Fermentation, Volume 10, Issue 6 (June 2024) – 29 articles

(1) Objectives: Traditional kombucha (K) is a fermented beverage obtained from black or green tea infusion. Besides traditional substrates, the possibility of using alternative ingredients resulted in changes in metabolic profile and biological activity. The aim of this work was to study an alternative kombucha (KJ) prepared by the addition of jujube powder to black tea. (2) Materials and Methods: Changes in pH, protein, sugars, phenolic (TPC), flavonoid (TFC), and vitamin C and B12 content were evaluated at different time points over a period of 45 days. The identification of polyphenols by HPLC DAD and the antioxidant capacity by DPPH, ABTS, and FRAP tests of all samples was also carried out. (3) Results: The results showed higher protein, total phenolic content, and antioxidant capacity in KJ samples than in K ones. Vitamin C content increased during fermentation and reached its maximum concentration on day 45 (7.1 ± 0.3 mg/100 mL) for KJ. Caffeine in the supplemented samples was the main biocompound among those identified. Vitamin B12 formed on day 4 in K and after 24 h in KJ samples, remaining constant at the initial value of 2.30 ± 0.01 mg/100 mL up to day 45. (4) Conclusions: The results highlight that the fortification of kombucha with jujubes improved its biological activity and the content of bioactive compounds. Full article

Investigating the intricate pathways through which FH06 fermentation broth exerts lipid-lowering and weight-loss effects is pivotal for advancing our comprehension of metabolic regulation and therapeutic interventions. Ultrahigh-performance liquid chromatography quadrupole electrostatic field orbit trap mass spectrometry (UHPLC-QE-MS) detection and the ChEMBL database were used to determine the effective compounds in the FH06 fermentation broth and predict their targets. The TTD database and DisGeNET database were used to query obesity-related targets. The STRING database was used to construct protein interaction information. The Gene Ontology (GO) database and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were used to perform biological function annotation (GO) and KEGG pathway enrichment analyses of the targets. Results: A total of 85 effective compounds were screened from the fermentation broth of FH06; these compounds may act on TP53, PPARG, TNF, and other targets through 10 signaling pathways, such as the chemical carcinogenesis-receptor activation and lipid and atherosclerosis pathways, and exert pharmacological effects, such as hypoglycemic effects and weight loss. They also have anti-inflammatory, antioxidant, antitumor, and immunoregulatory effects. These findings reveal the active ingredients of FH06 fermentation broth and its multi-target and multi-channel characteristics in lipid lowering and weight loss. This study has positive implications for the clinical treatment of obesity using FH06, providing a theoretical and scientific basis for further developing of FH06-assisted lipid-lowering products. Full article

In addition to energy recovery, the anaerobic digestion of agro-industrial byproducts can also produce different high-value-added compounds. Two-stage and single-stage reactors were compared for microbial communities’ selection and long-chain fatty acid (LCFA) accumulation to investigate which microbial genera are most linked to the production of these compounds. The microbial communities present in the two reactors’ configuration in the steady state were characterised by 16S rRNA amplicon sequencing, while LCFAs were extracted and quantified from digestate samples by gas chromatography. The results showed the differentiation of the microbially dominant families in the two setups: Defluviitaleaceae and Clostridiaceae in the acidogenic and methanogenic reactor of the two-stage reaction respectively, while Dysgonomonadaceae in the single-stage set-up. LCFA accumulation was significantly detected only in the acidogenic reactor, with palmitic (2764 mg/kg), linoleic (1795 mg/kg) and stearic (1751 mg/kg) acids as the most abundant. The dominance of Defluviitaleaceae UCG 011, along with the low abundance of the LCFA oxidiser Syntrophomonas spp. in the acidogenic reactor, could be linked to the accumulation of such compounds. Therefore, the different microbial communities shaped by the two reactors’ configuration affected the accumulation of LCFAs, indicating that the two-stage anaerobic digestion of agro-industrial byproducts was more effective than single-stage digestion. Full article

Irradiation with ultraviolet A (UVA) plays an important role in the pathogenesis of skin photoaging since it increases oxidative stress and inflammation in the epidermis. There is an urgent need to screen, investigate, and apply the potential anti-photoaging active ingredients. Agaricus blazei Murill (ABM) polysaccharides have a wide range of promising pharmacological applications. Previous studies have confirmed their antioxidant effect, but whether it has an anti-photoaging effect is unclear. In this study, two ABM polysaccharides (AB-J and AB-K) were obtained to discuss the potential photodamage-protective capacity. The free radical scavenging abilities in vitro, the safety assessment, and their protective effects and mechanisms on UVA-induced human fibroblasts (HSFs) were evaluated. The intracellular antioxidant enzyme levels and extracellular matrix proteins, such as COL-I and ELN, were significantly accelerated, and metalloproteinases (MMP-1, and MMP-9) were decreased by AB-J and AB-K. The Keap-1-Nrf2/ARE signaling pathway was activated, thus inducing the upregulated expression of downstream genes (Ho-1 and Nqo-1). The suppression of P38 and Jnk1 by AB-J and AB-K was speculated to be the inducer of the activation of the Keap-1-Nrf2/ARE signaling pathway. Owing to the excellent exhibition of AB-J, its safety assessment and the structural characterization are discussed further. Full article

