Search Results (25,854)

In this study, we examined the enhancement of erythritol production by the Yarrowia divulgata strain 1485. Although erythritol fermentation has been thoroughly investigated in earlier studies, the influence of inoculum ratio has not been comprehensively addressed. Therefore, this parameter was selected as the focus of the present work. Since industrial-scale erythritol production is typically carried out using more efficient fungal strains, further improvements in economic viability are primarily expected through integration with other biotechnological processes, allowing the simultaneous generation of multiple valuable products. To this end, the erythritol fermentation was coupled with microbial pigment production, and the potential recovery of additional compounds—such as biodetergents and cosmetic ingredients—were also explored. Based on the results, the fermentation with a 15% inoculation rate appears to be the most effective, producing 67.9 ± 6.0 g/L of erythritol, and 61.81 ± 0.02 mg/L of pigment was successfully extracted at the end of the pigment fermentation. The cells seem capable of increasing the skin’s moisturizing effect according to our preliminary tests when glass bead cell disruption is used, and the emulsifier has also proven to be effective, maintaining an emulsification index (EI) above 50% even after 24 h. When performing a kinetic model, we found that the measured data matched the model predictions and confirmed optimal inoculation size (15%), providing a solid basis for subsequent techno-economic analysis. The integration of the two basic fermentations (erythritol and pigment) is therefore considered successful, and the Yarrowia divulgata strain appears to have great biotechnological potential. Full article

Granite residual soil (GRS) is highly susceptible to water-induced softening, posing significant risks of slope instability and collapse. Conventional impermeable grouting often exacerbates these hazards by blocking groundwater drainage. This study investigates the efficacy of a permeable water-reactive polyurethane (PWPU) in stabilizing GRS, aiming to resolve the conflict between mechanical reinforcement and hydraulic conductivity. Uniaxial compression tests were conducted on specimens with varying initial water contents (5%, 10%, and 15%) and PWPU contents (5%, 10%, and 15%). To reveal the multi-scale failure mechanism, synchronous acoustic emission (AE) monitoring and digital image correlation (DIC) were employed, complemented by scanning electron microscopy (SEM) for microstructural characterization. Results indicate that PWPU treatment significantly enhances soil ductility, shifting the failure mode from brittle fracturing to strain-hardening, particularly at higher moisture levels where failure strains exceeded 30%. This enhancement is attributed to the formation of a flexible polymer network that acts as a micro-reinforcement system to restrict particle sliding and dissipate strain energy. An optimal PWPU content of 10% yielded a maximum compressive strength of 4.5 MPa, while failure strain increased linearly with polymer dosage. SEM analysis confirmed the formation of a porous, reticulated polymer network that effectively bonds soil particles while preserving permeability. The synchronous monitoring quantitatively bridged the gap between internal micro-crack evolution and macroscopic strain localization, with AE analysis revealing that tensile cracking accounted for 79.17% to 96.35% of the total failure events. Full article

Bacterial zoonoses pose a serious threat to the development of animal husbandry, food safety, and public health. Staphylococcus aureus (S. aureus) is a major infectious and food-borne pathogen worldwide, and there was an urgent need to develop relevant methodologies for the control of bacterial infections. This study aimed to evaluate the effectiveness of cell-free supernatants (CFSs) produced by selected strains of Lactiplantibacillus plantarum (L. plantarum), Lacticaseibacillus rhamnosus (L. rhamnosus), Streptococcus thermophilus (S. thermophilus), and Bifidobacterium longum subspecies infantis (B. infantis) to inhibit in vitrogrown S. aureus BNCC 186335. CFSs of S. thermophilus, B. infantis, L. plantarum, and L. rhamnosus not only showed good antibacterial activity against S. aureus but also have strong stability and tolerance, which could destroy the integrity of cell membrane, lead to changes in cell morphology, and then strongly and rapidly kill bacteria. Notably, the primary antimicrobial substances in the CFSs of L. plantarum and L. rhamnosus were organic acids and protein components, whereas the main antimicrobial substances in the CFSs of S. thermophilus and B. infantis were organic acids. Meanwhile, four CFSs achieved substantial removal of biofilms and inhibited decreased ATP content. These findings suggest that the CFSs of S. thermophilus, B. infantis, L. plantarum, and L. rhamnosus may have potential applications as biological preservatives to control the contamination of S. aureus in the food industry and animal husbandry. Full article

