Search Results (581)

Tannins are known for their ability to modify digestion and reduce CH₄ emissions in ruminants. Novel forages able to tolerate water deficits often contain low-to-moderate levels of dietary tannins. The aim of the study was to compare the effect of tannic acid (hydrolysable tannin, HT) and Tannivin (quebracho, condensed tannins, CTs) added to a total mixed ration at a concentration of 2.5% on rumen fermentation over time using in vitro methods. The substrates were incubated with buffered rumen fluid at 39 °C for 0, 3, 6, 12, 24, and 48 h to study dry matter (DM) degradability, tannin disappearance, utilizable protein (uCP), and rumen fermentation parameters. In parallel, gas production was measured using the ANKOM-RF Gas Production System. Gas composition was determined after 24 and 48 h of incubation. DM degradability was influenced by the incubation time (p < 0.001), reaching approximately 50% after 48 h, with a similar course of degradability for both tannin types. Tannin disappearance was significantly influenced by the type of tannins and the incubation time (both p < 0.001), reaching 50% in HTs and 39% in CTs within the first 6 h of fermentation. Production of individual and total VFA and uCP increased during incubation (p < 0.001) but were not influenced by the tannin type. However, the formation of uCP was relatively stable over time. Ammonia-N production increased during the first 12 h of fermentation with both tannin types and the increase continued with HTs (p < 0.001). Gas and methane production increased during fermentation and the increase was more substantial in HTs (p < 0.001). Our results suggest that at moderate concentrations, tannins mainly affect protein metabolism, with a minor effect on rumen fermentation. Full article

Today, PHB and its copolymers—potential plastic substitutes—are produced by fermenting sugar, which is not scalable to the volumes of plastic consumption. PHB from CH₄ can offer a sustainable process route, with CH₄ potentially produced from a variety of waste biomass streams through anaerobic digestion, gasification, and methanation. The high molar mass (M_w) of PHB is a key determinant of its mechanical properties, and strain, culture conditions and downstream processing influence it. In this work, the strain Methylocystis sp. GB 25 (DSMZ 7674) was grown on natural gas as the sole carbon and energy source and air (1:1) in a loop reactor with 350 L active fermentation volume, at 35 °C and ambient pressure. After two days of continuous growth, the bacteria were limited in P and N for 1, 2, and 2.5 days to determine the optimal conditions for PHB accumulation and the highest Mw as the target. The biomass was then centrifuged and spray-dried. For downstream processing, chloroform solvent extraction and selected enzymatic treatment were deployed, yielding ~40% PHB from the biomass. The PHB obtained by solvent extraction exhibited high average weight molar masses of M_w ~1.1–1.5 × 10⁶ g mol⁻¹. The highest M_w was obtained after one day of limitation, whereas enzyme treatment resulted in partially degraded PHB. Cold chloroform maceration, interesting due to energy savings, did not achieve sufficient extraction efficiency because it was unable to extract high-molar-mass PHB fractions. The extracted PHB has a high molar mass, more than double that of standard commercial PHB, and was characterized by DSC, which showed a high degree of crystallinity of up to 70% with a melting temperature of close to 180 °C. Mechanical tensile properties measurements, as well as dynamic mechanical thermal analysis (DMTA), were performed. Degradation of the PHB by enzymes was also determined. Methanotrophic PHB is a promising bioplastics material. The high M_w can limit and delay polymer degradation in practical processing steps, making the material more versatile and robust. Full article

This study evaluated the effects of replacing soybean hulls with dried grape pomace (DGP) on feed intake, milk production and composition, and rumen N degradability in dairy cows. A 3 × 3 Latin square design was used with three rumen-fistulated Holstein cows, three corn silage-based diets containing 0%, 3%, or 6% of DGP, and three 23-day periods. Measurements were taken from days 15 to 21, with in situ incubations of two protein sources during the last 2 days. At trial end, cows continued on experimental diets to determine the degradability of soybean hulls and DGP. Compared to soybean hulls, DGP presented higher fiber content and lower in situ rumen dry matter and N degradability. Condensed tannin disappearance from DGP increased over time, reaching almost 50% after 48 h. Diet did not affect feed intake, milk production, and composition, except for milk urea N and ruminal total short-chain fatty acids concentration, which showed a quadratic response, suggesting both imbalances between fermentable energy and rumen degradable protein and potential effects of DGP bioactive compounds on rumen function. The N degradation rate of rapeseed meal was unaffected, but soybean meal degradability tended to increase with higher DGP inclusion. This was also detected when combining protein sources across diets. Although DGP influenced rumen function, further research integrating omics and detailed microbiota profiling is needed. Overall, despite its low energy content and rumen degradability, DGP comprises a sustainable feed resource for high-producing animals, supporting circular economy approaches and mitigating the environmental impacts of grape pomace disposal. Full article