Recently, there has been worldwide growth in consumer nutrition awareness, which has resulted in a market-driven increase in the demand for “functional food”, which, in addition to traditional nutrients, also contains ingredients with specific properties that have a beneficial effect on human health. One of the types of functional food is so-called “probiotic food”, which includes, for example, frozen desserts. These products appear attractive to the consumer because of their sensory, nutritional and refreshing qualities. Due to progress in science, genetics, the acquisition of new sources of probiotic microorganisms and new plant varieties, the beneficial effects of the characteristic metabolites of the microbiome—so-called postbiotics—and also aspects of NGPs (Next Generation Probiotics), work is under way to optimize the technology used during the production of such products. At the same time, there is an observed market-based increase in the supply of new formulations based only on plant-origin materials with different technological modifications, including prebiotic enrichment, which allows for the production of a synbiotic product. Therefore, the objective of this study is a narrative review, in combination with the authors’ own experiments, concerning the impact of various factors on functional, plant-origin frozen desserts, from the point of view of maintaining their quality. Full article

2-phenylethanol (2-PE) is a valuable aromatic alcohol with diverse applications in cosmetics, food, beverages, and pharmaceutical industries. Currently, 2-PE is produced either through chemical synthesis or by extraction from plant materials. However, both conventional production methods have their own limitations. Therefore, there is a need for more eco-friendly and cost-effective approaches to produce natural 2-PE. Biotechnological routes, particularly microbial fermentations, hold promise for natural 2-PE production, especially when using low-cost substrates. In this study, 2-PE was produced by de novo synthesis via the shikimate pathway, using the yeast Yarrowia lipolytica in a medium composed of sugar beet molasses (SBM) and yeast extract (YE) as carbon and nitrogen sources, respectively. A genetically engineered strain was generated, in which the SUC2 gene was transformed, expressing the invertase enzyme, enabling Y. lipolytica to efficiently utilize SBM as a cost-effective substrate. A central composite design allowed for the optimization of the concentrations of the carbon and nitrogen sources, resulting in approximately 0.71 g_(2-PE)/L_{(culture medium)}. The results obtained highlight the potential of utilizing SBM as a low-cost substrate for 2-PE production, advancing biotechnological approaches in fragrance synthesis. Full article

Extra energy consumption, inefficient nitrogen removal, and excessive sludge production are major challenges faced by wastewater treatment plants (WWTPs) that rely on the traditional activated sludge process. Fermentation of wasted activated sludge (WAS) and novel nitrogen removal technologies based on partial nitrification (PN) have emerged as promising solutions to these issues. Recent studies have revealed an innovative strategy that integrates these two processes by supplementing fermentation liquid into activated sludge to induce PN. This review summarizes the research progress on PN establishment induced by the fermentation process. The microbiology and establishment methods of PN are briefly introduced, followed by a detailed discussion on the process, influencing factors, and product characteristics of WAS fermentation. The core section focuses on the side-stream and main-stream approaches of fermentation-induced PN, comparing their performance and application prospects. The potential mechanisms are explored, with an emphasis on the roles of free ammonia for the side-stream approach and the high tolerance of ammonium oxidizers to in-site fermentation stress for the main-stream approach. Finally, the limitations of the current research and future perspectives are discussed, highlighting the need for further investigation into microbial ecology, process optimization, and long-term stability. This review aims to provide insights into the synergistic integration of WAS fermentation and PN for sustainable and energy-efficient wastewater treatment. Full article

The Cornus kousa tree, which is of Asian origin, is often cultivated for ornamental purposes and used in traditional medicine. The tree produces sugar-rich fruits, which are potential habitats for natural yeasts. The identification of new yeast strains has many advantages for the industry and research. This study aimed to isolate and identify yeast species from C. kousa fruits and to understand their microbial ecology. Ripe and rotten fruits, which had fallen on the ground naturally, were collected and soaked in culture media, followed by plate spreading for colony growth. The morphological examination revealed three distinct colony types, including two from the ripe fruits and one from the rotten fruits. The analysis of the internal transcribed spacer 1 region indicated three yeast strains corresponding to the three colony types: Torulaspora delbrueckii and Pichia kluyveri from the ripe fruits and Saccharomyces cerevisiae from the rotten fruits. The metabolic characterizations demonstrated that all three yeasts efficiently consumed glucose and produced alcohol. S. cerevisiae exhibited the strongest fermentation ability and the highest growth rate. These findings showed that Cornus kousa fruit is a source of diverse yeast species, with distinct species associated with different states of fruit decomposition. Full article

