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Light emitted by luminescent bacteria is sensitive to several toxic compounds; therefore, some luminous species have been used to evaluate the quality of water environments. In the present study we carried out the phenotypic characterization and molecular identification of a marine luminescent isolate (CBM-784) from the NW Cuban coast. The identification of the CBM-784 luminous isolate was based on phenotypic and genotypic characteristics. Phenotypically, the CBM-784 strain revealed the following characteristics: Gram negative, positive to oxidase and catalase reactions,bioluminescent, and facultative anaerobic respiration. The bacterial strain produces enzymes with gelatinase, lysine carboxylase and amylase activity. Taken together, these assays indicated that CBM-784 showed a high phenotypic similarity to the Vibrio harveyi ATCC 14126 strain. On the basis of 16S rRNA gene sequencing, CBM-784 was closely related to Vibrio harveyi and Vibrio rotiferianus (94% similarity). Sequence analysis of gyrB gene, has shown that CBM-784 shares taxonomic position with Vibrio campbellii and Vibrio harveyi isolates, with 95% of bootstrap value. In addition, sequence analysis of pyrH gene, grouped this isolate to the Vibrio harveyi cluster with a strong bootstrap support (99%). The multilocus sequence analysis and phenotypic characterization of CBM-784 indicated that this strain have a strong relation to Vibrio harveyi.

In effect-directed analysis (EDA) with high-performance thin-layer chromatography (HPTLC), the effect is often detected using images. Thus, an approach to create inhibition chromatograms from these images was developed using the example of the HPTLC- bioluminescence inhibition test. A comparison between the cuvette test and the HPTLC test shows that the test on the plate is significantly more sensitive. To describe the strength of the effect, the EC50 value is determined from the dose-response relationship. However, the inhibiting compounds are generally unknown and thus their concentrations are also unknown. Therefore, instead of the concentration, the known application volumes are used. This enables the calculation of the application volume necessary to achieve 50% inhibition. Since the volume is inversely proportional to the concentration, the reciprocal value of the calculated volume is indicated and is referred to as the reciprocal iso-inhibition volume (RIV). Using this RIV-concept, it is now possible to compare inhibition bands within and between plates. The entire evaluation is described by the means of two samples from a contaminated site using the bioluminescence inhibition.

Although magnetic ionic liquids (MILs) are not yet industrially applied, their continued development and eventual commercial use may lead to their appearance into the aquatic ecosystem through accidental spills or effluents, consequently promoting aquatic contaminations. Furthermore, the deficient information and uncertainty surrounding the environmental impact of MILs could be a major barrier to their widespread industrial application and international registration. Thus, in the present work, a range of cholinium salt derivatives with magnetic properties was synthesized and their ecotoxicity was evaluated towards the luminescent bacteria Vibrio fischeri. The results suggest that all MILs structures tested are moderately toxic, or even toxic, to the bacteria. Furthermore, their toxicity is highly dependent on the structural modifications of the cation, namely the alkyl side chain length and the number of hydroxyethyl groups, as well as the atomic number of the metal anion. Finally, from the magnetic anions evaluated, the [MnCl4]2- is the less toxic. In order to improve the knowledge for the prospective design of environmentally safer MILs, it is important to expand this study to other aquatic organisms at different trophic levels. published

Chlorination is essential to the safety of reclaimed water; however, this process leads to concern regarding the formation of disinfection byproducts (DBPs) and toxicity. This study reviewed the formation and control strategies for DBPs and toxicity in reclaimed water during chlorination. Both regulated and emerging DBPs have been frequently detected in reclaimed water during chlorination at a higher level than those in drinking water, indicating they pose a greater risk to humans. Luminescent bacteria and Daphnia magna acute toxicity, anti-estrogenic activity and cytotoxicity generally increased after chlorination because of the formation of DBPs. Genotoxicity by umu-test and estrogenic activity were decreased after chlorination because of destruction of toxic chemicals. During chlorination, water quality significantly impacted changes in toxicity. Ammonium tended to attenuate toxicity changes by reacting with chlorine to form chloramine, while bromide tended to aggravate toxicity changes by forming hypobromous acid. During pretreatment by ozonation and coagulation, disinfection byproduct formation potential (DBPFP) and toxicity formation potential (TFP) occasionally increase, which is accompanied by DOC removal; thus, the decrease of DOC was limited to indicate the decrease of DBPFP and TFP. It is more important to eliminate the key fraction of precursors such as hydrophobic acid and hydrophilic neutrals. During chlorination, toxicities can increase with the increasing chlorine dose and contact time. To control the excessive toxicity formation, a relatively low chlorine dose and short contact time were required. Quenching chlorine residual with reductive reagents also effectively abated the formation of toxic compounds.

The widespread use of organic ultraviolet (UV) filters in personal care products raises concerns about their potentially hazardous effects on human and ecosystem health. In this study, the toxicities of four commonly used benzophenones (BPs) UV filters including benzophenone (BP), 2-Hydroxybenzophenone (2HB), 2-Hydroxy-4-methoxybenzophenone (BP3), and 2-Hydroxy-4-methoxybenzophenone-5-sulfonicacid (BP4) in water were assayed in vitro using Vibrio fischeri, SOS/umu assay, and yeast estrogen screen (YES) assay, as well as in vivo using zebrafish larvae. The results showed that the luminescent bacteria toxicity, expressed as logEC50, increased with the lipophilicity (logKow) of BPs UV filters. Especially, since 2HB, BP3 and BP4 had different substituent groups, namely -OH, -OCH3 and -SO3H, respectively, these substituent functional groups had a major contribution to the lipophilicity and acute toxicity of these BPs. Similar tendency was observed for the genotoxicity, expressed as the value of induction ratio=1.5. Moreover, all the target BPs UV filters showed estrogenic activity, but no significant influences of lipophilicity on the estrogenicity were observed, with BP3 having the weakest estrogenic efficiency in vitro. Although BP3 displayed no noticeable adverse effects in any in vitro assays, multiple hormonal activities were observed in zebrafish larvae including estrogenicity, anti-estrogenicity and anti-androgenicity by regulating the expression of target genes. The results indicated potential hazardous effects of BPs UV filters and the importance of the combination of toxicological evaluation methods including in vitro and in vivo assays.

