Haloalkaline environments are of particular interest for research, as they are characterized by a unique diversity of extremophilic microorganisms that are adapted to high salinity and alkalinity. Among these extremophilic microorganisms, strains that degrade various aromatic and aliphatic compounds, which have detrimental effects on ecosystems and human health, deserve special attention. Strain SJ1gcor, identified as a member of the genus Stutzerimonas, was isolated from the coastal soil of a technogenic saline-alkaline reservoir located within the Verkhnekamsk potassium-magnesium salt deposit (Berezniki, Perm Krai). Analysis of the 16S rRNA gene of the studied strain revealed the highest level of similarity (99.69%) to the homologous gene of Stutzerimonas zhaodongensis NEAU-ST5-21T. The strain is capable of growing as a sole source of carbon and energy on phthalates: dibutyl phthalate (DBP) and dimethyl phthalate (DMP), as well as the possible degradation products of these compounds: ortho-phthalic acid (OPA), benzoic acid (BA) and butanol. It was demonstrated that the strain is capable of growing on DBP as a substrate with a NaCl content of up to 70 g/L in the culture medium. The highest specific growth rate of the strain SJ1gcor was found when cultivating in a medium containing 30 g/L NaCl, and the maximum optical density was recorded in a medium containing 70 g/L NaCl. The benA gene encoding the α-subunit of benzoate 1,2-dioxygenase, a key enzyme in BA degradation, was identified in the strain's genome. Based on the data obtained, two alternative DBP degradation pathways were proposed for the strain SJ1gcor. Therefore, the strain Stutzerimonas sp. SJ1gcor is of interest for further research and holds promise for biotechnological applications.

Six benzoic acid-degrading bacteria of the genus Dietzia were isolated from the saline ecotopes of the Verkhnekamskoe and Yakshinskoe salt deposits (Perm region, Komi Republic, Russia). Benzoic acid (BA) may accumulate in ecosystems through technogenic processes, as well as during the microbiological decomposition of complex organic compounds containing an aromatic ring. The strains studied here were found to be closely related to D. psychralcaliphila, D. kunjamensis subsp. kunjamensis, D. cercidiphylli, and D. maris. It was shown that they are halotolerant and able to thrive on BA as their sole carbon and energy source in the absence of salt or in the presence of 50–70 g/L NaCl. They also contain benA genes encoding the α-subunit of benzoate 1,2-dioxygenase, the key enzyme of BA degradation. The highest level of similarity (79.32–91.38%) was observed between the nucleotide sequences of the benA genes of the strains considered and the homologous sequences of Actinomycetes representatives from genera such as Dietzia, Mycolicibacterium, Geodermatophilus, Pseudonocardia, Corynebacterium, and Raineyella. The described active BA degraders belonging to the genus Dietzia have the potential to aid in the development of bioremediation techniques for environmental objects contaminated with mono(poly)aromatic pollutants and subject to salting.

Four salt-tolerant and aromatics degrading strains used in this study were isolated from polluted technogenic soil on the territory of the Verkhnekamsk potash deposit (Russia). The strains were aerobic, Gram-stain-positive, non-motile, non-endospore-forming irregular rods, exhibiting a marked rod-coccus growth cycle. They contained lysine-based peptidoglycan, teichulosonic acid and poly(glycosyl phosphate) polymers in the cell walls. The major menaquinone was MK-9(H2), the predominant fatty acids were saturated, anteiso- and iso-branched, and the major compounds of polar lipid profiles included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and two glycolipids (monogalactosyldiacylglycerol and dimannosylglyceride). The strains showed the highest 16S rRNA gene sequence similarity to Arthrobacter crystallopoietes (99.6–99.9

