In this study, the contribution of nonenzymatic (ascorbate, glutathione) and enzymatic antioxidants (superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase) in the first hours of recovery of the resurrection plant Haberlea rhodopensis from drought- and freezing-induced desiccation was assessed. The initial stage of recovery after desiccation is critical for plants, but less investigated. To better understand the alterations in the activity of antioxidant enzymes, their isoenzyme patterns were determined. Our results showed that ascorbate content remained high during the first 9 h of rehydration of desiccated plants and declined when the leaves′ water content significantly increased. The glutathione content remained high at the first hour of rehydration and then strongly decreased. The changes in ascorbate and glutathione content during recovery from drought- and freezing-induced desiccation showed great similarity. At the beginning of rehydration (1–5 h), the activities of antioxidant enzymes were significantly increased or remained as in dry plants. During 7–24 h of rehydration, certain differences in the enzymatic responses between the two plant groups were registered. The maintenance of a high antioxidant activity and upregulation of individual enzyme isoforms indicated their essential role in protecting plants from oxidative damage during the onset of recovery.

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.

Cultivars suitable for organic production systems differ in many aspects from those adapted to a conventional one. The present study aimed to evaluate 23 white lupine genotypes for a range of traits: stability, biomass productivity and related parameters, tolerance to Fusarium oxysporum, and nutritional forage value. The goal was to identify white lupine genotypes suitable for organic production conditions in Central Northern Bulgaria. Among the genotypes, Solnechnii, Termis Mestnii, and Tel Keram exhibited the highest dry mass productivity, surpassing 14 t/ha. Solnechnii and Termis Mestnii showed no symptoms of F. oxysporum infection but were unstable in terms of forage yield. On the other hand, the genotypes Bezimenii 1, Barde, 17 Nahrquell, and WAT showed a satisfactory level of stability. Ranking according to basic parameters of biochemical composition, energy, and protein nutritional value determined ranks 1 and 2 for Pink Mutant and Kijewskij Mutant. A genotype with a good balance and complex suitability for organic conditions, considering stability, productivity, and tolerance to F. oxysporum, was identified as Bezimenii 1. This genotype exhibited both stability and productivity while demonstrating high resistance to F. oxysporum (infestation index of 7.18%).

The choice of nitrogen source in a cultivation medium can specifically affect the physiology and biochemistry of microalgae. To increase the production of low-cost valuable biomass, the preferred nitrogen form for each alga should be determined. The aim of our study was to analyze the effects of different nitrogen sources and cultivation times on the growth, biochemical composition and the activities of glutamine synthetase, glutamate synthase, glutamate dehydrogenase, malate dehydrogenase, aspartate aminotransferase and proteases of Chlorella vulgaris R-06/2. Media supplemented with urea or ammonium nitrate provided similarly (p>0.05) high growth rates for a short cultivation time (4 days). The two nitrogen compounds applied simultaneously ensured better biomass yield but for prolonged cultivation. In the exponential growth phase, ammonium nitrate stimulated (p<0.05) protein production, whereas urea enhanced (p<0.05) the carbohydrate content in older cultures as compared to the other nitrogen sources. The activity of each of the studied metabolic enzymes of C. vulgaris R-06/2 varied specifically depending on the nitrogen source and the growth phase, ensuring the maintenance of efficient, balanced metabolism under all cultivation conditions. When using large-scale cultivation to produce biomass for various useful applications, the selection of nitrogen source should be based on algal metabolism.

Biochemical and physiological parameters, such as: the antioxidant capacity, the content of total polyphenols and photosynthetic pigments, and the activity of the photosynthesis (the light phase), as measured by means of chlorophyll fluorescence were studied in 22 varieties of chickpeas (Cicer arietinum L.). At the start of the blooming stage, a strong decrease of the air temperatures was recorded, suggesting an impact of chilling stress. It was found out that PIABS (out of the fluorescence parameters) was mostly affected by the decrease of temperatures. Conversely, individual varieties of chickpea were able to stand out from the whole on the basis of their increased photosynthetic activity during this cold period. The cultivar, showing the highest increase in photosynthesis (133%) under chilling was “Blanco Lechoso” with 7.73 a.u. of the performance index immediately after the chilling. Concerning the antioxidant activity and phenolic content, it was discovered that only the antioxidant activity, as measured by the FRAP method, correlated to the phenolic content. On the other hand, both antioxidant methods strongly correlated to the concentration of carotenoids. These parameters had a weak inverse relation to the seed yield.