Application of the luminous bacterium Photobacterium phosphoreum for toxicity monitoring of selenite and its reduction to selenium(0) nanoparticles.

Luminous marine bacteria are traditionally used as a bioassay due to the convenience and high rate of registering the intensity of their physiological function - luminescence. This study aimed to develop the application of Photobacterium phosphoreum in traditional and novel fields - toxicity monitoring and biotechnology. We demonstrated (1) effects of selenite ions on bioluminescence, and (2) biotransformation of selenite to selenium(0) in the form of nanoparticles.

Cytotoxic and radical activities of metal-organic framework modified with iron oxide: Biological and physico-chemical analyses.

Metal-organic framework (MOF) modified with iron oxide, FeO-MOF, is a perspective drug delivery agent, enabling magnetic control and production of active hydroxyl radicals, •OH, via the Fenton reaction. This paper studies cytotoxic and radical activities of Fe-containing nanoparticles (NPs): FeO-MOF and its components - bare FeO and MOF (MIL-88B). Luminous marine bacteria Photobacteriumphosphoreum were used as a model cellular system to monitor bioeffects of the NPs.

Effects of Endohedral Gd-Containing Fullerenols with a Different Number of Oxygen Substituents on Bacterial Bioluminescence.

Gadolinium (Gd)-containing fullerenols are perspective agents for magnetic resonance imaging and cancer research. They combine the unique paramagnetic properties of Gd with solubility in water, low toxicity and antiradical activity of fullerenols. We compared the bioeffects of two Gd-containing fullerenols with a different number of oxygen groups-20 and 42: Gd@COH and Gd@COH.

For Special Issue "Molecular Mechanisms of Responses to Low-Intensity Exposures 2.0" of .

The intention of this Special Issue is to highlight the peculiarities of low-intensity/low-concentration exposures for organisms and to examine the molecular mechanisms of the organismal responses [...

Water-Soluble Polymer Polyethylene Glycol: Effect on the Bioluminescent Reaction of the Marine Coelenterate Obelia and Coelenteramide-Containing Fluorescent Protein.

The current paper considers the effects of a water-soluble polymer (polyethylene glycol (PEG)) on the bioluminescent reaction of the photoprotein obelin from the marine coelenterate and the product of this bioluminescent reaction: a coelenteramide-containing fluorescent protein (CCFP). We varied PEG concentrations (0-1.44 mg/mL) and molecular weights (1000, 8000, and 35,000 a.

Introduction to the Special Series "Environmental Monitoring on Global and Local Scales".

The ecosystems of Siberia provide valuable services to the human population and afford important climate feedback. However, they are subject to anthropogenic pressures leading to the transformation of ecosystem structure and functions such as deforestation; extraction and transportation of fossil hydrocarbons; mining, refining, and smelting industrial activities; damming of rivers by high-pressure hydroelectric plants, and other activities. The articles in this special series deal with the monitoring of natural ecosystems of Siberia that are located on vast areas of Eurasia, many of which are hard to reach and sparsely populated.

Functionalized Magnetite Nanoparticles: Characterization, Bioeffects, and Role of Reactive Oxygen Species in Unicellular and Enzymatic Systems.

The current study evaluates the role of reactive oxygen species (ROS) in bioeffects of magnetite nanoparticles (MNPs), such as bare (Fe3O4), humic acids (Fe3O4-HA), and 3-aminopropyltriethoxysilane (Fe3O4-APTES) modified MNPs. Mössbauer spectroscopy was used to identify the local surrounding for Fe atom/ions and the depth of modification for MNPs. It was found that the Fe3O4-HA MNPs contain the smallest, whereas the Fe3O4-APTES MNPs contain the largest amount of Fe2+ ions.

Toxicity of Different Types of Surfactants via Cellular and Enzymatic Assay Systems.

