It was shown for the first time that preliminary deuteration of Esherichia coli bacteria with deuterium oxide (D 2 O) at concentrations from 5 to 10% in a medium leads to an enhancement of the SOS response in the biosensors E. coli MG1655 (pColD::lux) and E. coli MG1655 (pRecA::lux) induced by UV at a dose of 12 J/m 2 . The biosensors used in this work contain hybrid plasmids carrying the luxCDABE operon of the Photorhabdus luminescens photobacterium, placed under the control of the cda ( colD ) and recA gene promoters. The induction of genotoxic factors in biosensors indicates the activation of the corresponding E. coli SOS system of gene expression. A simultaneous study of the intensity of luminescence and the cell viability of the E. coli MG1655 biosensor (pCol-lux) bacteria showed that UV irradiation at a dose of 12 J/m 2 increases the intensity of luminescence from 2111.1 in a medium without D 2 O to 5030.3 RLU for 10 7 viable cells in a medium with D 2 O. The intensity of luminescence of the biosensor was 2.5 times higher in the medium with deuterium than without it.

In connection with the requirements of international and national organizations to comply with ethical principles for experiments using animals, alternative test systems are being sought and tested to replace animals in ecological, toxicological, and genotoxicological studies. One such alternative may be the nematode Caenorhabditis elegans, which has a biotransformation system of chemical compounds similar to the mammalian system. The genotoxicity of the pesticide paraquat and the antibacterial agent furacilin was studied on C. elegans by horizontal gel electrophoresis of total DNA in order to assess its integrity. It has been shown that paraquat in concentrations of 0.01 to 0.05 mol/L and furacilin in concentrations of 0.0001 and 0.00025 mol/L caused DNA breaks in nematode cells. The antioxidant N-acetylcysteine at a concentration of 0.01 mol/L reduced the genotoxicity of both compounds.

The first data on the diversity of cyanobacteria found in the littoral zone of six different lakes on the Stornes Peninsula in the Larsemann Hills oasis (East Antarctica) are presented. Examination of samples by light microscopy revealed 27 cyanobacterial morphospecies. An annotated list with detailed morphological description of the morphospecies is given. In addition, a general characteristic of the algal-bacterial communities is provided, their composition and the dominant species are determined.

We have studied the expression of the E. coli ada and alkA genes and the luxA lux-operon gene in the plasmid and under the control of the alkA gene promoter methyl methanesulfonate (MMS) in the cells of deuterated and non-deuterated bacteria of the E. coli K12 MG1655 biosensor (pAlkA–lux) using the RT‑PCR method. The constitutively expressed rrsA 16S ribosome RNA gene was used as a reference. Deuteration of the bacterial culture was carried out in a medium containing 7.5% deuterium oxide (D2O). The numbers of PCR cycles in the cells of deuterated and non-deuterated bacteria were different; exponential emergence of the curve of dependence of the expression level of the studied genes on the number of PCR cycles occurred earlier during deuteration than in non-deuterated bacteria. This difference in the number of cycles (Сt) was 4, 6, and 9 for the luxA, alkA, and ada genes, respectively.

One rare (Dinobryon cylindricum) and two new (Gonium pectorale, Staurastrum orbiculare) for the Antarctic algal flora species were found in the waterbodies of Schirmacher Oasis (East Antarctica). Their locations are described. Data on morphology, ecology and distribution of the recorded species are summarized.

The lux biosensor of E. coli MG1655 (pDinI::lux) was constructed and a comparative study of the SOS response of three biosensors E. coli MG1655 (pRecA::lux), E. coli MG1655 (pColD::lux), and E. coli MG1655 (pDinI::lux) under the action of genotoxic agents was performed. The listed biosensors were named, respectively, PRecA, PColD, and PDinI. The response amplitude (RA) was chosen as an indicator of the SOS response level of lux biosensors. It was shown that RA of the PDinI biosensor was more expressed than RA of the PRecA biosensor under the action of hydrogen peroxide, alkylating agents such as NMU, MMS, and streptozotocin, antibacterial agent such as dioxidine, and cytostatics such as mitomycin C and cisplatin. Antimetabolite 5-fluorouracil showed activity only with PDinI. Furacilin and 4-NQO, whose metabolites form adducts with DNA, were more active on PColD than on PRecA and PDinI. DNA gyrase inhibitors such as nalidixic acid and ciprofloxacin were less active on PDinI than on PColD and PRecA. Overall, among 13 tested substances, 8 more actively induced SOS response in the PDinI biosensor than in PColD and PRecA. At the same time, 5-fluororacil induced SOS response only with the PDinI biosensor. It was concluded that the PDinI biosensor can be successfully used for the primary detection of potential genotoxicants by their ability to induce SOS response in E. coli cells.

It has been demonstrated that deuterium oxide enhances the SOS response of Escherichia coli cells induced by chemical genotoxicants and mutagens. This demonstrates that the heavy nonradioactive hydrogen isotope deuterium can be considered to be a comutagen.