Phthalates has been widely used in children's toys as plastic plasticizers and softeners. The aim of this study was to extract chemically phthalates from 20 toy samples and determine toxicity using the Vibrio fischeri luminescent bacteria test. Subsequently the (the concentration producing 50% of maximal effect) was employed to characterize the toxicity of the sample and select the appropriate solvent from methanol, ethanol or glycerol in order to assess the adverse effects of di-n-butyl phthalate (DBP) or di-2-ethylhexyl phthalate (DEHP) and not solvent interference on Vibrio fischeri. Data showed that toxicity of glycerol was relatively low when the concentration was less than 0.44 mol/L. Therefore glycerol was selected as solvent. DBP and DEHP produced toxicity on Vibrio fischeri in the order of DEHP > DBP. The was 0.437 and 0.182 mol/L, respectively. This study provides the foundation for examination of combined toxic effects of the mixture of DBP and DEHP on Vibrio fischeri which is of signif...

Biological effects and ecotoxicity of NPs CeO2 with particle size Δ50 =16 nm and hydrobionts tolerance was measured in simulation based on test-reactions of a group of organisms representing major trophic levels of aquatic ecosystem. Biological activity of NPs CeO2 was noted against bacterial biosensor Ekolum, Сhlorella v. B.,Parameciumc., Daphniam. S. and Danior. Toxicity and hazard level of NPs CeO2 were measured using biotesting and hydrobionts. Toxicity of NPs CeO2 against luminescent bacteria Ekolum and Parameciumc. and Danior. was not established (L(E)С50 > 100 mg/l). In accordance with SGS and EC 93/67/EEC, NPs CeO2 is considered highly toxic (acute toxicity Level 1). Biomarkers and NPs CeO2 tolerant hydrobionts were determined. Range of tolerance of hydrobionts to NPs was established. The upper limit of tolerance was determined for certain hydrobionts by values of L(E)С50: 0.009 mg/l (by volume of Chl a) for Сhlorella v. B. and 46.15 mg/l (by mobility) for Daphniam. S.

Tungsten(VI) oxide, WO3, was studied and used as a heterogeneous catalyst for the liquid-phase oxidative abatement and solid-phase decontamination of simulants of chemical warfare agents, CWAs. The catalytic performance of WO3 was compared to the one of a soluble W-containing model catalyst, W(IV)-heptaisobutyl polyhedral oligomeric silsesquioxane, W-POSS. In liquid-phase abatement tests, WO3 promoted a complete degradation of the toxic agent simulant within 24 h, in the presence of aqueous hydrogen peroxide, at room temperature. In solid-phase decontamination tests, when WO3 was mixed with sodium perborate as a solid oxidant, it was also tested in the decontamination of a cotton textile support from organosulfide and organophosphonate agents (simulants of blistering and nerve CWAs, respectively), showing promising performances comparable to, or sometimes better than, a nanostructured TiO2 catalyst, taken as a reference material. The environmental impact of the WO3 catalyst was assessed on bioluminescent Photobacterium leiognathi Sh1 bacteria, over which no acute nor chronic detrimental effects were recorded. Then, when in contact with a vegetable species such as Phaseolus vulgaris L. (common bean), WO3 did not cause damage to the photosynthetic apparatus of the plant, whereas a clear inhibition of the seed germination was evidenced.

As the application of nanoparticles (NPs) and their release to the environment has increased, it is important to verify their toxicity, with a special emphasis on particle solubilization and the interaction of NP mixtures. In the current study, a model luminescent bacteria, Vibrio fischeri, was employed to test the acute toxicity of individual NPs and their binary mixtures, including metal NPs (ZnNPs, CuNPs) and metal oxide NPs (ZnONPs, CuONPs). The independent action model was used to reflect the synergistic, additive, or antagonistic interactions of binary mixtures of these NPs. The results showed that the median effective concentration (EC50) inhibited the luminescence of V. fischeri were 20.5, 4.1, 11.6, and 118.7 mg L−1 for ZnNPs, CuNPs, ZnONPs, and CuONPs, respectively, suggesting that the toxicity of these NPs to V. fischeri were as the following order: CuNPs > ZnONPs > ZnNPs > CuONPs. The combined effect of NPs were found to be antagonistic for CuNPs-ZnONPs and CuNPs-CuONPs, synergistic for CuONPs-ZnNPs, CuNPs-ZnNPs, and ZnONPs-CuONPs, and additive for ZnNPs-ZnONPs, revealing a complex pattern of possible interactions. The differences of dissolved metal ions partly accounted for the different combined toxicity of binary mixtures of NPs. The findings have important implications for better understanding the true environmental risk of NP mixtures.

Often ingredients of personal care products are present in treated wastewaters, e. g grey water (GW), and are discharged into aquatic systems. Conventional treatment of GW does not fully eliminate micropollutants such as the UV filter substance 2-phenylbenzimidazole-5-sulfonic acid (PBSA). Photolysis has been proposed as an alternative treatment method for other micropollutants, but it is not clear yet whether it can also be used to eliminate PBSA. One goal of this study was to better understand the basic pathways involved in this process. It aimed to identify photo-transformation products (PTPs) by using, in the test conditions, an initial concentration of PBSA higher than those expected in the environment. The photolysis experiments were carried out using Xenon and UV lamps. Under Xenon irradiation only slight primary elimination was found. UV irradiation resulted in almost complete primary elimination of PBSA but not in full mineralization. Four isomeric mono-hydroxylated PTPs were identified by high resolution mass spectrometry (HRMS) which could be confirmed by other studies. A modified luminescent bacteria test (LBT) with Vibrio fischeri was employed to assess acute and chronic toxic effects of the irradiated photolytic mixtures. A strong correlation was found between the kinetics of two of the PTPs and luminescence inhibition indicating bacterial toxicity. Using a set of in silico quantitative structure-activity relationship (QSAR) models, this study also offered new insights concerning the environmental fate and toxicity of the TPs of PBSA as the TPs generated by UV-treatment are more persistent and partly more toxic than PBSA.

A biosensitive element in the form of bacterial Photobacterium phosphoreum cells immobilized in poly(vinyl alcohol) cryogel was tested for the determination of different mycotoxins under discrete and flow-through analysis conditions. The immobilized bioluminescent cells made it possible to quantify the presence of Ochratoxin A, Sterigmatocystin, Zearalenone, and Deoxynivalenon in aqueous media in a wide range of their concentrations (0.017&ndash, 56 mg/L, 0.010&ndash, 33 mg/L, 0.009&ndash, 14 mg/L, and 0.026&ndash, 177 mg/L, respectively) via measuring the quenching of cell luminescence. The flow conditions allowed the analysis sensitivity to be improved by an order of magnitude in terms of detected concentrations. Using the immobilized luminescent bacterial cells, we have shown the possibility of evaluating the efficiency of the mycotoxins&rsquo, hydrolysis under the action of enzymes. In this way, a 94 &plusmn, 4.5% efficiency of Zearalenone hydrolysis with hexahistidine-containing organophosphorus hydrolase for 1h-long treatment of the mycotoxin solution (100 mg/L) was shown.

