Differences in Production, Composition, and Antioxidant Activities of Exopolymeric Substances (EPS) Obtained from Cultures of Endophytic Fusarium culmorum Strains with Different Effects on Cereals

Abstract

Exopolymeric substances (EPS) can determine plant-microorganism interactions and have great potential as bioactive compounds. The different amounts of EPS obtained from cultures of three endophytic Fusarium culmorum strains with different aggressiveness—growth promoting (PGPF), deleterious (DRMO), and pathogenic towards cereal plants—depended on growth conditions. The EPS concentrations (under optimized culture conditions) were the lowest (0.2 g/L) in the PGPF, about three times higher in the DRMO, and five times higher in the pathogen culture. The EPS of these strains differed in the content of proteins, phenolic components, total sugars, glycosidic linkages, and sugar composition (glucose, mannose, galactose, and smaller quantities of arabinose, galactosamine, and glucosamine). The pathogen EPS exhibited the highest total sugar and mannose concentration. FTIR analysis confirmed the β configuration of the sugars. The EPS differed in the number and weight of polysaccharidic subfractions. The EPS of PGPF and DRMO had two subfractions and the pathogen EPS exhibited a subfraction with the lowest weight (5 kDa). The three EPS preparations (ethanol-precipitated EP, crude C, and proteolysed P) had antioxidant activity (particularly high for the EP-EPS soluble in high concentrations). The EP-EPS of the PGPF strain had the highest antioxidant activity, most likely associated with the highest content of phenolic compounds in this EPS.

Genome-wide comparison deciphers lifestyle adaptation and glass biodeterioration property of Curvularia eragrostidis C52

“…EPS production was determined as g/L according to the procedure described by Jaroszuk-Ściseł et al (2020) 44 . Strain C52 was grown on a Czapek–Dox broth agar medium for 72 h at 30 °C.…”

Differences in the Production of Extracellular Polymeric Substances (EPS) and Other Metabolites of Plenodomus (Leptosphaeria) Infecting Winter Oilseed Rape (Brassica napus L.)

“…EPS was precipitated from the solution using 96% ethanol (Linegal Chemicals, Blizne Łaszczy ńskiego, Poland) in a 1:1 ratio for 24 h at 4 • C. After this time, EPS was separated from the supernatant by centrifugation at 10,000 rpm, 15 min and 4 • C (MPW 350-R, Warszawa, Poland), and dried at 75 • C for 8 h in three cycles (Laboratory dryer MOV-112S, Sakata, Oizumi-Machi, Ora-Gun, Gunma Panasonic, Japan). The EPS synthesis yields were expressed in g/L or mg/g [31].…”

“…The ability to synthesise EPS itself may also depend on strain interactions with plants. For example, a Fusarium culmorum strain characterised as a PGPF synthesised EPS at the lowest level of 0.2 g/L, compared to a phytopathogen (1.1 g/L) [ 31 ].…”

Effect of the Concentration of Extracellular Polymeric Substances (EPS) and Aeration Intensity on Waste Glycerol Valorization by Docosahexaenoic Acid (DHA) Produced in Heterotrophic Culture of Schizochytrium sp

“…Many factors determine EPS production by microorganisms, including nutrients present in the culture medium-such as carbon or nitrogen [51,52] and their concentration ratio, and also physical parameters, such as temperature, pH, or mixing speed [53,54]. EPS are essential for proper microalgae growth in the medium as they increase their mobility, serve as a carbon source for bacteria and microfauna, and finally elicit various effects on physical and chemical parameters of the culture medium, including porosity, mechanical stability, or density [55,56]. Besides, they preserve the structure of cell aggregates and protect them against drying out [57].…”