搜索结果：Enzyme and microbial technology

Green peas are highly perishable and susceptible to microbial and quality deterioration, posing challenges to microbial safety and quality preservation. This study investigated the efficacy of sequential sodium hypochlorite (NaClO) washing and continuous in-package dielectric barrier discharge (DBD) plasma treatment for the inactivation of Listeria monocytogenes and Escherichia coli O157:H7 on fresh green peas. Treatments were applied individually and in combination for two treatment times: 48 s (CP48) and 120 s (CP120). For L.monocytogenes, individual treatments of CP48, CP120, and NaClO achieved reductions of 1.81, 2.21, and 1.13 log CFU/g, respectively, while combined treatments (NaClO-CP48 and NaClO-CP120) significantly enhanced inactivation to 2.97 and 3.74 log CFU/g. Similarly, E. coli reductions were 2.03, 2.81, and 1.97 log CFU/g for CP48, CP120, and NaClO, respectively, which increased to 3.95 and 4.03 log CFU/g under NaClO-CP48 and NaClO-CP120 treatments. This enhanced efficacy of NaClO-CP combined treatment is attributed to severe disruption of cell membrane integrity, with E. coli exhibiting greater susceptibility than L.monocytogenes. In addition, combined treatments effectively suppressed native aerobic bacteria (>2 log reduction) and molds and yeasts (>1.9 log reduction), maintaining microbial levels below 2.5 log CFU/g throughout 7-day refrigerated storage. Reductions in firmness and ascorbic acid were observed under combined treatments. Combined treatments resulted in greater inhibition of peroxidase and lipoxygenase activities compared to individual treatments, with reductions of >50% relative to the control after 7 days of storage, contributing to improved oxidative stability. These findings demonstrate that the sequential NaClO and in-package DBD plasma hurdle strategy effectively enhances the microbial safety and enzymatic stability of fresh green peas, with acceptable quality trade-offs.

Biogas slurry is a residue left after anaerobic digestion that is commonly applied as an organic fertilizer; however, its microbial potential for enzyme production has received comparatively limited attention. In the present study, biogas slurry was examined as a source of lignocellulolytic bacteria to evaluate the multi-enzyme producing capabilities for applications in biomass degradation and waste valorisation. Using culture-dependent techniques, 31 bacterial isolates were obtained and characterized based on morphological and biochemical properties. The isolates were initially screened for cellulase, xylanase, amylase and laccase activities using substrate-specific agar plate assays, and selected isolates were further evaluated for quantitative enzyme production. Considerable variation in enzyme activity was observed among the isolates, with maximum activities of 1.374 ± 0.059 U/ml for carboxymethyl cellulase, 0.484 ± 0.006 U/ml for filter paperase, 0.649 ± 0.017 U/ml for β-glucosidase, 2.060 ± 0.066 U/ml for amylase and 1.241 ± 0.031 U/ml for xylanase. Molecular identification based on 16 S rRNA gene sequencing indicated that the predominant enzyme producing isolates belonged to Bacillus subtilis, Bacillus albus, Serratia nematodiphila, and Pseudomonas aeruginosa, which was validated through phylogenetic analysis. Based on enzyme production, Bacillus subtilis BCA-1 was selected for biomass degradation and optimization studies using alkali-treated corn cob under solid-state fermentation. Maximum cellulase activity (3.830 ± 0.102 U/ml) was observed at pH 7, 45 °C, and 72 h, while xylanase (2.033 ± 0.058 U/ml) and β-glucosidase (3.290 ± 0.095 U/ml) activities were highest at pH 6, 45 °C, and 72 h. The results demonstrated that biogas slurry contains functionally diverse lignocellulolytic bacteria capable of coordinated multi-enzyme production. Enhanced enzyme production by Bacillus subtilis BCA-1 under optimized conditions indicates substrate-induced enzyme expression and supports its potential application in lignocellulosic biomass conversion.