The development of real-time online warning system for toxicity materials is important to ensure the safety of water supply. This study for the first time constructs luminescent bacteria (Vibrio fischeri) biofilm to deliver both electrical and optical real-time response for Cu(II) toxic shock in a bioelectrochemical system (BES) sensor. Compared to biocathode, bioanode was more suitable as sensitive elements. With three tested concentrations of Cu(II), i.e., 1 mg/L, 3 mg/L and 6 mg/L, electrical signals were raised. But optical signal failed to respond to the lowest concentration, suggesting that electrical signal then was produced by chemical reaction of Cu(II) on the electrode surface. For 3 mg/L and 6 mg/L Cu(II) shock, more rapid optical signals were observed than electrical signal, indicating that both the biofilm's surface and inner was affected. In addition, high concentration of Cu(II) toxic as 6 mg/L caused irreversible damage in the biosensor as there were great fluctuation in the recovery curve and large recovery ratio up to -10.39% for optical signal. These results provided a comparison between optical and electrical signals simultaneously produced by a biosensor and visual evidences for better understanding of the toxicity process in the biosensor.

This study presented a HPTLC platformed luminescent biosensor system for screening captan residue. First, the potential bio-effects of layers materials on the detectability of a luminescent bacteria Photobacterium phosphoreum (ATCC 11040) as the sensor cell were assessed. From comparison, it was noteworthy that the combination of sensor cells with normal silica gel layer exclusively gave outstanding detectability (10 ng/zone). On this basis, HPTLC mediated separation and biosensing was further optimized. Then, the obtained graphic results were digitally quantified via software processing, offering satisfactory selectivity, linearity (R

Environmentally persistent free radicals (EPFRs) are detected in the clay, mineral or humic part of the soil, especially in soil contaminated with phenolic compounds. To clarify the detailed information on the formation of EPFRs, we used the contaminated soil with catechol to mimic their formation process in laboratory scale and tested their biotoxicity with luminescent bacteria (Photobacterium phosphoreum, P. phosphoreum). Our results showed that the concentration of EPFRs reached the maximum at pyrolysis temperature of 300 °C, and EPFRs could significantly inhibit the luminescence of P. phosphoreum. Based on the detection of OH radicals in the aquatic system we used, we speculated that the generation of OH may be a crucial contributor to the toxicity of EPFRs. Our results aid to understand the detailed process on the formation of EPFRs in contaminated soil, as well as the basic biotoxicity data of EPFRs, which will be helpful and essential for their potential environmental risk assessments.

The removal of acetaminophen (AAP) in aqueous solution by the UV/chlorine process was evaluated. The effect of chlorine dose, the initial AAP concentration, pH value, and UV intensity on the reaction were also investigated. The degradation mechanism and the ecological risk were further discussed. The results indicated that AAP degradation fitted pseudo-first-order kinetics. Compared with UV alone or dark chlorination, the combination of UV and chlorine significantly accelerated the degradation process. The AAP degradation was positively affected by chlorine dose and UV intensity, while negatively affected by the initial AAP concentration and ammonia nitrogen concentration during the UV/chlorine process. The frontier orbital theory analysis shows that the C5 position in the benzene ring of AAP is likely to be the first site attacked by HO• and Cl• radical to form the products. Twelve intermediates were identified by Q-TOF and GC-MS. The possible degradation pathways were also proposed. Luminescent bacteria experiment and ECOSAR prediction both revealed that acute toxicity of AAP degradation could only be partially reduced. Ecological risks during the UV/chlorine process need to be further evaluated.

Predicting the crucial effect of single metal pollutants against the aquatic ecosystem has been highly debatable for decades. However, dealing with complex metal mixtures management in toxicological studies creates a challenge, as heavy metals may evoke greater toxicity on interactions with other constituents rather than individually low acting concentrations. Moreover, the toxicity mechanisms are different between short term and long term exposure of the metal toxicant. In this study, acute and chronic toxicity based on luminescence inhibition assay using newly isolated Photobacterium sp.NAA-MIE as the indicator are presented. Photobacterium sp.NAA-MIE was exposed to the mixture at a predetermined ratio of 1:1. TU (Toxicity Unit) and MTI (Mixture Toxic Index) approach presented the mixture toxicity of Hg2+ + Ag+, Hg2+ + Cu2+, Ag+ + Cu2+, Hg2+ + Ag+ + Cu2+, and Cd2+ + Cu2+ showed antagonistic effect over acute and chronic test. Binary mixture of Cu2+ + Zn2+ was observed to show additive effect at acute test and antagonistic effect at chronic test while mixture of Ni2+ + Zn2+ showing antagonistic effect during acute test and synergistic effect during chronic test. Thus, the strain is suitable and their use as bioassay to predict the risk assessment of heavy metal under acute toxicity without abandoning the advantage of chronic toxicity extrapolation.

The real antibiotic industrial wastewater with the characteristics of complex compositions, biological toxic, and degradation-resistant, is still biologically toxic to the ecosystem and human health even if the discharge standards have been met after treatment by traditional methods. Therefore, the biological harmless treatment of real antibiotic industrial wastewater is a valuable and meaningful research field. For the first time, a novel Ti/SnO2-Sb anode/air diffusion cathode/UV dual photo-electro catalysis coupling system (T-A-PE) for real antibiotic industrial wastewater treatment was investigated. Non-significant degradation was found in raw wastewater with high TOC = 2.61 × 103 mg·L−1. However, the increasing TOC removal with more dilution times indicated adaptability of T-A-PE system with lower organic matter loading. The highest 95.6% removal of TOC was obtained at 120 min, with 7.06 mA·cm−2 of current density and 200 dilution times. The high mineralization efficiency of T-A-PE system surpassed those of pure photo and electro catalysis combined, suggesting a significant synergistic effect between photo and electro catalysis. Neutral condition and current density = 7.06 mA·cm−2 are prior for pollutants mineralization, while acidic/alkaline conditions and unproper current density may cause faster side reactions. The GC–MS results demonstrated that the number of pollutant category dropped from 26 to 6 after treatment, with the concentrations of remained ones also remarkably decreased. The acute toxicity analysis using a luminescent bacteria method indicated that the treated wastewater by T-A-PE system was biological harmless.