Simultaneous conversion of syngas and sugars is a promising approach to overcome limitations of syngas fermentation. Clostridium autoethanogenum LAbrini, obtained by adaptive laboratory evolution, is known to show improved autotrophic process performance. Under purely autotrophic conditions, C. autoethanogenum LAbrini exhibits substantially faster growth and biomass formation compared to the wild-type in fully controlled, stirred-tank bioreactors with a continuous gas supply. In mixotrophic processes, the pre-culture strategy has a significant impact on the growth and metabolic activity of C. autoethanogenum LAbrini. C. autoethanogenum LAbrini can metabolize sugars (D-fructose, D-xylose, or L-arabinose) and CO simultaneously. All mixotrophic batch processes showed increased growth and product formation compared to the autotrophic process. The mixotrophic batch process with D-fructose enabled superior production of alcohols (10.7 g L⁻¹ ethanol and 3.2 g L⁻¹ D-2,3-butanediol) with a heterotrophic pre-culture. Using an autotrophic pre-culture and L-arabinose resulted in a total alcohol formation of more than 13 g L⁻¹. The formation of meso-2,3-butanediol (>0.50 g L⁻¹) occurred exclusively under mixotrophic conditions. Thus, C. autoethanogenum LAbrini, clearly representing notable improvements over the wild-type strain in mixotrophic batch processes, offers a good basis for further strain improvements to shift the product range even further towards more reduced products. Full article

The craft beer market is continually expanding, driven by the consumers’ demand for product diversification, which leads to innovation in the brewing industry. While traditional brewing focuses on consistency and high-volume efficiency using standard yeasts, craft brewing prioritizes small-batch experimentation and flavor complexity. Traditionally, Saccharomyces cerevisiae (Ale beer) and Saccharomyces pastorianus (Lager beer) yeast are used in brewing. The craft brewing revolution introduced the use of non-conventional yeast. These yeasts possess distinct technological characteristics compared to commercial starters, such as a richer enzyme profile. This biological diversity produces beers with novel, complex aroma profiles, and opens exciting avenues for flavor creation. Recently, non-alcoholic beer and low-alcoholic beer (NABLAB), and functional beer have become the new horizons for the application of non-conventional yeasts. In recent years, the brewing potential of these alternative yeasts has been extensively explored. However, some aspects relating to the interactions between yeast and raw materials precursors involved in the aroma of the final beer, and the management of yeasts in fermentation, remain unexplored. This review systematically outlines the various innovative ways in which non-conventional yeasts are applied in brewing, including healthier beer. Here, we explore how these yeasts can foster innovation in the beer sector and provide the possibility for sustainable development in contemporary brewing. Full article

Cheese whey, the major by-product of the dairy industry, poses an environmental challenge due to its high organic load but simultaneously represents a nutrient-dense matrix suitable for biotechnological valorization. This review synthesizes recent advances positioning whey as (i) a fermentation substrate for lactic acid bacteria, yeasts/fungi, and microalgae, enabling the production of functional biomass, organic acids, bioethanol, exopolysaccharides, enzymes, and wastewater bioremediation; (ii) a platform for postbiotic generation, supporting cell-free preparations with functional activities; and (iii) a food-grade encapsulating material, particularly through whey proteins (β-lactoglobulin, α-lactalbumin), which can form emulsions, gels, and films that protect biotics and bioactive compounds during processing, storage, and gastrointestinal transit. We analyze key operational variables (whey type and pretreatment, supplementation strategies, batch and continuous cultivation modes), encapsulation routes (spray drying, freeze-drying, and hybrid protein–polysaccharide systems), and performance trade-offs relevant to industrial scale-up. Finally, we outline future directions, including precision fermentation, mixed-culture processes with in situ lactase activity, microfluidics-enabled encapsulation, and life-cycle assessment, to integrate product yields with environmental performance. Collectively, these strategies reframe whey from a high-impact waste into a circular bioeconomy resource for the food, nutraceutical, and environmental sectors. Full article

