Dhurrin, a prevalent cyanogenic glycoside in sorghum, serves as a critical precursor to the carcinogen ethyl carbamate, making its accurate detection essential for ensuring the safety of alcoholic beverage production. This work reports a novel aptamer-based method for rapid detection of dhurrin in sorghum. Using the improved Capture-SELEX technique, a high-affinity aptamer (named DHU1) was first selected with a dissociation constant (Kd) of (66.06 +/- 3.92) nmol & sdot;L-1. Subsequently, DHU1 aptamer was optimized to obtain a truncated aptamer (DHU1-23), demonstrating even higher affinity with a Kd of (41.2 +/- 2.05) nmol & sdot;L-1. It was found that DHU1-23 aptamer can enhance the laccase-mimic activity of octahedral Ag2O particles, and the complex formed between dhurrin and DHU1-23 was first confirmed to synergistically amplified the laccase-mimic activity. This mechanism enabled the construction of a highly sensitive and convenient aptasensor for dhurrin, achieving a detection limit as low as 0.074 & micro;g mL-1. The aptasensor exhibited the spike recovery rates of 89.66% to 100.87% in actual sorghum samples, showing no significant difference compared with results validated by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). The developed aptasensor enables on-site, rapid-response, and cost-efficient method for dhurrin detection, offering considerable prospect for quality control and safety guarantee in the liquor production industry.

Acetamiprid (ACE), a neonicotinoid pesticide broadly used in agricultural production, can accumulate in the food chain due to excessive or incorrect use, thereby posing a threat to human health. In this manuscript, a colorimetric aptasensor assisted by a smartphone was established, relying on the S-18 aptamer-mediated amplification of the laccase-mimic activity of spherical Ag2O nanoparticles (NPs). The S-18 aptamer strengthens the interaction and facilitates electron transfer between the Ag2O NPs and oxidative substrates, which significantly improves the laccase-mimic activity of the Ag2O NPs. When acetamiprid is present, the S-18 aptamer preferentially binds to the target molecule, forming a steady aptamer-acetamiprid complex. This binding interaction prevents the aptamer from promoting the catalytic behavior of the Ag2O NPs, producing a distinct and quantifiable color variation in the reaction system. Monitoring the concentration-dependent colorimetric response enables the quick and accurate identification of acetamiprid. The colorimetric aptasensor achieved a limit of detection (LOD) of 8.69 mu g center dot L-1 markedly lower than the maximum residue limits defined by the national standard (GB 2763-2019) for acetamiprid in fruits and vegetables. Furthermore, the aptasensor demonstrates satisfactory recovery rates in actual samples analyses of cabbage, apple, and tomato, confirming its practical potential for on-site food safety oversight.

Enhancing the quality of Fuqu, a traditional fermentation agent used in Baijiu production, is crucial for aroma enrichment of Baijiu to address the thin aroma caused by a single microbial species in fermentation. The physicochemical factors and enzymatic, flavor-omics, and transcriptomics were employed to evaluate the effect of adding agarwood on Aspergillus Fuqu through 4 groups: S1 (bran), S2 (bran + agarwood), A1 (bran + Aspergillus tubingensis), and A2 (bran + agarwood + A. tubingensis). Although the addition of agarwood inhibited the activity of hydrolytic enzymes (glucoamylase and acid protease) of A. tubingensis, it enhanced the complexity and content of the flavor of Aspergillus Fuqu. Specifically, the number of detectable flavor compounds in A2 (52) was approximately 52.94% more than in A1 (34). A2 exhibited a total flavor content of 34.18 mg/g, which was about 2.20-fold greater than the 15.77 mg/g observed in A1. The addition of agarwood upregulated the expression of key proteins (AroAT, AACT, and AROM protein) in A. tubingensis, indicating that carbohydrate and amino acid metabolic fluxes were redistributed. This makes the content of 4-vinylguaiacol (sauce flavor characteristic) and ethyl palmitate (prolonged empty cup fragrance) in A2 3.45-fold and 96.75-fold higher than A1, respectively. It provides a novel strategy for the industrial production of baijiu by directing and regulating the flavor of fermenting agents through the addition of natural substrates.

