Small-scale photobioreactors (PBRs) in the inoculum stage were designed with internal (red or green) and external white LED light as an initial step of a larger-scale installation aimed at fulfilling the integral biorefinery concept for maximum utilization of microalgal biomass in a multifunctional laboratory. The specific growth rate of Scenedesmus obliquus (Turpin) Kützing biomass for given cultural conditions was analyzed by using MAPLE software. For the determination of total polyphenols, flavonoids, chlorophyll “a” and “b”, carotenoids and lipids, UHPLC-HRMS, ISO-20776/1, ISO-10993-5 and CUPRAC tests were carried out. Under red light growing, a higher content of polyphenols was found, while the green light favoured the flavonoid accumulation in the biomass. Chlorophylls, carotenoids and lipids were in the same order of magnitude in both samples. The dichloromethane extracts obtained from the biomass of each PBR synergistically potentiated at low concentrations (0.01–0.05 mg/mL) the antibacterial activity of penicillin, fluoroquinolones or oregano essential oil against the selected food-borne pathogens (Staphylococcus aureus, Escherichia coli and Salmonella typhimurium) without showing any in vitro cytotoxicity. Both extracts exhibited good cupric ion-reducing antioxidant capacity at concentrations above 0.042–0.08 mg/mL. The UHPLC-HRMS analysis revealed that both extracts contained long chain fatty acids and carotenoids thus explaining their antibacterial and antioxidant potential. The applied engineering approach showed a great potential to modify microalgae metabolism for the synthesis of target compounds by S. obliquus with capacity for the development of health-promoting nutraceuticals for poultry farming.

The study aimed to investigate exopolysaccharides (EPSs) produced by two Antarctic yeasts isolated from Livingston Island. The species were identified as Vishniacozyma victoriae (V) and Tremellomycetes sp. (T) based on a molecular genetic analysis of ITS1-5.8S-ITS4 regions of the 18S rRNA gene. The EPS production was investigated under stress conditions in culture flasks and a bioreactor. Different chromatographic (HPLC-RID, HPSEC-RID) and spectral (FT-IR) analyses were employed to characterize EPSs. Tremellomycetes sp. accumulated 7 g/L biomass and 4.5 g/L EPS after 120 h of cultivation. The total carbohydrate content of V-EPS and T-EPS was 75.4% and 79.0%, respectively. The EPSs mainly consisted of mannose (30–32%), which was followed by glucose, xylose, galactose, and small amounts of uronic acids (6.3–7.0%). EPSs had appreciable amounts of proteins (11–12%). The FT-IR spectra contained absorption bands typical for hetero-mannans and β-glucans (797–1033 cm⁻¹). EPSs were heterogeneous with a broad molecular weight distribution range (47 × 10⁴–68 × 10⁴ g/mol). In conclusion, both yeasts synthesized high-molecular-weight heteromannans, and Tremellomycetes sp. stood out as being a better producer than V. victoriae. The current study also formed a basis for a better assessment of the potential for practical application of EPSs and yeasts in biochemical engineering and biotechnology.

Isolate AL62 isolated from Antarctic soil was identified as Cryptococcus laurentii AL62 based on its morphological, cultural and physiological properties and was selected as an active producer of exopolysaccharide. Different carbon sources (pentoses, hexoses and oligosaccharides) were investigated for biosynthesis of biopolymer and sucrose was chosen as the most suitable and available carbon source. The time course of exopolysaccharide synthesis, biomass and pH on different sucrose concentration (30, 40, 50 g/L) were studied. The heteropolysaccharide was composed of the following monosaccharides: xylose, 45.2%; mannose, 33.6%; glucose, 18.4%. It was characterized by polydispersity of the polymer molecule, 60% of it having molecular mass of 8000 Da.

The concept of food packaging plays a crucial role in ensuring consumer satisfaction and extending the shelf life of food products. The rising trend of introducing innovative materials for food packaging has become prominent in recent years. The present study aims to investigate the impact of rosehip seed oil (RSO) on the physical, physicochemical, antioxidant, and antimicrobial properties of edible films based on chitosan for potential fruit packaging applications. Scanning electron microscopy revealed a uniform distribution of the incorporated emulsion throughout the edible film. The addition of RSO increased the deformation at break in both tensile and puncture test, thereby improving the elastic properties of the films. The resulting films exhibited a light-yellow color with high opacity. The immobilization of RSO led to a decrease in water content by almost two times and an increase in water vapor permeability of the films. The films showed enhanced antioxidant activity and retained good protective properties against the yeast S. cerevisiae. Consequently, these newly formulated multicomponent films are found to be suitable for applications in the development of active food packaging because of their physical, antioxidant, and antimicrobial properties.