This study presents results of research on isolation new bacteria strain Achromobacter xylosoxidans able to effect on the structure of high-density polyethylene (HDPE), polymer resistant to degradation in environment. New strain of A. xylosoxidans PE-1 was isolated from the soil and identified by analysis of the 16S ribosome subunit coding sequences. The substance to be degraded was HDPE in the form of thin foil films. The foil samples were analyzed with Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) as well as scanning electron microscope (SEM), and the results revealed degradation of chemical structure of HDPE. About 9 % loss of weight was also detected as a result of A. xylosoxidans PE-1 effect on HDPE foil. On the basis of comparative spectral analysis of the raw material before the bacteria treatment and the spectrum from a spectra database, it was assumed that the HDPE was the only source of carbon and energy for the microorganisms. No fillers or other additives used in the plastic processing were observed in HDPE before experiments. This is the first communication showing that A. xylosoxidans is able to modify chemical structure of HDPE, what was observed both on FTIR, in mass reduction of HDPE and SEM analysis. We also observed quite good growth of the bacteria also when the HDPE was the sole carbon source in the medium. These results prove that A. xylosoxidans is an organism worth applying in future HDPE biodegradation studies.

Plants have developed various acclimation strategies in order to counteract the negative effects of abiotic stresses (including temperature stress), and biological membranes are important elements in these strategies. Brassinosteroids (BR) are plant steroid hormones that regulate plant growth and development and modulate their reaction against many environmental stresses including temperature stress, but their role in modifying the properties of the biological membrane is poorly known. In this paper, we characterise the molecular dynamics of chloroplast membranes that had been isolated from wild-type and a BR-deficient barley mutant that had been acclimated to low and high temperatures in order to enrich the knowledge about the role of BR as regulators of the dynamics of the photosynthetic membranes. The molecular dynamics of the membranes was investigated using electron paramagnetic resonance (EPR) spectroscopy in both a hydrophilic and hydrophobic area of the membranes. The content of BR was determined, and other important membrane components that affect their molecular dynamics such as chlorophylls, carotenoids and fatty acids in these membranes were also determined. The chloroplast membranes of the BR-mutant had a higher degree of rigidification than the membranes of the wild type. In the hydrophilic area, the most visible differences were observed in plants that had been grown at 20 °C, whereas in the hydrophobic core, they were visible at both 20 and 5 °C. There were no differences in the molecular dynamics of the studied membranes in the chloroplast membranes that had been isolated from plants that had been grown at 27 °C. The role of BR in regulating the molecular dynamics of the photosynthetic membranes will be discussed against the background of an analysis of the photosynthetic pigments and fatty acid composition in the chloroplasts.

The article attempts to assess the usefulness of the Taguchi method to optimise the purification process of synthetic textile wastewater (pH 6.7 - 7.2, Conductivity = 6.71 - 6.84 mS/cm, Salinity = 3581 - 3648 mg NaCl/l, Colour = 560 - 4710 mg Pt/l, COD = 2220 - 2290 mg O2/l, TOC = 394 - 551 mg/l) using K2FeO4. The research was conducted using 3 types of wastewater containing anionic detergent (sodium lauryl sulfate, 100 mg/l) and differing only in the concentration of azo dye Acid Green 16 (AG 16). Technical K2FeO4 was used as an oxidiser, which was subjected to physico-chemical analysis (purity, UV-VIS spectrum, surface characteristics and chemical composition using SEM and EDX methods). For planning and optimising the wastewater treatment process, the Taguchi method was used for four input parameters: pH (2, 7, 12), reaction time (10, 30, 50 min), AG 16 concentrations (20, 120, 220 mg/l) and K2FeO4 concentrations (25, 125, 225 mg/l), for which 9 experiments were performed in accordance with the plan adopted. Test result analysis allowed to indicate the optimal values for individual input parameters (pH 2, time = 50 min, AG 16 = 20 mg/l, K2FeO4 = 125 mg/l). Under these conditions, visual discoloration of wastewater was obtained (AG 16 = 0.4 mg/l, ↓98% ), colour removal (66 mg Pt/l, ↓88%) and DOC (249 mg/l, ↓37%).