Emerging contaminants, including brominated flame retardants and microplastics, in agricultural soils pose a serious threat to crop security and ecosystem health. This study aimed to provide an understanding of the toxicity-induced effects of decabromodiphenyl ether (BDE-209) and polylactic acid (PLA) on Spinach (Spinacia oleracea) in the soil system by examining Spinach biomass, chlorophyll content, antioxidant enzyme activity, and microbial community composition after a 42-day exposure. The pre- and post-structural, morphological, and surface chemical group analyses of PLA and BDE-209 in contact with the soil system were analyzed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The data show that the combined treatment caused the most significant growth inhibition, with a 95% reduction in shoot dry weight and a 25% reduction in chlorophyll content, suggesting continued photosynthetic damage. Antioxidant enzyme analyses revealed an impaired defence system, wherein superoxide dismutase (SOD) activity increased (BDE-5: 48.4%, and BDE-6: 44.2%), whereas catalase (CAT) and peroxidase (POD) activities decreased (0.4-2.3%) across treatments, indicating metabolic blockage and subsequent hydrogen peroxide accumulation. The soil microbial composition in response to stress showed significant structural changes, including an increase in stress-tolerant genera, such as Bacillus (30-39%), and a decrease in beneficial Oligotrophic bacterial populations (58.9-74.0%). The degradation of PLA was confirmed by FTIR and SEM, which revealed surface interaction with BDE-209 and exhibited reduced absorbance between 1200 and 1000 cm-1, accompanied by a reduction in particle size (70-90 μm). These findings suggest that PLA may be a co-pollutant exacerbating BDE-209 toxicity by increasing oxidative stress and altering the soil microbial community.

Soil salinization is a global problem constraining agricultural and forestry development. Utilizing micro-bial symbiosis to enhance the salt tolerance of woody plants is a sustainable and effective strategy. We conducted a pot experiment to investigate the regulatory mechanisms of single and combined inoculation with Funneliformis mosseae (Fm) and Piriformospora indica (Pi) on two-month-old 'Red Kernel Walnut' (Juglans regia) seedlings under salt stress. There were five treatments, including 1) non-stress control (CK), 2) salt stress (0.8% NaCl, S), 3) salt stress + Fm inoculation (S+Fm), 4) salt stress + Pi inoculation (S+Pi), and 5) salt stress + combined Fm and Pi inoculation (S+FmPi). We measured the growth parameters, chlorophyll content, antioxidant enzyme activities, osmotic regulatory substances, and endogenous hormone levels at 10, 20, and 30 days after the initiation of treatments. The results showed that the inhibitory effect of salt stress on plants intensified over time. Inoculation treatments effectively alleviated stress damage at all time points, with combined inoculation (FmPi) demonstrating superior efficacy compared to single inoculations. At 10, 20, and 30 days after treatment, compared to the salt stress group (S), the S+FmPi treatment increased seedling biomass by 6.6%, 18.4%, and 24.2%, respectively; leaf chlorophyll a content by 43.3%, 84.9%, and 56.5%, chlorophyll b content by 19.6%, 107.6%, and 98.6%; root superoxide dismutase activity by 40.6%, 10.8%, and 9.7%, and ascorbate peroxidase activity by 44.7%, 57.3%, and 22.6%; while decreased root malondialdehyde content by 26.0%, 28.3%, and 28.9%. Hormonally, compared with the salt stress group (S), combined inoculation (S+FmPi) resulted in 1.0% decrease, 4.0% increase, and 3.3% reduction in leaf indole-3-acetic acid content at 10 d, 20 d, and 30 d, respectively. Moreover, abscisic acid content was decreased by 15.9% at 10 d, increased by 2.0% at 20 d, and decreased by 7.9% at 30 d. Comprehensive evaluation using principal component analysis and membership function values ranked the alleviating effects of inoculation treatments as S+FmPi >S+Fm>S+Pi. Combined inoculation of Fm and Pi significantly enhanced salt tolerance of walnut seedlings through synergistic multi-pathway regulation. These findings would provide a theoretical foundation for applying mycorrhizal technology in walnut cultivation on saline soils. 土壤盐渍化是制约农林业发展的全球性问题,利用微生物共生技术提升木本植物耐盐性是一种可持续的有效途径。为探究摩西斗管囊霉(Fm)和印度梨形孢(Pi)单接种及双接种对盐胁迫下核桃幼苗的调控机制,本研究以‘红仁核桃’实生2月龄幼苗为材料进行盆栽试验,设5个处理:1)非胁迫对照(CK),2)盐胁迫(0.8% NaCl,S),3)盐胁迫+Fm接种(S+Fm),4)盐胁迫+Pi接种(S+Pi),5)盐胁迫+FmPi双接种(S+FmPi),分别于处理后10、20、30 d测定幼苗生长指标、叶片叶绿素含量、根系抗氧化酶活性、渗透调节物质及叶片内源激素含量。结果表明:与CK相比,盐胁迫对植株的抑制效应随时间加剧,接种处理在不同时期均能有效缓解盐胁迫损伤,其中双接种表现优于单接种。处理10、20、30 d时,S+FmPi处理幼苗生物量较S处理分别提高6.6%、18.4%、24.2%;叶片叶绿素a含量分别提高43.3%、84.9%、56.5%,叶绿素b含量分别提高19.6%、107.6%、98.6%;根系超氧化物歧化酶活性分别提高40.6%、10.8%、9.7%,抗坏血酸过氧化物酶活性分别提高44.7%、57.3%、22.6%;根系丙二醛含量分别降低26.0%、28.3%、28.9%。与S处理相比,S+FmPi处理叶片吲哚乙酸含量在处理10 d时降低1.0%,20 d时升高4.0%,30 d时又降低3.3%;脱落酸含量在处理10 d时降低15.9%,20 d时升高2.0%,30 d时又降低7.9%。基于主成分综合得分计算的隶属函数值排序表明,各接种处理缓解盐胁迫的效果为S+FmPi>S+Fm>S+Pi。Fm和Pi双接种通过多途径协同调控显著增强了核桃幼苗的耐盐性,为盐渍土核桃栽培中菌根技术的应用提供了理论依据。.