Because olive pomace (the main by-product of olive oil production) is phytotoxic, new applications must be investigated to minimize its negative environmental impact. In this work, olive pomace was fermented for 4 and 32 days at room temperature, having in view its valorization as a novel food, thereby creating opportunities for the food industry and addressing a challenge of the olive oil sector. The chemical and microbiological modifications that occurred along the fermentation were followed. The results showed no significant differences (p > 0.05) in total protein between the control and the fermented samples; however, the latter exhibited higher levels of essential amino acids. The major nonessential and essential amino acids were glutamic acid and leucine in all samples. There was a significant increase in the total fat of the 32-day sample and the main fatty acid was oleic acid in all samples. There were considerable reductions in total vitamin E, phenolics, and antioxidant activity values post-fermentation. Hydroxytyrosol replaced oleacein as the main phenolic in the 32-day sample. A sharp increase in total microorganisms occurred (2.20 × 10² to 3.00 × 10⁴–2.01 × 10⁷ colony forming units/mL) but no pathogenic microorganisms were detected. Overall, olive pomace fermentation creates novel products for the food industry with a balanced nutritional composition. Full article

Lactobacillus delbrueckii garners interest for its contributions to gut microecological balance, diarrheal prevention and treatment, immune modulation, growth promotion, and meat quality enhancement in livestock. However, its impact on the gut microbiota and liver metabolism in weaned piglets is less documented. This study involved 80 Duroc-Landrace-Yorkshire weaned piglets aged 28 days, randomized into two groups with four replicates each and ten piglets per replicate. Over a 28-day period, the piglets were fed either a basal diet (control group) or the same diet supplemented with 0.1% Lactobacillus delbrueckii microcapsules (≥1.0 × 10¹⁰ CFU/g) (Lactobacillus delbrueckii group). The principal findings are as follows: During the initial phase of the experiment, supplementation with Lactobacillus delbrueckii increased the levels of L-phenylalanine and L-lysine in the liver while reducing the L-alanine levels, thereby enhancing the aminoacyl–tRNA synthesis pathway in weaned piglets. In the later phase, Lactobacillus delbrueckii supplementation boosted the liver arachidonic acid content, strengthening the arachidonic acid metabolic pathway in the piglets. The gut microbiota and their metabolites likely play a role in regulating these processes. These results indicate that, compared to the control group, Lactobacillus delbrueckii reduced weaning stress-induced liver damage and metabolic disorders, increased liver glycogen content, and enhanced liver antioxidant function by improving the metabolism of lipids and carbohydrates. Consequently, the liver functioned more healthily. Full article

Gas fermentation is gaining attention as a crucial technology for converting gaseous feedstocks into value-added chemicals. Despite numerous efforts over the past decade to investigate these innovative processes at a lab scale, to date, the evaluation of the technologies in relevant industrial environments is scarce. This study examines the fermentative production of acetate from biomass-derived syngas using Moorella thermoacetica. A mobile gas fermentation pilot plant was coupled to a bubbling fluidized-bed gasifier with syngas purification to convert crushed bark-derived syngas. The syngas purification steps included hot filtration, catalytic reforming, and final syngas cleaning. Different latter configurations were evaluated to enable a simplified syngas cleaning configuration for microbial syngas conversion compared to conventional catalytic synthesis. Fermentation tests using ultra-cleaned syngas showed comparable microbial growth (1.3 g/L) and acetate production (22.3 g/L) to the benchmark fermentation of synthetic gases (1.2 g/L of biomass and 25.2 g/L of acetate). Additional fermentation trials on partially purified syngas streams identified H₂S and HCN as the primary inhibitory compounds. They also indicated that caustic scrubbing is an adequate and simplified final gas cleaning step to facilitate extended microbial fermentation. Overall, this study shows the potential of gas fermentation to valorize crude gaseous feedstocks, such as industrial off-gases, into platform chemicals. Full article

