Search Results (727)

Surfactin is a lipopeptide biosurfactant with significant industrial potential, but high production costs have hindered its commercialization. In this study, we developed a sustainable and cost-effective bioprocess for surfactin biosynthesis using Bacillus subtilis 55033, utilizing kitchen waste as the primary fermentation substrate without any previous pretreatment—an advantage that simplifies the process and reduces costs compared to previous reports. To maximize productivity, the fermentation parameters were systematically optimized through single-factor and orthogonal experimental designs. The optimal conditions were as follows: a fermentation temperature of 31 °C, a duration of 48 h, a 5% v/v inoculum, a 7% w/v solid-to-liquid ratio, an initial pH of 7.5, and an agitation speed of 200 rpm. Under these conditions, the surfactin yield reached 371.67 mg/L, an increase of 100.5% from 185.4 mg/L prior to optimization. We performed a comparative analysis of the surfactin biosynthetic gene clusters between B. subtilis 55033 and the model strain B. subtilis 168. The produced surfactin exhibited potent antagonistic activity against aquatic pathogens, significantly inhibiting the growth of several species of Vibrio and the division and hatching of Cryptocaryon irritans Tomonts. These findings demonstrate that our platform not only provides a high-value valorization route for organic waste but also enables preliminary exploration of surfactin applications in aquaculture, in line with the principles of a circular bioeconomy. Full article

The introduction of sustainable practices into waste management can have a favorable environmental impact, increase resource value, and yield economic gains. Hydrothermal technologies have strong potential for the production of up-cycled ingredients from biowaste (amino acids, sugars, phenols, pharmacologically active compounds, etc.), enabling high energy recovery (50–80%) from biowaste with net-negative carbon emissions. This review discusses the use of subcritical and supercritical water technologies for sustainable valorization of biowaste and conversion of biomass into high-value chemicals and biofuels. The potential for the extraction/generation of bioactive compounds from plant and animal waste is presented, emphasizing the efficiency, compound stability, and bioactivity of the fractions obtained. The possibilities of simultaneous extraction of added-value compounds and hydrolysis of feedstock biopolymers by these technologies are elaborated. The review further addresses the production of biofuels through hydrothermal carbonization for solid fuels, hydrothermal waste liquefaction for liquid fuels, and supercritical water gasification for gaseous fuels. The paper highlights the environmental and economic advantages of technologies based on sub- and supercritical water over conventional chemical and fermentative routes, emphasizing their contribution to a circular bioeconomy by converting biowaste into value-added products and sustainable energy sources. Full article

Seasonal fluctuations in open solid-state fermentation drive batch-to-batch variability in Chinese Baijiu Daqu; however, how environmental shifts reshape microbial functional expression and non-volatile flavour precursors in medium-high-temperature Daqu remains poorly resolved. In this study, data-independent acquisition (DIA)-based quantitative metaproteomics and untargeted liquid chromatography–mass spectrometry (LC-MS) metabolomics were integrated to characterise winter and summer Daqu from Luzhou, Sichuan. Among 2904 annotated non-volatile metabolites, orthogonal partial least squares discriminant analysis (OPLS-DA) revealed clear seasonal separation; 1472 differential metabolites (560 up- and 912 downregulated in winter vs. summer; variable importance in projection [VIP] > 1, p < 0.05) were enriched in glycolysis/gluconeogenesis, the tricarboxylic acid (TCA) cycle, amino acid biosynthesis, and starch/sucrose metabolism. DIA-based quantitative metaproteomics further resolved season-specific enzyme expression: summer Daqu exhibited elevated saccharolytic, glycolytic and amino-acid-converting enzymes (β-glucosidase, 6-phosphofructokinase, pyruvate dehydrogenase), whereas winter Daqu was enriched in glucose oxidase, phosphoenolpyruvate carboxykinase and aldehyde dehydrogenase, consistent with a pattern suggestive of carbon-storage prioritisation. Proteome–metabolome integration established a coherent “enzyme protein abundance–inferred metabolic tendency–metabolite accumulation” correlative framework axis: higher hydrolytic and central-carbon enzyme abundance in summer corresponded to increased maltose, lactate, acetate, L-glutamate and L-aspartate. Therefore, production season reshapes Daqu quality chiefly by corresponding to distinct patterns of in situ enzyme protein abundance, providing a DIA quantitative metaproteome-anchored mechanistic framework for screening high-expression starters and stabilising seasonal Daqu quality. Full article