Pit bottom wastewater (PBW), a high-strength organic effluent from sauce-flavored Baijiu production, poses considerable environmental challenges. This study explores its valorization as a nutrient medium for biosynthesis of high-value compounds using Monascus purpureus MP-1 isolated from Daqu. Cultivation in 10% PBW-supplemented medium increased biomass by 150% and enhanced hydrolytic enzyme activities. Integrated metabolomic and transcriptomic analyses revealed that PBW supplementation suppressed Monascus pigment biosynthesis but activated the putrescine (Puu) pathway for γ-aminobutyric acid (GABA) synthesis, increasing yield by 50.38% (121.28 μg/mL). Concurrently, organic pollutants were effectively degraded via enhanced lignin catabolism and redox activities. This work establishes a sustainable waste-to-value strategy, demonstrating the potential of Monascus spp. for simultaneous resource recovery and functional metabolite production, offering dual benefits of waste reduction and value creation for the food industry.

The efficacy of chitooligosaccharides (COS) is closely related to their degree of polymerization (DP), with higher-DP COS offering significant bioactivities and stability advantages. The objective of this study is to enhance the product specificity of chitosanase for producing higher-DP COS. In this study, we proposed a novel strategy to enhance the affinity and activity of the chitosanase Csn75 through the fusion of a carbohydrate-binding module CBM32 (specifically its DD1 subdomain) using rigid or flexible linkers of varying lengths. The fusion chitosanase with a 10-amino-acid rigid linker (Csn-E2-DD1) demonstrated optimal activity at 50 °C and pH 5.5, exhibiting a 60% increase in crude enzyme activity compared to the native Csn75. Kinetic analysis revealed its higher substrate affinity (Km = 0.668 mg·mL-1) and catalytic efficiency. The hydrolysis product profile shifted from DP 2-5 to DP 2-6, and a final yield exceeding 95% was obtained. This strategy offers a potential alternative for the bioproduction of desirable COS to meet the requirements of application in food systems, providing an efficient strategy for the targeted production of high-DP COS.

ABSTRACT Daqu is an essential fermentation starter that drives the formation of the characteristic flavor of Maotai-flavor liquor, yet the ecological and metabolic mechanisms underlying its regional differentiation and maturation remain poorly resolved. Here, we performed genome-resolved metagenomic and untargeted metabolomic analyses on 48 new and aged Daqu samples collected from four major Maotai-flavor liquor-producing regions in Guizhou Province, China. We reconstructed 163 high-quality metagenome-assembled genomes (MAGs) spanning 16 bacterial and 3 archaeal phyla and identified 2,642 metabolites across ionization modes. Distinct regional microbial signatures were observed, with Jinsha Daqu showing the greatest genomic diversity and unique MAGs, whereas Maotai Daqu exhibited the highest community similarity with other regions. Aged Daqu significantly increased microbial richness and functional capacity, enriching thermophilic and spore-forming taxa (e.g., Bacillus, Lentibacillus, Kroppenstedtia) and enhancing carbohydrate-active enzymes (GH13, GH43, and GH3), amino acid degradation, lipid metabolism, and secondary metabolic pathways. Metabolomic profiling revealed elevated amino acid derivatives, fatty acids, esters, and phenolic compounds in aged Daqu, indicating intensified biochemical activity. Multi-omics integration linked dominant microorganisms—including Bacillus thuringiensis, Actinomycetaceae bacterium, and Methylocaldum szegediense to pyrazine biosynthesis, amino acid catabolism, and lipid oxidation, forming coordinated microbial–metabolite modules that underlie region-specific flavor precursor formation. These findings establish a mechanistic model in which microbial terroir, aging-driven succession, and metabolic specialization jointly shape the maturation and flavor potential of Maotai-flavor liquor.IMPORTANCEThis study provides the first genome-resolved, multi-omics framework for understanding how geographic origin and storage aging co-regulate the ecological assembly, functional specialization, and metabolic transformation of Maotai-flavor liquor. By linking specific MAGs, functional pathways, and key flavor precursors, our results offer mechanistic insights into microbial terroir and provide a scientific foundation for microbiome-guided optimization of Maotai-flavor liquor quality.