Cherry is a fruit which contains elevated amounts of antioxidant compounds, such as anthocyanins, pigments, and vitamins. Furthermore, it possesses high water, sugar, mineral, and indolamine contents. The general objective of this study was to characterise a cherry-based fermented beverage (the ‘sweetheart’ variety) and analyse the effects of its ingestion on (i) circulating serum levels of melatonin and serotonin, (ii) inflammatory response, and iii) serum total antioxidant capacity in rats (Rattus norvegicus). For cherry-based fermented beverage manufacturing, the cherries were washed, the stems and woody endocarps were removed, and ascorbic acid was added (to avoid enzymatic browning). After the homogenisation of the cherry fruit, lactic acid bacteria were inoculated, and the fermentation process was conducted for 36 h. The main bioactive compounds in the cherry beverage were characterised, as well as their total antioxidant capacity. Moreover, an in vivo assay was developed, in which rats ingested the fermented beverage ad libitum for seven days. The inflammatory mediators, the total antioxidant capacity, and the serum levels of melatonin and serotonin were measured. Based on these results, the intake of the cherry-based fermented beverage assayed in this study increased the total antioxidant status of rats, elevated the melatonin and serotonin levels in the serum, and improved the regulation of the inflammatory systemic processes. Full article

Seaweed is a fast-growing biomass source that is currently studied as feedstock for sustainable industrial production in a wide variety of markets. Being composed mostly of polysaccharides, macroalgae can be integrated in biorefineries for obtaining bioproducts via fermentation. Kappaphycus alvarezii has been introduced experimentally to Brazil’s south coastline in 1995 and is now cultivated on a large scale to keep up with the high carrageenan demand in various industrial sectors. In this review article, an introduction is given on renewable biomass and environmental issues, focusing especially on third-generation biomass and its promising features and use advantages. Later on, the processing of K. alvarezii for the use of its saccharide portion for fermentative processes is approached. The current state of research conducted alongside challenges and hurdles in K. alvarezii hydrolysate fermentation processes provides insight into future studies needed to make new fermentation processes viable. Next, some fermentation products are discussed, and the metabolism of galactose in microorganisms is also presented to bring to light other possible fermentation products that are not yet, but can be, obtained from K. alvarezii. Finally, a simple and comprehensive scheme for K. alvarezii fermentation biorefinery is presented to demonstrate a generic example for a possible configuration for obtaining valuable bio-products. In the literature, production of ethanol and lactic acid were already reported from K. alvarezii. This review aims to help envision new industrial processes that can be developed for this most valuable macroalga. Full article

Four lactic acid bacteria (LAB) strains isolated from naturally ensiled broccoli waste were characterized, and their effects on the fermentation quality of high-moisture broccoli waste silage were studied. The four isolated strains were assessed using the morphological, physiological and biochemical tests. The four strains were added to broccoli waste at three moisture contents (90%, W0; 87%, W1; 80%, W2) and ensiled for 60 days. All strains (CB89, CB94, CB112, and CB120) grew at 15–45 °C, pH 3.0–7.0, and in 3.0–6.5% NaCl and were identified as Lactiplantibacillus plantarum by 16S rDNA sequencing. Inoculation of CB120 significantly (p < 0.05) increased lactic acid, starch, and non-structural carbohydrate content, and significantly (p < 0.05) decreased pH values and aerobic bacteria count compared with control (CK) at all three moisture contents. In conclusion, CB120 improved the fermentation quality and nutritional value of broccoli waste silage at three moisture contents and could be applied as a promising additive for high-moisture material. Full article

In beer production, 1,2-dicarbonyl compounds such as 3-deoxyglucosone (3-DG) and 3-deoxymaltosone (3-DM) are formed via Maillard reaction or caramelization especially during malt kilning or wort boiling, resulting in substantial concentrations in wort. Consequences of dicarbonyl compounds for yeast metabolism are widely unknown. In the present study, the handling of 3-DG and 3-DM by Saccharomyces strains from different habitats in wort and during beer fermentation was investigated. We show that beer yeast strains induced a faster 3-DG degradation in Pilsner wort and were additionally more stress-resistant to 3-DG compared to yeasts isolated from natural habitats. In fermentation experiments comparing a light wort and a dark wort prepared from malt extracts, it could be shown that high levels of 3-DM in dark wort influence the utilization of 3-DG by yeasts, and thus higher levels of 3-DG remain in the wort. Beer yeast strains showed an increased formation of 3-deoxyfructose (3-DF) with up to 220 µM, which is possibly due to a preferred metabolization of 3-DM, as indicated by the low degradation rate of 3-DG. In contrast, yeasts isolated from natural habitats produced significantly lower amounts of 3-DF. This suggests an adaptation of technologically used yeasts to metabolization of dicarbonyl compounds, possibly as a result of beer yeast domestication. Full article