Photocatalytic degradation of typical pharmaceuticals in natural sunlight and in actual water is of great significance. In this study, the oxygen or nitrogen linked heptazine-base polymer (ONLH) was successfully incorporated with TiO2 nanoparticles and formed a TiO2/ONLH nanocomposite which was responded to the natural sunlight. Under natural sunlight, the TiO2/ONLH can effectively degrade ten types of pharmaceuticals. In particular, fluoroquinolone containing N-piperazinyl, and cardiovascular drugs containing long aromatic side chains were easily degraded. The half-life of the best degradation performance of propranolol was less than 5 min. The rate constants of propranolol using the TiO2/ONLH were approximately six- and eight-fold higher than those of pristine TiO2 and ONLH, respectively. Two reactive species (OH and O2-) facilitated the rapid degradation of propranolol, which occurred primarily through the hydroxyl radical addition, ring-opening, and ipso substitution reactions. An acute toxicity test using luminescent bacteria indicated that the toxicity of the propranolol reaction solution gradually decreased with lower total organic carbon (TOC). According to the toxicity evaluation of monomer products, the TiO2/ONLH also reduced the generation of toxic transformation products. The effects of actual water/wastewater have further shown the TiO2/ONLH might be applied for the removal of pharmaceuticals in wastewater.

Wastewater containing high concentrations of antibiotics may inhibit the biological treatment processes, and it could also result in an increase in antibiotic resistant genes in the biological treatment system, causing risks in the environmental waters. Therefore, in this study, taking advantage of the unstable characteristics of tetracycline in alkaline conditions, dual-chamber microbial fuel cells (MFCs) were coupled with the heater to drive the alkaline thermal hydrolysis of tetracycline in the cathode chamber, making tetracycline degradation without contact with microorganisms in the anode chamber. It was observed that tetracycline degradation rates under closed circuit conditions were faster than those under open circuit conditions due to the rising pH in the cathode chamber of closed circuit MFCs, and the temperature increase could result in a decrease in half-life of tetracycline degradation. The TOC analysis showed that most TOC was not removed after 48 h reaction, suggesting tetracycline was mainly transformed to byproducts in the cathode chamber. High resolution mass spectrometry identified the transformation products resulting from the alkaline thermal hydrolysis of tetracycline, and the minimum pharmacophore of tetracycline was altered, which would lead to the loss of antibacterial activity. Microtox tests confirmed the reduction in the toxic effect of tetracycline to luminescent bacteria after treatment in the cathode chamber. Our results have demonstrated the effective degradation of tetracycline using MFC-driven alkaline thermal hydrolysis, which will have potential to be a pretreatment process to assist the subsequent biological treatment processes to destroy high concentrations of antibiotics in the wastewater.

Bioremediation using microorganisms is a promising technique to remediate soil contaminated with heavy metals. In this study, Sporosarcina pasteurii (S. pasteurii) bioremediation by mixing method was used to remediate soils contaminated with lead (Pb), zinc (Zn) and cadmium (Cd). A significant reduction of heavy metal leaching concentrations was observed in S. pasteurii bio-treated samples. Furthermore, urease hydrolyzing bacteria have additional advantages of accelerating metal precipitation by increasing pH. The soluble-exchangeable Pb, Zn and Cd was reduced by 33.3 % ∼ 85.9 %, 21.4 % ∼ 66.0 %, 13.6 % ∼ 29.9 % respectively after bioremediation. The primary objective of metal stabilization was achieved by reducing the bioavailability through immobilizing the Pb, Zn and Cd in the urease-driven carbonate precipitation. Luminescent bacteria toxicity experiments revealed that the metal toxicity of contaminated soil was reduced after bioremediation using S. pasteurii. When subjected to severe environmental conditions, S. pasteurii bioremediation was superior to chemical precipitation technology in terms of long-term stability.

Natural sunlight is a vital environmental element and plays a significant role in the ecological storage of reclaimed water (RW), but its impacts on RW quality are poorly understood. In this study, sunlight-induced changes in RW with a focus on dissolved organic matter (rDOM) and 52 residual micropollutants were investigated in the field during the summer and winter seasons. The results indicated that sunlight exposure led to the dissipation of chromophoric DOM (CDOM) in the summer (55% loss) and winter (19% loss) after 14 consecutive sunny days. During open storage of RW, CDOM absorption in UVC regions was preferentially removed in the summer, while during the winter there was preferential removal of CDOM in UVA regions. The results also showed higher fluorescent DOM (FDOM) removal in summer than in winter (49% and 28%, respectively). Results in both seasons indicated that humic acid-like compounds were the most photolabile fractions and were preferentially removed under sunlight exposure. Sunlight also induced attenuation of micropollutants in the summer and winter at reductions of 66% and 24% from the initial values, respectively. Significant attenuation (>75%) was only observed for endocrine-disrupting chemicals, pharmaceuticals, and sunscreens in the summer, but they accounted for 76% of the total concentrations. Vibrio fischeri toxicity tests demonstrated that sunlight constantly decreased the luminescent bacteria acute toxicity of RW, which was estimated to be caused mainly by the sunlight-induced changes of FDOM and CDOM, while the detected micropollutants could only explain 0.02%–2% of acute toxicity. These findings have important implications regarding our understanding of the ecological storage of reclaimed water and the contribution of management strategies.