Heavy metal pollution, particularly copper (Cu) and cadmium (Cd), poses a serious threat to aquatic ecosystems due to its toxicity and bioaccumulation potential. This study investigated the effects of individual and combined exposure to Cu and Cd on largemouth bass, focusing on the gut-liver axis and the TLR4/NF-κB pathway in hepatotoxicity. A total of 480 size-matched fish were randomly assigned to four groups (Control, Cu, Cd, and Cu + Cd) and exposed to sublethal concentrations of CuSO₄ (9.275 mg/L) and CdCl₂·2.5H₂O (1.15285 mg/L) for 14 days, followed by physiological, molecular, and omics analyses. Results showed that both single and combined exposures disrupted intestinal structure and barrier function, accompanied by downregulation of tight junction genes. Oxidative stress responses were tissue-specific, with increased reactive oxygen species (ROS) and MDA levels in the intestine but decreased levels in the liver, along with suppressed antioxidant enzyme activities. Inflammatory responses were activated, as indicated by elevated cytokine levels and upregulation of TLR4/MyD88/NF-κB signaling in the liver. Microbiota analysis revealed that Cd exposure increased gut microbial diversity, whereas Cu + Cd co-exposure reduced α-diversity and altered microbial composition, with increased Proteobacteria and decreased beneficial taxa such as Bacteroidota and Firmicutes. Untargeted metabolomics showed that hepatic metabolic profiles were altered, mainly affecting lipid, energy, and immune-related pathways. Overall, combined Cu + Cd exposure exerted stronger toxic effects than single exposures, inducing more severe intestinal damage, microbial dysbiosis, and metabolic disturbances. These findings highlight the critical role of the gut-liver axis in mediating heavy metal toxicity.

Soilless cultivation is a major component of modern protected agriculture; however, often lack the beneficial microbial communities that support plant health in natural soils. This study explored hydrophyte root microbiomes as an eco-friendly and novel source of plant growth-promoting bacteria (PGPB) for engineering beneficial microbial communities in soilless systems. Bacteria associated with the roots of Eichhornia crassipes, Pistia stratiotes, and Alternanthera philoxeroides, expressing PGP traits were assessed for their growth-promoting potential on lettuce (Lactuca sativa L. cv. 'Lolo Red') using cocopeat-based soilless media and soil under polyhouse conditions. Hydrophyte associated rhizobacteria exhibited diverse PGP functions, including nutrient solubilization and phytohormone production, similar to those exhibited by rhizobacteria associated with terrestrial plants. Under soil and soilless conditions, lettuce crop inoculated with hydrophyte associated rhizobacteria significantly enhanced germination, plant biomass, root architecture, photosynthetic pigments and leaf quality traits, including TSS (total soluble solids), total phenolics, vitamin C, anthocyanins, antioxidant enzyme activities, DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging and FRAP (Ferric Reducing Antioxidant Power) responses in both the cultivation systems. Two strains viz. Bacillus aerius Aq35 and Pseudomonas protegens Aq45 were particularly very promising. Under soilless cultivation, Aq35 enhanced root fresh weight and surface area by 90.0% and 83.5%, respectively, while Aq35 and Aq45 increased lettuce yield by 39.62% and 28.70%, respectively. Bacterial inoculation significantly enhanced the availability of soil and plant macro (N, P, and K) and micronutrients (Fe, Mn, Zn, and Cu) along with a marked increase in enzymatic activities and microbial biomass carbon (MBC). Under soilless substrate, dehydrogenase activity increased from 43.40 to 64.65 µg TPF g⁻¹ day⁻¹, while alkaline phosphatase activity increased from 261.53 to 380.87 µg PNP g⁻¹h⁻¹ inoculated (Aq35) treatment over uninoculated treatment indicating enhanced substrate biological quality. These results demonstrate that hydrophytes as rich, pre-adapted reservoirs of potent PGPB, and strains such as B. aerius Aq35 and P. protegens Aq45 hold strong potential as biostimulants for sustainable soilless agriculture.