Cyclic di-GMP (bis-(3′ → 5′) cyclic dimeric guanosine monophosphate) is a ubiquitous bacterial second messenger that regulates a wide range of cellular processes, including biofilm formation, motility, virulence, and environmental adaptation. Its intracellular levels are dynamically controlled by diguanylate cyclases (DGCs), which synthesize c-di-GMP from GTP, and phosphodiesterases (PDEs), which degrade it into linear pGpG or GMP. The functional effects of cytoplasmic c-di-GMP are mediated through diverse effector proteins, including PilZ domain-containing receptors, transcription factors, and riboswitches. In Leptospira interrogans, a major pathogenic species responsible for leptospirosis, the regulatory roles of c-di-GMP remain poorly understood. Here, we performed a comprehensive bioinformatics and structural analysis of all predicted c-di-GMP related proteins in L. interrogans serovar Copenhageni strain Fiocruz L1-130, a serovar generally associated with severe manifestations of leptospirosis in humans. Our analysis identified seventeen proteins containing GGDEF domain, five proteins containing both GGDEF and EAL domains, four proteins containing EAL domain, five proteins containing HD-GYP domain, twelve proteins containing PilZ domain, and one protein containing an MshEN domain. Comparative analysis with well-characterized bacterial homologs suggests that L. interrogans possess a complex c-di-GMP signaling network, likely involved in modulating biofilm formation, host–pathogen interactions, and environmental survival. These findings provide new insights into the c-di-GMP regulatory network and on signal transduction in Leptospira and lay the foundation for future functional studies aimed at understanding its roles in physiology, virulence, and persistence. Full article

Influenza viruses are characterized by their high mutation rates which require continuous molecular surveillance to ensure the annual effectiveness of influenza vaccines. The current study aimed to investigate the molecular evolution and vaccine match of the 2009 pandemic (A(H1N1) pdm09) virus circulating in Riyadh, Saudi Arabia. A total of 380 nasopharyngeal aspirates (NPAs) were collected during the 2020–2023 winter seasons from patients with influenza-like illness. Influenza A virus (IAV) detection, typing, and amplification of hemagglutinin (HA) and neuraminidase (NA) genes were achieved using one-step RT-PCR. The full-length HA and NA genes of 14 selected A(H1N1) pdm09 isolates were sequenced and used for sequence and phylogenetic analysis, which also included sequences of seven A(H1N1) pdm09 isolates collected in Riyadh during the 2024–2025 season. IAV was detected in 17.11% samples; A/H3N2 (9.21%) was somewhat more prevalent than A(H1N1) pdm09 (7.89%). Children aged 0–4 years had the highest incidence rate of infection. Comparing the HA1 domain of A(H1N1) pdm09 isolates circulating in Riyadh to the current vaccine strains (A/Wisconsin/67/2022 and A/Victoria/4897/2022), a total of 24 amino acid substitutions were identified. O-linked and N-linked glycosylation sites in the HA and NA proteins of the Riyadh isolates coincided with those of the two vaccine strains. The receptor-binding domain (130-loop) of the HA1 domain showed a persistent S137P substitution in all study isolates; this mutation is not present in the current vaccination strain. This finding suggests a potential antigenic mismatch between the current vaccine and the circulating A(H1N1) pdm09 strains in Riyadh, warranting hemagglutination inhibition (HAI) assays to confirm the impact of the S137P substitution on antigenicity and immune evasion. As shown above, ongoing molecular surveillance is essential for guiding the yearly selection of vaccine candidates to increase efficacy. Full article

