люминесцентных бактерий позволяет лучше прогнозировать во времени проявления возмущений магнитного поля Земли.

The aim of the study was ecological risk assessment (ERA) of the agricultural soils located in the vicinity of the highly industrialized area and exposed to different emission sources of polycyclic aromatic hydrocarbons (PAHs). In this study, we demonstrated the combination of generic and site-specific ERA approach for screening assessment and delineation of the area of a high ecological risk. Generic approach was based on a hazard quotient and indicated that 62% of the research area needs further assessment. For site-specific evaluation, the Triad approach was utilized. Information from three lines of evidence (LoE): chemical, ecotoxicological and ecological, was integrated into one environmental risk (EnvRI) index. The chemical risk was derived from toxic pressure coefficients based on the total PAHs concentration. The ecotoxicological LoE included an acute toxicity testing: the luminescent bacteria Aliivibrio fischeri activity in both liquid- and solid-phase samples and the ability of crustacean Thamnocephalus platyurus to food uptake. The ecological LoE comprised microbial parameters related to soil respiration and enzymatic activity. Integrated EnvRI index ranged from 0.44 to 0.94 and was mainly influenced by high values of chemical LoE risk, while the ecotoxicological and ecological LoE indicated no or low risk. Due to the relatively high uncertainty associated with the contradictory information given by LoEs, there is the need to confirm potential risk in a tier 2 analysis.

Fish carpaccio is a ready-to-eat product with a very limited shelf life. In the present work, the use of high pressure treatment (HP) and/or antimicrobial edible film was studied in order to improve quality and stability of salmon carpaccio. In a preliminary part of the work, a film composed of gelatin plus chitosan incorporating clove essential oil was selected, based on its physicochemical and antimicrobial properties. Eugenol and β-caryophyllene, the main volatile components of the film, migrated to salmon muscle, the release being favored by HP and storage time. Concurrently, reducing power of the muscle increased, resulting in prevention of lipid oxidation derived from either HP or refrigerated storage. HP treatment reduced total microbial counts by 1.5 log cycles from the onset of storage, whereas the film reduced it by 2 log cycles after 3 days. The combination of HP and edible film exerted the most intense antimicrobial effect, total bacterial counts, luminescent bacteria, HS-producing organisms, pseudomonads, enterobacteria, and lactic acid bacteria remaining constant or under detection limit over the whole storage period (11 days). The combined use of HP treatment and gelatin–chitosan–clove essential oil film is an effective way of improving quality and stability of salmon carpaccio., This research was financed by the Spanish Ministry of Economy and Competitiveness (projects I3-200670l141, AGL2014-52825-R). Author López de Lacey was funded by the JAE-CSIC predoc program and Gómez-Estaca by the “Juan de la Cierva” program.

It has been stated by researchers that the antibiotic polymyxin B sulfate (POL) is a key component inducing time-dependent antagonism in freshwater luminescent bacteria, Vibrio qinghaiensis sp.-Q67, exposed in the ternary mixture system of the ionic liquids, pesticide and antibiotics. However, the previous statement is limited to ternary and quaternary mixtures without considering situations such as the binary system. In order to prove the direct inducing of antagonism by POL in a more complete and systematic way, two categories of experiments (adding POL in non-antagonistic ternary system and decomposing antagonistic ternary system with POL into the binary system) have been conducted in this paper. The results showed that quaternary mixture systems (adding POL to non-antagonism ternary mixture, up verification) exhibit antagonistic action in a majority of rays, at some point in the experiment. However, by decomposing the antagonistic ternary mixtures with POL into binary mixtures (down verification), the combined toxicities of binary mixtures at all time points in the experiment are additive. Obviously, the POL has a significant contribution to antagonism only in the ternary and quaternary mixtures, but not in the binary mixtures. We can draw a new conclusion that the antagonism of the multi-component mixtures is induced by at least three components (including POL), with complex chemical interactions. Therefore, considering POL's influence of antagonism as an example, future environmental protection practitioners and academic researchers should construct more scenarios of mixtures when assessing the influences and reactions of certain chemicals causing pollutions.

In this study, the applicability of UV absorbance at 254 nm (UV254) and volatile fatty acids (VFAs) to serve as reliable surrogates to predict acute toxicity of traditional Chinese medicine (TCM) wastewater was investigated. The medicine residues and VFAs were identified as main components of the TCM wastewater, and their individual and joint toxicity assays were operated with luminescent bacteria. The median effective concentration (EC50) values of medicine residues and VFAs were in the range of 26.46-165.55 mg/L and 11.45-20.58 g/L, respectively. The joint toxicity action modes of medicine residues, VFAs and medicine residues-VFAs were identified as additive, additive and synergistic respectively. UV254 and VFAs showed better correlations with acute toxicity according to the correlation analysis, compared with other conventional parameters. The regression model was a good fit for toxic unit (TU50) as a function of UV254 and VFAs according to the stepwise regression method (adjusted R2 = 0.836). Validation of the model to the pilot-scale samples provided satisfactory prediction results in the influent and hydrolysis acidification effluent samples tests, but for EGSB effluent and final effluent samples, the model needed further optimization. Surrogates prediction using UV254 and VFAs provided a valuable and cost-saving tool for rapid or on-line monitoring of acute toxicity of TCM wastewater.