Today, nanomaterials have significant potential for practical application in a variety of research areas, in industrial production, the agrarian sector and in everyday life. Nanomaterials have received considerable attention due to the complex of their special properties, including taking into account the large specific surface area and high biological activity [1, р. 97-114; 2 р. 5728-5743]. In connection with the rapid development of nanotechnologies, nanomaterials of various shapes and diameters were obtained, which were then used in the production of products and products [3, р. 2064-2110; 4, р. 1504-1534]. On the one hand, skilled application of nanoparticles opens up new opportunities in many areas of human activity, and on the other hand due to its small size and the ability to penetrate through tissues can cause toxic effects in relation to living organisms. Therefore, scientific research must be aimed at studying the influence of nanomaterials on biological objects of different levels of organization, in particular on the analysis of the state of subcellular, cellular, organ levels and the whole organism [5, p. 51-56]. The aim was to investigate the effect of nanocomposites and their component nanosized SiO 2 on different types of microorganisms. Materials and methods. Influence of nanomaterials was studied using beer yeast, bioluminescent bacteria and associative culture of aerobic bacteria. Nanomaterials were provided by the Research Institute of Molecular Technologies in Milan, Italy. An associative culture was used ( Pseudomonas pseudo alcaligenes 102 , Bacillus subtilis 138 , Stenotrophomonas maltophilia 5246 UKM) from the collection of the Institute of Microbiology and Virology. D.K. Zabolotnoy National Academy of Sciences of Ukraine. The associative culture in the ratio 1: 1: 1 was cultivated on a nutrient medium (Himedia, India) during the day. After incubation, the suspension was applied to an agarified nutrient medium. In the center of the Petri dish, with a lawn crop, the agar blocks (hungry 4% agar with concentrations of nanomaterials) were sterilized. The culture was incubated for 2 days at a temperature of 28 0 C and the analysis was performed taking into account the fact and size of the growth retardation of the colonies (mm) [6, р. 273]. The biological effects of the NPs and NC were studied in form colloidal water mixtures obtained in appropriate volumes of 3% of sodium chloride. Three strains of luminescent bacteria ( V. fischeri F1, P. leiognathi Sh1) from collection of Crimean State Medical University (Simferopol, Ukraine) To determine the acute (toxicity) of samples, in blisters of a luminometer BLM 8801, a mixture of 0.8-0.9 ml of the test solution in a 2.5-3% solution of NaCl, 100 μl of a buffer solution with pH = 7.0 (phosphate) and 50 μl of bacterial suspension. The change in the intensity of the bioluminescence was recorded for 30-120 minutes using a recorder (LKB Bromma, Sweden). The analyzes were carried out at a temperature of 28-30 ° C. The biological effect of the samples was evaluated qualitatively by the nature of the graphic dependences of the intensity of the bioluminescence on the sample concentration. The presence of pronounced concentration inhibition of bioluminescence, reduction of bioluminescence to 50% and lower were treated as toxic [7, р. 93-97]. To study the influence of nanomaterials on beer yeast, they took a pure culture of Saccaromyces cerevisiae strain U-517 from the collection of the Institute of Microbiology and Virology. D.K. Zabolotny. Cultivated on a medium of YPD (yeast extract - 1%, peptone - 2%, glucose / dextrose - 2%, agar - 2.5%) during the day at 28 0 C. The daily subplanted culture at a concentration of 105 cells / ml in 25 ml of YPD medium with certain concentrations of nanomaterials: 150 mg / L, 300 mg / L, 450 mg / L, 600 mg / l and incubated for 1 day. Cultivate the day statically in falcons of 50 ml. The number of cells was calculated by the method of counting in the camera Goryaevа. Cell counting occurred in a heterogeneous population of Saccaromyces cerevisiae in a stationary phase of growth. MTT test was performed as follows. After daily processing with nanomaterials, 100 μl of yeast culture was incubated in the presence of 20 μl of 5 mg / ml MTT for 3.5 hours at 37 ° C in a 96-well plate in three replicates. After incubation, the culture medium was removed and the formazan crystals were dissolved in 150 μl DMSO. Incubated in the presence of DMSO in dark 15 minutes and measured the performance of the optical density (CO) formazan at a wavelength of 620 nm with a Multiskan FC device with version 1.00.94 and serial number 357-902509 [8, р. 383-393]. Research results. Having studied the influence of nanomaterials on the associative culture of aerobic bacteria, no toxic effects were found. The results of the experiment indicate the absence of antibacterial action of newly synthesized nanocomposites based on saponites on aerobic soil bacteria. For the action of nanosized SiO 2 material at a concentration of 600 mg / l around the agar block, there was no significant growth retardation of the colonies of aerobic bacteria. Thus it can be argued that the antibacterial activity of this material is weak in the associative culture of soil bacteria at a concentration of 600 mg / l. In the study of the acute effects of nanomaterials on bioluminescent bacteria, in 10 and 30 minutes, the newly synthesized nanocosities did not exhibit inhibitory activity, depending on the time and concentrations. The study of acute toxicity of samples showed that SiO 2 nanomaterial suppressed bacterial bioluminescence. During the 10-minute incubation of bacteria in solutions of nanomaterials 150 mg / l, 300 mg / l, 450 mg / l and 600 mg / l, the intensity of the luminescence of bacteria decreased by 18.5%, 54.5%, 61.5% and 59 , 5% respectively. During the 30-minute incubation, the light concentrations decreased by 20.61%, 56.2%, 61.3%, 62.5%, respectively. Accordingly, one can conclude that the inhibitory effect of the nanomaterial depends on the concentrations, and by increasing the incubation time, the change in the inhibitory effect was not significant. Accordingly, the curvature of the bioluminescence of bacteria V. Fischeri , similarly to the previous results, was not detected in the bacteria Р. leiognathi , the inhibitory effect of nanocomposites on the basis of saponites. The nanosized SiO 2 material reduced the intensity of the glow of bacteria. Thus, with a 10-minute incubation in solutions of nanomaterials of 150 mg / l, 300 mg / l, 450 mg / l and 600 mg / l, the intensity of bioluminescence decreased by 13.3%, 35.2%, 41.4% and 42.3%. During incubation for 30 minutes the indices did not change significantly. Having studied the influence of nanomaterials on bacteria, the next step was to investigate the effect of nanomaterials on the growth of yeast cells. It has been established that under the influence of saponite-based nb-containing nanocomposites, the number of S. cerevisiae cells is significantly increased. The nanosized SiO 2 material in the range of 450-600 mg / L showed an inhibitory effect, the number of cells in the samples at concentrations of 450 mg / l and 600 mg / l was 1.96 ∙ 10 8 cells / ml and 1.87 ∙ 10 8 cells / ml, respectively , whereas in the control the given index was 2.06 ∙ 10 8 кл / ml. S. cerevisiae cells are susceptible to the effect of nanomaterials on them. To confirm the preliminary results and obtain more detailed information on the influence of nanomaterials on the intensity of biochemical processes in cells, an MTT test was performed. According to the MTT test, the most pronounced effect compared with the control was found for nanocomposites Nb-Saponite (Cl) and Nb-Saponite (Et) at concentrations of 300-600 mg / l. On average, for optical nanocomposites, the optical density was 0.547 y.o. and 0.645 y.o., while in control it was 0.32 y.o. As in previous experiments on counting the number of cells, we obtain the reproducibility of the results in determining the cytotoxicity of niobium-containing nanocomposites. The growth of optical density speaks of the properties of nanocomposites, in relation to the activation of biochemical processes in cells of S. cerevisiae . Nanomaterial SiO 2 did not exhibit cytotoxic action against S. cerevisiae cells. An insignificant decrease in this indicator for the effects of SiO 2 was observed at concentrations of 450 mg / l and 600 mg / l, it decreased by 9.37% and 12.5% respectively, compared with the control. Conclusion. The influence of Nb-containing nanocomposites based on saponites and their component - nanosized SiO 2 is studied in this work. It was noted that nanocomposites did not exhibit a toxic effect in the concentration range of 150-600 mg / l in relation to bioluminescent, aerobic bacteria and S. cerevisiae . For the action of nanosized SiO 2 , an inhibitory effect was observed to the listed microorganisms. Such results can be justified by the fact that the nanosize SiO 2 material caused inhibition of the parameters, since it is about 20 nm in size so the nanomaterial can penetrate the cell wall of microorganisms and cause a negative effect. In composite materials, SiO 2 during synthesis was agglomerated into large structures, ranging in size from 40-100 nm, thus losing its toxic properties. Keywords: nanomaterials, microorganisms, bacteria, brewer's yeast, nanocomposites

