Candida antarctica: lipase B (CALB) is the most widely studied enzyme, due to its high selectivity and catalytic activity in organic and polymer synthesis. To avoid organometallic catalysts in the synthesis of biodegradable polyesters, the enzymatic ring-opening polymerization of cyclic esters can be carried out with CALB as a biocatalyst. This paper reviews selected examples of the application of lipases in polymer chemistry covering the synthesis of cyclic ester monomers, linear and star oligomers, as well as well-defined high molar mass polymers with improved mechanical properties. It is shown that by the selection of appropriate conditions of temperature and solvent assortment, CALB effectively catalyzes the polymerization of large size lactones obtaining polyesters with M_n up to 80 kg mol⁻¹. The chemical structure and main applications of described materials are also discussed. As the polymer recycling is an important topic from environmental point of view, we also described the potential applications of CALB in degradation process of aliphatic polyesters.

Plants are a valuable source of biologically active molecules, mainly phenolic compounds. In the present study, the total phenolic content (TPC), DPPH^· and ABTS⁺ scavenging activity as well as ferric reducing ability (FRAP) of aqueous ethanolic (70%) extracts of Cistus incanus L. and Asarum europaeum L. herb, Geum urbanum L. rhizome, Angelica archangelica L. root, white mulberry (Morus alba L.), lemon balm (Melisa officinalis L.), red raspberry (Rubus idaeus L.) and Betula pendula Roth. leaves were determined. In addition, the phenolic profiles of the studied plant extracts and antibacterial activity have been investigated. The extracts from C. incanus and G. urbanum demonstrated the highest TPC and antioxidant capacity, while the extracts from A. archangelica and white mulberry were characterized by the lowest values. A remarkable correlation was also found between the TPC and antioxidant activity of the examined extracts. HPLC analysis showed that the studied extracts were sources of both phenolic acids and flavonoids. More flavonoids than phenolic acids were identified in the extracts of C. incanus, M. alba, R. idaeus and B. pendula compared to the other extracts tested. Not all extracts showed a significant impact on the growth of the tested bacterial strains. Escherichia coli was the most sensitive strain to lemon balm extract (MIC, 0.125 mg/mL), whereas the strains of Acinetobacter baumannii and Bordetella bronchiseptica were sensitive to the G. urbanum extract (MIC, 0.125 mg/mL). Among Gram-positive bacteria, Enterococcus faecalis was the most sensitive to G. urbanum extract. In turn, Staphylococcus aureus and Staphylococcus epidermidis were sensitive to the extracts from C. incanus herb (MIC, 0.125 mg/mL), red raspberry (MIC, 0.125 mg/mL) and lemon balm leaves (MIC. 0.25 mg/mL). Based on the obtained results, the applicability of the studied plant extracts as additives to food and cosmetic products may be considered in the future.

The low-temperature plasma process is an advanced technology that has recently enjoyed great popularity due to its eco-friendly nature and antibacterial efficacy. Plasma-activated water (PAW)—a product of non-thermal plasma reaction with water, containing a rich variety of highly reactive oxygen and nitrogen species (RONS), is a green prospective solution for decontamination of microorganisms in a wide range of biotechnology aspect. Here, we present a succinct review of the formation of PAW and its properties in the context of inactivation of microorganisms. Among the wide range of articles on plasma-activated water, there is no comprehensive overview of the mechanism of microbial inactivation, the influence of reactive oxygen and nitrogen species on cell components, or the role of growth phases in PAW effectiveness in inactivation. This review aims to summarize the results of research in this area, taking into account the directions of potential applications of PAW in the field of medical sciences and food technology, indicating the species or strains of inactivated microorganisms.

Gamma-decalactone is an interesting flavuring compound with an intense oily-peachy aroma. It is commonly used in food and cosmetic industry. Biotechnological methods of its synthesis are based on the processes of fatty acid degradation, mainly ricinoleic acid, which is the main component of castor oil. The aim of this study was to compare the productivity of gamma-decalactone in batch cultures of two strains of Yarrowia lipolytica, wild strain W29 and its derived mutant MTLY40-2p, grown in flasks and a bioreactor. We analyzed the concentration of gamma-decalactone in the aqueous and oil phase, the optical density of the medium, the yield of yeast dry matter and the particle size distribution in the particular media. The modified strain had a higher aroma synthesis capacity. This strain grown in flasks produced thrice as much gamma-decalactone (5.5 ± 0.16 g/L) as compared to the wild-type strain (1.8 ± 0.03 g/L). During the 7-day biotransformation, the mutant strain did not have the ability to degrade gamma-decalactone, whereas in the biotransformation using the wild-type strain, reutilization was observed after the third day. Regardless of the type of culture, larger amounts of gamma-decalactone were accumulated in the lipid phase. Cultivation in a bioreactor resulted in a lower biomass yield and a lower concentration of lactone compared to flask culture, regardless of the strain used. The MTLY40-2p strain grew in mycelium form and tended to aggregate cells.

The production of gamma-decalactone (GDL) by Yarrowia lipolytica is mainly based on the biotransformation of ricinoleic acid, derived from castor oil triglycerides. The main difficulty in this process is the multitude of factors that determine the growth rate of microorganisms, and thus affect the efficiency of lactone synthesis. In order to improve the technological aspects of GDL biosynthesis in batch culture, the influence of three factors was determined: substrate concentration, medium mixing intensity, and its pH, using the Taguchi solid design method (based on orthogonal array design). On the basis of four bioreactor batch cultures, the most favorable culture conditions in terms of GDL synthesis were selected using the statistical Taguchi method. The statistical method of experimental planning has shown that the optimal parameters of lactone biosynthesis are a constant pH at the level of 7, a variable mixing speed in the range of 200–500 rpm, and a substrate concentration at the level of 75 g/L. Using these parameters, about 2.93 ± 0.33 g/L of aroma was obtained. The intensity of mixing turned out to be the most important factor influencing the increase in GDL concentration in the medium.

Extraction is one of the most commonly used methods for obtaining and purifying chemical compounds for commercial usage. The aim of this study was to evaluate the effect of unconventional permeabilization and cell disruption methods on the yield of lipid extraction from cells of the oleaginous yeast Yarrowia lipolytica. Batch cultures in a medium with molasses and waste post-frying oil were carried out. The biomass was subjected to pulsed electric field (PEF), high-pressure processing (HPP), ultrasounds (US), and several conventional processing techniques with chemical and mechanical agents (glass beads, acetone, Triton and Tween surfactants). The effectiveness of the applied methods, either on cell permeabilization or cell disruption, was investigated by analyzing the oil and total protein extraction yield and oil leaching efficiency, as well as by using microscope images. The PEF and US treatments proved to be effective permeabilization methods as a step of sample pretreatment for extraction. These unconventional physical methods could efficiently increase intracellular lipid extraction yield in solvent applications.