Currently, more and more attention is paid to the study of microorganisms living in various extreme environments and those characterized by high salinity and alkalinity, in particular. The microbial communities of natural halo -alkaline ecosystems have been studied well. However, there is insufficient knowledge about the microorganisms of artificial ecosystems formed under the influence of technogenic factors. This work was aimed to study the diversity of cultivated bacteria in the microbial community of the bottom sediments of an alkaline technogenic reservoir located on the territory of the Verkhnekamsk potassium -magnesium salt deposit (Perm Krai, Russia). The studied reservoir is an extreme ecosystem characterized by a high content of watersoluble salts, heavy metals, and alkalinity of the environment. Various organic pollutants, namely, aromatic and aliphatic compounds can be found there as well. In this regard, the study was aimed to search for haloalkaliphilic destructor bacteria that are promising for bioremediation of saline/alkaline media (soils, water bodies) contaminated with toxic organic compounds. Thirty-three strains of alkalitolerant and halophilic/halotolerant bacteria were isolated from the bottom sediments of the alkaline technogenic reservoir. Based on the analysis of the nucleotide sequences of the 16S rRNA gene, the isolated strains belonged to the classes Bacilli , Gammaproteobacteria , Alphaproteobacteria , and Actinomycetes . The dominant group among the identified cultivated microorganisms were bacteria of the Bacillaceae family (13 strains), represented by the genera Evansella , Oceanobacillus , Bacillus , Alkalihalobacillus , Paralkalibacillus , Salipaludibacillus , Cytobacillus and Exiguobacterium . Most of the isolates were extremophiles capable of growing at high concentrations of NaCl (up to 250 g/l) and pH 7-11. Strains Microbacterium sp. & Scy;XP-56, Brachybacterium sp. CXP-58, Salipaludibacillus sp. CX3-6 and Alkalihalobacillus sp. CX2-3.1 were obligate alkalophiles which grow in the pH range of 9.5-10.5. Alkalihalobacillus spp. CX2-3 and CX2-3.1, Salipaludibacillus sp. CX3-6 may be described as new taxa because these new strains had low percentage of similarity in 16S rRNA genes (97.27; 97.12 and 97.75%) with closely related type strains. Most of the isolated strains had biodegradable properties and were able to use naphthalene, biphenyl, ortho- phthalic, benzoic acids, and diesel fuel as the sole source of carbon and energy. The destructor strains, which carry out effective decomposition of aromatic compounds at high alkalinity and salinity of the environment, presented interest, namely, Kocuria sp. CXP-33, Evansella sp. & Scy;X2-1, Halomonas sp. CX2-8, Micrococcus sp. CXP-15, Brevibacterium spp. CXP-21, CXP-53, and Brachybacterium spp. CXP-46, CXP-58.

The study is devoted to the ability of the bacterial strain 5A-K4, isolated from the rhizosphere of Puccinellia distans (Jacq.) Parl. plants, growing on the territory of industrial development of the Verkhnekamsk salt deposit (Perm krai), to grow on dibutyl phthalate (DBP) as the single carbon source was studied. Based on analysis of the 16S rRNA gene, the strain was identified as a representative of the genus Rhodococcus. Strain 5A-K4 had the highest level of the 16S rRNA gene similarity (99.86%) with Rhodococcus erythropolis NBRC 15567T. The strain grew effectively on a DBP substrate without addition of salt and at a content of 30 g/L NaCl in the cultivation medium. It has been shown that Rhodococcus sp. 5A-K4 is capable of growth at high concentrations of DBP (up to 12 g/L). The genome of the strain 5A-K4 contained the dpeH and mpeH genes, the products of which are involved in the initial stages of DBP degradation. The nucleotide sequences of the dpeH and mpeH genes are homologous to the sequences of the α/β hydrolase genes of strains of the classes Actinomycetes and Bacilli. Based on the data obtained, a pathway for the degradation of DBP by strain 5A-K4 was proposed. Thus, the rhizosphere DBP degrading strain Rhodococcus sp. 5A-K4 can be used as a bacterial agent in the development of phytoremediation methods for soils contaminated with phthalates.

Various natural saline and alkaline habitats have recently been widely investigated, but knowledge of anthropogenic habitats with more complex environmental conditions is still lacking. This research looks at the structure of microbial communities in 18 bottom sediment samples from a technogenic water body with saline and alkaline composition. The core samples were collected from 2 columns in the western and eastern parts of an artificial water body at the Verkhnekamskoe Salt Deposit (Russia). The microbial community structure was studied using high-throughput 16S rRNA gene sequencing. The bottom sediment composition (salinity, pH, and toxic element content) varies greatly with depth and laterally throughout the study area. The study found a considerable difference in bacterial community diversity between the 2 columns, but no considerable difference was found between the communities at various depths of the studied layers. Proteobacteria, Firmicutes, and Actinobacteria, which are common in both natural and artificial saline and alkaline environments, make up the majority of the bacteria found in the samples. Studies have shown that salinity and total alkalinity are the key factors influencing the formation of microbial communities. Ralstonia and Pseudomonas were the two most common genera in the sediment samples. These two genera are known for having high metabolic flexibility, which means they can survive in extreme environments and use a variety of carbon compounds as energy sources. The study also found that Ralstonia is indicator bacteria in samples with the highest concentrations of toxic elements compared to the other samples. A relatively high microbial diversity was discovered in the studied anthropogenic water reservoir despite the extreme alkaline and saline conditions, but it is considerably lower than that found in natural, less alkaline habitats. This research offers insight into the mechanisms behind microbial community formation in complex anthropogenic environments and covers key factors in microbial community distribution.