The antipsychotic drug quetiapine (QUT) has been frequently detected in sewage treatment plants. However, information on the fate of QUT in aquatic environments and its behavior during UV treatment is limited. In this study, QUT is shown not to be readily biodegradable in the Closed Bottle Test and the Manometric Respirometry Test according to OECD guidelines. The main biotransformation product (BTP) formed in the tests, a carboxylic acid derivative, was identified by means of high-resolution mass spectrometry. This BTP is presumably a human metabolite and showed higher detection rates than QUT in a river sampling campaign conducted in northern Germany. UV elimination kinetics of QUT at different initial concentrations (226.5, 45.3, 11.3, and 2.3 μmol L −1 ) were faster at lower initial concentrations. All seven phototransformation products (PTPs) could be still identified at initial concentration of 11.3 μmol L −1 . The photolytic mixture generated after 128 min of photolysis of QUT was not better biodegradable than QUT. Initial UV treatment of QUT led to the formation of several additional BTPs. Four of them were identified. The bacterial cytotoxicity and genotoxicity before and after phototransformation of QUT in a modified luminescent bacteria test (LBT) and the umu-test (ISO/FDIS 13829) showed cytotoxic effects in the LBT for QUT. Furthermore, PTPs had similar cytotoxic effects on luminescent bacteria. The umu-test did not reveal any genotoxic activity for QUT or PTPs. In conclusion, the release of QUT into sewage treatment plants and aquatic environments could result in the formation of a main BTP. Additional UV treatment of QUT would lead to the formation of additional BTPs. Moreover, treatment did not result in lower toxicity to tested organisms. In conclusion, UV treatment of QUT should be considered critically as a potential treatment for QUT in aquatic systems.

Explosive-contaminated soil is harmful to people’s health and the local ecosystem. The acute toxicity of its extracting solution was tested by bacterial luminescence assay using three kinds of luminescent bacteria to characterize the toxicity of the soil. An orthogonal test L 16 (45) was designed to optimize the soil extracting conditions. The optimum extracting conditions were obtained when the ultrasonic extraction time, ultrasonic extraction temperature, and the extraction repeat times were 6 h, 40 °C, and three, respectively. Fourier transform infrared spectroscopy (FTIR) results showed that the main components of the contaminated soil’s extracting solution were 2,4-dinitrotoluene-3-sulfonate (2,4-DNT-3-SO3 −); 2,4-dinitrotoluene-5-sulfonate (2,4-DNT-5-SO3 −); and 2,6-dinitrotoluene (2,6-DNT). Compared with Photobacterium phosphoreum and Vibrio fischeri, Vibrio qinghaiensis sp. Nov. is more suitable for assessing the soil extracting solution’s acute toxicity. Soil washing can remove most of the contaminants toxic to luminescent bacterium Vibrio qinghaiensis sp. Nov., suggesting that it may be a potential effective remediation method for explosive-contaminated soil.

Three distinct textile samples were investigated for color and toxicity (S1–chemical/textile industry; S2–final textile effluent; S3 - standard textile produced effluent–untreated blue). Radiation processing of these samples were carried out at Dynamitron Electron Beam Accelerator and color and toxicity removal were determined: color removal by radiation was 96% (40 kGy, S1); 55% (2.5 kGy, S2) and 90% (2.5 kGy, S3). Concerning toxicity assays, Vibrio fischeri luminescent bacteria demonstrated higher reduction after radiation than the other systems: removal efficiencies were 33% (20 kGy, S1); 55% (2.5 kGy, S2) and 33% (2.5 kGy, S3). Daphnia similis and Brachionus plicatilis fitted well for S3 effluents. Hard toxic volumes into biological treatment plant may be avoided if radiation would be previously applied in a real plant. Results reveled how indispensable is to run toxicity to more than one living-organism.

The wastewater generated in pharmaceutical process generally contains residual organic solvents (ROSs) which will cause the toxicity and inhibition of the micro-organisms in treating wastewater, thus affecting the treatment effect of wastewater. The aim of this study was to establish a system for the analysis and evaluation of microtoxicity and biodegradability of ROSs in pharmaceutical wastewater. The quantitative structure activity relationship models were used to predict the toxicity and biodegradability; meanwhile, the biological toxicity was tested by the method of dehydrogenase activity (DHA) as well as luminescent bacteria and biodegradability was measured by shaking experiment. The proposed system was applied to predict and evaluate toxicity and biodegradability of toluene, acetone, isopropanol and dichloromethane in pharmaceutical wastewater. The results showed that the actual measured values fitted well with the calculated values. The microtoxicity of toluene was the highest and the degr...