The relationship between DM yield/cutting and the fermentable organic matter (FOM) content of tropical grasses was appropriately investigated to re-assess optimal grass maturity to feed dairy cattle. Nine different grass species belonging to the genera Brachiaria spp. (Mulato II, Ruzi), Panicum spp. (Guinea, Hamil, Mombasa, TD58), and Pennisetum spp. (King, Napier, VA06) were chemically analysed and subjected to an in vitro gas production (IVGP) test. For 72 h, gas production (GP) was continuously recorded with fully automated equipment. A triphasic, nonlinear, regression procedure was applied to analyse GP profiles. Across all the grasses, it was found that the neutral detergent fibre (NDF) contents increased with increasing maturity of the grass while the CP contents decreased with increasing NDF contents. In all nine grasses, digestible organic matter (dOM) was significantly affected by the week of cutting but IVGP was similar between the weeks of cutting in Ruzi, Hamil, Mombasa, and Napier grasses. Except for Guinea grass, the lowest dOM values were found when the grasses were cut after ≥5 weeks of regrowth. Harvesting grass one or two weeks earlier than the normal cutting time is a practically relevant intervention in increasing forage quality and productivity of dOM and fermentation potential. Full article

Yeasts play a crucial role in the winemaking process contributing to the typicity and originality of wines in a region. Therefore, the aim of the present study was to isolate, characterize, and select yeasts from the Geographical Indication “Pozo de Los Algarrobos”, San Juan, Argentina. Yeasts were directly isolated from grapes and at different stages of spontaneous fermentations of Vitis vinifera Viognier and Chardonnay varieties. Molecular and intraspecific identification of Saccharomyces cerevisiae yeasts was conducted using the D1/D2 domain and interdelta, respectively, observing 13 different yeast strains from Viognier and 12 from Chardonnay vinifications. Based on the enological traits assayed, two strains, V22 (Viognier) and C14 (Chardonnay), were selected for further studies. Microvinifications with these yeasts were carried out with Viognier and Chardonnay grape must in 2 L flasks, and the resulting wines were analytically and sensorially evaluated. Overall, strain V22 produced wines with positive and particular sensory properties, associated with fruity and floral aromas, color intensity, sweetness, aromatic persistence, and varietal typicity. Consequently, biomass propagation of V22 was conducted to inoculate pilot- (100 L) and industrial (12,000 L)-scale fermentations. V22 resulted in a correct wine fermentation performance obtaining a final product with distinctive and genuine properties. Full article

The shift from fossil fuels to renewable energy sources is crucial in addressing environmental challenges. Vegetable oils have been focused on as the main potential source for biodiesel and biolubricant production. However, due to their fatty acid (FA) composition they are characterized by low stability to oxidation and variable viscosity. Single-cell oils (SCOs) from oleaginous microorganisms are a possible alternative to vegetable oils: their composition is more suitable, and it can further be improved by controlling the fermentation’s physiological conditions. In the present study, the production of SCOs with targeted technological properties from Lipomyces starkeyi in fermentation under controlled temperatures was assessed. A dairy effluent (scotta) was used as the fermentation substrate to improve the economic sustainability of the process. Batch aerobic fermentations were carried out in a fermenter at two different temperatures (25 °C and 30 °C). The fermentation yields and SCO FA profiles were analyzed. The highest yields of biomass (9.76 g L⁻¹) and microbial oil (1.83 g L⁻¹) were obtained from fermentations carried out at 30 °C. Furthermore, a significantly lower content (46% vs. 55%) of unsaturated FAs and higher content (11% vs. 1.5%) of shorter-chain saturated FAs, with myristic acid almost matching stearic acid, were detected at 30 °C in comparison to 25 °C. Very low peroxide values were also found (0.14 meq O₂ kg⁻¹ at 30 °C and 0 meq O₂ kg⁻¹ at 25 °C). These results indicate that these SCOs were highly oxidation-resistant, and that a higher fermentation temperature improves their oxidative stability and tribophysical features. The biodiesels’ technological properties, calculated from the FA composition, were within the limits of both U.S. standards and E.U. regulations. Then, SCOs produced from L. starkeyi by fermentation of dairy effluents carried out under controlled temperature can be considered a suitable alternative to vegetable oils to produce biodiesel and biolubricants. Full article