This study investigated the degradation of diesel fuel (DF) by an aerobic halotolerant strain, Dietzia sp. NDT10 (VKM Ac-2994D), under high salinity conditions. Dietzia sp. strain NDT10 has been isolated from diesel-contaminated rhizosphere soil of Dactylis glomerata L. on the territory of industrial production and processing of potassium salts (Solikamsk, Perm Krai, Russia). The 16S rRNA gene sequence analysis showed that the strain NDT10 is phylogenetically close (99.89 % similarity) to the type strains of two species, Dietzia maris DSM 43672T and Dietzia kunjamensis subsp. The ability of the strain NDT10 to degrade diesel fuel without salt and in the presence of up to 125 g NaCl/L was found. When adding 30, 50, and 70 g NaCl/L to the culture medium, the diesel fuel degradation ability of strain NDT10 was markedly increased, especially in the case of long-chain hydrocarbons (С15–С20) compared with short-chain hydrocarbons (С9–С14). An improvement in the degradative activity of Dietzia sp. NDT10 correlated with an increase in cell surface hydrophobicity in the presence of NaCl in the medium. Using the NDT10 strain as an example, a positive effect of diesel fuel components on the salt tolerance of bacteria was established. The results obtained can be used to develop biotechnological strategies for the clean-up of contaminated sites with DF and other petroleum products.

The taxonomic composition of soil (Technosol and Retisol) bacterial communities near the salt dump of a potassium enterprise (Solikamsk, Perm krai) was analyzed by the method of high-throughput sequencing of the 16S rRNA gene. Soil samples without plants and of the rhizosphere of plants of the species Calamagrostis epigeios (L.) Roth from plots located 1–1.5, 8, and 780 m and 11 km from the salt dump were studied. It was found that bacteria of the phyla Pseudomonadota, Bacteroidota, Actinomycetota, Acidobacteriota, Verrucomicrobiota, and Gemmatimonadota predominated in all soil samples. The impact of halite waste on the taxonomic composition of bacterial communities in soils was the greatest on plots in the salinization zone in the immediate vicinity of the salt dump (1–1.5 m). In soil samples without plants taken in these areas, bacteria of the order “Candidatus Actinomarinales“ predominated, the proportion of representatives of the phyla Acidobacteriota and Verrucomicrobiota, the class Actinobacteria, and the family Chitinophagaceae decreased, and the proportion of bacteria of the family Xanthomonadaceae in bacterial communities increased in comparison with nonsaline soils (at a distance of 8 and 780 m and 11 km from the salt dump). In the rhizosphere bacterial communities of plants, growing in the salinization zone, the proportion of representatives of the phylum Acidobacteriota and of the families Chitinophagaceae and Enterobacteriaceae decreased, while the proportion of the families Xanthomonadaceae and Flavobacteriaceae became greater. The influence of the salt dump on soil bacterial communities from plots located 8 m and 730 m from the salt dump was revealed: it was manifested in the presence of representatives of the order “Candidatus Actinomarinales“ (1.4–1.6