High-temperature Daqu, a key fermentation starter for Baijiu production, is significantly influenced by indigenous environmental microorganisms. To address quality variations across regions and explore strategies for quality enhancement, this study investigated the effects of supplementing functional microorganisms via Air Supplementation (AS) (spraying into Qu-room air) and Daqu Supplementation (DS) (adding into Daqu) on Daqu quality. Microbial communities and flavor compounds in High-Quality Daqu (HD) and Low-Quality Daqu (LD) were compared, revealing significant differences in the functional microbe Bacillus and the key flavor compound tetramethylpyrazine (TTMP). Two high-TTMP-yielding strains, Bacillus velezensis W7 and Bacillus licheniformis C11, were isolated from HD. These strains were supplemented into LD production via the two methods. Results showed that both methods perturbed the microbial community structure of LD. Fungi such as Paecilomyces were effectively inhibited by DS. The relative abundance of Bacillus was increased by DS. Crucially, the TTMP in Daqu of DS (13.93 ± 1.15 mg kg-1) was almost of 34-fold of that of the CK (0.41 ± 0.12 mg kg-1). In contrast, Air Supplementation (AS) had a limited impact on Daqu flavor. This study confirms that targeted supplementation of functional microorganisms is an effective strategy for directionally improving the flavor quality of Daqu, providing a feasible pathway for the standardization and quality upgrading of high-temperature Daqu production.

Hydroxycinnamate decarboxylase (HCDC) can decarboxylate Hydroxycinnamic acid to produce vinylphenol. In this study, a new heat-resistant HCDC (WaHCDC) was obtained from Wickerhamomyces anomalus WA64 isolated from Daqu, the fermentation starter of Chinese Baijiu. Subsequently, WaHCDC was expressed in P. pastoris GS115. After purification with Ni2+-NTA resin, WaHCDC was obtained at 25 mg·L-1 with a molecular weight of 45 kDa. The enzyme activity of WaHCDC was 12.69 ± 0.07 U·mg-1. The relative activity of WaHCDC was still retained 57 % after incubating at 80 °C for 90 min. To enhance acid resistance, WaHCDC was immobilized on covalent organic frameworks (COFs) via in-situ encapsulation, achieving 80 % loading efficiency and a capacity of 1.5 mg·g-1. The immobilized activity was 14.35 ± 0.11 U·mg-1. The stability of the immobilized WaHCDC was improved at pH 3-6. Its conversion rate of ferulic acid (FA) to 4-vinylguaiacol was 13 % higher than that of the free WaHCDC after incubating at 40 °C for 120 min. The activity of immobilized WaHCDC was above 60 % after 7 cycles reusing. This study provides a new heat-resistant enzyme resource and efficient immobilization strategy for the green biosynthesis of vinylphenol.

Bioaerosols critically influence Daqu's microbial communities during open fermentation, but their regulatory mechanisms remain unclear. This study examined microbiota succession in bioaerosols and Daqu alongside secondary pollutant dynamics to reveal environmental-microbial interactions. The fermentation room showed cyclic temperature variations with decreasing bioaerosol sulfate (4.06-1.40 mu g/m3), nitrate (1.30-0.79 mu g/m3), and ammonium (3.43-2.04 mu g/m3) levels. Center Daqu demonstrated higher enzymatic activity than surface counterparts. Microbial analysis revealed Aspergillus (28.4 %) and Cladosporium (15.7 %) dominated in bioaerosols, while Saccharomyces (32.6 %) and Monascus (61.4 %) dominated in Daqu. Correlation analysis linked spoilage microbes positively with secondary pollutants, while fermentative species showed inverse relationships. Environmental gradients governed microbial succession: temperature-humidity drove surface Daqu community assembly, whereas acidity-regulated enzymatic activation controlled center Daqu metabolism. This environment-microbe framework advances standardization strategies for sustainable Daqu production.