Abstract: The peptidomes from the literature of 24 prolyl-endopeptidase-treated beers during fermentation, declared gluten-free, and 13 untreated beers have been characterised and subjected to an extensive study to investigate their safety for celiac patients. The analysis contains 1996 gluten peptides, ascribed to the treated beers, and 1804 to the untreated beers. The prolyl-endopeptidase-untreated malt beers are hazardous for celiac patients. Peptides of most of these beers showed matches with complete celiac immunogenic motifs, and an additional 28% of the peptides have partial matches with complete immunogenic motifs. On the other hand, after the enzyme treatment during fermentation no celiac hazardous gluten peptides are identified in the treated beers. Due to partial matches with complete celiac immunogenic motifs, 11% potentially hazardous gluten peptides are still identified in the treated beers. Only a maximum of 17% of these peptides can be detected by ELISA analysis. A mass spectrometry analysis or the recently developed method based on G12/A1 monoclonal antibody lateral flow immunochromatographic assay seems necessary to thoroughly reveal the potential risk of the treated beers. The actual immune response of treated beer, described in the literature by the response of the serum antibodies of celiac disease (CD)-active patients and by in vitro immune response, could not be related to the presence of known (partial) CD-immunogenic motifs in the gluten peptides. Full article

At present, non-alcoholic and low-alcoholic beers (NABLABs), in addition to their premature sensitivity to oxidation, still suffer from a lack of fruity fermentation aromas. Maltose/maltotriose-negative yeasts offer a highly attractive alternative for creating diversified pleasant aromas and/or eliminating off-flavors in NABLAB production. The aim of this study was to explore the potential of Saccharomyces cerevisiae var. chevalieri, SafBrew^TM LA-01 to release fruity polyfunctional thiols from glutathionylated (G-) and cysteinylated (Cys-) precursors. Interestingly, it proved to release free thiols from their glutathionylated S-conjugate much more efficiently (0.34% from G-3-sulfanylhexanol in 15 °P wort after seven days at 24 °C) than the best S. pastorianus strains previously screened (0.13% for lager yeast L7). On the other hand, despite its classification as a S. cerevisiae strain, it showed an inefficient use of cysteinylated precursors, although the release efficiency was slightly higher under NABLAB fermentation conditions (6 °P; 3 days at 20 °C). Under these conditions, as expected, LA-01 consumed only glucose, fructose, and saccharose (0.4% v/v ethanol formation) and produced only low levels of fermentation esters (1.6 mg/L in total) and dimethylsulfide (5 µg/L). The POF+ character of LA-01 also brought significant levels of 4-vinylguaiacol (810 μg/L), which could give to NABLABs the flavors of a white beer. Full article

It is widely known that mushrooms present several properties with applications in the medicinal and pharmaceutical sectors, including antimicrobial, immunomodulatory, antioxidant, hypotensive, neuroprotective, and anti-inflammatory activities. This article aims to review examples of the bioactive metabolites responsible for those activities, such as polysaccharides, phenols and polyphenols, terpenes, peptides, alkaloids, and steroids, which are produced by several relevant mushroom species. It also discusses their production through solid-state fermentation and submerged fermentation, as well as the processes of obtention of mushroom bioactive extracts and considerations on their stability aiming industrial applications. In addition, the article examines the patent landscape surrounding mushroom-derived bioactives, shedding light on the intellectual property history and innovations driving this field forward. Examples of recently deposited patents in the field are highlighted, as well as the main depositors. China and the United States are the major depositor countries in this field (52% and 35% of patents, respectively), and the principal compounds on the patents are polysaccharides and alkaloids. The article also provides insights into the current market landscape, showcasing mushroom-derived products in the pharmaceutical field available to consumers. From dietary supplements to skincare formulations, the market offerings reflect the growing interest in harnessing the health benefits of mushroom bioactives. Full article

Hydrogen is ideal for replacing fossil fuels because upon combustion it generates only water. Dark fermentation (DF) from lignocellulose might be a competitive process for hydrogen production at the industrial scale. However, lignocellulose must be pretreated to obtain fermentable sugars, which is costly and creates pollution. Microorganisms from bovine rumen efficiently degrade lignocellulose. Unfortunately, they have scarcely been explored for the production of hydrogen. Therefore, deeper studies on the culture conditions have to be undertaken to understand the behavior of microbial consortia from the rumen of bovines (MCRB) during hydrogen production. In this work, we evaluated the production of hydrogen by DF with MCRB by varying the incubation time, two culture media (MB and Rhodospirillaceae), headspace (40 and 80 mL), and thermal treatment. It was found that the production of hydrogen was maximum at 16 h MCRB incubation in MB. An amount of 80 mL headspace resulted in a threefold production of hydrogen as compared to 40 mL; the MCRB without heat treatment had a higher H₂ yield. The production of hydrogen with 32 MCRB was highly variable, ranging between 21 and 696 mL. Our findings show a different perspective on the treatment of MCRB for the production of hydrogen and give insights on the impact of the culture conditions for increasing hydrogen production. Full article