Background:Hydroxylated biphenyls are currently recognized as secondary pollutants that are hazardous to animals and humans. Bacterial degradation is the most effective method for the degradation of hydroxylated biphenyls. Several strains capable of degrading polychlorinated biphenyls have been described, which also degrade hydroxylated biphenyls. Objectives:1) To study the biodegradative properties of the Rhodococcus opacus strain KT112-7 towards mono-hydroxylated biphenyls. 2) To analyze the genome of the Rhodococcus opacus strain KT112-7. 3) To identify the genetic basis for the unique biodegradative potential of the Rhodococcus opacus strain KT112-7. Methods:A genome analysis of the strain KT112-7 was conducted based on whole-genome sequencing using various programs and databases (Velvet, CONTIGuator, RAST, KEGG) for annotation and identification of protein-coding sequences. The strain KT112-7 was cultivated in a K1 mineral medium supplemented with mono-hydroxy biphenyls or mono-hydroxybenzoic acids as the carbon source. For the growth test mono-hydroxybiphenyls or mono-hydroxybenzoic acids were dosed at concentrations of 0.5 g/L and 1.0 g/L correspondently, and the bacterial growth was monitored by the optical density. For the biodegradative activity test, mono-hydroxybiphenyls were dosed at a concentration of 0.1 g/L in vials, inoculated with late exponential phase bacteria previously acclimated on biphenyl. Compound analysis was performed using GC-MS, HPLC, and spectrophotometry. Results:It was found that the genome of strain KT112-7 consists of a chromosome and 2 plasmids. Biphenyl degradation genes (bph genes) were identified on plasmid PRHWK1 and the chromosome, as well as hydroxybenzoic acid degradation genes on the chromosome. The strain KT112-7 was shown to degrade mono-hydroxylated biphenyls to basal metabolic compounds of the cell, with the highest destructive activity observed towards 3- and 4-hydroxylated biphenyls (98%). Discussion:Analysis of the translated sequences of the bph genes from strain KT112-7 revealed that the amino acid sequences of the bph operon, located on plasmid pRHWK1, exhibit high similarity to homologous enzymes of the "upper" pathway for biphenyl degradation in Rhodococcus jostii RHA1, whose bph genes are also plasmid-borne. The deduced amino acid sequences encoded by the bphA1A2B genes, located on the chromosome of strain KT112-7, show a high degree of similarity to enzymes from Rhodococcus strains that mediate naphthalene degradation. The genes of the "lower" biphenyl pathway in strain KT112-7 are located on the chromosome and share a high level of similarity with the bph genes of Acidovorax sp. KKS102. Analysis of the deduced sequences of the pcaGHBCDF, pcaIJfadA, and catABC genes, along with the metabolites identified during the cultivation of strain KT112-7 on hydroxylated biphenyls, suggests the presence of both classical and unique metabolic pathways for hydroxylated benzoic acids in strain KT112-7. Conclusion:The Rhodococcus opacus strain KT112-7 is characterized by genetic systems that contribute to its high biodegradative potential towards mono-hydroxylated biphenyls and their metabolites. Thus, the strain KT112-7 is promising for use in hydroxybiphenyl degradation technologies.

Using the method of high-throughput sequencing of the 16S rRNA gene, the taxonomic composition of soil bacterial communities (Technosol and Retisol) near the salt dump of a potassium enterprise (Solikamsk, Perm region) was analyzed. Soil samples without plants and the rhizosphere of plants of the species Calamagrostis epigeios (L.) Roth) from areas located 1–1.5, 8, 780 m and 11 km from the salt dump were studied. It was found that bacteria from the phyla Pseudomonadota, Bacteroidota, Actinomycetota, Acidobacteriota, Verrucomicrobiota and Gemmatimonadota predominated in all soil samples. Halite waste had the greatest impact on the taxonomic composition of bacterial communities on the soils of areas (in the salinity zone) located in the immediate vicinity of the salt dump (1–1.5 m). In soil samples without plants collected in these areas, relative to soils samples without salinity (at a distance of 8, 780 m, 11 km from the salt dump), bacteria of the order “Candidatus Actinomarinales” predominated; the proportion in the bacterial communities of representatives of the phyla Acidobacteriota, Verrucomicrobiota, class Actinobacteria and the Chitinophagaceae family, the proportion of bacteria of the family Xanthomonadaceae increased. In rhizosphere bacterial communities of the plants growing in the salinity zone, the proportion of representatives of the phylum Acidobacteriota and the families Chitinophagaceae, Enterobacteriaceae decreased, and the proportion of the families Xanthomonadaceae and Flavobacteriaceae increased. The influence of the salt dump on the soil bacterial communities from areas located 8 m and 730 m from the salt dump was revealed, manifested in the presence of representatives of the order “Candidatus Actinomarinales” (1.4–1.6%), families Nitrosomonadaceae (3.0–6.1%), Saprospiraceae (1.0–1.9%), the genus Ilumatobacter (1.6–2.8%) and unculturable bacteria of the family Rhodanobacteraceae (1.3–1.5%).