This work aims to enhance the stability of the Mg/Al₃Y interface through first-principles investigations of low-cost dopants. Density functional theory calculations were employed to systematically examine the bulk properties of Mg and Al₃Y, as well as the structural stability, electronic characteristics, and alloying element effects at the Mg(0001)/Al₃Y(0001) interface. The calculated lattice parameters, elastic moduli, and phonon spectra demonstrate that both Mg and Al₃Y are dynamically stable. Owing to the similar hexagonal symmetry and a small lattice mismatch (~1.27%), a low-strain semi-coherent Mg(0001)/(2 × 2)Al₃Y(0001) interface can be constructed. Three representative interfacial stacking configurations (OT, MT, and HCP) were examined, among which the MT configuration exhibits significantly higher work of adhesion, indicating superior interfacial stability. Differential charge density and density of states analyses reveal pronounced charge transfer from Mg to Al/Y atoms and strong orbital hybridization, particularly involving Y-d states, which underpins the enhanced interfacial bonding. Furthermore, the segregation behavior and adhesion enhancement effects of typical alloying elements (Si, Ca, Ti, Mn, Cu, Zn, Zr, and Sn) were systematically evaluated. The results show that Mg-side interfacial sites, especially Mg₂ and Mg₃, are thermodynamically favored for segregation, with Zr and Ti exhibiting the strongest segregation tendency and the most significant improvement in interfacial adhesion. These findings provide fundamental insights into interfacial strengthening mechanisms and offer guidance for the alloy design of high-performance Mg-based composites. Full article

Background/Objectives: Serratia liquefaciens is a bacterium commonly found in the rhizosphere and may possess PGPR capabilities. The present study aimed to elucidate the genomic, phylogenomic, and metabolic characteristics of S. liquefaciens strain UNJFSC002 to determine whether it is an effective PGPR. Methods: The genome of strain UNJFSC002 was obtained from NCBI and annotated using Prokka. Functional genome prediction, phylogenetic reconstruction, and comparative genomics were performed using bioinformatics tools. A GEM model was reconstructed to simulate metabolic fluxes associated with nitrogen fixation, phosphate solubilization, and phytohormone biosynthesis. Computational phenotyping and in silico functional validation were also performed. Results: The draft genome (5.19 Mb, GC 55.33%) contained 4792 protein-coding genes, 4 rRNAs, and 81 tRNAs, with 100% completeness. ANI and core genome phylogeny confirmed its taxonomic position within S. liquefaciens, with an identity higher than 98.8%. Pangenome analysis of 25 Serratia genomes revealed an open and highly dynamic pangenome (30,515 orthologous groups), indicating extensive genetic plasticity. Functional annotation identified key genes associated with nitrogen and phosphate acquisition, as well as the biosynthesis of IAA and GABA, findings that were supported by GEM simulations, reinforcing its potential as a biofertilizer. Conclusions: The genomic approach confirmed that strain UNJFSC002 harbors multiple active genes and metabolic pathways associated with plant growth promotion and environmental resilience. Full article

Space-borne SiGe-based electronics are confronted with high-energy particles and may suffer from displacement damage effects. Here, primary radiation damage of a strain-engineering-based SiGe/Si heterostructure was investigated by molecular dynamics simulations in two cases of independent and overlapping collision cascades. The results showed that among 1 keV, 3 keV, and 5 keV primary knock-on atoms (PKAs) of Si and Ge, 3 keV Ge PKAs generated the most point defects at the heterointerface, which was associated with adequate PKA energy dissipated around the heterointerface. Meanwhile, the Frenkel pairs at the heterointerface continued increasing merely in the first three cascades and tended to annihilate subsequently, whereas the antisites both in the whole heterostructure and at the heterointerface accrued from the first to the fifth cascades. In addition, the spatial distribution of point defects surviving in each collision cascade was dominated by the melting region, and it could be superimposed on the subsequent ones during the overlapping cascades. Overall, this work explored the evolution of the defect and temperature as well as the overlapping effects during the collision cascades in a strain-engineering-based SiGe/Si heterostructure, which shall shed light on radiation effects of SiGe/Si heterostructures and pertinent radiation-hardening techniques of SiGe-based electronics. Full article