This study aimed to evaluate the effects of dietary supplementation with 3-nitrooxypropanol (3-NOP) on growth performance, ruminal fermentation, and enteric methane emissions of beef cattle using a meta-analytic approach. The final meta-analysis database included results from 15 scientific articles. The response variables were analyzed through random effects models, where the results were reported as weighted mean differences (WMD) between the treatments without 3-NOP and those supplemented with 3-NOP. The dietary inclusion of 3-NOP decreased (p < 0.001) dry matter intake but did not affect (p > 0.05) average daily gain and increased (p < 0.05) feed efficiency. In the rumen, 3-NOP supplementation increased (p < 0.01) the pH and ruminal concentration of propionate, butyrate, valerate, isobutyrate, and isovalerate. In contrast, dietary supplementation with 3-NOP decreased (p < 0.001) the rumen concentration of ammonia nitrogen, total volatile fatty acids, acetate, and the acetate/propionate ratio. Furthermore, daily methane (CH₄) emission, CH₄ yield, and CH₄ emission as a percentage of gross energy ingested decreased (p < 0.001) in response to 3-NOP dietary supplementation. In conclusion, dietary supplementation with 3-nitrooxypropanol can be used as a nutritional strategy to improve feed efficiency and ruminal fermentation in beef cattle and, at the same time, reduce enteric methane emissions. Full article

Melanoidins are heterogeneous polymers with a high molecular weight and brown color formed during the Maillard reaction by the combination of sugars and amino acids at high temperatures with the potential to inhibit the microbial activity in bioprocesses. This study assessed the impacts of melanoidins on the kinetic of substrate conversion and production of organic acids via dark fermentation using microbial consortia as inoculum. The investigations were carried out in fed-batch reactors using synthetic melanoidins following glucose-to-melanoidin ratios (G/M; g-glucose g⁻¹ melanoidins) of 0.50, 1.50, 1.62, 1.67, and 5.00, also considering a melanoidin-free control reactor. The results showed that melanoidins negatively impacted the kinetics of glucose fermentation by decreasing the first-order decay constant (k₁): when dosing equivalent initial concentrations of glucose (ca. 3 g L⁻¹), the absence of melanoidins led to a k₁ of 0.62 d⁻¹, whilst dosing 2 g L⁻¹ (G/M = 1.5) and 6.0 g L⁻¹ (G/M = 0.5) of melanoidins produced k₁ values of 0.37 d⁻¹ and 0.27 d⁻¹, respectively. The production of butyric and acetic acids was also negatively impacted by melanoidins, whilst the lactic activity was not impaired by the presence of these compounds. Lactate production reached ca. 1000 mg L⁻¹ in G/M = 1.67, whilst no lactate was detected in the control reactor. The presence of melanoidins was demonstrated to be a selective metabolic driver, decreasing the microbial diversity compared to the control reactor and favoring the growth of Lactobacillus. These results highlight the importance of further understanding the impacts of melanoidins on melanoidin-rich organic wastewater bioconversion, such as sugarcane vinasse, which are abundantly available in biorefineries. Full article

Long-term aging has traditionally been associated with issues such as color fading and oxidation; therefore, it limits grape wine production. Here, we analyzed 90 bottles of mulberry wine aged for various periods (up to 12 years) and observed unique trends in color, flavor, and aroma compounds during prolonged aging. Results from Somers and methylcellulose precipitation (MCP) assays indicated that the tannin and anthocyanin concentrations in newly fermented mulberry wines were 167 to 216 mg/L and 1.04 to 1.37 g/L, respectively. The total phenolics, tannins, and anthocyanin contents exhibited significant negative correlations with aging years, while the non-bleachable pigment content and hue showed positive correlations with aging times. High-performance liquid chromatography–electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) analysis further revealed a positive correlation between the content of pyranoanthocyanins (including cyanidin-3-O-glucoside-pyruvic acid, cyanidin-3-O-glucoside-acetaldehyde, cyanidin-3-O-glucoside-4-vinocatechol, and cyanidin-3-O-glucoside-4-vinophenol) and aging times, whereas the impacts of aging on the polymeric pigment (cyanidin-3-O-glucoside-epicatechin) were not observed. This suggests that the anthocyanins in mulberry wine primarily transformed into pyranoanthocyanins rather than polymeric pigments during aging. The aging-induced reductions in protein, polysaccharide, and key aroma compounds (contributing to the fruity, sweet and floral odors) remained unaffected by prolonged aging. Full article

