Background/Aim: A number of biologically active substances were proved as an alternative to conventional anticancer medicines. The aim of the study is in vitro investigation of the anticancer activity of mono- and di-Rhamnolipids (RL-1 and RL-2) against human breast cancer. Additionally, the combination with Cisplatin was analyzed. Materials and Methods: Breast cell lines (MCF-10A, MCF-7 and MDA-MB-231) were treated with RLs and in combination with Cisplatin. The viability was analyzed using MTT assay, and investigation of autophagy was performed via acridine orange staining. Results: In contrast to the healthy cells, both tested cancer lines exhibited sensitivity to RLs treatment. This effect was accompanied by an influence on the autophagy-related acidic formation process. Only for the triple-negative breast cancer cell line (MDA-MB-231) the synergistic effect of the combined treatment (10 µM Cisplatin and 1 µg/mL RL-2) was observed. Conclusion: Based on studies on the reorganization of membrane models in the presence of RL and the data about a higher amount of lipid rafts in cancer cell membranes than in non-tumorigenic, we suggest a possible mechanism of membrane remodelling by formation of endosomes. Shortly, in order to have a synergistic effect, it is necessary to have Cisplatin andRL-2 as RL2 is a molecule inducingpositive membrane curvature.

α-Galactosidase production by the fungal strains Penicillium chrysogenum LN33 and Aspergillus niger M47 cultivated in shaking and stationary conditions using soya meal extract as nutrient medium wa...

Isolation and characterization of new biologically active substances affecting cancer cells is an important issue of fundamental research in biomedicine. Trehalose lipid was isolated from Rhodococcus wratislaviensis strain and purified by liquid chromatography. The effect of trehalose lipid on cell viability and migration, together with colony forming assays, were performed on two breast cancer (MCF7—low metastatic; MDA-MB231—high metastatic) and one “normal” (MCF10A) cell lines. Molecular modeling that details the structure of the neutral and anionic form (more stable at physiological pH) of the tetraester was carried out. The tentative sizes of the hydrophilic (7.5 Å) and hydrophobic (12.5 Å) portions of the molecule were also determined. Thus, the used trehalose lipid is supposed to interact as a single molecule. The changes in morphology, adhesion, viability, migration, and the possibility of forming colonies in cancer cell lines induced after treatment with trehalose lipid were found to be dose and time dependent. Based on the theoretical calculations, a possible mechanism of action and membrane asymmetry between outer and inner monolayers of the bilayer resulting in endosome formation were suggested. Initial data suggest a mechanism of antitumor activity of the purified trehalose lipid and its potential for biomedical application.

Cultivation of microalgae in waste digestate is a promising cost-effective and environmentally friendly strategy for algal biomass accumulation and valuable product production. Two different digestates obtained as by-products of the anaerobic fermentation at 35 °C and 55 °C of wheat straw as a renewable source for biogas production in laboratory-scale bioreactors were tested as cultivation media for microalgae after pretreatment with active carbon for clarification. The strains of microalgae involved were the red marine microalga Porphyridium cruentum, which reached 4.7 mg/mL dry matter when grown in thermophilic digestate and green freshwater microalga-Scenedesmus acutus, whose growth was the highest—7.3 mg/mL in the mesophilic digestate. During cultivation, algae reduced the available nutrient components in the liquid digestate at the expense of increasing their biomass. This biomass can find further applications in cosmetics, pharmacy, and feed. The nitrogen and phosphorus uptake from both digestates during algae cultivation was monitored and modeled. The results led to the idea of nonlinear dynamic approximations with an exponential character. The purpose was to develop relatively simple nonlinear dynamic models based on available experimental data, as knowing the mechanisms of the considered processes can permit creating protocols for industrial-scale algal production toward obtaining economically valuable products from microalgae grown in organic waste digestate.