Bacteria make a huge contribution to the purification of the environment from toxic stable pollutants of anthropogenic and natural origin due to the diversity of their enzyme systems. For example, the ability to decompose 3-chlorobenzoate (3CBA) by the four representative genera of Actinobacteria, such as Rhodococcus, Gordonia, Microbacterium, and Arthrobacter, was studied. In most cases, the formation of 4-chlorocatechol as the only key intermediate during the decomposition of 3CBA was observed. However, Rhodococcus opacus strain 1CP was an exception, whose cells decomposed 3CBA via both 3-chloro- and 4-chlorocatechol. The enzyme 3-Chlorobenzoate 1,2-dioxygenase (3CBDO) induced during the growth of these bacteria in the presence of 3CBA differed significantly in substrate specificity from the benzoate dioxygenases induced upon growth in the presence of benzoate. The R. opacus 6a strain was found to contain genes encoding chlorocatechol 1,2-dioxygenase, chloromuconate cycloisomerase, and dienelactone hydrolase, whose nucleotide sequence was 100% consistent with the sequences of the corresponding genes encoding the enzymes of the modified 4-chlorocatechol ortho-cleavage pathway of the strain R. opacus 1CP. However, the gene encoding chloromuconolactone dehalogenase (clcF) was not found in the representatives of the actinomycete genera, including Gordonia and Arthrobacter. A linear mega-plasmid carrying 3-chlorocatechol degradation genes remained stable after maintaining the R. opacus 1CP strain on an agar-rich medium for 25 years. In general, a similar plasmid was absent in actinobacteria of other genera, as well as in closely related species of R. opacus 6a.

Phthalic and terephthalic acids (PA and TPA) are widely used in the chemical industry as plasticizers, for the production of polymer materials, and therefore are common eco-pollutants. The ability of the strain Paenarthrobacter sp. SA101, isolated from a sample of a chemical plant wastewater (Perm), to growth on high concentrations of PA and TPA was studied. It was shown that strain SA101 is capable of efficient growth on these substrates at concentrations up to 20 g/l, which is shown for the representatives of the genus Paenarthrobacter for the first time. Higher strain growth parameters were recorded in media with PA, than in media with TPA: the maximum value of OD600 (1.64), the highest specific growth rate (0.073±0.003 h-1) and the shortest lag phase were observed in a medium with 10 g/l of PA. The highest specific growth rate (0.04±0.002 h‑1) and the maximum value of OD600 (1.6) were observed with 20 g/l of TPA, however, the lag phase of growth was longer than in the medium with 10 g/l of TPA. The strain SA101 was able to utilize 76% of PA in 39 hours and 74.2% of TPA in 71 hours of cultivation, when using these substrates at a concentration of 10 g/l. The cells of the strain SA101 contain a plasmid with a molecular weight of ~ 100 bp. The strain SA101 is promising for the development of biotechnological methods for cleaning phthalate-contaminated soils and industrial effluents.

Proton magnetic resonance spectroscopy was used for investigation of the pool of compatible solutes accumulated in the cells of Glutamicibacter sp. strain SMB32 in response to abiotic environmental factors. The original habitat of the strain was anthropogenically salinated soil at the Verkhnekamsk deposit of potassium and magnesium salts (Perm krai, Russia). The strain grew within the temperature range from 5 to 35°C. At 5 and 32°C, the intracellular content of trehalose in the cells of Glutamicibacter sp. SMB32 was significantly higher than at 25°C. Glutamicibacter sp. SMB32 was able to grow both in the absence of NaCl and at its concentrations up to 11