The effects of 29 substances, including known antioxidants, anti-radiation agents, amino acids, and vitamins, on the luminescence intensity of E. coli K12 MG1655 (pSoxS-lux) and MG1655 (pKatG-lux) bacterial cells induced by paraquat and peroxide, respectively, were studied. The luminescence of biosensors occurs as a result of activation of the soxS and katA gene promoters in response to an increase in the concentration of superoxide radicals and H2O2 in the cell. In the case of an antioxidant effect exerted by a substance under study, the intensity of the induced luminescence decreases, and in the case of a prooxidant effect, the luminescence intensity increases. Antioxidant activity was exhibited by 23 of 29 substances (79%) on the pKatG-lux biosensor and 22 of 29 substances (76%) on the pSoxS-lux biosensor. The studied anti-radiation agents (ten substances) showed different degrees of pro- and antioxidant activity. Lithium salt of glutathione disulfide, glutoxim, ginestein, and indraline significantly reduced the level of induced luminescence in both biosensors; magnesium salt of glutathione disulfide, zinc salt of reduced glutathione, and molixane, only in the pSoxS-lux biosensor; and cistamine and 5-AED, only in the pKatG-lux biosensor. Among the anti-radiation agents, a high prooxidant activity on the pKatG-lux biosensor at low concentrations was shown by lithium and magnesium salts of glutathione disulfide, zinc salt of reduced glutathione, molixane, and indralin (B-190); and on the pSoxS-lux biosensor, by genistein, cystamine, and 5-АED. The applicability of lux-biosensors for primary evaluation of the potential antioxidant and radioprotective activity of chemicals is discussed.

Because of the involvement in motivational processes, opioid receptors are potential targets for apathy treatment in schizophrenia. We therefore searched for associations between the opioid receptor gene polymorphisms (OPRM1 (rs1799971) and OPRD1 (rs1042114, rs533123)) and apathy measured with the Apathy Evaluation Scale-S in a group of 284 schizophrenia patients. We analyzed individual genotypes, haplotypes, and the digenic interaction and observed nominally significant associations of rs1042114 genotypes and the rs1042114*rs1799971 interaction with behavioral apathy scores. The associations, however, did not withstand correction for multiple comparisons. Thus, the results did not provide enough evidence for the opioid receptor gene effects on apathy in schizophrenia patients.

It has been shown for the first time that preliminary incubation of bacteria in a medium containing deuterium oxide (D2O) at concentrations of 2.5 to 10% leads to an increase in recA expression induced by hydrogen peroxide at concentrations of 2.2–8.8 mmol/L. The induction of recA in deuterated and non-deuterated (control) cultures was compared using a biosensor based on the E. coli strain K12 MG1655 (pRecA-lux), where luminescence occurs as a result of recA promoter activation in response to DNA damage caused by H2O2. The most effective D2O concentrations were 5.0 and 7.5%. To explain the phenomenon, expression of the catalase gene was studied in deuterated and non-deuterated cultures of E. coli K12 MG1655 (pKatG-lux) biosensor. The luminescence of this biosensor results from activation of the katG promoter in response to an increase in the concentration of H2O2 in the cell. It was found that D2O downregulated katG expression, which can lead to H2O2 accumulation, and, as a consequence, to an increase in the level of DNA damage as seen by an increase in recA expression.

This study has shown for the first time that deuterium oxide (D 2 O) enhances expression of the E. coli ada -regulon induced by alkylating compounds, N -nitroso- N -methylurea (NMU) and methyl methanesulfonate (MMS). To compare the induction of ada -regulon in deuterated and in non-deuterated (control) cultures of E. coli , a biosensor based on the E. coli strain K12 MG1655 (pAlkA–lux) luminescing as a result of activating the alkA gene promoter in response to DNA alkylation was used. Depending on the D 2 O concentration from 5 to 10% in the pre-deuterium medium, these alkylating compounds at a concentration of 0.005 M induced expression of the alkA gene from 1.3 to 5 times higher as compared to induction in nondeuterated culture. It is suggested that deuterium can be one of the main factors in stabilizing the bond between the promoter and the alkylated Ada protein, leading to increased transcription of the ada -regulon.

Representatives of the genus Stichosiphon live predominantly in fresh waterbodies epiphytic on algae and higher plants. Eight species of the genus have a tropical distribution, two species were found in central European countries, three species were described from the northwest of European Russia and one species lives in the highlands of Tibet. New species of the genus Stichosiphon, S. subarcticus is described. S. subarcticus was found in the desalinated pool at the upper littoral at Bolshoy Solovetskiy Island (Solovetskiy Archipelago, the White sea) growing on copepods. Morphological and ecological notes are given. Pseudofilaments solitary or in groups, straight or curved, uniseriate, not or sometimes slightly widened at the terminal part, mature pseudofilaments 25–55 μm long, 0.9–1.5(2.2) μm wide, exocytes and basal cells (0.6)0.85–1.45(2.2) μm long, 0.8–1.5(2.2) μm wide. This species is similar to S. sansibaricus var. marinus by short single-row and unbranched pseudofilaments, differs by width of pseudofilaments, exocyte dimensions and proportions (exocytes of S. sansibaricus var. marinus always longer than wide). Due to unstable conditions in the only known habitat salinity preferences of S. subarcticus are unclear. The location is the northernmost for this genus.