Denis Victorovich Axenov-Gribanov

1. Biogenic amines serve crucial roles as hormones, neuromodulators, and neurotransmitters. These compounds are present in all living organisms–including animals, plants, and microorganisms – where...

Pharmaceutical pollutants, including ibuprofen, are now ubiquitously detected in global aquatic ecosystems, exerting significant negative ecological impacts. Lake Baikal organisms have been documented to accumulate ibuprofen and related contaminants. This study quantified ibuprofen concentrations within Lake Baikal’s endemic amphipod fauna using high-performance liquid chromatography coupled with mass spectrometry. We analyzed specimens representing key ecological groups across the genera Eulimnogammarus , Brandtia , Ommatogammarus , and Pallasea . Ibuprofen concentrations ranged from 4.19 ng/g to 1,151.32 ng/g (wet weight), confirming consistent contamination in both littoral and deep-water endemic amphipod populations. Crucially, our data provide the first evidence suggesting amphipods, or their associated symbiotic microbiota, may metabolize ibuprofen. Interspecific accumulation patterns were identified, with Eulimnogammarus sp. and Brandtia sp. exhibiting distinct profiles. Furthermore, accumulation was significantly higher during spring compared to autumn samples. A negative correlation emerged between ibuprofen concentration and amphipod body mass within species. Several populations contained non-detectable levels. These findings demonstrate that endemic amphipods within Lake Baikal’s natural environment are exposed to and bioaccumulate the pharmaceutical pollutant ibuprofen, exhibiting species-specific, seasonal, and allometric variation in uptake.

Изучение влияния пищевой добавки на основе трюфелевых грибов на гематологические и физиологические показатели лабораторных крыс

One of the current challenges on a global scale is the problem of antibiotic resistance. Excessive and inappropriate use of drugs in healthcare and agriculture has accelerated the development of diseases caused by antibiotic-resistant bacteria. In an effort to combat such resistance, it is extremely important to explore alternative sources of new molecules with biological activities. Truffles have become a promising source of new compounds because they contain a wide range of biologically active ingredients. In addition, they are a consortium of symbiotic microorganisms that produce natural products. The aim of this study was to study the antibiotic and growth stimulating effects of methanolic extracts of truffle fruiting bodies collected in Russia in 2020-2022. The extracts demonstrated inhibitory activity against St. carnosus, E. persicina, and kanamycin-resistant E. coli. Also, for the first time, we have demonstrated that truffle extracts have biological activity in terms of stimulating the growth of C. vulgaris. We have observed the effects of short-term and long-term growth stimulation. Thus, truffles can become a promising source of new active ingredients in medicine, agronomy, and different life sciences.

Исследование антагонистической активности грибных симбионтов черного трюфеля

The complex symbiotic relationships between truffles and their microbiota, coupled with their obligate mycorrhizal lifestyle, present significant challenges for obtaining axenic mycelium and achieving controlled cultivation. This study aimed to characterize the microbial communities within the surface and gleba of truffle ascomata using 16S and 18S rRNA gene sequencing and identify the taxonomic composition and ecological roles of these microbiota. Specimens of Tuber magnatum (white truffle) and Tuber macrosporum (smooth black truffle) were collected, with T. magnatum representing the first documented discovery of this species in Russia. Metabarcoding profiling identified both species-specific and shared microbial taxa, with the yeast-like fungus Geotrichum spp. emerging as a core symbiont in both truffle species. Its consistent detection in surface and gleba tissues suggests a critical role in mycorrhizal establishment and spore dispersal, potentially mediated by sulfur volatiles that attract mycophagous fauna. In T. magnatum, the bacterial community was dominated by Proteobacteria, particularly Alphaproteobacteria and Gammaproteobacteria, with the nitrogen-fixing genus Bradyrhizobium being especially abundant. The truffle microbiota predominantly comprised soil-derived microorganisms (e.g., nitrogen-fixing Rhizobiaceae spp., phenol-degrading Mycoplana spp.) and plant-associated symbionts (e.g., ectomycorrhizal Sebacina spp.), implicating these communities in nutrient cycling, xenobiotic degradation, and host plant interactions. By elucidating the taxonomic and functional profiles of truffle-associated microbiota, this study provides foundational insights into their ecological contributions. Chemical differences align with tissue-specific microbial communities, suggesting microenvironmental specialization in bioactive compound synthesis. These findings advance efforts to replicate critical symbiotic interactions in vitro, a prerequisite for developing sustainable cultivation protocols for T. magnatum and T. macrosporum under controlled conditions.

Pharmaceutical pollutants, including ibuprofen, are now ubiquitously detected in global aquatic ecosystems, exerting significant negative ecological impacts. Lake Baikal organisms have been documented to accumulate ibuprofen and related contaminants. This study quantified ibuprofen concentrations within Lake Baikal’s endemic amphipod fauna using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). We analyzed specimens representing key ecological groups across the genera Eulimnogammarus, Brandtia, Ommatogammarus , and Pallasea . Ibuprofen concentrations ranged from 4.19 ng/g to 1151.32 ng/g (wet weight), confirming consistent contamination in both littoral and deep-water endemic amphipod populations. Crucially, our data provide the first evidence suggesting amphipods, or their associated symbiotic microbiota, may metabolize ibuprofen. Interspecific accumulation patterns were identified, with Eulimnogammarus sp. and Brandtia sp. exhibiting distinct profiles. Furthermore, accumulation was significantly higher during spring compared to autumn samples. A negative correlation emerged between ibuprofen concentration and amphipod body mass within species. Several populations contained non-detectable levels. These findings demonstrate that endemic amphipods within Lake Baikal’s natural environment are exposed to and bioaccumulate the pharmaceutical pollutant ibuprofen, exhibiting species-specific, seasonal, and allometric variation in uptake.

Microorganisms inhabiting extreme environmental conditions receive special attention because they possess different adaptations to adverse conditions. Currently, their biotechnological potential and ability to isolate biologically active metabolites have increased. The increasing mortality due to different diseases has become particularly important as one of the notable challenges in modern healthcare. This highlights the necessity of discovering new producers of natural products (NPs). The aim of this study was to evaluate the genetic and biotechnological potential through the assessment of NP synthesis and genome annotation of the thermophilic strain Streptomyces sp. LPB2020-019-1HS. The thermophilic strain was isolated from the Baikal endemic cold water sponge Lubomirskia baikalensis. Subsequently, Streptomyces sp. LPB2020-019-1HS was cultivated at six temperatures (13°C, 28°C, 37°C, 45°C, 55°C, and 65°C) in twelve nutrient media with different compositions (nutrient rich and nutrient poor). Using high-performance liquid chromatography and mass spectrometry approaches, the synthesis of compounds by the strain was assessed at 13°C, 28°C, and 37°C. Antimicrobial activity was evaluated at all temperatures (from 13°C to 65°C). We demonstrated the presence of antibiotic activity against Bacillus subtilis for strains cultivated at 28°C, 37°C, and 45°C. Additionally, we observed activity against Mycobacterium smegmatis when the strain was cultivated at 28°C, 37°C, 45°C, and 55°C. Furthermore, the strain exhibited activity against Escherichia coli, Pseudomonas putida, and Candida glabrata when cultured at 37°C. Overall, we found that Streptomyces sp. LPB2020-019-1HS produces a family of NPs related to Nocardamine and hypothesized that freshwater Actinobacteria have mechanisms for chelating iron ions, making them available for plants/sponges or other symbiotic organisms. Therefore, our research findings underscore the importance of studying extremophilic microorganisms from Lake Baikal in the context of developing new pharmaceuticals and biotechnological solutions for contemporary healthcare challenges.