Biosurfactants produced by halophilic bacteria are gaining attention as eco-friendly and biocompatible alternatives to synthetic surfactants due to their high surface activity, stability under extreme conditions, and intrinsic antimicrobial properties. These amphiphilic biomolecules hold great promise for bioremediation, biomedical, and pharmaceutical applications. In this study, moderately halophilic bacteria capable of biosurfactant production were isolated from saline mud collected at the Burgas solar salterns (Bulgaria). The halophilic microbiota was enriched in Bushnell–Haas (BH) medium containing 10% NaCl amended with different carbon sources. Primary screening in BH liquid medium evaluated the isolates’ ability to degrade n-hexadecane while at the same time producing biosurfactants. Thirty halophilic bacterial strains were isolated on BH agar plates supplemented with 2% n-hexadecane, 2% olive oil, or 2% glycerol. Four isolates—BS7OL, BS8OL, BS9GL, and BS10HD—with strong emulsifying activity (E₂₄ = 56%) and reduced surface tension in the range of 27.3–45 mN/m were derived after 7 days of batch fermentation. Strain BS10HD was chosen as the most potent biosurfactant producer. Its phylogenetic affiliation was determined by 16S rRNA gene sequence analysis; according to the nucleotide sequence, it was assigned to Halomonas ventosae. The extract material was analysed by thin-layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). Upon spraying the TLC plate with ninhydrin reagent, the appearance of a pink spot indicated the presence of amine functional groups. FTIR analysis showed characteristic peaks for both lipid and peptide functional groups. Based on the observed physicochemical properties and analytical data, it can be suggested that the biosurfactant produced by Halomonas ventosae BS10HD is a lipopeptide compound.

Surfactants are widely used in industrial applications, creating a growing demand for sustainable and cost-effective production processes. Biosurfactants, on the other hand, are environmentally friendly alternatives to synthetic surfactants because of their biodegradability, low toxicity, and diverse functional properties. Among biosurfactant-producing microorganisms, filamentous fungi remain comparatively underexplored despite their considerable biotechnological potential. This study evaluated the biosurfactant-producing ability of filamentous fungi isolated from petrochemical waste-contaminated soil collected near a fuel station in Sofia, Bulgaria. Three isolates grown on n-hexadecane and olive oil were selected as promising fungi for biosurfactant production, following surface tension reduction and enhancement of emulsification. Based on ITS region sequencing, the isolates were identified as Penicillium cavernicola LL-1 (LC899784.1), Trichoderma longibrachiatum LL-2 (LC899785.1), and Aspergillus niger LL-3 (LC899786.1). Culture conditions were optimized, and the use of mineral–organic media supplemented with 2% sunflower seed oil at pH 7 was found most appropriate. The optimal cultivation temperature was 28 °C for P. cavernicola LL-1 and 35 °C for both T. longibrachiatum LL-2 and A. niger LL-3. Maximum biosurfactant activity occurred during the stationary growth phase. Among the isolates, T. longibrachiatum LL-2 reduced the surface tension to 31.8 mN/m and achieved an emulsification index (E₂₄) of 58% with motor oil, whereas P. cavernicola LL-1 reduced the surface tension to 34.8 mN/m and E₂₄ = 56% for gasoline, and A. niger LL-3 reduced the surface tension to 37.4 mN/m and E₂₄ was 57% for triolein. E₂₄ assay was performed with the same hydrophobic substrates (gasoline, diesel fuel, motor oil, olive oil or trioleins) for all of the studied strains. Based on the primary screening experiments (E₂₄ assay and surface tension measurement), T. longibrachiatum LL-2 was chosen as the most promising biosurfactant producer. For this reason, subsequent experiments were conducted with this strain for a deeper investigation, as it is the least researched. The combined chromatographic, spectroscopic, and mass-spectrometric analyses suggest that the bioproduct obtained from T. longibrachiatum LL-2 exhibits features consistent with a glycolipid compound and certain characteristics reported for sophorolipid-like compounds. However, these preliminary findings do not allow the carbohydrate moiety to be identified conclusively. This novel bioproduct exhibited pronounced surface-active properties, indicating its potential as a fungal-derived biosurfactant for sustainable biotechnological applications.