Large-scale production of Bacillus thuringiensis, one of the most widely used biopesticides, is often limited by the high cost of conventional culture media. In this study, fermented cassava paste water (EFM), ripe mango pulp juice (CM), and cashew apple juice (JPC) were evaluated as alternative substrates for the liquid fermentation of B. thuringiensis var. kurstaki HD-1. Physicochemical analyses revealed acidic pH values and classified the substrates into two clusters: CM with high C/N ratios, organic matter, total sugars, and proteins, and EFM and JPC with lower C/N ratios and nutrient levels. Fermentation results indicated that JPC supported the highest biomass production (8.29 × 10¹³ CFU mL⁻¹), exceeding that in the standard Tryptone Soy Broth (TSB) medium. However, CM promoted the highest sporulation rate (1.46 × 10¹³ CFU mL⁻¹) and the greatest bioactive lipopeptides—iturins (102.2 mg L⁻¹) and surfactins (554.7 mg L⁻¹)—surpassing TSB. The antifungal activity of crude fermented CM, EFM, and TSB was evaluated against Sclerotium rolfsii. All samples significantly inhibited mycelial growth of the pathogen with no significant differences among substrates or concentrations tested. This study highlights the potential of B. thuringiensis-fermented agrowaste as a cost-effective, environmentally friendly biocontrol tool for Sclerotium rolfsii. Full article

Amaranthin is a major red-violet betacyanin of Amaranthaceae and an increasingly relevant natural pigment for food, cosmetic, nutraceutical, and biotechnological applications. This review integrates knowledge from over 100 studies, addressing amaranthin as a chemically defined betalain, distinguishing it from other scientific uses of the term, and evaluates its natural sources, analytical methods, extraction strategies, in vitro production systems, biosynthetic regulation, and biological activity. Cultivated Amaranthus species are among the richest plant sources, with total betacyanins of 46.1–199 mg/100 g fresh weight and amaranthin comprising, on average, 80.9% of the pigment fraction. Reliable identification and quantification rely on high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and ultraviolet–visible (UV–Vis) spectrophotometry. Microwave- and ultrasound-assisted extraction can improve pigment recovery under optimized conditions, although its stability depends strongly on pH, temperature, solvent, time and storage parameters. While plant in vitro cultures, including callus, suspension, and shoot systems, have clarified biosynthetic regulation and offer controlled production platforms, engineered yeast systems have recently expanded production options, with Yarrowia lipolytica reaching 2.97 ± 0.029 g L⁻¹ amaranthin in fed-batch fermentation. Amaranthin-rich extracts and amaranthin-type pigments show antioxidantand anti-inflammatory potential, while antimicrobial and antiviral activities have mainly been reported for mixed betacyanin fractions; direct mechanistic, bioavailability, and in vivo evidence for purified amaranthin remains limited. Standardized analytical protocols, further investigation of stable high-yield sources, physicochemical stability assessment, and structure–activity studies are identified as priorities for advancing future application-oriented research on this multipotential pigment. Full article

Efficient recovery of long-chain dicarboxylic acids (LCDAs) from aqueous fermentation broths is a key challenge for the industrial development of bio-based LCDA production. This study evaluates liquid–liquid extraction (LLE) as a downstream recovery strategy, comparing physical extraction (PE) and reactive extraction (RE) for DCA 12, DCA 16, and DCA 18. The novelty of this work lies in demonstrating that LCDA extraction is governed by mechanisms fundamentally different from those of short- and medium-chain dicarboxylic acids. Whereas shorter chain dicarboxylic acids are mainly controlled by dissociation degree, LCDA recovery is strongly influenced by carbon-chain apolarity, low aqueous solubility, and compound losses through agglomeration, precipitation, and/or micellization. PEs enabled the selective recovery of the more hydrophobic DCA 16 and DCA 18 over DCA 12, confirming the dominant role of chain length in LCDA separation. In contrast, RE with Aliquat^®336 maximized total LCDA recovery, achieving extraction efficiencies above 85%, but with reduced selectivity. Validation in autoclaved fermentation broth from UCO feedstock confirmed the potential of Aliquat^®336 in octanol for high LCDA recovery, while revealing lower extraction efficiencies than in model mixtures due to broth matrix complexity. Overall, this study establishes LLE as a promising platform for LCDA recovery and highlights that future downstream process design must balance total recovery, chain-length selectivity, and broth-specific matrix effects. Full article

