Dried salted fish is a traditional dry-cured fish that is sprinkled with salt before the curing process. With a unique flavor as well as diverse varieties, dry-cured fish is popular among consumers worldwide. The presence of various microbial communities during the curing process leads to numerous metabolic reactions, especially lipid oxidation and protein degradation, which influence the formation of flavor substances. However, during industrial curing, the quality of dry-cured fish is difficult to control, leading to the formation of products with diverse flavors. This review describes the curing process of dried salted fish, the key microorganisms involved in the curing process of typical dried salted fish products at home and abroad, and the correlation between biological metabolism and flavor formation and the underlying mechanism. This review also investigates the prospects of dried salted fish products, proposing methods for the analysis of improved curing processes and the mechanisms of dried salted fish. Through a comprehensive understanding of this review, modern production challenges can be addressed to achieve greater control of microbial growth in the system and improved product safety. In addition to advancing our understanding of the processes by which volatile flavor compounds are formed in conventional dry-cured fish products, we expect that this work will also offer a theoretical framework for enhancing their flavor in food processing.

The unconventional yeasts Metschnikowia spp. represent a valuable microorganisms with enormous yet untapped potential. Metschnikowia species are briefly reviewed, demonstrating that taxonomic and genomic analysis can open numerous opportunities to exploit their unique character and potential in the development of modern winemaking and brewing, probiotics and biocontrol, and the synthesis of single-cell proteins. These yeasts can be used in both bioprocesses and biorefineries, contributing to the production of biofuels and unique products recovered from agro-industrial wastes. This review, through a comprehensive bibliographic analysis, examines various green strategies for the production of alcohols, lipids, unsaturated fatty acids, and other valuable metabolites. Furthermore, the article discusses the challenges and barriers hindering the full implementation of Metschnikowia spp. in new approaches and technologies.

The agricultural sector generates substantial waste that harms both the environment and human health. This study aimed to utilise Metschnikowia yeasts to convert native agricultural wastes without chemical pretreatment. Ten Metschnikowia isolates were assessed using API tests to identify their assimilation profiles and enzymatic activities. Yeast growth was evaluated via the plate count method. The culture media containing molasses, brewery spent grain, and postharvest sunflower parts were characterised chromatographically, and the in vitro impact on Verticillium tenerum phytopathogen was evaluated. The effect of the yeast preparations on Caco-2, IEC-6, and HaCaT cell lines was also investigated. Solid waste materials without preliminary chemical pretreatment supported yeast multiplication to 4.5 × 10⁷–1.3 × 10⁸ CFU/mL. The metabolite composition and enzymatic activity of lipase, glucosidase, and protease in post-culture media suggest that they may act as growth inhibitors of the Verticillium strain. For post-cultivation samples, inhibition coefficients were equal to 1.24–2.00, depending on the kind of substrate and yeast strain used. Antimicrobial activity was also noted in cell-free samples after yeast cultivation on sunflower stalks and brewery spent grain. The toxicological analysis showed that the yeast preparations did not cause toxic effects on the tested cell lines. This research offers a sustainable approach using Metschnikowia yeasts, highlighting the importance of a holistic method that combines microbiological, biochemical, and toxicological aspects for sustainable waste management and the development of new applications, such as feed supplements and biocontrol agents.

Biopolymer-based composites incorporating natural fillers were developed as carriers for various microbiological applications. Three commercially available biodegradable and bio-based polymers: poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and polylactide (PLA)were used as matrices. Brewer’s spent grain (BSG), a by-product of the brewing industry, was employed as a natural filler. A series of biocomposites containing 20, 30, and 40 wt% BSG were fabricated. The structure and thermal properties of the composites were characterized using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Surface properties were evaluated by measuring contact angles with two probe liquids, enabling calculation of surface energy and its polar and dispersive components. In turn, microscopic studies were conducted to evaluate the adhesion and colonization of Metschnikowia andauensis cells on the prepared carriers. The biocontrol activity of the cell–carrier system was assessed using the agar plate method. The results identified the most promising formulations: PHBV with 40 wt% BSG and PLA with 20–40 wt% BSG, especially with 30 wt% BSG. However, the highest biocontrol efficacy among cells adhered to the biocomposite materials was observed with the last one. This study explored the relationship between the physicochemical properties of BSG-filled biopolymers and their suitability for microbial colonization, highlighting their potential as functional carriers for yeast cells.