Non-grain cropland reclamation is a critical initiative in China to ensure food security. However, the degradation of soil microbial functions caused by long-term cash crop cultivation severely restricts soil fertility restoration. This study focused on soil fertility improvement in bamboo forests, a typical non-grain land use in Dongwu Town, Ningbo City, Zhejiang Province. A fertilization regime involving maize-faba bean rotation combined with 50% replacement of chemical fertilizers by organic fertilizer and biochar was implemented. High-throughput sequencing, network topology analysis, and multifactor correlation models were employed to systematically elucidate the mechanisms by which different fertilization modes drive the reconstruction of soil microbial communities. The results revealed that fertilization significantly altered the spatiotemporal patterns of soil microbial diversity. During the maize maturation stage, soil diversity was less affected, whereas bacterial diversity in faba bean maturation-stage soil decreased significantly, with fungi exhibiting an inverse response. For microbial community structure, fertilization markedly reshaped bacterial community configurations in the faba bean season. Pure chemical fertilization in the maize season formed highly complex networks but had the lowest modularity index, indicating that excessive nutrient inputs reduced system stability. In the faba bean season, 50% organic fertilizer substitution fostered a highly mutualistic network dominated by Acidobacteriota, with clustering coefficients significantly higher than those in other treatments. Correlation analysis demonstrated that bacterial diversity in the maize season was positively correlated with TC, TN, and TP, and fungal richness was closely linked to ACP enzyme activity, while microbial communities in the faba bean season were significantly associated with pH and AK. This study clarifies the biological mechanisms by which organic amendments enhance the ecological functions of reclaimed lands through remodeling microbial interaction networks, providing a theoretical foundation for precision fertility management in degraded croplands.

Root rot is a major threat to red kidney beans (Phaseolus vulgaris), caused mainly by Fusarium oxysporum. This study tested single/combined inoculation of Bacillus mojavensis BA23 and Rhizobium indicum RH64 on disease control, plant growth, and systemic defense in greenhouse pots. Both single strains reduced disease index and improved growth, but coinoculation was better: vs single BA23/RH64, it increased plant biomass by 11.05%/23.81% and reduced disease index by 18.87%/40.27%. BA23 inhibited F. oxysporum (80.54% in vitro) and activated plant defense (e.g., boosted antioxidant enzyme activity), while RH64 had nitrogen-fixing activity (253.22 U·L-1) and recruited beneficial rhizobacteria. Coinoculation enriched taxa like Sphingomonadaceae and Vicinamibacteraceae (key for disease suppression and growth promotion) and enhanced rhizosphere microbial network stability (e.g., higher modularity and average degree). Partial least squares path modeling (PLS-PM) showed that bacterial community structure was significantly correlated with reduced disease index and increased plant biomass. In conclusion, coinoculating BA23 and RH64 effectively controls red kidney bean root rot and promotes plant growth by inducing systemic defense-related responses and beneficially reshaping the rhizosphere microbiome.