Microbial fermentation is an important means to enhance the nutrition and functionality of food, and soybean fermentation has a long history and a wide variety of products. This study systematically compared the effects of fermentation and post-ripening processes of Bacillus subtilis natto JLCC513 on the nutritional components, active substances, and sensory characteristics of soybeans. The experimental results showed that, in terms of basic nutrition, fermentation led to a significant decrease in fat and reducing sugar content, followed by an initial increase and then a decrease in total protein content. In contrast, water-soluble protein continued to increase, and the total amount of free amino acids surged. The active nutritional indicators before and after soybean fermentation showed that nattokinase activity continued to increase during fermentation and post-ripening. At the same time, the number of viable bacteria decreased slightly during post-ripening. The increase in the proportion of easily absorbed aglycone-type isoflavones before and after soybean fermentation is accompanied by a sustained increase in vitamin K2 and gamma aminobutyric acid (GABA) content. In terms of sensory quality, color-difference analysis shows a decrease in brightness (L value) and an increase in redness (a value), resulting in the characteristic yellow-brown color of natto. In terms of texture characteristics, the hardness decreases, while the viscosity and elasticity are significantly enhanced. Through GC-IMS analysis of volatile aromas during soybean fermentation and post-ripening, it was found that esters (such as ethyl acetate) and pyrazines (such as 2,3-dimethylpyrazine) increased, and the product flavor shifted from grassy to fruity and nutty. In summary, natto bacteria enhance the digestibility, nutritional value, and sensory acceptance of soybeans through enzymatic hydrolysis and metabolic transformation. The post-ripening stage plays a key role in flavor maturation and further accumulation of active ingredients. Full article

The worldwide population is anticipated to reach 10.12 billion by the year 2100, thereby amplifying the necessity for sustainable agricultural methodologies to secure food availability while reducing ecological consequences. Conventional synthetic pesticides, while capable of increasing crop yields by as much as 50%, present considerable hazards such as toxicity, the emergence of resistance, and environmental pollution. This review examines biopesticides, originating from microbial (e.g., Bacillus thuringiensis, Trichoderma spp.), plant, or animal sources, as environmentally sustainable alternatives which address pest control through mechanisms including antibiosis, hyperparasitism, and competition. Biopesticides provide advantages such as biodegradability, minimal toxicity to non-target organisms, and a lower likelihood of resistance development. The global market for biopesticides is projected to be valued between USD 8 and 10 billion by 2025, accounting for 3–4% of the overall pesticide sector, and is expected to grow at a compound annual growth rate (CAGR) of 12–16%. To mitigate production costs, agro-industrial byproducts such as rice husk and starch wastewater can be utilized as economical substrates in both solid-state and submerged fermentation processes, which may lead to a reduction in expenses ranging from 35% to 59%. Strategies for process intensification, such as the implementation of intensified bioreactors, continuous cultivation methods, and artificial intelligence (AI)-driven monitoring systems, significantly improve the upstream stages (including strain development and fermentation), downstream processes (such as purification and drying), and formulation phases. These advancements result in enhanced productivity, reduced energy consumption, and greater product stability. Patent activity, exemplified by 2371 documents from 1982 to 2021, highlights advancements in formulations and microbial strains. The integration of circular economy principles in biopesticide production through process intensification enhances the safety, quality, and sustainability of food systems. Projections suggest that by the 2040s to 2050s, biopesticides may achieve market parity with synthetic alternatives. Obstacles encompass the alignment of regulations and the ability to scale in order to completely achieve these benefits. Full article

Pile fermentation is a crucial process for developing the characteristic mellow taste and aged aroma of dark tea, yet the internal quality transformation mechanism of this process is still unclear. This study employed a high-sensitivity analytical platform based on gas chromatography–mass spectrometry (GC-MS) to systematically investigate the dynamic interplay between key chemical components, enzyme activities, and volatile compounds during the pile fermentation of primary dark tea. Our findings revealed a significant decrease in ester-type catechins, crude protein, and protopectin, alongside a notable accumulation of non-ester-type catechins, gallic acid, and soluble components. The multi-enzyme system—comprising PPO/POD, pectinase/cellulase, and protease—cooperatively drove the oxidation of phenols, cell wall degradation, and the release of aromatic precursors. This was complemented by GC-MS analysis, which identified and quantified 103 volatile compounds across nine chemical classes. The total content of volatile compounds increased significantly, with alcohols, esters, and aldehydes/ketones being the dominant groups. Floral and fruity compounds such as linalool and geraniol accumulated continuously, while esters exhibited an initial increase followed by a decrease. Notably, carotenoid degradation products, including β-ionone, were significantly enriched during the later stages. This study revealed a “oxidation–hydrolysis–reconstruction” metabolic mechanism co-driven by microbial activity and a multi-enzyme system, providing a theoretical foundation for the precise regulation of pile fermentation and targeted quality improvement of primary dark tea. Full article