Surfactants have a widespread occurrence, not only as household detergents, but also in their application in industry and medicine. There are numerous bioassays for assessing surfactant toxicity, but investigations of their impact on biological systems at the molecular level are still needed. In this paper, luminous marine bacteria and their coupled NAD(P)H:FMN-oxidoreductase + luciferase (Red + Luc) enzyme system was applied to examine the effects of different types of surfactants, including cationic cetyltrimethylammonium bromide (CTAB), non-ionic polyoxyethylene 20 sorbitan monooleate (Tween 80) and anionic sodium lauryl sulfate (SLS), and to assess whether the Red + Luc enzyme system can be used as a more sensitive indicator of toxicity.

Marine Bacteria under Low-Intensity Radioactive Exposure: Model Experiments.

Radioactive contaminants create problems all over world, involving marine ecosystems, with their ecological importance increasing in the future. The review focuses on bioeffects of a series of alpha and beta emitting radioisotopes (americium-241, uranium-(235 + 238), thorium-232, and tritium) and gamma radiation. Low-intensity exposures are under special consideration.

Assessment of air toxicity in the megalopolis of Krasnoyarsk using long-term monitoring of suburban pine forests.

The present study develops the application of suburban forests as bioindicators, with the industrial metropolis of Krasnoyarsk (Central Siberia, Russia) taken as an example. Huge forests, such as those found in large Siberian territories, are climate-forming for the entire planet. Hence, their conservation is essential at both the local and global scales.

Endohedral Gd-Containing Fullerenol: Toxicity, Antioxidant Activity, and Regulation of Reactive Oxygen Species in Cellular and Enzymatic Systems.

The Gd-containing metallofullerene derivatives are perspective magnetic resonance imaging contrast agents. We studied the bioeffects of a water-soluble fullerene derivative, gadolinium-endohedral fullerenol, with 40−42 oxygen groups (Gd@Fln). Bioluminescent cellular and enzymatic assays were applied to monitor toxicity and antioxidant activity of Gd@Fln in model solutions; bioluminescence was applied as a signaling physiological parameter.

Adaptation of a Bacterial Bioluminescent Assay to Monitor Bioeffects of Gold Nanoparticles.

Our current study aimed to adapt a bioluminescent bacteria-based bioassay to monitor the bioeffects of gold nanoparticles (AuNPs). Luminous marine bacteria and AuNPs modified with polyvinylpyrrolidone were employed; low-concentration (≤10 g/L) bioeffects of AuNPs were studied. Bioluminescence intensity was used as an indicator of physiological activity in bacteria.

Development of Cellular and Enzymatic Bioluminescent Assay Systems to Study Low-Dose Effects of Thorium.

Thorium is one of the most widespread radioactive elements in natural ecosystems, along with uranium, it is the most important source of nuclear energy. However, the effects of thorium on living organisms have not been thoroughly studied. Marine luminescent bacteria and their enzymes are optimal bioassays for studying low-dose thorium exposures.

Toxicity and Antioxidant Activity of Fullerenol C with Low Number of Oxygen Substituents.

Fullerene is a nanosized carbon structure with potential drug delivery applications. We studied the bioeffects of a water-soluble fullerene derivative, fullerenol, with 10-12 oxygen groups (F10-12); its structure was characterized by IR and XPS spectroscopy. A bioluminescent enzyme system was used to study toxic and antioxidant effects of F10-12 at the enzymatic level.

Enzymatic Responses to Low-Intensity Radiation of Tritium.

The present study considers a possible role of enzymatic reactions in the adaptive response of cells to the beta-emitting radionuclide tritium under conditions of low-dose exposures. Effects of tritiated water (HTO) on the reactions of bacterial luciferase and NAD(P)H:FMN-oxidoreductase, as well as a coupled system of these two reactions, were studied at radioactivity concentrations ≤ 200 MBq/L. Additionally, one of the simplest enzymatic reactions, photobiochemical proton transfer in Coelenteramide-containing Fluorescent Protein (CLM-FP), was also investigated.

Humic Substances Mitigate the Impact of Tritium on Luminous Marine Bacteria. Involvement of Reactive Oxygen Species.

The paper studies the combined effects of beta-emitting radionuclide tritium and Humic Substances (HS) on the marine unicellular microorganism-luminous bacteria-under conditions of low-dose radiation exposures (<0.04 Gy). Tritium was used as a component of tritiated water.