Background/Objectives: Multidrug resistance (MDR) remains a critical global public health concern, compromising the efficacy of currently available antibiotics. As the development of new antibiotics offers limited long-term solutions, alternative approaches such as efflux pump inhibition have gained attention. This study reports the development of nanostructured lipid carriers (NLCs) co-loaded with Norfloxacin (NOR) and the efflux pump inhibitor 2-amino-thiophen-6CN-Ethyl, to modulate NOR activity against resistant Staphylococcus aureus strains overexpressing efflux pump genes. Methods: NLCs were produced via the hot emulsion method followed by sonication. The formulations were characterized for encapsulation efficiency (EE%), particle size, polydispersity index (PDI), zeta potential, X-ray diffraction (XRD), infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), in vitro release kinetics, and stability. Antibacterial activity was evaluated against S. aureus 1199B and K2068 strains. Results: The NLC formulation containing norfloxacin and 6CN-Ethyl (NLC10NOR + 106CN) demonstrated high EE% for both compounds (99.50% for 6CN-Ethyl and 90.91% for NOR) and physicochemical stability over 60 days (particle size < 255 nm, PDI < 0.3, zeta potential < −20 mV). Structural analyses confirmed amorphization and effective encapsulation of the active constituents. Antibacterial assays showed that NLC10NOR + 106CN significantly increased NOR activity compared to the free drug and physical mixture; the effect in 1199B was notably superior to the NOR + CCCP (carbonyl cyanide m-chlorophenylhydrazone) combination. Conclusions: These findings highlight the potential of NLC-based co-delivery systems as innovative strategies to overcome bacterial resistance, particularly through efflux pump inhibition enhancing antibiotic efficacy. Full article

Background/Objectives: Maternal rectovaginal carriage of Group B Streptococcus (GBS, Streptococcus agalactiae) is a major risk factor for vertical transmission and early-onset neonatal infection. Intrapartum antibiotic prophylaxis reduces early-onset disease but does not address antenatal carriage and may affect the maternal–neonatal microbiota. Microbiota-directed interventions, including probiotics, are being explored as complementary strategies. Methods: This prospective, single-centre, open-label pilot intervention study included 10 pregnant women (18–40 years) with singleton pregnancies and a positive vaginal and/or rectal GBS swab, without pre-gestational or gestational diabetes and without antibiotic use in the 4 weeks before enrolment. Participants received OMNi-BiOTiC^® FLORA plus (multi-strain lactic acid bacteria, including Lactobacillus crispatus) orally at 2 × 2 g/day from the 15th to the 34th gestational week. Microbiological swabs were obtained at qualification (12–15 weeks), mid-pregnancy (22–25 weeks), and late pregnancy (34–35 weeks). Outcomes were described descriptively. Results: Among 56 screened pregnant women, 10 were GBS-positive (17.9%) and enrolled. All participants were GBS-positive at baseline. At 22–25 weeks, 5/10 (50%) had a negative GBS result. At 34–35 weeks, 9/10 (90%) were GBS-negative, while 1/10 (10%) remained colonised. Time to first negative result ranged from 7.6 to 20.2 weeks from supplementation start (median 8.6 weeks). No recurrences (negative-to-positive transitions) were observed between the second and third sampling points. No adverse events related to supplementation were reported. In contrast, among the 46 women who were GBS-negative at screening and did not receive probiotic supplementation, 14 (30.4%) were found to be GBS-positive at routine screening performed at 35–37 weeks of gestation. Conclusions: In this pilot single-arm study, oral supplementation with a multi-strain probiotic preparation during pregnancy was associated with a time-dependent reduction in rectovaginal GBS carriage and was well tolerated. These preliminary findings support the feasibility of larger randomised controlled trials incorporating microbiome profiling and neonatal outcomes. Full article