Metal-organic frameworks (MOFs) are new porous materials that attract wide attention due to their environmentally-friendly photocatalytic characteristics. However, poor charge separation in most MOFs largely limits their photocatalytic activity. In this study, a novel Fe-based bi-MOFs heterojunctions material, namely NH2-MIL-88B(Fe)@MIL-100(Fe) was prepared by internal extended growth of MIL-100(Fe) on spindle-like NH2-MIL-88B(Fe). Compared with pure NH2-MIL-88B(Fe) and MIL-100(Fe), the synthesized Fe-based bi-MOFs structure catalyst displayed excellent photocatalytic degradation of tetracycline (TC), with optimal removal of 99.9% achieved in 90 min under neutral conditions. This result is attributed to the sufficient visible light absorption, and the enhanced separation and transfer of h+ and e− by the bi-MOFs structure. In particular, ∙O2−, h+ and ∙OH showed synergistic effects in the photodegradation process, and Fe-based bi-MOFs displayed high stability after five cycles. The inhibition ratio of luminescent bacteria of the degraded solution was lower than 24%, indicating the high efficiency and safety of this Fe-based bi-MOFs for the treatment of antibiotic-contaminated water.

There is a need for rapid simple and informative environmental assessment methods. The present investigation is aimed at assessing the possibility of using the combined enzyme system of luminescent bacteria: NAD(P)H:FMN-oxidoreductase + luciferase (Red + Luc) for predicting the potential toxicity of industrial urbostratozems sampled in the city of Krasnoyarsk. Three groups of urbostratozems polluted with fluorine, arsenic and lead, were tested by the methods of chemical analysis and enzymatic bioassay. Only the assessment of the arsenic-contaminated soil samples showed the dependence between the reduced activity of the enzyme system and the arsenic concentration variations. The results reveal that the sensitivity of the Red + Luc enzyme system to the soil pollutants depends on the properties of the studied soil samples. Moreover, the solubility of lead in the soil samples affects the accuracy of the enzymatic bioassays for soil toxicity testing. The results of the enzymatic bioassay of the fluoride-contaminated soil samples are ambiguous. The obtained data show the relevance of the sample preparation during integral bioassays. In addition, soil properties should be taken into account as well. The current study emphasizes the importance of conducting chemical and biological testing as a combined set to obtain comprehensive information about the anthropogenic load.

Advanced oxidation processes (AOPs) have been widely applied for the advanced treatment of recalcitrant wastewater. However, the toxicity changes during AOPs are still unclear because in some cases the intermediate products could exhibit equivalent or even higher toxicity compared with the original pollutants. Therefore it is necessary to evaluate the toxicity evolution during AOPs. This review mainly focused on the toxicity changes of wastewater during various AOPs treatment, including Fenton/Fenton-like oxidation, ozonation/catalytic ozonation, persulfate radical-based oxidation, photocatalytic oxidation, ionizing radiation, electro-catalytic oxidation, ultrasound oxidation and wet oxidation. Firstly, the toxicity assessment methods were summarized, including acute toxicity (such as luminescent bacteria assay, fish assay, water flea assay and algae assay), genetic toxicity (Ames assay, SOS/umu assay, comet assay and micronucleus assay), estrogenic activity, immunity toxicity, and endocrine disrupting effect (such as yeast two-hybrid assay and fish endocrine disrupting assay), the applications of these methods in determining the toxicity changes of wastewater during AOPs treatment were summarized and analyzed in detail. Secondly, the toxicity prediction by computational simulation was introduced, mainly focusing on two common software, including TEST and ECOSAR. Thirdly, the strategies for eliminating the toxicity of wastewater after AOPs treatment were proposed. Finally, the concluding remarks and perspectives were presented for further study. This review will deepen to understand the toxicity evolution of wastewater during AOPs.