Kanamycin (KAN) can generate a serious threat to human health due to its tendency to accumulate in food. Current colorimetric strategy for KAN detection still faces some challenges, and nanozyme-based colorimetry is an ideal alternative approach. Herein, a non-copper-based multivalent laccase mimic named Mn-Car is first synthesized through a self-assembly of manganese ions and the endogenous biomolecule carnosine, which is further used to develop a novel colorimetric method for ultrasensitive and selective detection of KAN. The laccase-like catalytic center is formed through the multidentate chelation bonds between manganese ions and imidazolium groups of histidine as well as carboxyl groups of beta-alanine in carnosine. The multivalent oxidation states of manganese dynamically regulate electron transfer pathways through synergistic coordination. The unique Mn-Car architecture drives the efficient generation of superoxide radicals (O2 center dot- ) and semiquinone radicals (SQ center dot-). Leveraging the excellent laccase-like activity of Mn-Car, a highly sensitive colorimetric method for KAN detection is developed. Mn-Car forms polydentate chelation with the amino and hydroxyl groups in KAN, which can trigger multi-step cascade oxidation reactions that disrupt the structural core of Mn-Car and lead to reduced colorimetric signals. The colorimetric method achieves a limit of detection (LOD) of 0.102 mu M and is successfully applied for on-site detection of KAN in water samples and honey, providing a novel platform for antibiotic residue analysis.

The detrimental growth of water pollutants such as heavy metals has become a life-threatening problem in the modern era. Challenges remain in the development of rapid and accurate methods for detecting pentavalent arsenic [As(V)] in environmental water. The octahedral Mn3O4 nanoparticles (NPs) did not display excellent laccase-mimicking catalytic activity, whereas the adsorbed As(V) on the surface significantly enhanced the catalytic activity. Meanwhile, the quinone imine generated from the substrates 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AAP) catalyzed by octahedral Mn3O4 NPs further quenched the carbon dots fluorescence. Thus, it is possible to establish a fast and accurate dual-mode sensor for detecting As(V). The developed dualmode method of As(V) detection has good sensitivity and selectivity. The limit of detection for As(V) in colorimetric mode is 6.96 mu g & sdot;L- 1, whereas in the fluorescent mode, it is as low as 2.56 mu g & sdot;L- 1. Moreover, the detection data obtained by the dual-mode method can be validated by each other, thereby ensuring the dependability of the sensing system. The constructed dual-mode method with merits of sensitivity, speed and accuracy can offer a powerful tool for As(V) detection in environmental water. Furthermore, the application of laccase-mimicking activity in dual-mode detection provides new strategies for other environmental hazard detection.

The flavor characteristics and sensory attributes of northern Sauce-flavored rounded-Baijiu (NR) and southern Sauce-flavored rounded-Baijiu (SR) were systematically studied. A total of 56 major flavor compounds were quantitatively detected through Gas chromatography-flame ionization detection (GC-FID). Besides, 20 kinds of key aroma compounds and 7 significant differential compounds were identified by calculating the odor activity values (OAVs) and orthogonal partial least squares discriminant analysis (OPLS-DA) of flavor compounds in NR and SR. And then, the relationship between sensory attributes and key aroma compounds were investigated by network analysis. Furthermore, A group of combined-Baijiu (the ratios of the first to the fifth round of Sauceflavored Baijiu in the north (NR1-5) were 5 % NR1, 35 % NR2, 30 % NR3, 20 % NR4, 10 % NR5) was closer to the style known for blending different proportions of SR into the combined-Baijiu. This study provided a guiding significance for the standardized production of sauce-flavored Baijiu.

Overuse of sulfonamides in aquaculture and agriculture leads to residual drugs that cause serious pollution of the environment. However, the residues of sulfonamides in the environment are not unique, and the existing microbial degradation technology has a relatively low degradation rate of sulfonamides. Therefore, in this study, a Pseudomonas stutzeri strain (DLY-21) with the ability to degrade four common SAs was screened and isolated from aerobic compost. Under optimal conditions, the DLY-21 strain degraded four sulfonamides simultaneously within 48 h, and the degradation rates were all over 90%, with the average degradation rates of SAs being sulfoxide (SDM) ≈ sulfachloropyridazine (SCP) > sulfa quinoxaline (SQ) > sulfadiazine (SQ). In addition, the main compounds of the strain DLY-21-degrading SAs were identified by LC-MS analysis. On this basis, four detailed reaction pathways for SA degradation were deduced. This is the first report of the use of a P. stutzeri strain to degrade four sulfonamide antibiotics (SQ, SDM, SCP, and SM1), which can improve the removal efficiency of sulfonamide antibiotic pollutants and thus ameliorate environmental pollution. The results showed that DLY-21 had a good degradation effect on four SAs (SQ, SDM, SCP, and SM1).