Co-cultivation has emerged as an effective strategy to mimic natural microbial interactions and modulate extracellular enzyme production. In this study, interactions between the white-rot fungus Bjerkandera adusta and the brown-rot fungus Gloeophyllum trabeum were investigated with respect to growth and production of lignocellulolytic enzymes in solid and liquid cultures. Growth assays on solid medium revealed mixed mycelial growth without pigment formation at the interface zone, indicating partial compatibility between species. Co-cultivation led to pronounced changes in the enzyme activities compared to monocultures. Oxidative enzyme activities were strongly stimulated, with peroxidase activities increasing 2-3-fold relative to B. adusta monoculture, despite the absence of peroxidase in G. trabeum. Conversely, cellulolytic and hemicellulolytic activities were significantly reduced under co-culture conditions compared to G. trabeum monoculture. Zymogram analysis and ion-exchange chromatography confirmed that peroxidase production was restricted to B. adusta and the co-culture. The enzyme cocktail obtained from co-culture exhibited superior performance in Remazol Brilliant Blue R decolorization (∼ 90%) compared to B. adusta monoculture (∼40%). These findings demonstrate that interspecific fungal interactions can selectively shift the enzymatic balance toward oxidative mechanisms, highlighting cocultivation as a promising approach for generating enzyme systems with improved potential for dye bioremediation.

2,5-Furandicarboxylic acid (FDCA) is a key monomer widely used in the plastic, dye, pharmaceutical, pesticide and resin industries. Presently, its biosynthesis via microbial fermentation is severely limited by the cytotoxicity of substrate 5-hydroxymethylfurfural (HMF). In this study, using Escherichia coli as a host, efficient biosynthesis of FDCA was achieved through multi-step metabolic engineering and protein engineering. The novel oxidative pathway for converting HMF to FDCA was constructed and optimized by screening candidate genes and optimizing gene combination, linkage strategies, copy number, and translation intensity. Subsequently, a comprehensive deep mutation screening of aldehyde dehydrogenase EcALDH was performed using the VenusFactory platform, and the mechanisms were elucidated through kinetic analysis and molecular dynamics (MD) simulations. The H263A mutant increased the catalytic efficiency toward the key intermediates 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) and 5-formyl-2-furancarboxylic acid (FFCA) by 828.4% and 340.3%, respectively. Further, FDCA production was enhanced by increasing the availability of the cofactors nicotinamide adenine dinucleotide (NAD+) and flavin adenine dinucleotide (FAD), while reducing extracellular leakage of the intermediate HMFCA. Transcriptomic analysis identified 26 significantly upregulated candidate genes potentially associated with HMFCA transport. Notably, inactivation of aromatic amino acid transporter (AroP) increased the FDCA concentration to 77.73 mM. Finally, fed-batch fermentation in a 5-L bioreactor produced 170.72 mM (26.65 g/L) FDCA with a molar yield of 94.8% relative to HMF added. These results demonstrate that the engineered E. coli strain constructed in this study can serve as a promising platform for efficient and sustainable production of FDCA, laying a solid foundation for industrial biomanufacturing.

High-temperature Daqu (HTD) is crucial for shaping the style of Moutai-flavor Baijiu, but its quality characteristics exhibit geographical and spatial heterogeneity, resulting in diminished typicity of products from non-core production regions. Therefore, this study employed multiphase detection techniques to analyze HTD samples from the typical region (Guizhou) and emerging region (Shandong), along with their surface and inner layers. Guizhou HTD possessed superior biochemical activity (especially on the surface) and higher response values for W1W, W2W, umami, and salty sensors. It also showed higher concentrations of key flavor compounds, such as pyrazines, acids, and alcohols. Targeted amplicon sequencing showed Kroppenstedtia, Thermoascus, and Thermomyces dominated all samples, but Guizhou HTD had greater microbial diversity and richness. Metagenomics indicated a higher proportion of bacteria in Guizhou HTD, represented by Kroppenstedtia eburnea and Oceanobacillus indicireducens, whereas fungi were more prevalent in Shandong HTD, with Paecilomyces varioti, Aspergillus chevalieri, and Rasamsonia emersonii as the dominant species. Functional annotation demonstrated that carbohydrate metabolism and amino acid metabolism were core biological functions of HTD, with gene abundances showing Guizhou > Shandong and inner > surface. Furthermore, species-enzyme contribution and metagenome-assembled genomes analyses confirmed that HTD exhibited functional redundancy at the ecological scale, yet the species responsible for these functions displayed regional specificity, explaining the phenotypic heterogeneity between Guizhou HTD and Shandong HTD. These findings highlight the pivotal role of the production region in HTD quality and offer insights for improving Moutai-flavor Baijiu flavor in non-core regions.