Lupin (Lupinus spp.), a legume known for its high protein content, holds great promise as a sustainable protein source to meet future global demands. Despite its nutritional benefits, including substantial dietary fibre and bioactive compounds, lupin remains underutilised in human diets due to several techno-functional and sensory limitations. This review delves into the techno-functional limitations of lupin, which include poor foaming capacity, low water and oil absorption, inadequate emulsification properties, and poor solubility. Lupin’s techno-functional limits are tied to the compact, heat-stable nature of its conglutin storage proteins and high insoluble fibre content. While research has been conducted on fermenting other legumes such as soybeans, chickpeas, peas, and lentils with Exopolysaccharide (EPS) producing bacteria, its application to lupin remains largely unexplored. Crucially, this work is one of the first reviews to exclusively link lupin’s unique protein and fibre structure with the specific polymer chemistry of bacterial EPS as a targeted modification strategy. Current research findings suggest that EPS-producing Lactic Acid Bacteria (LAB) fermentation can significantly improve the techno-functional properties of legumes, indicating strong potential for similar benefits with lupin. The analysis highlights various studies demonstrating the ability of EPS-producing LAB to improve water retention, emulsification, and overall palatability of legume-based products. Furthermore, it emphasises the need for continued research in the realm of fermentation with EPS-producing bacteria to enhance the utilisation of lupin in food applications. By addressing these challenges, fermented lupin could become a more appealing and nutritious option, contributing significantly to global food security and nutrition. Full article

The context of food science and biotechnology is undergoing a profound transformation, characterized by an evolutionary shift from conventional large-scale fermentation to precision biomanufacturing, positioning Lactic Acid Bacteria (LAB) as versatile cellular biofactories for next-generation functional foods. This review analyzes the evolutionary role of LAB, their utilization as probiotics, and the technological advances driving this shift. This work also recognizes the fundamental contributions of pioneering women in the field of biotechnology. The primary methodology relies on the seamless integration of synthetic biology (CRISPR-Cas editing), Multi-Omics analysis, and advanced Artificial Intelligence/Machine Learning, enabling the precise, rational design of LAB strains. This approach has yielded significant findings, including successful metabolic flux engineering to optimize the biosynthesis of high-value nutraceuticals such as Nicotinamide Mononucleotide and N-acetylglucosamine, and the development of Live Biotherapeutic Products using native CRISPR systems for the expression of human therapeutic peptides (e.g., Glucagon-like Peptide-1 for diabetes). From an industrial perspective, this convergence enhances strain robustness and supports the digitalized circular bioeconomy through the valorization of agri-food by-products. In conclusion, LAB continue to consolidate their position as central agents for the development of next-generation functional foods. Full article

The global change toward sustainable manufacturing has intensified the development of alternatives to petrochemical-based surfactants, which are environmentally recalcitrant and fossil dependent. Biosurfactants have emerged as the most promising petrochemical-based surfactant substitutes, due to their biodegradability, low toxicity, and robust performance under extreme conditions; however, their industrial use is hindered by high production costs, limited productivity, and complex downstream processing, for instance high protein content can make the ultrafiltration (downstream strategy) unfeasible. This review critically examines recent advances in integrated bioprocess design to overcoming these constraints, with particular emphasis on the convergence of enzymatic catalysis and microbial fermentation. Comparative assessment across key biosurfactant classes demonstrates that tailored enzymatic transformations, enabled by lipases, glycosyltransferases, acyltransferases, and oxidoreductases, offer precision in structural modification unattainable through fermentation alone, enabling programmable amphiphilicity and improved functional performance. Thus, the translation of enzymatic and hybrid routes to industry remains restricted by enzyme stability, cofactor regeneration, and process engineering challenges. Emerging strategies such as continuous fermentation, in situ product recovery, and machine learning-based process control show strong potential to enhance productivity and reduce energy demands. By integrating molecular design, metabolic engineering, and intensified bioprocessing, this review delineates a strategic framework for advancing next-generation biosurfactants toward commercial viability within circular and sustainable value chains. Full article

