Seaweed biomass is globally underutilized as a source of proteins despite its nutritional potential, with much of its use focused on hydrocolloid extraction. This study evaluated the nutritional quality and digestibility of protein and amino acids from two brown seaweeds (Durvillaea spp. and Macrocystis pyrifera), one green seaweed (Ulva spp.), and a novel mycoprotein derived from Durvillaea spp. through fungal fermentation. Using an in vitro gastrointestinal digestion Megazyme assay kit, protein digestibility-corrected amino acid scores (PDCAASs) and digestible indispensable amino acid scores (DIASSs) were determined. Compared with seaweeds, seaweed-derived mycoprotein presented significantly greater protein contents (~33%) and amino acid profiles (2.2 times greater than those of Durvillaea spp. and M. pyrifera), with greater digestibility (~100%) than seaweeds (<60%). The PDCAAS values were 0.37, 0.41, 0.53, and 0.89 for Ulva spp., Macrocystis pyrifera, Durvillaea spp., and mycoproteins, respectively. The DIASSs highlighted the superior nutritional quality of the mycoprotein, particularly for lysine (0.59) and histidine (0.67). SDS-PAGE revealed soluble peptides (<25 kDa) in Durvillaea spp., Macrocystis pyrifera, and mycoproteins, whereas Ulva spp. proteins exhibited limited solubility due to structural aggregation. These findings highlight the need to characterize the nutritional properties of edible seaweeds in Chile further and emphasize the importance of optimized processing techniques, such as fermentation or bioconversion, to improve the nutritional potential of seaweeds and develop high-quality food ingredients for diverse applications.

This study aimed, for the first time, to determine the nutritional composition, beta-glucan and ergosterol contents, phenolic compound composition, and biological and functional activities of a novel mycoprotein produced through a bioconversion process of Durvillaea spp., a brown seaweed. An untargeted metabolomics approach was employed to screen metabolites and annotate molecules with nutraceutical properties. Two products, each representing a distinct consortia of co-cultured fungi, named Myco 1 and Myco 2, were analysed in this study. These consortia demonstrated superior properties compared to those of Durvillaea spp., showing significant increases in total protein (~238%), amino acids (~219%), and β-D-glucans (~112%). The protein contains all essential amino acids, a low fatty acid content, and exhibits high antioxidant activity (21.5–25.5 µmol TE/g). Additionally, Myco 2 exhibited the highest anti-alpha-glucosidase activity (IC₅₀ = 16.5 mg/mL), and Myco 1 exhibited notable anti-lipase activity (IC₅₀ = 10.5 mg/mL). Among the 69 top differentially abundant metabolites screened, 8 nutraceutical compounds were present in relatively high concentrations among the identified mycoproteins. The proteins and polysaccharides in the mycoprotein may play a crucial role in the formation and stabilization of emulsions, identifying it as a potent bioemulsifier. In conclusion, the bioconversion of Durvillaea spp. results in a mycoprotein with high-quality protein, significant nutritional and functional value, and prebiotic and nutraceutical potential due to the production of unique bioactive compounds.

Bacterial nanocellulose (BNC) is a highly pure biopolymer with promising applications in the biomedical, food, and textile industries. However, the high production costs and low yields obtained in static conditions limit its scalability and industrial applications. This study addresses the sustainable production of BNC using a rotary disk bioreactor (RDB) and explores the use of grape pomace extract as an alternative carbon source for BNC production. Parameters such as the BNC production and biomass yield were evaluated using Komagataeibacter xylinus ATCC 53524 under different operational conditions (disk surface, rotation speed, and number of disks). The results showed that cellulose production increased using silicone-coated disks at 7–9 rpm (up to 2.72 g L⁻¹), while higher yields (5.23 g L⁻¹) were achieved when using grape pomace extract as the culture medium in comparison with conventional HS medium. FTIR and TGA characterizations confirmed that BNC obtained with grape pomace extract presents the same thermal and chemical characteristics than BNC produced with HS medium. This work provides insight into the feasibility of upscaling BNC production using a bioprocessing strategy, combining production in the RDB system and the use of an agro-industrial waste as a sustainable and cost-effective alternative.

Background/Objectives: The increasing emergence of antimicrobial-resistant Staphylococcus pseudintermedius has limited the effectiveness of conventional therapies for canine pyoderma, highlighting the need for alternative topical strategies. This study aimed to develop hydrogels incorporating essential oils (EOs) from Peumo (Cryptocarya alba) and Tepa (Laureliopsis philippiana) as potential topical treatments against Staphylococcus pseudintermedius skin infections in veterinary medicine. Methods: EOs were obtained by steam distillation, chemically characterized by gas chromatography–mass spectrometry (GC–MS), and evaluated for antibacterial activity against S. pseudintermedius strains. Carbopol^®-based hydrogels incorporating the EOs of C. alba (HCA), L. philippiana (HLP), and a control vehicle (HVE) were formulated and characterized in terms of physicochemical properties, microbiological safety, and stability under accelerated and refrigerated conditions. Preclinical dermal safety was evaluated in BALB/c mice by repeated topical administration for five days. The analysis included clinical observation, skin irritation scoring, and histological analysis. Additionally, a preliminary microbiological evaluation was conducted in client-owned dogs with superficial pyoderma to assess the performance of the formulations in the target species. Skin lesion swabs were collected at baseline and after 21 days of treatment, followed by bacterial culture and automated identification using the VITEK^® system. Bacterial detection and bacterial load were evaluated to determine changes in microbiological status over the treatment period. Results: GC–MS analysis identified sabinene and eucalyptol as the main compounds in CA-EO, and linalool, eucalyptol, and safrole in L. philippiana EO. Both EOs exhibited moderate antibacterial activity against S. pseudintermedius (inhibition zones 4.9–10.8 mm; MIC ≥ 2.048 mg mL⁻¹). The hydrogels were microbiologically safe. Among formulations, HLP demonstrated superior physical stability and comparable rheological properties to the vehicle. In vivo safety evaluation demonstrated no signs of systemic toxicity, behavioral alterations, or skin irritation, and histological analysis confirmed preserved skin architecture without evidence of inflammation or tissue damage. In the preliminary microbiological evaluation in dogs, all animals were positive for Staphylococcus spp. at baseline. On Day 21, bacterial elimination was observed in the active treatment groups, but not in the HVE group, with elimination rates of 50.0% for Inveclor^® and 25.0% for both HCA and HLP. In parallel, HLP showed the highest proportion of dogs reaching minimal bacterial load levels (75%), followed by Inveclor^® (50.0%) and HCA (37.5%), whereas no dogs in the vehicle group reached this category. Conclusions: EOs from C. alba and L. philippiana presented antibacterial activity and were successfully incorporated into microbiologically safe hydrogel formulations. Notably, HLP demonstrated superior stability and a favorable preclinical safety profile, supporting its potential. In the preliminary microbiological evaluation in dogs, numerical differences in bacterial elimination and bacterial load categories were observed among groups; however, these differences were not statistically significant and should be interpreted as exploratory.