This study systematically investigated the phosphorus (P) adsorption and release behaviors of biofilm extracellular polymeric substances (EPS) in a sequencing batch biofilm reactor (SBBR). Batch experiments, enzyme activity assays, P forms, and spectral characterizations (3D-EEM, FTIR, XPS) were integrated to elucidate the independent role of EPS in biofilm P metabolism. The results quantified the independent P adsorption and release capacities of EPS as 1.68 mg/g and 2.46 mg/g, respectively. Different from cell-dependent biological P metabolism, EPS-mediated P transformation was insensitive to dissolved oxygen variation and carbon addition, and was mainly dominated by physicochemical adsorption. EPS-derived orthophosphate (Orth-P) and polyphosphate (Poly-P) contributed over 67% and less than 12% to the total Orth-P and Poly-P metabolism of biofilms, respectively. Although polyphosphate kinase (PPK) and polyphosphate hydrolase (PPX) activities were detected in EPS, the lack of effective carbon utilization capacity restricted their involvement in Poly-P transformation. Metal-mediated complexation served as the core immobilization pathway, in which Ca2⁺ and Mg2⁺ bound with phosphate groups, as well as carboxyl and amino functional groups of tryptophan- and tyrosine-rich proteins in EPS. Beyond the inherent physicochemical adsorption properties of EPS, microbial cells further regulated EPS content by aerobic biosynthesis and anaerobic biodegradation. Such microbial regulation synergistically optimized the P adsorption-release performance of EPS, verifying that EPS acts as the dominant functional component responsible for P transformation in biofilm systems. This study clarifies the intrinsic mechanisms underlying EPS-mediated P adsorption and release, and provides a theoretical basis for the development of low-carbon and high-efficiency P recovery technologies.

High-altitude regions of the Pangi-Chamba Himalayas (PCH) provide a distinctive environment for isolating extremophilic lignocellulolytic bacteria. This study reports the isolation of lignocellulolytic enzyme-producing bacteria from decaying wood samples. Among 54 bacterial isolates, 24 demonstrated lignocellulose hydrolysis potential, producing laccase, xylanase, and cellulase enzymes. Eight morphologically distinct isolates belonging to the phylum Bacillota were selected for further experiments. Quantitative analysis identified Bacillus sp. PCH491 as an efficient producer of xylanase using alkaline-pretreated wheat straw, whereas Bacillus sp. PCH494 produced laccase using alkaline-pretreated sugarcane bagasse. Notably, Bacillus sp. PCH492 produced multiple enzymes, laccase, xylanase, and cellulase, using various agro-residues. Further, characterization of laccase and xylanase enzymes revealed activity across a broad pH (4.0-12.0) and temperature (4-90 ℃). Xylanase from Bacillus sp. PCH491 showed maximum activity (38.86 IU/mL) at pH 7.0 and 50 ℃, whereas laccase from Bacillus sp. PCH494 reached peak activity (31.20 IU/mL) at pH 3.0 and 50 ℃. SEM and FTIR analyses confirmed significant structural and functional group modifications in the biomass, highlighting these high-altitude isolates as robust candidates for industrial biorefineries.

The oxidation-reduction potential (ORP) is a primary factor influencing the growth and metabolism of anaerobic microorganisms and regulates anaerobic fermentation. Our research on ORP-regulated silage fermentation revealed that initial ORP regulation significantly affects fermentation. Nevertheless, how the ORP regulates microbial dynamics, enzyme activity, and metabolic pathways remains underexplored. We investigated the regulatory effects of ORP on Lactobacillus acidophilus growth, fermentation quality, and metabolic activity in Sudan grass silage. Redox agents l-cysteine (Cys, ORP-increasing) and potassium iodate (KIO3, ORP-decreasing) were applied to establish distinct ORP gradients. Results revealed that a decreased initial ORP (0.01C/200-220&#xa0;mV and 0.05C/120-140&#xa0;mV) can significantly increase L. acidophilus proliferation and accelerate lactic acid production, yielding superior fermentation quality with lower pH and ammonia nitrogen level (P&#xa0;<&#xa0;0.05). Moreover, it increased beneficial bacteria abundance (Lactiplantibacillus, Lacticaseibacillus, and Leuconostoc) during early ensiling. Conversely, an increased initial ORP (0.2&#xa0;K/420-440&#xa0;mV) inhibited microorganisms proliferation and delayed fermentation. Metabolomics revealed that decreased ORP facilitated efficient substrate utilization, increasing lactic acid bacteria (LAB) dominance to promote silage fermentation, while maintaining core metabolic stability and reducing dulcitol levels. In contrast, increased ORP delayed fermentation by initially inhibiting microbial growth, reallocating metabolic flux, increasing the cis-aconitic acid concentration and decreasing ascorbic acid levels. Enzyme assays further demonstrated that decreased ORP optimized NADH availability and glycolytic flux, whereas oxidative conditions from increased ORP triggered compensatory metabolic responses. These findings highlight the ORP as a critical determinant of silage efficiency and offer practical insights for the efficient utilization of forage.