Antibiotic resistance and biofilm-associated infections require sustainable antimicrobial platforms that combine efficacy with biocompatibility. Fermented matrices are attractive for green nanomaterial production because they provide reducing metabolites and surface-active capping compounds. Rooibos kombucha is a polyphenol-rich fermentation system with potential to serve as a biosynthetic matrix for silver nanoparticles (AgNPs). The present work aimed to develop a rooibos kombucha-enabled platform for the green biosynthesis of phytochemical-capped silver nanoparticles, AgNPs-K, and evaluate their antibacterial, antibiofilm, and in vivo activity. Rooibos kombucha was fermented for 14 days and profiled by liquid chromatography–tandem mass spectrometry (LC–MS/MS). AgNPs-K were generated using kombucha extract and AgNO₃, purified, and characterized by ultraviolet–visible spectroscopy (UV–Vis), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and nanoparticle tracking analysis. Antibacterial activity against eight Gram-positive and Gram-negative reference pathogens was assessed by EUCAST-based microdilution and time-kill assays. Biofilm inhibition was measured by the crystal violet assay. In vivo toxicity and therapeutic efficacy were evaluated in Galleria mellonella larvae. AgNP formation was confirmed by a surface plasmon resonance (SPR) peak at 415 nm. TEM showed predominantly spherical nanoparticles with a main size range of 20–30 nm, a hydrodynamic diameter of 98 nm, and a zeta potential of −14.62 ± 0.04 mV. AgNPs-K showed overlapping minimum inhibitory concentration and minimum bactericidal concentration values of 1.14 µg/mL for Gram-positive species and 1.33 µg/mL for Gram-negative species. Time-kill assays showed rapid bactericidal activity after threshold concentrations were reached, with sustained suppression at 24 h. Biofilm formation was abolished at 40 µg/mL and strongly reduced at lower concentrations. AgNPs-K were non-toxic up to 400 µg/mL and improved survival in six of seven infection models. Fermented rooibos kombucha functions as an effective biosynthetic matrix for the green production of phytochemical-capped AgNPs. The resulting nanoparticles combine low-dose antibacterial and antibiofilm activity with favorable in vivo tolerability and efficacy, supporting fermentation-enabled nanobiotechnology strategies against biofilm-associated infection. Full article

This study investigated the effects of single-strain fermentation (using Lactobacillus paracasei XY1-4 and Saccharomyces cerevisiae XX1-2) and 1:1 mixed fermentation on the differential metabolites and in vitro cholesterol-lowering activity of Cyperus esculentus L. tuber milk. A non-targeted metabolomics approach based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied, and the dynamic changes in physicochemical properties and in vitro cholesterol-lowering rates during fermentation were determined to systematically compare the metabolite profiles and functional characteristics of tuber milk samples subjected to single-strain fermentation and mixed fermentation for 12 h and 24 h, respectively. The results showed that a total of 1085 differential metabolites were screened across all fermentation groups under the criteria of VIP ≥ 1, p < 0.05, and FC ≥ 2 or FC ≤ 0.5, which were primarily classified as lipids and lipid-like molecules as well as organic acids and their derivatives. Enrichment analysis of these differential metabolites identified ten metabolic pathways closely associated with fermentation progression and functional activity, including arginine biosynthesis, the tricarboxylic acid (TCA) cycle, and glutathione metabolism. Further correlation analysis demonstrated that key metabolites such as succinic acid and L-glutamic acid were significantly and positively correlated with the in vitro cholesterol-lowering rate. This study clarifies the effects of different fermentation treatments on the metabolome and functional properties of tuber milk, laying a solid theoretical foundation for the development and quality optimization of functional fermented Cyperus esculentus L. products. Full article

Saccharomyces cerevisiae (SC), an important unicellular yeast species in the biotechnology, beverage, and food industries, has remarkable applications in ethanol production. Lipids in SC play a crucial role in stress management during the fermentation process. Despite the importance of SC yeasts, comprehensive lipid profiling across multiple yeast strains remains limited. This study aimed to elucidate the comprehensive lipidomic profiles of 48 wine yeast strains of the SC species using a nontargeted liquid chromatography–mass spectrometry approach. A total of 135 lipid species were identified, representing five major lipid categories. Among the SC strains, strain 19 contained the highest relative concentrations of α-linolenic acid (ω-3) and linoleic acid (ω-6). Levels of polyunsaturated fatty acids were 4.6-fold higher in SC46 compared to SC13, suggesting strain-specific variations. Glycerolipids were the most abundant lipid components, with triacylglycerols showing the highest relative abundance in SC10, SC41, and SC48. These findings should be interpreted in light of the semi-quantitative nature of the dataset. Interestingly, bioactive lipids, such as N-acyl lysophosphatidylethanolamines, were putatively identified and structurally characterized using high-resolution mass spectra and MS/MS fragmentation patterns. This study provides insight into strain-specific differences in the yeast lipidome and may help improve our understanding of fermentation kinetics and industrial wine quality. Full article