Effects of Modified Magnetite Nanoparticles on Bacterial Cells and Enzyme Reactions.

Current paper presents biological effects of magnetite nanoparticles (MNPs). "Relations of MNP' characteristics (zeta-potential and hydrodynamic diameters) with effects on bacteria and their enzymatic reactions were the main focus.".

Monitoring of Low-Intensity Exposures via Luminescent Bioassays of Different Complexity: Cells, Enzyme Reactions, and Fluorescent Proteins.

The current paper reviews the applications of luminescence bioassays for monitoring the results of low-intensity exposures which produce a stimulative effect. The impacts of radioactivity of different types (alpha, beta, and gamma) and bioactive compounds (humic substances and fullerenols) are under consideration. Bioassays based on luminous marine bacteria, their enzymes, and fluorescent coelenteramide-containing proteins were used to compare the results of the low-intensity exposures at the cellular, biochemical, and physicochemical levels, respectively.

Reactive Oxygen Species and low-dose effects of tritium on bacterial cells.

The paper continues study of exposures of luminous marine bacteria to low-dose radiation of tritium; tritiated water (HTO) was applied as a source of the irradiation. Hypothesis on involvement of Reactive Oxygen Species (ROS) to signaling mechanism of bacterial cells under exposure to low-intensity tritium radiation was verified. Bacterial bioluminescence intensity was considered as a tested physiological parameter; it was compared to the ROS production in the bacterial environment of different activity concentrations: 0.

Antioxidant Activity and Toxicity of Fullerenols via Bioluminescence Signaling: Role of Oxygen Substituents.

Fullerenols are nanosized water-soluble polyhydroxylated derivatives of fullerenes, a specific allotropic form of carbon, bioactive compounds, and perspective basis for drug development. Our paper analyzes the antioxidant activity and toxicity of a series of fullerenols with different number of oxygen substituents. Two groups of fullerenols were under investigation: (1) CO(OH), CO(OH), where x + y = 24-28 and (2) CO(OH), FeCO(OH), Gd@CO(OH), where x + y = 40-42.

Protein-based fluorescent bioassay for low-dose gamma radiation exposures.

The study suggests an application of a coelenteramide-containing fluorescent protein (CLM-CFP) as a simplest bioassay for gamma radiation exposures. "Discharged obelin," a product of the bioluminescence reaction of the marine coelenterate Obelia longissima, was used as a representative of the CLM-CFP group. The bioassay is based on a simple enzymatic reaction-photochemical proton transfer in the coelenteramide-apoprotein complex.

Fluorescent coelenteramide-containing protein as a color bioindicator for low-dose radiation effects.

The study addresses the application of fluorescent coelenteramide-containing proteins as color bioindicators for radiotoxicity evaluation. Biological effects of chronic low-dose radiation are under investigation. Tritiated water (200 MBq/L) was used as a model source of low-intensive ionizing radiation of beta type.

Variability of fluorescence spectra of coelenteramide-containing proteins as a basis for toxicity monitoring.

Nowadays, physicochemical approach to understanding toxic effects remains underdeveloped. A proper development of such mode would be concerned with simplest bioassay systems. Coelenteramide-Containing Fluorescent Proteins (CLM-CFPs) can serve as proper tools for study primary physicochemical processes in organisms under external exposures.

Bioluminescent Enzymatic Assay as a Tool for Studying Antioxidant Activity and Toxicity of Bioactive Compounds.

A bioluminescent assay based on a system of coupled enzymatic reactions catalyzed by bacterial luciferase and NADH:FMN-oxidoreductase was developed to monitor toxicity and antioxidant activity of bioactive compounds. The assay enables studying toxic effects at the level of biomolecules and physicochemical processes, as well as determining the toxicity of general and oxidative types. Toxic and detoxifying effects of bioactive compounds were studied.

Ultraviolet fluorescence of coelenteramide and coelenteramide-containing fluorescent proteins. Experimental and theoretical study.

Coelenteramide-containing fluorescent proteins are products of bioluminescent reactions of marine coelenterates. They are called 'discharged photoproteins'. Their light-induced fluorescence spectra are variable, depending considerably on external conditions.