We developed a rapid, convenient, and viable cell-selective sensing system for Escherichia coli (E. coli) based on a sequential enzymatic reaction on an intact cell surface. In food safety and infectious disease diagnostics, it is crucial to selectively detect viable cells that represent actual infection risk. However, conventional methods such as culture-based method and polymerase chain reaction are time-consuming and require specialized equipment, limiting their applicability for on-site testing. The proposed system is based on a cooperative reaction of antibody-enzyme complexes, in which chemiluminescent signals are generated only when two types of antibody-enzyme complexes localize in proximity on the bacterial surface. The system allows for homogeneous detection of E. coli simply by mixing reagents, eliminating washing and separation steps. The chemiluminescence intensity showed a concentration-dependent response and an approximately linear relationship with log (CFUmL-1) over the range of 1-104&#x202f;CFU&#x202f;mL-1. Importantly, the signal was generated only in the presence of viable E. coli cells, indicating that the cooperative enzymatic reaction proceeds selectively on intact bacterial surface. This property allows clear discrimination between viable and dead cells, which has been difficult with conventional methods. Overall, the proposed approach provides a rapid, convenient, and viable-cell-selective platform for on-site microbial monitoring and risk assessment.

This study aimed to characterize the chemical composition of essential oil (EO) obtained by hydrodistillation from leaves of Tunisian Pistacia lentiscus (yield: 0.18%) and to evaluate its antibiofilm, antioxidant, and enzyme-inhibitory activities. The composition was determined by GC-MS and compared with other Tunisian EOs reported in the literature using multivariate analysis. The EO was rich in &#x3b1;-pinene (19.95%) and terpinen-4-ol (15.49%). Antibiofilm activity was assessed by crystal violet and MTT assays against five bacterial strains (three Gram-negative and two Gram-positive), with Escherichia coli and Pseudomonas aeruginosa being the most sensitive. Enzyme inhibition was evaluated spectrophotometrically against cholinesterases, &#x3b1;-glucosidase, and &#x3b1;-amylase. Acetylcholinesterase showed the highest sensitivity (IC50&#xa0;=&#xa0;1.10&#xa0;mg/mL). Overall, the EO represents a promising natural source of antibiofilm agents and enzyme inhibitors, with potential applications in the control of bacterial biofilms and in targeting enzymes relevant to metabolic and neurodegenerative disorders.

Beneficial rhizobacteria can enhance plant growth and stress resilience through multiple, complementary mechanisms. In this study, we investigated the combined effects of Azotobacter chroococcum, Pseudomonas putida, and Bacillus subtilis on tomato plants subjected to drought stress. The primary objective was to assess whether a combined bacterial inoculation could mitigate the negative impacts of drought on tomato growth and productivity. We hypothesized that the consortium would act synergistically to improve drought tolerance by enhancing physiological performance and biochemical defense systems, including photosynthetic activity and antioxidant enzyme responses. The combined application of beneficial rhizobacteria significantly increased total chlorophyll content from 0.85 to 1.70&#xa0;mg g&#x207b;&#xb9; FW and relative water content from 55.41 to 72.06%, while maintaining higher photosynthetic pigment levels than drought-stressed controls. Biochemical analyses revealed markedly higher activities of antioxidant enzymes, with superoxide dismutase increasing to 35.4 &#xb5;mol min&#x207b;&#xb9; mg&#x207b;&#xb9; FW, catalase to 74.6 &#xb5;mol min&#x207b;&#xb9; mg&#x207b;&#xb9; FW, and peroxidase to 0.89 &#xb5;mol g&#x207b;&#xb9; FW, indicating more effective mitigation of drought-induced oxidative stress. All individual rhizobacterial treatments significantly increased tomato yield relative to drought stress, reaching 0.81, 0.86, and 0.88&#xa0;kg plant&#x207b;&#xb9; under inoculation with (A) chroococcum, P. putida, and (B) subtilis, respectively. The bacterial consortium produced the highest yield of 0.94&#xa0;kg plant&#x207b;&#xb9;. Overall, these findings demonstrate that synergistic plant-microbe interactions can substantially enhance drought tolerance and productivity in tomato. Future studies should examine the long-term stability and field performance of microbial consortia, their interactions with native soil microbiomes, and their scalability for sustainable crop production in water-limited agroecosystems.