The ability of three bacterial strains of the class Actinomycetes, isolated from the rhizosphere of bluegrass (Poa pratensis L.) plants growing in the industrial development area of the Verkhnekamsk salt deposit (Perm krai), to grow on dibutyl phthalate (DBP) as the only source of carbon and energy was studied. Based on 16S rRNA gene analysis, it was shown that the strain Rh7bel showed similarity at 100% level with Rhodococcus wratislaviensis NBRC 100605T, and strains NKDBFbel and NKDBFgelt are phylogenetically close to two type strains of the species Pseudarthrobacter oxydans and Pseudarthrobacter polychromogenes (99.83% similarity). DBP-degrading strains are characterized by efficient growth on the key metabolite of DBP degradation, ortho-phthalic acid, and utilization of this metabolite. The strain Rhodococcus sp. Rh7bel demonstrated the highest rates of DBP utilization: the maximum specific substrate consumption rate was 0.018±0.002 h-1, substrate utili-zation was 70.7% in 72 hours (initial DBP concentration 0.2 g/L). Thus, rhizosphere DBP-degrading strains Rhodococcus sp. Rh7bel, Pseudarthrobacter spp. NKDBFbel and NKDBFgelt are promising for further study and development of technology for phytoremediation of soils contaminated with phthalates.

The phylogenetic diversity of archaea and bacteria was investigated for the first time in marl samples of the Verkhnekamsk salt deposit of Perm Krai (Russia). Two libraries of 16S rRNA genes from the marl sample (depth of 70.5 m) obtained by molecular genetic methods (cloning of 16S rRNA genes, RFLP analysis and sequencing) were distributed in 3 archaeal OTUs (80 clones) and 11 bacterial OTUs (86 clones). Phylogenetic analysis showed a low diversity of Archaea, closely related to the Thaumarchaeota phylum (phylogenetic cluster Marine Group I). Thereto, all archaeal OTUs were similar in the 16S rRNA gene with an uncultured archaeal clone isolated from groundwater of the Permian period. Molecular phylogeny revealed that bacterial diversity was presented by the phyla Proteobacteria, Actinobacteria and Acidobacteria. The dominant phylum Proteobacteria (75.54

The unique ecosystem of industrial development area of the Verkhnekamsk salt deposit (VSD) (Perm krai, Russia) is characterized by the combined effect of salinization and contamination by organic pollutants, including polycyclic aromatic hydrocarbons (PAH). The purpose of the present study was to examine the degradative potential in relation to naphthalene, as a model PAH, under different salinity of bacterial consortium SMB3, previously isolated from soil of the VSD region, as well as the effect of long-term exposure to high salinity on the taxonomic composition of the consortium. The consortium SMB3 was able to grow on naphthalene both in the presence of NaCl up to 90 g/L, and in its absence. With an increase in the concentration of NaCl to 90 g/L, the growth rate of the consortium decreased by 2.1 times (compared with that of the consortium in a salt-free medium), and the naphthalene utilization estimated after 72 hours of cultivation decreased by 22.9 times. As a result of long-term cultivation in a mineral medium with naphthalene in the presence of 70 g/L NaCl, moderately halophilic strains Halomonas sp. SMB31 and Salinicola socius SMB35 T , not using naphthalene as the sole source of carbon and energy, and naphthalene degraders �hodococcus spp. SMB37 and SMB38 were shown to preserve in the consortium, while strains Glutamicibacter sp. SMB32, Microbacterium sp. SMB33, ‘‘ Thalassospira permensis ’’ SMB34 T , not growing on naphthalene, were eliminated. Thus, using the model experiments with the bacterial consortium SMB3, it has been shown that the soil autochthonous microbocenosis in the VSD salt-mining area is able to degrade persistent toxic organic compounds in a wide range of salinity, and prolonged exposure to a high salt concentration leads to a decrease in species richness.

Screening of ability to utilize benzoate as the sole carbon and energy source was carried out for 124 strains of the family Halomonadaceae (genera Halomonas, Chromohalobacter, Salinicola, and Kushneria) isolated from mining sites of the Upper Kama deposit of potassium and magnesium salts. Active growth on benzoate (in the presence of 30‒70 g/L NaCl) was shown for 28 Halomonas strains closely related to the species H. taeanensis, H. olivaria, H. ventosae, H. titanicae, H. alkaliantarctica, H. neptunia, H. radicis, and H. sulfidaeris. Strains of the genera Chromohalobacter, Salinicola, and Kushneria either did not grow on benzoate or carried out its transformation (two Chromohalobacter strains). PCR screening for the benA gene encoding the α-subunit of benzoate 1,2-dioxygenase (1,2-DO), the key enzyme for benzoate degradation, within the family Halomonadaceae revealed its presence in all benzoate-degrading Halomonas strains. The sequences of the amplified fragments had the highest similarity (not exceeding 95.50%) with the genes encoding the α-subunits of benzoate 1,2-DO, 2-chlorobenzoate 1,2-DO, and other dioxygenases of Halomonas strains containing Rieske-type [2Fe-2S] clusters. New data on the genetic systems regulating benzoate degradation in Halomonas isolates are of interest for better understanding of molecular mechanisms of aromatics degradation under salinization conditions. The isolated active benzoate degraders may be used to develop the technologies for bioremediation and monitoring of polluted soils.

