Both hormonal balance and plant growth may be shaped by microorganisms synthesizing phytohormones, regulating its synthesis in the plant and inducing plant resistance by releasing elicitors from cell walls (CW) by degrading enzymes (CWDE). It was shown that the Trichoderma DEMTkZ3A0 strain, isolated from a healthy rye rhizosphere, colonized the rhizoplane of wheat seedlings and root border cells (RBC) and caused approximately 40% increase of stem weight. The strain inhibited (in over 90%) the growth of polyphagous Fusarium spp. (F. culmorum, F. oxysporum, F. graminearum) phytopathogens through a mechanism of mycoparasitism. Chitinolytic and glucanolytic activity, strongly stimulated by CW of F. culmorum in the DEMTkZ3A0 liquid culture, is most likely responsible for the lysis of hyphae and macroconidia of phytopathogenic Fusarium spp. as well as the release of plant resistance elicitors. In DEMTkZ3A0 inoculated plants, an increase in the activity of the six tested plant resistance markers and a decrease in the concentration of indoleacetic acid (IAA) auxin were noted. IAA and gibberellic acid (GA) but also the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) enzyme regulating ethylene production by plant were synthesized by DEMTkZ3A0 in the liquid culture. IAA synthesis was dependent on tryptophan and negatively correlated with temperature, whereas GA synthesis was positively correlated with the biomass and temperature.

The separation of phenolic compounds by supercritical fluid extraction has been widely studied throughout the last two decades. This is evidenced by a number of publications and articles. Supercritical fluid extraction (SFE) has become thus the effective method of separating the mentioned group of compounds. On the other hand, SFE is a beneficial approach in plant waste materials utilization and reduction of environmental burdens caused by the wastes. The aim of the study is to gather and systematize available information on the phenolic compounds separation that have been reported so far as well as to evaluate whether there is one optimal supercritical fluid extraction method for the phenolic compounds.

Key message Liquid chromatography is the main method for assaying bioactive compounds in biomass. Total phenolic content and antioxidant capacity are measured with spectroscopy. Phenolics are the most important bioactive substances in short rotation coppice. Secondary metabolites of black locust, willow and poplar have many different activities. The richest source of bioactive compounds are flowers, bark and buds. Abstract The black locust (Robinia pseudoacacia), willow (Salix spp.) and poplar (Populus spp.) may be the source of the biomass obtained from natural habitats as well as intentionally established plantations in the system of short rotation coppice. These species are promising candidates as an alternative source of bioactive compounds in researches for developing new bioproducts for multidirectional uses, including polymers, lubricants, construction materials, pharmaceuticals, as well as bioenergy and fuels. Various parts of plants, such as leaves, flowers, seeds, bark, woods, buds, catkins, whole tree material and bee products (honey, propolis) are a source of bioactive compounds. The characterization of these compounds, especially phenolic compounds (flavonoids, stilbenes, lignans, phenolic acids, tannins and phenolic glucosides), fatty acids, sterols, etc. may be determined by a variety of analytical (spectroscopy, chromatography) and extraction methods. This review contains 131 references and systematize all available data on the characterization of the bioactive compounds in the biomass of black locust, poplar and willow by analytical and extraction methods.

In this study, potential antifungal properties of a brown alga Fucus vesiculosus were evaluated. The algal extract was obtained with the use of supercritical fluid extraction (scCO2) at a temperature of 50 °C under a pressure of 300 bar. The aqueous solution of the extract at the concentration of 0.05%, 0.2%, 0.5% and 1.0% was studied against pathogenic fungi on a liquid RB medium. This study is the first report on antifungal properties of the brown algae F. vesiculosus scCO2 extract against Fusarium culmorum and Fusarium oxysporum phytopathogens. The concentrations of the studied extract (0.5% and 1.0%) were demonstrated to have an ability to inhibit 100% growth of macroconidia within 144 h, as well as an ability to cause their total degradation. As a result of the study, the antifungal effect of fucosterol against F. culmorum was also indicated. The total macroconidia growth was inhibited by 1.0% fucosterol. Moreover, at lower concentrations (0.05–0.2%) of fucosterol, macroconidia were characterized by shorter length and structural degradation was observed. The mycelial growth of Fusarium oxysporum (Fo38) by 1% scCO2 F. vesiculosus extract was analyzed at the level of 48% after 168 h of incubation, whereas 100% extract was found to be effective in F. culmorum (CBS122) and F. oxysporum (Fo38) growth inhibition by 72% and 75%, respectively after 168 h of incubation.

Given the health-beneficial properties of compounds from hop, there is still a growing trend towards developing successful extraction methods with the highest yield and also receiving the products with high added value. The aim of this study was to develop efficient extraction method for isolation of bioactive compounds from the Polish “Marynka” hop variety. The modified two-step supercritical fluid extraction allowed to obtain two hop samples, namely crude extract (E1), composed of α-acids, β-acids, and terpene derivatives, as well as pure xanthohumol with higher yield than that of other available methods. The post-extraction residues (R1) were re-extracted in order to obtain extract E2 enriched in xanthohumol. Then, both samples were subjected to investigation of their antibacterial (anti-acne, anti-caries), cytotoxic, and anti-proliferative activities in vitro. It was demonstrated that extract (E1) possessed more beneficial biological properties than xanthohumol. It exhibited not only better antibacterial activity against Gram-positive bacteria strains (MIC, MBC) but also possessed a higher synergistic effect with commercial antibiotics when compared to xanthohumol. Moreover, cell culture experiments revealed that crude extract neither inhibited viability nor divisions of normal skin fibroblasts as strongly as xanthohumol. In turn, calculated selectivity indexes showed that the crude extract had from slightly to significantly better selective anti-proliferative activity towards cancer cells in comparison with xanthohumol.