White-rot basidiomycetes such as Trametes versicolor are major producers of lignin-modifying enzymes (LMEs). Here, we quantified laccase and MnP production by T. versicolor BCC159 under simultaneous and sequential copper/xylidine supplementation regimes and profiled early transcriptional responses using long-read Nanopore cDNA sequencing with poly(A) tail-length estimation. Cultures were grown in submerged fermentation with copper sulphate (1&#x202f;mM), xylidine (0.5&#x202f;mM), or both, added either at inoculation or on day 3. Extracellular laccase and MnP activities were quantified, and long-read RNA-seq (Nanopore cDNA-seq) was used to profile differential gene expression and poly(A) tail length. Copper strongly induced laccase and MnP production, whereas xylidine alone triggered a stress-like response but negligible enzyme secretion. The combined treatment yielded the highest titers, with laccase activity reaching 97.1&#x202f;U/mL when xylidine was added to copper-preconditioned cultures on day 3. Transcriptomic analysis showed that copper upregulated multiple laccase genes together with copper-binding and detoxification factors while downregulating copper transporters, whereas xylidine mainly induced stress- and translation-related genes. Co-treatment integrated elements of both responses and was associated with treatment-specific changes in poly(A) tail length for selected laccase and MnP transcripts. These findings identify copper as the primary inducer of LMEs biosynthesis in T. versicolor BCC159, with xylidine acting mainly as a context-dependent modulator of stress signaling and post-transcriptional control, and indicate that appropriately timed copper-xylidine supplementation can be used to improve LMEs titers in controlled biotechnological settings.

Fraxinus xanthoxyloides Wall. ex DC (Family-Oleaceae) is a tiny tree found in arid highlands, often referred to as "Afghan ash". This study aimed to explore F. xanthoxyloides bark extract as a potential anti-diabetic agent by conducting GC-MS analysis along with in vitro and in vivo studies. F. xanthoxyloides bark methanol extract (FXBM) was fractionated with n-hexane (FXBH), followed by chloroform (FXBC), ethyl acetate (FXBE), and residual aqueous fraction (FXBA). GC-MS and HPLC-MS analysis of the total extract were performed. The inhibitory activities against &#x3b1;-amylase, &#x3b1;-glucosidase,&#xa0;and DPP4 were assessed for the extract and its fractions. The in vivo&#xa0;study included five groups: control group, diabetic control, groups pretreated with alloxan (150 mg/kg) + glibenclamide (5 mg/kg), group pretreated with alloxan (150 mg/kg) + FXBH (200 mg/kg), and group pretreated with alloxan (150 mg/kg) + FXBH (400 mg/kg). Further, a histopathological investigation was conducted. GC-MS analysis of FXBM revealed the presence of 17 compounds predominated by esters (17.9%), polyols (16.35%), and O-glycosides (12.24%). Among all extract/fractions, FXBH showed maximum &#x3b1;-amylase, &#x3b1;-glucosidase, and DPP4 inhibition when compared to acarbose and berberine, respectively. It also achieved the highest glucose uptake among all extract/fractions when compared with metformin. HPLC-DAD analysis showed the presence of gallic acid (3.29 &#xb5;g/mg), catechin (4.23 &#xb5;g/mg), caffeic acid (6.05 &#xb5;g/mg), ferulic acid (2.99 &#xb5;g/mg), and quercetin (6.4 &#xb5;g/mg). FXBH-treated rats showed a significant increase in body weight and reduced blood glucose levels (p&#x2009;<&#x2009;0.05) from days 1-30. The biochemical parameters like triglyceride, low-density lipoprotein, cholesterol, lipase, amylase, C-reactive protein, alanine aminotransferase, aspartate aminotransferase, creatinine, HbA1c, and urea were decreased, while high-density lipoprotein was elevated, compared to diabetic control. Histopathological studies demonstrated restoration of pancreatic &#x3b2;-cells. In conclusion, F. xanthoxyloides bark extract exhibited potential antidiabetic effects; meanwhile, further studies are recommended to characterize the pharmacodynamics, pharmacokinetics, and synergistic effects with standard drugs.