Flax, Linum usitatissimum, cultivars are grown throughout the world. Flax oil is a dietary source of polyunsaturated fatty acids, vitamin E, as well as phospholipids, sterols, and phenolic acids. Linseed plays a pivotal role in protecting cells from oxidative damage associated diseases, i.e., atherosclerosis, neurodegenerative disorders, cancer, and inflammation. In this study, two groups of L. usitatissimum seeds were used to evaluate and compare the content and composition of tocochromanols (vitamin E) and fatty acids. Group I included accessions originating from Poland and the Ukraine, while Group II encompassed worldwide flax cultivars (such as from the United States, Argentina, and Italy). A comparison of the tocochromanol profiles showed a higher content in Group I, although there were no significant differences in tocopherol content and composition between the genotypes within this group. All accessions in Groups I and II contained γ-tocotrienol and plastochromanol-8, which confirms the high nutritional value of flaxseeds. The composition of fatty acids varied depending on the varieties, with linolenic acid showing the greatest discrepancy. Based on the tocochromanol content and fatty acid composition, we conducted a principal component analysis (PCA) and cluster analysis, which revealed a greater similarity among the accessions in Group I. An analysis of the tocochromanol and fatty acid composition of flaxseeds is important from an agronomic and medicinal perspective and can be used to select the most appropriate flax cultivar.

-The greenhouse effect results in warming the planet's surface and a higher ocean heat content. It causes changes of the water circulation frequency and turbulent mixing, delivering warm water, phytoplankton nutrients and CO2 from deeper layers of water to the water surface. All of these changes can have an impact on Earth's ecosystems. In the present study the effect of changing environmental temperature on a model diatom species, Thalassiosira pseudonana was tested under laboratory conditions. The purpose of the work was to analyze the temperature effect on fluidity and chemical composition of the thylakoid membranes. The photosynthetic activity and photosynthetic pigment contents of diatoms adapted to different temperatures were also determined. Our result show decreases of the growth rate and chlorophylls concentration in diatom cells cultured at lower temperature. It was also detected that increases of the polyunsaturated and decreases of saturated fatty acids, as well as changes in lipids:proteins ratio, resulted in stabilization of the thylakoid membranes fluidity and photosynthetic efficiency (Fv/Fm) in a physiological range of the temperature. The result show that the regulation of the concentration and interaction of fatty acids, proteins and pigments is the most important factor in the adaptation strategies of diatoms to the environmental temperature changes. Additionally, the regulation of membrane fluidity was demonstrated as important mechanism of the diatom adaptation to greenhouse effects. We also postulate that the adaptive mechanisms to temperature changes are differently expressed in the polar or hydrophobic regions of photosynthetic membranes.

The article compares the classic Fenton reagent (Fe2+/H2O2) with its modification with zero-valent iron (ZVI/H2O2) to remove azo dye Acid Red 27 from aqueous solutions at a concentration of 100 mg/L. For both methods, the most favorable parameter values ​​were determined at which visual discoloration of the solutions tested was obtained (for Fe2+/H2O2:pH 3.5, H2O2=60 mg/L, Fe2+/H2O2=0.3, t=15 min, and for ZVI/H2O2: pH 3, H2O2=40 mg/L, ZVI=80 mg/L, t=15 min). Under these conditions, the COD value was reduced by 71.5% and 69.2% for the classic Fenton and its modification, respectively. A reduction in toxicity was also obtained for Vibrio fischeri bacteria to below 25% by using the Microtox test. ZVI digestion at acidic pH for 10 minutes allowed to shorten the reaction time by about four times - from 15 to 4 minutes. BET analysis showed that the specific surface area increases with the digestion time, which significantly accelerates the reaction. The visual discoloration of aqueous solutions was obtained, and the final COD values ​​were very small, ranging from 49-53 mg O2/L. According to the Vibrio fischeri toxicity classification test for water samples, all solutions of dyes tested can be considered as non-toxic (toxicity value <25%). In the study presented, results of decreasing the COD value and concentration of the dye in the ZVI/H2O2 method obtained are slightly worse compared to the Fe2+/H2O2 method. However, taking the decolorisation time as a criterion, a four times faster decolorisation time was obtained in the ZVI/H2O2 method, compared to the Fe2+/H2O2 method.

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Abstract. New bacterial strains resistant to high concentration of mercury were obtained and character iz ed focusing on their potential application in bioremediation. The biological material was isolated from soil contaminated with mercury. The ability to removal of Hg from the liquid medium and the effect of the various pH and mercury concentrations in the environment on bacterial strains growth kinetics were tested. The selected strains were identified by analysis of the 16S ribosome subunit coding sequenc es as Pseudomonas syringae. The analysis of Hg concentration in liquid medium as effect of microb ial metabolism demonstrated that P. syringae is able to remove almost entire metal from mediu m after 120 hours of incubation. Obtained results revealed new ability of the isolated strain P. syrin ga e . Analyzed properties of this soil bacteria species able to reduce concentration of Hg or immob i lize this metal are promising for industrial wastewater treatment and bioremediation of the soils pollu t ed especially by mercury lamps scrapping, measuring instruments, dry batteries, detonators or burning fuels made from crude oil, which may also contain mercury. Selected bacteria strains provide efficient and relatively low-cost bioremediation of the areas and waters contaminated with Hg.