The aggregation behavior of a novel amphiphilic photosensitizer - pyropheophorbide-[Formula: see text] 17-diethylene glycol ester 1 was studied in aqueous and aqueous-organic mixtures by means of steady-state absorption and fluorescence emission spectroscopy. The formation of [Formula: see text]-aggregates with a bathochromic shift of the absorption bands, weak fluorescence and resonance enhancement of the light scattering was observed in the mixed water-organic solvents. Solubilization studies in micellar cationic surfactant solutions of alkyl trimethylammonium bromides (C[Formula: see text]TAB) and alkyl triphenylphosphonium bromides (C[Formula: see text]TPPB) resulted in the most effective stabilization of the fluorescent monomolecular form of 1 in C[Formula: see text]TPPB micelles. It was shown that [Formula: see text]-aggregate formation in submicellar surfactant solutions is the initial stage of the solubilization process, which significantly increases in phosphate buffer medium at pH 7.4. Fluorescence lifetime ([Formula: see text] of 1 in DMSO was found to be 7.4 ns, fluorescence quantum yield - 34% and singlet oxygen quantum yield - 62%. The results obtained indicate the need for further studies of compound 1 solubilized in C[Formula: see text]TPPB micelles as the most promising prototype of the drug formulation for mitochondria-targeted photodynamic therapy of cancer.

Biodegradative characteristics were investigated for the commercially available mixtures of polychlorinated biphenyls (PCBs) Trikhlorbifenil and Sovol degraded by the Rhodococcus wratislaviensis КT112-7, Rhodococcus wratislaviensis CH628 and Rhodococcus ruber P25 strains isolated from the natural habitats. For bioutilization of the Trikhlorbifenil, all three strains were found to have a high biodegrading potential: the complete destruction was achieved in 10–14 days. For the mixture Sovol, the bioutilization parameters were found to be of lower values: the degradation of the PCBs congeners was 96–98% after 14 days. For the tested polychlorobiphenyl mixtures, the structural specificities of congeners are discussed, the genes encoding monooxygenases are revealed, and explanation is given to the differences in biodegradative characteristics of the Rhodococcus strains towards di-, tri-, tetra-, penta-, hexa- and heptachlorobiphenyls. The presented data are highly relevant for environmental remediation of objects polluted with the extremely hazardous polychlorobiphenyls.

This article provides the first description of the bacterial diversity in the Permian rock of the Upper Pechora salt basin. Halophilic and halotolerant bacteria of the classes Gammaproteobacteria (from the genera Halomonas , Marinobacter , and Idiomarina) and Actinomycetia (from the genus Dietzia) were isolated from the brines extracted during the underground dissolution of carnallite rocks in the pilot well of the Yakshinskoe deposit (Komi Republic, Russia) of potassium-magnesium salts. The analysis of 16S rRNA gene sequences cloned from the total DNA of the floatable part of the insoluble brine resi-dues revealed the following bacterial classes: Gammaproteobacteria (closely related to the genera Idio-marina , Marinimicrobium , Marinobacter , Methylophaga , and Pseudidiomarina), Betaproteobacteria (phenologically similar to the genera Achromobacter and Methylotenera), as well as Alphaproteobacteria and Flavobacteriia (related to the genera Sulfitobacter and Salegentibacter , respectively). Several identified phy-lotypes (clones 113YS, 8YS, 150YS, and 157YS) had a low level of similarity with the closest type strains of the genera Methylophaga (M. nitratireducenticrescens JAM1T , 96.86%), Salegentibacter (S. salarius ISL-6T , 98.58%), and Methylotenera (M. versatilis 301T , 98.05% and 98.19%). This indicates that the brine samples contained new, previously undescribed, bacterial taxa. The results obtained define and shape the future prospects for studying the phylogenetic and functional diversity of microorganisms in the salt strata of the Yakshinskoe deposit.