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала. This study assesses the comparative sensitivity and possibility of obtaining fast results of various methods of biotesting for several surfactants: Tween 85, sodium dodecyl sulfate (SDS), Fairy dishwashing gel, and Mif washing powder. The following test organisms are used for the study: luminescent bacteria Photobacterium phosphoreum (Beijerinck), preparation of Ecolum luminescent bacteria, unicellular algae Scenedesmus quadricauda (G.M. Smith), infusorian Paramecium caudatum (Ehrenberg), and crustacean Daphnia magna (Straus). It has been revealed that Fairy dishwashing gel possesses the strongest toxicity against the studied test objects. Daphnia and algae are most sensitive to the effects of Fairy and SDS, protozoan and luminescent bacteria are most sensitive to SDS, and Ecolum is most sensitive to Mif washing powder. The tested aquatic organisms and Ecolum are most tolerant to the effect of Tween 85.

In this study the adsorption of the dye Acid Red 357 (AR357) present in dyeing effluent, through the use of chromium tanned leather waste (CTLW) as an adsorbent is investigated. The results demonstrate an adsorption capacity of 148.2 mg g −1 , and the removal of approximately 58% of the dye present in solution. In addition the data for adsorption in dyeing effluent, when compared to the data for aqueous solution, demonstrate that competition for adsorption sites by other chemical compounds present in the effluent takes place. The dyeing effluent presents elevated toxicity to microcrustacea, fish and luminescent bacteria, however, after treatment by adsorption, the toxicity is reduced by up to 90% compared to the untreated effluent.

2,4-DCP is a high-toxicity phenol compound, which is difficult to remove, harmful to the health of people and seriously influences the aquatic ecosystems. In this study, the degradation of 2,4-DCP using UV/persulfate (UV/PS) process was investigated for the first time. The results showed pseudo-first-order rate constants of 2,4-DCP photo-degradation by UV/PS was 35.1 × 10−3 min−1. The reaction rate constants increased with pH increasing from 5 to 7 and then decreased at pH 8. Different anions (Cl−, HCO3− and NO3−) in water presented different effects on the photo-degradation reaction. The photo-degradation rates of 2,4-DCP in three actual water conditions (Xidong water works, Xijiu reservoir, Henshan reservoir) were higher than in the ultrapure water. Two possible (hydroxylated and dechlorinated) pathways for the degradation of 2,4-DCP by UV/PS were proposed. The luminescent bacteria inhibition rate greatly decreased with the concentration of 2,4-DCP decreasing in the reaction process.

The possibility of using 2 test kits – the display on the basis of the characteristics of lichens and bioassays based on luminescent bacteria for rapid assessment of the state of air pollution in the example area in Shchelkovo district, Moscow region. The number of detected lichen species, the classes of their resistance to pollution and changes in the morphology of lichens thalli and cell diameters of lichen photobionts and toxicity of tree bark in the allocation of lichens was estimated.

Vibrio fischeri bioluminescence inhibition has been widely used to test acute toxicities of metals and organics contaminants. However, the differences of metals and organics acute toxicities to V. fischeri have not been compared. Here, four heavy metals (Zn2+, Cu2+, Cd2+, Cr6+) and five organics (phenol, benzoic acid, p-hydroxy benzoic acid, nitro-benzene and benzene) acute toxicities to V. fischeri were investigated. Heavy metals toxicities to V. fischeri were increased along with the reaction time, while the organics toxicities kept the same level in different reaction times. In order to explain the difference, the relative cell death rate of V. fischeri was detected. In metals toxicities tests, the bioluminescence inhibition rate of V. fischeri was found to be significantly higher than the relative cell death rate (P

Psychoactive drug diazepam is one of benzodiazepines widely used in human medicine. It has been found to be relatively resistant to chlorination and photolysis. Here we investigated the transformation mechanism of diazepam in aqueous solution through UV/chlorine and simulated sunlight/chlorine treatments. The results showed that the UV/chlorine and sunlight/chlorine processes significantly increased the degradation of diazepam in water. These observed degradations can be elucidated by in-situ generation of reactive species including hydroxyl radical (HO ), reactive chlorine species (RCS) and ozone (O3) during photolysis of chlorine. In the UV/chlorine treatment, the degradation efficiency of diazepam for HO , chlorine, UV and RCS reaction at 90 min was calculated to be 62.1%, 3.8%, 11.9% and 12.3%, respectively. In the simulated sunlight/chlorine treatment, the calculated degradation of 53.1%, 8.1% and 11.2% was attributed to HO , chlorine and RCS reaction, with negligible loss by O3 reaction and sunlight irradiation. In the UV/chlorine and sunlight/chlorine treatments, a total of 70 transformation products was detected using a high-resolution TripleTOF mass system. Six transformation pathways have been tentatively proposed for the diazepam, which includes hydroxylation, chlorination, hydrolyzation, N-demethylation, loss of phenyl group, benzodiazepine ring rearrangement and contraction. Most of the obtained transformation products were less toxic to aquatic organisms including fish, daphnia and green algae than diazepam itself according to the toxicity prediction tool, and did not cause significant changes in toxicity to luminescent bacteria.

Residual trace organic pollutants (TOPs) and associated biological effects from secondary effluent (SE) are attracting much attention because of their safety concerns. Granular activated carbon (GAC) adsorption, due to its low cost and high efficiency, is widely applied for further wastewater treatment, but its selective removals of TOPs and biological effects are poorly understood. In the present study, the surface physicochemical characteristics of four types of typical GACs were investigated, and their correlation with luminescent bacteria toxicity was discussed. Based on the biological effect control, shell GAC, with a great adsorption capacity and high functional group contents was selected for further study, including for the removal of fluorescent dissolved organic matter (DOM), 21 TOPs, and 3 biological effects. The shell GAC showed a promising property of removing fluorescent DOM and TOPs. The total concentration of 21 detected TOPs, including 12 pesticides and 9 pharmaceuticals, achieved 82% removal when 30 g/L shell GACs was added. Individual chemicals removal by GAC adsorption was not well described by an individual parameter (e.g., logD, molecular size, charge, functional groups), but rather by a variety of physical and chemical interactions among TOPs, DOM, and GAC. The biological effects from SE were mainly caused by TOPs and DOM. Hence, shell GACs also showed high removal efficiencies of luminescent bacteria toxicity, genotoxicity, and photosynthetic inhibition effect. The removal mechanisms of the three biological effects from SE were deeply discussed. Therefore, the GAC treatment is considered to be one of the most suitable options to ensure the ecological safety of discharged wastewater, because it can effectively control DOM, TOPs, and associated biological effects.