The optimization of volatile fatty acid (VFA) production from complex wastes under anaerobic conditions remains constrained in terms of productivity by the common use of long hydraulic retention times (HRTs, 20–30 days). Extended HRTs can limit process productivity by reducing substrate turnover and reactor throughput, while promoting further conversion of VFAs into methane and other end products. Despite its importance, the combined influence of pH and HRT on VFA yields and process optimization has not been comprehensively evaluated. This study investigates the effects of pH and short HRT on VFA production, microbial community structure, and hydrolysis and acidification efficiency in continuous stirred-tank reactors (CSTRs) fed with carbohydrate-rich feedstock (carrot residue pulp). Operating at an HRT of 11 days and an organic loading rate (OLR) of 4.4 g COD·L⁻¹·d⁻¹ at 25 °C under pH 5.1 resulted in a VFA bioconversion efficiency of ~45% and an acidification efficiency of 84%, without compromising VFA profile or productivity compared to reactors operated at 14 days HRT and 3.3 g COD·L⁻¹·d⁻¹. The shorter HRT and higher OLR enhanced hydrolysis efficiency (60%) and promoted greater microbial diversity, supporting robust hydrolytic activity and stable production dominated by acetic and butyric acids. These findings challenge the conventional assumption that longer retention times inherently improve process stability and demonstrate that operational conditions might improve reactor space–time yield in VFA-oriented fermentations. Full article

The genus Aspergillus comprises over 600 species of filamentous fungi. This genus significantly impacts human health, food fermentation, and industrial biotechnology. With the in-depth research and applications of Aspergillus species in many fields, the establishment of efficient gene editing technologies is crucial for functional genomics studies and cell factory development. The clustered regularly interspaced short palindromic repeats and associated protein (CRISPR-Cas9) system, as a newly developed and powerful genome editing tool, has demonstrated exceptional potential for precise genetic modifications in various Aspergillus species. The continuous advancement of CRISPR-Cas9 technology has enabled precise gene editing and modification in both pathogenic and industrial Aspergillus strains, thereby driving innovations in pathogenicity attenuation, metabolic engineering, and functional genomics. Therefore, this review provides a concise overview of the CRISPR-Cas9 system, detailing its composition, working mechanism, and key functional features such as the role of the Cas9 protein and the protospacer adjacent motifs (PAMs). Subsequently, we focus on the transformative applications of CRISPR-Cas9 in Aspergillus species, discussing its pivotal roles in elucidating pathogenic mechanisms, disrupting mycotoxin biosynthesis, and employing metabolic engineering to enhance the production of industrial enzymes, organic acids, and valuable natural products. Finally, we discuss future challenges and promising opportunities for applying CRISPR-Cas9 technology to advance the industrial biotechnology of Aspergillus species. Full article

Against the backdrop of the continuous expansion of the global aquaculture industry and the growing demand for high-quality feed protein, the development of sustainable alternative protein sources to fishmeal is crucial. Cottonseed protein, particularly cottonseed protein concentrate, has emerged as a highly promising plant-based alternative raw material due to its high protein content and cost advantages. This review systematically evaluates the application effects, challenges, and mechanisms of action of cottonseed protein in fish feed. Core analysis indicates that the primary limiting factor of cottonseed protein is the antinutritional factor free gossypol. High-level replacement (typically >30%) of fishmeal can inhibit fish growth, reduce protein deposition, and impair intestinal health. These adverse effects are closely associated with the downregulation of the hepatic mTOR signaling pathway—a central regulator of protein synthesis and cell growth—shifting the organism’s energy allocation from growth to stress adaptation. Furthermore, the unique fatty acid profile of cottonseed protein may exacerbate energy metabolism imbalance. To overcome gossypol toxicity, physical, chemical, and biological detoxification technologies have been widely applied. Among these, biological methods (such as Bacillus subtilis fermentation and CotA laccase-catalyzed degradation) are particularly outstanding, not only efficiently removing gossypol (removal rate > 90%) but also degrading macromolecular proteins into more digestible and absorbable small peptides and amino acids, significantly enhancing the nutritional value of cottonseed protein. Although the application prospects for cottonseed protein are broad, gaps remain in current research, particularly concerning the deeper metabolic pathways, nutrient utilization efficiency, and long-term impacts on metabolic homeostasis of detoxified cottonseed protein in fish. Future research needs to employ molecular nutrition and multi-omics technologies to elucidate its metabolic mechanisms and optimize detoxification processes and precision feeding strategies. Glandless cottonseed varieties, which fundamentally address the gossypol issue, are considered the most transformative development direction. Through continuous technological innovation, cottonseed protein is expected to become a core feed protein ingredient promoting the sustainable development of the global aquaculture industry. Full article