Effective hydrolysis of lignocelluloses for producing reducing sugar is impeded by the covalent binding of hemicellulose and cellulose through lignin, which could be eliminated by laccases. This study identified a novel thermostable laccase from Bacillus safensis TCCC 111022 and created an iterative mutant E231D/Y441H, exhibiting 1.59-fold greater specific activity and a 183 % greater half-life at 80°C than the wild-type enzyme. Computational analysis revealed that the stability and activity of the E231D/Y441H could be simultaneously enhanced by increasing the flexibility of the ring around the substrate binding pocket. Additionally, the saccharification efficiency of sugarcane bagasse and corn stalks were both enhanced by 235 % in the system adding E231D/Y441H, mixed-cellulases, and mediator (1-hydroxybenzotriazole) compared to the samples treated with mixed-cellulases. The findings of this research provide a reference for the degradation of lignocellulosic substrates and contribute to the sustainable development of biomass-based industries.

The colorimetric methods for histamine detection still face some challenges in accuracy and stability. Herein, a novel colorimetric aptasensor for sensitive and highly selective detection of histamine was developed based on the enhancement of silver citrate (AgCit) laccase-mimic activity. It has been confirmed that H2 aptamer enhances the affinity of AgCit to the chromogenic substrate, and promotes the generation of semiquinone radical in the laccase-mimic catalytical system. The color change of the sensing solution can be distinguished by the naked eye, and easily converted to the corresponding RGB value by a smartphone for the quantitative and rapid detection of histamine. The aptasensor has a limit of detection (LOD) as low as 27 mu g L -1 , and maintains high selectivity for histamine in the presence of other competitive substances. It is strongly believed that the design of a colorimetric aptasensor can provide a simple and versatile platform for histamine detection in food.

Blueberry wine is popular among consumers due to its high nutritional value, appealing color, and potential health benefits. However, the instability of its color during the brewing process poses challenges for storage and the overall growth of the blueberry wine industry. This study found that vinylphenolic pyranoanthocyanins in blueberry wine provide a more stable color than their anthocyanin precursors. The presence of yeast with hydroxycinnamic acid decarboxylase (HCDC) enhances the formation of vinylphenolic pyranoanthocyanins. Metschnikowia pulcherrima Y4, isolated from decayed blueberry peels, promotes the production of six specific vinylphenolic pyranoanthocyanins in blueberry wine: malvidin-4-vinylcatechol, delphinidin-3-arabinoside-4vinylcatechol, cyanidin-3-galactoside/glucoside (C3G)-4-vinylcatechol, cyanidin-3-O-arabinoside-4vinylcatechol, malvidin-3-O-glucoside/galactoside-4-vinylcatechol, and C3G-4-vinylphenol. Blueberry wine fermented solely with M. pulcherrima Y4 exhibits a 25% increase in light stability under direct outdoor light conditions and a 19% increase in temperature stability at 60 degrees C compared to Saccharomyces cerevisiae K1. Furthermore, the use of M. pulcherrima Y4 in fermenting blueberry wine significantly decreases the time required to form vinylphenolic pyranoanthocyanins to eight days. Hence, M. pulcherrima Y4 is highly effective in accelerating the synthesis of these compounds, providing a valuable approach for improving the stability and color of blueberry wine.

