Maria Curie-Skłodowska University

Purpose. The application of plant growth promoting rhizobacteria (PGPR) is considered to have the potential to improve plant development in water-stressed agroecosystems. The current study was designed to screen PGPR for a broad spectrum of functional traits that that can enhance plant growth and soil microbial activity under drought stress conditions. Methods. This study characterised selected indigenous bacterial strains isolated from the rhizosphere of Lactuca sativa, focusing on their ability to enhance nutrient bioavailability, phytostimulation and produce biofilms and exopolysaccharides. The isolates’ functional potential was validated under controlled conditions by evaluating plant biomass and soil enzymatic activity under two treatments: moderate drought stress and well-watered control. Results. Using the biological GEN III test, the strains tested were found to be metabolically diverse. Furthermore, the results indicate that all strains solubilize phosphate, fix nitrogen and synthesize indole-3-acetic acid (IAA) - like compounds. Most of them were active producers of siderophores and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Out of 15 strains, 3 were strong biofilm producers, while all strains were extracellular polymeric substances (EPS) producers. The results of the pot experiment showed that decreasing irrigation significantly reduced the total biomass of lettuce by 36.2

The higher-order WKB Mathematica code for computing quasinormal modes, whose accuracy was significantly enhanced through extensions to higher orders and, in particular, through the use of Padé resummation, has been widely employed in numerous studies over the past several years. In this work, we present an updated and optimized version of the code. The main improvement consists in expanding the effective potential in a Taylor series around its maximum, rather than evaluating the full analytic expression of the WKB formula for each specific potential. This modification leads to a substantial reduction in computation time. In cases where the effective potential is complicated and involves non-rational functions, the speed gain can reach several orders of magnitude, while preserving the accuracy of the method.

Understanding the reproductive biology and breeding system of rare species is crucial for effective conservation. We examined floral biology, assessed the true pollinators, and investigated the reproductive effect of six pollination treatments (spontaneous and induced autogamy, geitonogamy, spontaneous and supplemental cross-pollination, control - flowers exposed to natural pollinators) on the fruit and seed set and their quality (size, viability) in two populations (artificial and natural) of clonal Scopolia carniolica (Solanaceae), a rare species distributed across Central and South-Eastern Europe. Hermaphroditic flowers of S. carniolica represent movement herkogamy and incomplete protogyny. Pollinators are necessary for transferring pollen onto stigmas (there was no fruit and seed set after a test for spontaneous self-pollination), and the species shows the system of obligatorily xenogamy (only cross-pollination guarantees the production of seeds with fertile embryos ensuring viable offspring) and self-incompatibility (no seeds are produced after within-flower self-pollination). Although fruits can be developed through geitonogamous self-pollination, this is associated with late-acting self-incompatibility because the seeds produced are non-viable (contain no embryos and endosperm). Bumble bees are the most effective pollinators; honeybees also contribute to pollen deposition. Conserving pollinator diversity is essential for rare clonal S. carniolica, sustaining reproduction, preventing inbreeding depression, and supporting long-term population viability.

This study focuses on developing a stable and selective cobalt-based catalyst for ethanol steam reforming (ESR) using a cost-effective and readily available alumina support. A bead-shaped alumina support (b-Al2O3), composed of more than 80 % alpha-Al2O3 and featuring a relatively high surface area, was synthesized using a polymer-templated method. To enhance the cobalt-alumina interaction and improve catalytic performance, two strategies were applied: (i) potassium doping of a cobalt catalyst prepared using the incipient wetness impregnation method (1 %K-Co/b-Al2O3_I), and (ii) cobalt deposition via a sonochemical method (Co/b-Al2O3_SC). Both approaches yielded stable catalysts that maintained 100 % ethanol conversion for 21 h under ESR conditions (500 degrees C, EtOH:H2O 1:4) while the dehydration pathway remained suppressed entirely. Detailed analysis of the fresh, reduced, and spent catalysts showed that both modification strategies effectively strengthened the interaction between cobalt and alumina. As a result, in both 1 %K-Co/b-Al2O3_I and Co/b-Al2O3_SC catalysts, most of the cobalt active phase remained anchored to the alumina support after the ESR reaction. In the first strategy, doping cobalt-based catalysts with potassium enhanced the cobalt-alumina interaction by altering the electronic properties of the catalyst surface. In the second strategy, using a sonochemical method to deposit cobalt led to the formation of a highly dispersed mixed cobalt-alumina phase at the interface between the active metal and the support. Both approaches led to a notably higher content of unreduced cobalt species-key for C-O and O-H bond cleavage-compared to the undoped, impregnated catalyst (Co/b-Al2O3_I).

The presence of cadmium (Cd) in wet phosphoric acid (WPA), a key intermediate in fertilizer production, poses a significant environmental and health risk due to the potential release of hazardous impurities throughout the fertilizer value chain. As global fertilizer demand intensifies, reducing Cd emissions has become a priority for sustainable production with regulatory compliance. This study evaluates the efficiency of sulfonic acid functionalized resins for the selective removal of Cd(II) ions from industrial WPA, aiming to support cleaner production practices and reduce the environmental footprint of the fertilizer industry. A series of batch experiments was conducted to assess the selectivity, capacity, and operational feasibility of selected cation exchangers under conditions representative of industrial operations. The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm model, with maximum monolayer capacities of 123.0 mg/g for K1131 S and 173.5 mg/g for K1461. Thermodynamic analysis confirmed that the process is spontaneous and endothermic, while surface characterization (SEM-EDX, XPS, FTIR-ATR) supported the proposed adsorption mechanisms. The results demonstrate that targeted Cd removal at the WPA purification stage significantly reduces the Cd load in downstream fertilizer products and minimizes the risk of soil and groundwater contamination. Overall, the findings indicate that ion exchange processes provide an effective strategy for improving WPA quality, thereby enabling the production of P-fertilizers that meet environmental and quality requirements.