Bolt connections are widely used in engineering structures but are susceptible to loosening during operation, which can result in significant safety concerns. Consequently, reliable bolt-loosening detection is of paramount importance. Conventional detection methodologies frequently exhibit deficiencies, including reduced efficiency, constrained accuracy, and the requirement for contact sensors. To overcome these limitations, this study proposes a novel non-contact approach for bolt preload monitoring based on Digital Image Correlation (DIC). In this method, an industrial camera captures speckle images of the bolt head before and after deformation, thereby enabling measurement of the surface strain. The DIC technique is employed to calculate the strain field on the bolt head surface, which exhibits a linear relationship with the bolt preload. The proposed method utilizes strain field tracking to facilitate effective and precise monitoring of bolt preload. Experimental results demonstrate that the method provides a precise, efficient, and user-friendly solution for bolt preload monitoring, showing great potential for applications in structural health monitoring. Full article

Rice blast and bacterial blight are two major diseases that seriously threaten rice production. Developing rice germplasm with enhanced resistance to multiple diseases while maintaining favorable agronomic traits is essential for sustainable breeding. In this study, two rice landraces from Motuo County, Xizang Autonomous Region, China, Benglinba and Gare, were used to simultaneously edit OsERF922 and Xa41 using a structurally optimized dual-target CRISPR/Cas9 vector, pRGEB32-2T. A total of 32 and 28 T₀ transgenic plants were generated in the Benglinba and Gare backgrounds, respectively. Targeted mutagenesis generated eight homozygous oserf922 mutants and three homozygous xa41 mutants in Benglinba, and four and five homozygous mutants in Gare. Twelve double homozygous mutant lines (nine Benglinba and three Gare) were selected for further analysis. Disease resistance assays showed that these double mutants exhibited significantly enhanced resistance to the rice blast fungus strain GDYJ7 and the bacterial blight pathogen strain GDXO-1, with markedly reduced lesion size or lesion length compared with wild-type plants (p < 0.001, Student’s t-test). Importantly, three independent T-DNA-free double mutant lines from each genetic background displayed no significant differences from their corresponding wild types in major agronomic traits, including plant height, effective panicle number, panicle length, seed-setting rate, or thousand-grain weight (p > 0.05). Grain quality parameters, such as brown rice rate, milled rice rate, amylose content, and gel consistency, were also unaffected. Overall, this study generated rice materials with enhanced resistance to rice blast and bacterial blight while maintaining elite agronomic and quality traits, providing valuable germplasm resources and a feasible strategy for the precise improvement of disease resistance in rice landraces from Xizang Autonomous Region. Full article

Manganese (Mn) toxicity, commonly triggered by soil acidification, poses a significant threat to citrus production. Arbuscular mycorrhizal (AM) fungi can alleviate heavy metal stress, while their specific function and quantitative effectiveness in conferring Mn tolerance to citrus remain unclear. This study investigated the physiological regulation conferred by four AM fungal species, Rhizophagus intraradices (Ri), Funneliformis mosseae (Fm), Paraglomus occultum (Po), and Diversispora epigaea (De), on trifoliate orange (Poncirus trifoliata L. Raf.) under Mn stress. Mn toxicity reduced root colonization in a species-dependent manner, significantly lowering colonization by all AM fungal isolates except Fm. It also severely inhibited plant growth and induced pronounced oxidative damage, accompanied by metabolic imbalance. Under Mn-stressed conditions, AM fungal inoculation, especially Ri, significantly enhanced plant biomass relative to the non-AM control, with respective increases of 148% in leaves, 33% in stems, and 64% in roots, demonstrating a marked species-specific efficacy. Furthermore, AM symbiosis effectively promoted chlorophyll index and limited Mn translocation to the leaves under both non-stress and Mn-stress conditions, with Ri being the most effective in reducing leaf Mn content. Symbiosis with AM fungi, particularly Ri, fine-tuned the antioxidant enzyme defense under Mn stress by selectively suppressing superoxide dismutase and peroxidase activities while further boosting catalase activity. Concurrently, AM fungi alleviated Mn-induced oxidative damage, with the magnitude of mitigation varying by species: Ri delivered the most comprehensive protection, most effectively reducing hydrogen peroxide and malondialdehyde levels in both leaves and roots, whereas Po was particularly effective in suppressing root superoxide anion radical and malondialdehyde levels in roots. Furthermore, AM fungi reversed Mn-induced shifts in organic osmolytes: they significantly reduced the excessive accumulation of soluble sugars and proline while mitigating the loss of soluble proteins, thereby assisting in restoring metabolic homeostasis. The alleviative effects varied significantly among AM fungal species, with Ri identified as the most efficient and Mn-tolerant strain. These findings highlight the potential of utilizing specific AM fungi, particularly Ri, as a sustainable biological strategy to enhance citrus productivity in acidified, Mn-contaminated soils. Full article