The current study depicts the isolation of luminescent bacteria from fish and squid samples that were collected from Veraval fish harbour. From Indian mackerel, total 14 and from squid, total 23 bioluminescent bacteria were isolated using luminescence agar medium. Two bioluminescent bacteria with highest relative luminescence intensity PBR1 and PBL1 were selected. These two isolates were subjected to detailed biochemical characterization and were tested positive for 5 out of 13 biochemical tests. Furthermore, both PBR1 and PBL1 were able to ferment cellobiose, dextrose, fructose, galactose, maltose, mannose, sucrose and trehalose with acid production. Based on 16S rRNA partial gene sequence analysis, PBR1 was identified as Vibrio alginolyticus and PBL1 as V. rotiferianus. Antibiotic susceptibility test using paper-disc method showed that PBR1 and PBL1 were sensitive to chloramphenicol, ciprofloxacin, co-trimoxazole, gatifloxacin, levofloxacin, linezolid ad roxithromycin out of 18 antibiotics tested. Moreover, both strains were evaluated for their exopolysachharide (EPS) producing ability where PBR1 and PBL1 were able to yield 1.34 g% (w/v) and 2.45 g% (w/v) EPS respectively from 5 g% (v/v) sucrose concentration. Heavy metal toxicity assessment was carried out using agar well diffusion method with eight heavy metals and both the strains were sensitive to As(III), Cd(II), Ce(II), Cr(III), Cu(II), Hg(II) and while they showed resistance to Pb(II) and Sr(II). Based on these results, a study was conducted to demonstrate bio-removal of Pb and Sr by EPS of PBR1 and PBL1. Fourier transform infrared (FTIR) spectra revealed the functional groups of EPS involved in interaction with the heavy metals. Owing to the sensitivity for the remaining heavy metals, these bioluminescent bacteria can be used further for the development of luminescence-based biosensor.

The possibility of using coffee silverskin, an industrial waste from the coffee roasting process, as an antifungal feedstock in wood preservative formulations was investigated. Silverskin hot water extract and its antifungal properties in vitro against Rhodonia (Poria) placenta, Gloeophyllum trabeum, and Trametes versicolor were characterized, and its in vitro effects on wood decay caused by Coniophora puteana were analyzed. A kinetic luminescent bacteria test was performed using Aliivibrio fischeri to measure the acute ecotoxicity of the silverskin extracts. The antifungal test showed 60–70% growth inhibition of the studied fungi at higher concentrations—3%—but did not meet the high inhibition—100%—of the commercial wood preservative. The phenolic compounds, such as chlorogenic acid and its derivatives, and caffeine derivatives, were the main constituents of the silverskin extracts and considered the responsible compounds of the fungal inhibition. The silverskin extracts were significantly less toxic than the commercial copper-based wood preservative. Revalorization of silverskin from industrial residues does not perform as a wood preservative but it remains a potential source of antifungal chemicals for wood preservative formulations.

Assessment of eco-toxicant using bioluminescent bacterial assay is a widely used and globally accepted method. In this work, a new luminescent bacterium was isolated from squid (Loligo duvauceli) and identified as Photobacterium leiognathi strain AK-MIE using 16S rRNA, phylogeny analysis. The predicted optimum conditions by RSM were 2.76% (w/v) NaCl, 2.28% (w/v) peptone, 0.34% (w/v) yeast extract, and pH 6.83 with 541,211.80 RLU of luminescent production whereas the predicted optimum conditions by ANN were 2.21% (w/v) NaCl, 2.27% (w/v) peptone, 0.39% (w/v) yeast extract, and pH 6.94 which produced 541,986.20 RLU. The validation analysis of both RSM and ANN show 0.60% and 0.69% deviation from the predicted results indicating that both models provided good quality predictions with ANN showing a superior data fitting capability for non-linear regression analysis. Toxicity tests show strain AK-MIE was sensitive to mercury (concentration causing 50% inhibition or IC50 of 0.00978 mg L − 1 ), followed by cadmium (IC50 of 0.5288 mg L − 1 ), copper IC50 of (0.8117 mg L − 1 ), silver (IC50 of 1.109 mg L − 1 ), and lead (IC50 of 10.71 mg L − 1 ) which are more sensitive than previously isolated luminescent bacteria, suggesting that strain AK-MIE has the potential to be used in toxicity assessment of heavy metals in the environment. Based on the field trial results, several sediment samples from industrial areas in Bangi, Selangor managed to inhibit the bioluminescence of strain AK-MIE. Validation method carried out using ICP-MS proved the presence of several toxic heavy metal elements.

Advanced oxidation processes (AOPs) can degrade heavy metal complexes in wastewater to improve the removal efficiency of metals. However, the influences of AOP treatments on toxicity induced by metal complexes are not well understood. This study compared the toxicity induced by EDTA-copper (Cu) after UV/persulfate (PS) and UV/H2O2 treatments on luminescent bacteria and human HepG2 cells. The results showed that EDTA-Cu complexes decreased Cu toxicity in luminescent bacteria but increased the cytotoxicity in HepG2 cells, indicating species-specific toxicity. The UV/PS and UV/H2O2 treatments under most pH values and [oxidant]/[EDTA-Cu] conditions decreased the toxicity of EDTA-Cu in HepG2 cells but increased the toxicity in luminescent bacteria. When the ratio of [oxidant] to [EDTA-Cu] was 10, low toxicity in treated solutions was observed in both UV treatment processes. The alkaline precipitation treatment had a significant influence on toxicity reduction after UV/PS treatment; however, it had minimal influence on the UV/H2O2 treatment system. The Cu and total organic carbon (TOC) removal efficiency cannot completely explain the results of toxicity assays. EDTA-Cu intermediates might play important roles in changing the toxicity of EDTA-Cu after both UV treatments. This study provides insights into evaluating the treatment efficiency of UV/PS and UV/H2O2 on EDTA-Cu decomplexation.

Here, we present a study of luminescent intestinal microflora of the fish inhabiting Bering and Okhotsk seas in summer and winter seasons. Sampling of intestinal luminescent microflora was carried for several years, with all recovered species belonging to psychrophilic bacteria of either Aliivibrio logei or Photobacterium phosphoreum species. A seasonal change in fish intestinal luminescent microflora detected include an increase in prevalence of P. phosphoreum bacteria in summer and an increase in prevalence of A. logei bacteria in winter seasons. In fact, 90% of all luminescent bacteria isolated in winter period (January-March) were A. logei, while 88% of luminescent isolates recovered in summer period (July-September) were that of P. phosphoreum species. Seasonal changes were similar across all six sampling expeditions, three in winter and three in summer seasons, evenly spread through 2010-2018 period.