Investigated the use as biological object in microbial fuel cells (MFC) of various microorganisms performing the transport of electrons in the processing of various substrates. Most MFC, uses complex substrates. Such MFC filled with associations of microorganisms. The article deals with certain types of microorganisms for use in the MFC, shows the characteristics of molecular electron transfer mechanisms microorganisms into the environment.

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. It was shown that the greatest inhibitory effect of the surfactants on the activity of luminous bacteria and the Red + Luc enzyme system was in the presence of SLS samples. The calculated IC₅₀ and EC₅₀ values of SLS were 10⁻⁵ M and 10⁻² M for the enzymatic and cellular assay systems, respectively. The results highlight the benefits of using the enzymatic assay system in ecotoxicology as a tool for revealing surfactant effects on intracellular proteins if the cellular membrane is damaged under a long-term exposure period in the presence of the surfactants. For this purpose, the bioluminescent enzyme-inhibition-based assay could be used as an advanced research tool for the evaluation of surfactant toxicity at the molecular level of living organisms due to its technical simplicity and rapid response time.

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. Bacterial luminescence intensity was considered as a tested physiological parameter. The bioluminescence response of the marine bacteria to tritium corresponded to the “hormesis” model: it included stages of bioluminescence inhibition and activation, as well as the absence of the effect. HS were shown to decrease the inhibition and activation effects of tritium, similar to those of americium-241, alpha-emitting radionuclide, studied earlier. Correlations between the bioluminescence intensity and the content of Reactive Oxygen Species (ROS) were found in the radioactive bacterial suspensions. The results demonstrate an important role of HS in natural processes in the regions of low radioactive contamination: HS can mitigate radiotoxic effects and adaptive response of microorganisms to low-dose radioactive exposures. The involvement of ROS in these processes was demonstrated.

Environmental pollution is becoming ubiquitous; it has a negative impact on ecosystem diversity and worsens the quality of human life. This review discusses the possibility of applying the plant microbial fuel cells (PMFCs) technology for concurrent processes of electricity generation and the purification of water and soil ecosystems from organic pollutants, particularly from synthetic surfactants and heavy metals. The review describes PMFCs’ functioning mechanisms and highlights the issues of PMFCs’ environmental application. Generally, this work summarizes different approaches to PMFC development and to the potential usage of such hybrid bioelectrochemical systems for environmental protection.