Additional control indexes should be considered for the operation and design of post-treatment systems, as the wastewater treatment objectives are developing toward protecting the safety of ecological environments. In this study, two control indexes were selected and examined systematically in pilot-scale shallow open-water unit (SOWU) ponds for domestic effluent polishing: micropollutants and biotoxicities. The total risk quotient (RQTotal ≤ 1) and effect-based trigger value (EBT) were set as the thresholds for known micropollutants and biological effects, respectively. The results showed that RQTotal of micropollutants (n = 46) could be mitigated to an acceptable level and the luminescent bacteria toxicity was in compliance with the EBT after SOWU polishing in the warm season. The reduction of micropollutants and biotoxicities in the SOWUs both fit the k–C* model well (R2 > 0.9) in the warm and cold seasons. Finally, the k–C* model integrated with the control indexes was developed to design the SOWU dimensions, and the results indicated that a pond area of 21.7–108.5 m2 was required for every 1 m3/d of effluent when micropollutants were set as the control index, while a pond area of 3.6–18.2 m2 was required when luminescent bacteria toxicity was set as the control index.

The evaluation of the ecotoxicological effects of water pollutants is performed by using different aquatic organisms. The effects of seven compounds belonging to a class of widespread contaminants, the benzo-fused nitrogen heterocycles, on a group of simple organisms employed in reference ISO tests on water quality (unicellular algae and luminescent bacteria) have been assessed to ascertain their suitability in revealing different contamination levels in the water, wastewater, and sediments samples. Representative compounds of benzotriazoles, benzothiazoles, and benzenesulfonamides, were tested at a concentration ranging from 0.01 to 100 mg L−1. In particular, our work was focused on the long-term effects, for which little information is up to now available. Species-specific sensitivity for any whole family of pollutants was not observed. On average, the strongest growth rate inhibition values were expressed by the freshwater Raphidocelis subcapitata and the marine Phaeodactylum tricornutum algae. R. subcapitata was the only organism for which growth was affected by most of the compounds at the lowest concentrations. The tests on the bioluminescent bacterium Vibrio fisheri gave completely different results, further underlining the need for an appropriate selection of the best biosensors to be employed in biotoxicological studies.

Highlights • UV-A irradiated epoxy coatings led to decreased ecotoxicological effects. • UV-A irradiated epoxy coatings released toxic transformation products. • 4-tert-Butylphenol was identified as main driver for ecotoxicological effects. • BPA and structural analogs contribute to estrogenic effects of irradiated materials., Organic coatings can guarantee long-term protection of steel structures due to causing a physical barrier against water and oxygen. Because of their mechanical properties and resistances to heat and chemicals, epoxy resin-based coatings are widely used for corrosion protection. Despite of the aromatic backbone and the resulting susceptibility to UV degradation, epoxy resins are frequently used as binding agent in top layers of anti-corrosion coating systems. Consequently, these organic polymers are directly exposed to sunlight and thus UV radiation. The present study was designed to investigate if toxic effects of epoxy resin-based-coatings are changed by UV-A irradiation. For this purpose, two epoxide-based top coatings were examined with and without UV aging for their bacterial toxicity and estrogenicity. In addition, chemical analyses were performed to identify released compounds as well as photolytic degradation products and to assign toxic effects to individual substances. UV-A irradiation of epoxy resin based top coatings resulted in an overall decrease of acute and specific ecotoxicological effects but as well to the formation of toxic transformation products. Both, in leachates of untreated and UV-A irradiated coatings, 4tBP was identified as the main driver of estrogenicity and toxicity to luminescent bacteria. BPA and structural analogs contributing to estrogenic effects in leachates were formed by UV-A irradiation. The combination of HPTLC coupled bioassays and LC-MS analyses supported the identification of bioactive compounds in terms of an effect-directed analysis. The present findings indicate that epoxide-based coatings are less suitable for the application as top coatings and more UV stable coatings like aliphatic polyurethanes should be preferred., Graphical abstract Image, graphical abstract

In the last decades, there has been an increasing concern about the human exposure to indoor dust. Therefore, it is imperative to assess the toxicity of indoor dust and associated dust extracts. In this study, the acute toxicity assessment of indoor dust was performed using a bioluminescence test, with Photobacterium phosphoreum T3 (PPT3) chosen as the test bacterium. The different indoor dust samples were collected from residences, offices, dormitories and laboratories in Shanghai, China. Our data reveal that PPT3 is more active to water-soluble ions and organic contaminants at low concentrations, while extract solutions elicit increased bacterial toxicity at high concentrations. The results of a bioluminescence assay by PPT3 indicated that the dust organic extracts exhibited increased toxicity compared with the water exacts. Dust extracts from the laboratory exhibited the greatest bacterial toxicity when compared with office, dormitory and residence samples. Moreover, office dust exhibited higher bacterial toxicity than residence dust. Furthermore, the comprehensive toxicity of dust on PPT3 was assessed by extracts toxicity -addition (i.e. IRaddition). The calculated values were close to the corresponding experimental data. The bioluminescence test showed the indoor dust samples are weakly toxic to PPT3, which are equivalent to 0.046–0.123 mg Hg•L−1. Different dust extracts among the different sampling sites showed varying toxicity to PPT3. This study provides some important information to understand the potential health risk from different indoor environment using a rapid bioluminescence assay.