Tetracycline antibiotics (TCs) are widely used as anti-infective drugs, but their residues pose a major threat to human health. Herein, a bimetallic metal-organic framework (CeCo-MOF) with laccase-like, oxidase-like, and peroxidase-like activities was carefully designed, which exhibited superior catalytic performance and stability due to the increased metal active sites and improved electronic structure compared with monometallic MOF. To further understand the bimetallic catalytic mechanism, the dual cycle synergistic catalytic pathways for bimetallic catalysis under different conditions have been proposed. An optical sensor array was constructed based on triple-enzyme-mimic activities of CeCo-MOF, and was used to identify five TCs by linear discriminant analysis and hierarchical cluster analysis. The five TCs were successfully distinguished in the range of 0.1-10 mu M, with limits of detection of 3.235 nM for minocycline, 3.262 nM for doxycycline, 4.045 nM for chlortetracycline, 1.559 nM for tetracycline, and 1.891 nM for oxytetracycline. Meanwhile, the quantification of single TCs and successful differentiation of TCs mixtures further validated the sensing performance. Besides, the reliability and practicability of the sensor array were confirmed by excellent anti-interference performance, satisfactory discrimination and recovery rate of TCs in actual samples tests, and the 96.67 % recognition accuracy for blind samples. Therefore, the detection performance of the established sensor array for TCs is obviously better than that of most optical sensors. This work first used the triple-enzyme-mimic activities of bimetallic MOFs for the rapid detection of multiple TCs in food, which provides a novel idea for the design of advanced sensor arrays.

Herein, a colorimetric biosensor for histamine detection in meat is first established based on the enhancement of DNAzyme with peroxidase-mimic activity. Histamine can boost the generation of G-quadruplex sequences, and make them more easily bond with hemin to produce many DNAzyme molecules. In addition, histamine increases the affinity of DNAzyme to the substrate 3,3 ',5,5 '-tetramethylbenzidine (TMB). Therefore, the obtained DNAzyme can catalyze H2O2 and dissolved oxygen to produce many reactive oxygen species (ROS), which cause the TMB molecule to lose two electrons and generate yellow products, exhibiting a clear absorption peak at 450 nm. The colorimetric biosensor has excellent sensitivity, and the detection limit is as low as 38 mu g center dot L-1 for histamine. Moreover, the biosensor has high selectivity and anti-interference ability, and exhibits a good recovery rate in actual meats. The above results show that the strategy has potential for application in the detection of trace histamine in meats.

During the fruit wine production, phenolic acid decarboxylase (PAD) converts free hydroxycinnamic acid into 4-vinyl derivatives that can then react spontaneously with anthocyanins, generating more stable pyranoanthocyanins that are responsible for the color stability of fruit wine. Nevertheless, the low PAD activity in yeast under the winemaking conditions has largely limited the generation of 4-vinyl derivatives. To bridge this gap, we expressed PAD from Bacillus amyloliquefaciens in Pichia pastoris and surface-displayed it on Saccharomyces cerevisiae. As a result, S. cerevisiae surface-displayed PAD (SDPAD) exhibited an enhanced thermal stability and tolerance to acidic conditions. Fermentation experiments showed that SDPAD can significantly increase the content of vinylphenolic pyranoanthocyanins and thus maintain the color stability of blueberry wine. Our study demonstrated the feasibility of surface display technology for color stability enhancement during the production of blueberry wine, providing a new and effective solution to increase the content of vinylphenolic pyranoanthocyanins in the fruit-based wines.

Due to the excellent oxidation effect on phenolic compounds, the present copper-based laccase-mimics are mostly used for the degradation and detection of phenolic pollutants in environment. As the oxidation substrates of laccase are only limited to compounds containing specific phenolic hydroxyl groups, which makes the application of laccase mimetics to non-phenolic pollutants faces great challenges and bottlenecks. Herein, a non-copper-based laccase mimics like cubic Ag2O nanoparticles is prepared. The maximum reaction velocity and affinity of cubic Ag2O nanoparticles to substrates are significantly better than that of natural laccase and most artificial laccase mimetics. Cubic Ag2O nanoparticles also exhibits high stability under various conditions and has good tolerance to organic solvents. Moreover, it is found that the laccase-mimic activity of cubic Ag2O nanoparticles can be effectively inhibited by kanamycin, which enable us to construct a colorimetric sensor for rapid detection of kanamycin in environment. The sensor has excellent sensitivity with the limit of detection (LOD) of 1.3 nM for kanamycin, and has high selectivity for other competitive substances. Besides, a standard curve for rapidly detecting kanamycin by smartphones is established, which expect to provide a novel idea for on-site monitoring of other hazards in environment.