Oxidative stress is a key contributor to aging and chronic diseases, highlighting the need for safe and effective natural antioxidants. Monascus yellow pigments (MYPs) and ginsenoside Rg3 exhibit antioxidant activity, but their applications are restricted by low solubility and limited natural abundance. In this research, a bidirectional liquid fermentation system of Monascus ruber using ginseng decoction was established for the simultaneous production of water-soluble MYPs (WSMYPs) and ginsenoside Rg3. Process conditions were optimized to enhance the yields and the antioxidant activity of the system. Antioxidant assays and H₂O₂-induced RAW264.7 cell models confirmed that WSMYPs were strongly correlated with antioxidant capacity, with ABTS and DPPH scavenging activities showing 2.28-fold and 3.33-fold increases, respectively, compared to the control. Their combination with Rg3 exerted synergistic protective effects by enhancing the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT). Network pharmacology and molecular docking further revealed that Monapurone C, a representative WSMYP, and Rg3 act through a multi-target, multi-pathway antioxidant network involving signaling pathways such as PI3K-Akt. This study demonstrates a cost-effective strategy for co-producing WSMYPs and Rg3, providing new insights into the value-added utilization of edible and medicinal resources. Full article

Bongkrekic acid (BKA) is a potent respiratory toxin produced by Pseudomonas cocovenenans. This toxin is commonly found in spoiled fermented rice- and wheat-based products, snow fungus, and black fungus and can cause severe foodborne illness. The development of a rapid onsite detection method can effectively prevent food poisoning incidents and ensure food safety. In this study, a highly specific anti-BKA monoclonal antibody was prepared, the reaction conditions were optimized, and an indirect competitive chemiluminescent enzyme-linked immunoassay (ic-CLEIA) system was developed for high-throughput screening of BKA in food. The results showed that the ic-CLEIA had good linearity in the range of 7.3–106.6 pg/mL, a limit of detection of 4.7 pg/mL, a limit of quantification of 7.3 pg/mL, a half-maximal inhibition concentration of 28.2 pg/mL, a spike recovery of 86.6–94.1%, a coefficient of variation of less than 10%, and no cross-reactivity with structural analogs. There was no significant difference between the detection results obtained with ic-CLEIA and ultraperformance liquid chromatography–tandem mass spectrometry for the samples. This method provides reliable technical support for food safety monitoring, especially for grassroots laboratories and large-scale sample screening. Full article

In this study, an acid-tolerant and high-fermentation performance strain of Kazachstania humilis (K. humilis 3-8) was screened from sourdough isolates and co-cultured with Fructilactobacillus sanfranciscensis (F. sanfranciscensis 5) to prepare liquid sourdough, which was further applied in mantou production. The effects on physicochemical properties, nutritional characteristics, and microbial interactions were investigated. K. humilis 3-8 exhibited strong gas production and acid tolerance, achieving a dough volume increase of 72.19% after 3 h fermentation. In co-culture, F. sanfranciscensis 5 maintained stable growth, while its metabolites significantly inhibited the growth of K. humilis 3-8 during mid-fermentation. The co-fermented dough showed decreased pH and increased total titratable acidity. Metabolomic analysis indicated enhanced carbohydrate metabolism and amino acid metabolism, suggesting carbon–nitrogen metabolic interactions between the two strains. When applied to Mantou production, the optimized co-culture system substantially enhanced product functionality, increasing resistant starch content by 76.7% (from 23.02% to 40.68%). Total phenolic content and antioxidant capacity were markedly enhanced. These findings elucidate complex microbial interactions governing sourdough ecosystems and establish a scientific foundation for the targeted improvement of traditional fermented cereal products through rational strain selection and process optimization. Full article