Microalgal biomass is an excellent platform for producing food, feed, nutraceuticals, pharmaceuticals, and biofuels. This study aimed to investigate the effect of the trophic mode of cultivation (phototrophic, heterotrophic, and mixotrophic) on the growth and biomass composition of Chlorella vulgaris S2. The contents of lipids and carbohydrates, as well as the fatty acid composition of total lipids, were studied. The effects of the carbon-to-nitrogen ratio (C:N) and the organic carbon concentration of the growth media under mixotrophic and heterotrophic conditions were also investigated. The C:N ratio of 30 mol mol⁻¹ favoured lipid synthesis, and the C:N ratio of 10 mol mol⁻¹ favoured carbohydrate synthesis. Maximal lipid and biomass productivities (2.238 and 0.458 g L⁻¹ d⁻¹, respectively) were obtained under mixotrophic conditions at the C:N ratio of 50 mol mol⁻¹ and glucose concentration of 50 g L⁻¹. Fed-batch cultivation conducted in a stirrer tank bioreactor under heterotrophic growth conditions increased biomass (2.385 g L⁻¹ d⁻¹, respectively) and lipid (0.339 L⁻¹ d⁻¹) productivities ~50 and ~60 times compared to the fed-batch phototrophic cultivation, respectively. The trophic mode, growth phase, and growth medium composition significantly influenced the fatty acid composition. Under mixotrophic and heterotrophic growth conditions, lipid accumulation is associated with an increase in oleic acid (C18:1) content. Mixotrophically grown biomass of Chlorella vulgaris S2 under optimised conditions is a suitable source of lipids for biodiesel production. Full article

The ability to model the kinetics of wine fermentation enables the early detection of abnormal, sluggish or stuck fermentations, and the prediction of present and future rates of energy, CO₂ and ethanol vapor release. While several wine fermentation models have been published, there are only a few that have been successfully adopted for commercial practice. In this work, the mathematical descriptions of wine fermentation are reviewed and compared. The common features of these include descriptions for the kinetics of yeast growth; substrate and nutrient consumption; product formation; and total and viable cell mass. Additional features include the inhibition of growth by ethanol; competitive inhibition of glucose and fructose uptake; glycerol formation; and the calculation of density from solution composition and solute properties. Three models were selected to compare their ability to describe the sugar, ethanol, biomass and nitrogen of benchtop fermentations at four temperatures, previously published. The models are assessed for their goodness of fit to the data in synthetic-medium fermentations and their suitability for analyzing and predicting commercial wine fermentations. Full article

Climate shifts have significantly affected livestock systems due to their environmental interdependence. Among the strategies adopted by livestock systems to fill the gaps in forage biomass, preserved forages are the most commonly used. This research assessed the nutritional profile of African Stargrass (Cynodon nlemfuensis Vanderyst) preserved as silage and haylage at different feed-out periods (45, 60, 90, and 120 days). We found greater dry matter (DM) content in haylage (29.7%), with no important variations in silage over time. Stargrass silage had crude protein (CP) levels greater (13.0%) than haylage (11.9%); the former was not affected by the duration of the preservation period. Silage had lower levels of neutral detergent fiber (NDF) and higher levels of in vitro dry matter digestibility (IVDMD). The net energy for lactation (NEL) was similar for the two types of preservations evaluated. A principal component analysis (PCA) revealed that most of the variance in the dataset (69.6%) was explained by two principal components. PC1 showed that the most relevant variables were ADF, α-NDF, dNDF30, d NDF48, and NDICP, while Ash, Ca, and insoluble CP were the most relevant variables in PC2. Unlike haylage, the nutritional value of silage remained constant (p > 0.05) up to 120 days of preservation. It is important to note that haylage should not be stored beyond 90 days, regardless of the type of preservation. Full article

Amino-acid-fermenting bacteria are wasteful organisms within the rumens of beef cattle that remove dietary amino nitrogen by producing ammonia, which is then excreted renally. There are currently no on-label uses for the control of this microbial guild, but off-label use of broad-spectrum antimicrobials has shown efficacy, which contributes to antimicrobial resistance. Plant-derived antimicrobials supplemented into the diets of cattle may offer worthwhile alternatives. This study sought to investigate the role of cannabidiol (CBD) as a terpenophenolic antimicrobial. Ex vivo cell suspensions were harvested from the rumen fluid of Angus × Holstein steers in non-selective media with amino acid substrates. The suspensions were treated with five concentrations of CBD (860 μg mL⁻¹–0.086 μg mL⁻¹) and incubated (24 h), after which ammonia production and viable number of cells per substrate and treatment were measured. The data demonstrated a ~10–15 mM reduction in ammonia produced at the highest concentration of CBD and negligible changes in the viable number of amino-acid-fermenting bacteria. CBD does not appear to be a biologically or economically viable terpenophenolic candidate for the control of amino acid fermentation in beef cattle. Full article