Drought is one of the most limiting abiotic stresses for agricultural production, especially in horticultural crops grown in arid and semi-arid areas. In the present study, we evaluated the potential of bacterial isolates obtained from coastal environments in Chile to improve drought tolerance in Lagenaria siceraria, a plant species increasingly used as a rootstock for cucurbit cropping. Rhizosphere bacteria were isolated from Sicyos baderoa, the only native cucurbit species of the Chilean coast, from which four isolates with plant growth-promoting traits, such as indole-3-acetic acid production, phosphorus solubilization, nitrogen fixation, and siderophore production, were selected. These isolates were inoculated on two L. siceraria genotypes, Illapel and Osorno, under both normal irrigation and water deficit conditions. The results showed that Peribacillus frigoritolerans showed a clearer positive effect on biomass and net photosynthesis under water deficit in the Illapel genotype, increasing shoot biomass by up to ~75% and restoring net photosynthetic rates by up to ~260% relative to non-inoculated drought-stressed plants. In contrast, responses associated with Staphylococcus succinus and those observed in the Osorno genotype were mainly expressed as trait- and tissue-specific adjustments, consistent with a more stabilizing response rather than broad growth stimulation. Additionally, malondialdehyde levels were reduced by up to ~25%, while free proline accumulation increased by more than 100% under water deficit. In contrast, total phenolic compounds showed more variable responses, indicating genotype- and strain-specific adjustment of antioxidant metabolism. Overall, the observed responses were heterogeneous and strongly dependent on the specific strain–genotype–trait combination and, therefore, should be interpreted as preliminary evidence supporting the potential value of native rhizobacteria for improving early drought-related traits in cucurbit rootstocks. Among the tested strains, Peribacillus frigoritolerans emerged as the most promising candidate for enhancing early drought tolerance in responsive genotypes such as Illapel, while highlighting the need for follow-up studies under replicated nursery and field conditions, including grafted plants, multiple drought intensities and combined inoculant strategies. Full article

Rhizoctonia solani anastomosis group (AG)-2-2IIIB and AG-4HGI are the main pathogens causing sugar beet seedling damping-off and crown and root rot disease. In this study, 1232 loci of simple sequence repeats (SSRs) were obtained via transcriptome sequencing, with 592 from AG-2-2IIIB and 640 from AG-4HGI. Fourteen and twenty loci of SSRs were selected for studying the genetic structure of the AG-2-2IIIB and AG-4HGI populations, respectively. A population of 134 strains of AG-2-2IIIB and 145 strains of AG-4HGI, sampled from three geographic regions in China, indicated that both AG-2-2IIIB and AG-4HGI had a high level of genetic diversity, and that the selected SSR markers could reliably capture the genetic variation. Genetic analysis indicated that the individual strains of AG-2-2IIIB and AG-4HGI randomly mated within their respective population, and that a considerable degree of inbreeding was present among the populations. High to moderate gene flow and low to moderate population subdivision were detected among the populations of AG-2-2IIIB and AG-4HGI, which indicated that weak differentiation existed in these two subgroups. In addition, a founder effect (genetic drift) or a bottleneck effect was inferred to have occurred in the AG-4HGI population. This study provides the first analysis of the population genetic structure of AG-2-2IIIB and AG-4HGI associated with sugar beet seedling damping-off and crown and root rot disease, and the present results offer useful guidance for developing effective integrated disease management. Full article