Yaks (Bos grunniens) on the Qinghai–Tibetan Plateau face severe nutritional limitations during the dry season due to dependence on highly lignified, low-quality roughage. Identifying safe and effective rumen regulators capable of enhancing fiber utilization in this species is therefore of great practical importance. This study employed a two-pronged approach integrating in vitro mechanistic investigation and in vivo validation to evaluate the effects of the amphoteric surfactant cocamidopropyl betaine (CAPB) on rumen fermentation, the micro-spatial distribution of digestive enzymes, apparent total tract digestibility, and the macroscopic growth performance of yaks. In the in vitro fermentation trial (Experiment 1), a randomized block design was employed where a straw-based high-forage diet was used as the substrate and supplemented with 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% CAPB (based on substrate dry matter, DM) for a 48 h batch culture. The results showed that as the CAPB supplementation level increased, cumulative gas production, the degradation rates of DM and neutral detergent fiber (NDF), and the yields of total volatile fatty acids and microbial protein all exhibited significant quadratic responses (p < 0.05), peaking at the 0.5–1.0% supplementation levels. Concurrently, CAPB significantly promoted the transfer and release of carboxymethyl cellulase and xylanase into the free liquid phase (p < 0.01). In the in vivo validation trial (Experiment 2), 24 healthy growing male yaks (initial body weight 131.2 ± 8.4 kg) were allocated in a completely randomized design to four groups and fed a basal diet supplemented with 0, 0.5, 1.0, or 2.0% CAPB for 44 days. The results indicated that, while maintaining a stable DM intake, the addition of 0.5% CAPB significantly increased the average daily gain (ADG) of yaks (p < 0.05), improved the feed-to-gain ratio, and significantly enhanced the apparent total tract digestibility of NDF and ether extract (p < 0.05). However, when the supplementation dose exceeded the safety threshold (≥2.5% in vitro and ≥2.0% in vivo), both fermentation parameters and growth advantages declined. In conclusion, under the present experimental conditions, 0.5% CAPB improved roughage fermentation efficiency, putatively through an ‘enzyme elution’ mechanism, and was associated with macroscopic improvements in NDF and EE apparent digestibility and ADG in growing yaks. These findings identify 0.5% CAPB as a promising candidate rumen regulator for improving roughage utilization in growing yaks; broader generalization will require larger-scale and longer-duration trials. Full article

Stevia residue (SR), a typical by-product of the stevia industry, is rich in organic matter and has great potential as a feed resource. However, its high fiber content and low utilization efficiency limit its practical application in poultry production. To improve the nutritional value and application potential of SR, this study first optimized the fermentation conditions of SR using response surface methodology (RSM) with chlorogenic acid as the key optimization index and then investigated the effects of different doses of SR and fermented SR (FSR) on laying performance, egg quality, antioxidant capacity, and immunity in laying hens. Six fermentation parameters, including pH, solid-to-liquid ratio, temperature, inoculation quantity, brown sugar addition, and soybean meal addition, were first screened using single-factor experiments and then optimized with RSM. Subsequently, 560 laying hens were randomly divided into seven groups and fed a basal diet supplemented with 0, 0.5%, 1.0%, and 1.5% of either SR or FSR for 28 days. The results showed that the optimal fermentation conditions were a solid-to-liquid ratio of 75.6%, brown sugar addition of 2.7%, temperature of 25 °C, inoculation quantity of 3%, and fermentation time of 9 days. In the animal study, dietary 0.5% SR and FSR reduced average daily feed intake and eggshell strength, whereas the plasma total antioxidant capacity was enhanced in all (SR or FSR) supplemented groups (p < 0.05). Moreover, plasma immunoglobulin (Ig) A level was increased in the 1.0–1.5% SR and 1.5% FSR groups, and plasma IgY was elevated in the 1.0% SR group (p < 0.05). Our results suggested that SR fermentation was effectively optimized through RSM, and dietary FSR supplementation at 1.0% improved the health of laying hens, representing the optimal inclusion level. Full article

The transition toward industrial-scale, year-round production of Pleurotus pulmonarius necessitates efficient and standardized spawn production. Liquid spawn technology plays a pivotal role in this process; however, recommended formulations and science-based quality criteria remain lacking. This study aimed to screen a high-performance liquid spawn medium and define key quality parameters for industrial application. Ten culture media formulations were evaluated to determine their effects on mycelial growth, as well as the subsequent yield and quality of fruiting bodies. The optimal formulation (Formula 4) contained glucose (1.6%), soybean meal (0.3%), corn flour (0.2%), peptone (0.2%), KH₂PO₄ (0.1%), and MgSO₄ (0.055%). The growth rhythm of the selected formulation was meticulously tracked, leading to the identification of a critical inoculation window between 4.75 and 5.5 days. Spawn within this window exhibited a mycelial biomass of 1.60~1.86 g/L, pellet diameter of 1.83~1.92 mm, pellet density of 12.25~13.75 per mL, and fermentation broth pH of 6.35~6.44, which were strongly correlated with peak yield (up to 284 g/bag) and premium-grade ratio (up to 87.97%). The multi-parameter composite standard is proposed as a practical tool for quality control in industrial fermenters, enabling precise harvest timing and ensuring the consistent, high-yield, and high-quality production of P. pulmonarius. Full article