共找到 20 条结果
Food microbiology is an increasingly interdisciplinary field, essential to modern global food systems [...].
Cigar tobacco fermentation is a microbially driven process that transforms raw tobacco leaves into a product with distinctive sensory attributes, yet the current understanding of the microbial roles in this process remains fragmented between descriptive community surveys and isolated mechanistic studies, with beneficial and detrimental microbial functions rarely integrated into a unified risk-benefit assessment. This review critically examines the microbiology of cigar fermentation through a dual-axis framework organized around beneficial metabolic functions and detrimental spoilage potential, each resolved into microbial identity, biochemical mechanism, and environmental modulation dimensions. We synthesize evidence from culture-dependent and culture-independent studies on microbial community assembly and succession, where Bacillus, Staphylococcus, and Aspergillus emerge as core fermentation genera, and evaluate the complementary three-pathway system - macromolecular enzymatic degradation, targeted biotransformation of tobacco alkaloids and polyphenols, and de novo biosynthesis of aroma-active volatiles - that drives flavor and quality enhancement. We further analyze the contrastive microbial balance governing tobacco-specific nitrosamine (TSNA) formation, where nitrate-reducing bacteria compete with nitrate-assimilating and nitrite-scavenging microorganisms to determine the net TSNA load. In parallel, we critically examine the mould spoilage microbiology of cigar fermentation, identifying the environmental thresholds - humidity above 80% RH, water activity above 0.85, and inadequate aeration - that select for mycotoxigenic Aspergillus and Penicillium species producing aflatoxins and ochratoxin A at levels that persist into the finished product. We survey emerging biotechnological strategies spanning bioaugmentation with defined starter cultures, biostimulation through environmental optimization, and biocontrol of spoilage fungi, and identify five critical research gaps - including the absence of gnotobiotic fermentation models and the predominance of correlative over causal studies - that must be addressed to translate microbial ecology into predictable fermentation biotechnology. By integrating microbial ecology, fermentation biochemistry, spoilage prevention, and applied biotechnology, this review is intended for researchers in tobacco microbiology and fermentation science, as well as cigar manufacturers, quality-control practitioners, and biotechnologists seeking microbiome-based strategies for quality improvement and risk mitigation.
Extremophilic actinomycetes are promising microbial candidates in biotechnology due to their ability to decompose various agricultural wastes and are used to produce several enzymes with important applied properties. This study explored the biotechnological potential of Streptomyces griseorubens NBR14 and Nocardiopsis synnemataformans NBR9 by evaluating their polygalacturonase production from wheat and bean straw, and assessing the enzyme's efficacy in fruit juice clarification, as well as their ability to decolorize crystal violet. To optimize enzyme production, experiments with four variables were conducted using Box-Behnken design (BBD), followed by analysis of variance (ANOVA). The enzyme was then partially purified using acetone, followed by analyzing its properties and potential applications in fruit juice clarification. The optimal conditions for polygalacturonase (PG) activity by NBR14 and NBR9 were 40 °C, pH 9 and 7, incubation for 7 days, and substrate concentrations 2 and 3 g/100 mL, resulting in enzyme yields of 3.54- and 2.20-folds respectively. Partially purified polygalacturonase resulted in 7.07 and 2.99-fold purification, with recoveries of 33.5% and 16.61%, and specific activities of 177.9 and 72.13 U/mg, respectively. Both NBR14 and NBR9 partially purified polygalacturonase exhibited high relative activity at 40 °C and pH value 7. It remained 90% and 88% active at pH 9.0 and 64% and 81% at 60 °C, respectively. The maximum clarity recorded for apple juice was 82.75% and 85.75%, while orange juice clarity was noted at 61.77% and 83.31% for NBR14 and NBR9, respectively. These results highlight the potential of thermo-alkali stable polygalacturonase from extremophilic actinomycetes as a long-term and cost-effective biocatalyst for agro-waste valorization and industrial fruit juice processing.
ObjectiveThis prospective study evaluated the therapeutic efficacy of Diosgenin in mitigating Oxazolone-induced ulcerative colitis in male BALB/c mice.MethodMice aged 10-11 weeks were randomized into five groups and subjected to a nine-day protocol involving skin sensitization and intra-rectal Oxazolone challenge. Diosgenin was administered orally at 3 mg/kg and 30 mg/kg twice daily, with Tofacitinib at 60 mg/kg as a reference control. Disease severity was assessed via clinical activity scores, which include tested parameters.ResultsOxazolone-induced acute colitis was characterized by significant weight loss, increased diarrhoea scores, and an >8-fold increase in rectal bleeding scores compared with vehicle-treated mice, confirming successful disease induction (p < 0.05). Diosgenin-treated mice showed significant recovery. Disease Activity Index (DAI) scores improved by 40% in the 3 mg/kg Diosgenin group, 45% in the 30 mg/kg Diosgenin group, and 67% in the Tofacitinib-treated group by Day 2. Stool consistency improved by 52%, 33%, and 49% on Day 1, and by 33%, 61%, and 64% on Day 2 in the 3 mg/kg and 30 mg/kg Diosgenin groups, and the 60 mg/kg Tofacitinib groups respectively. Molecular analysis revealed a dose-dependent suppression of Th2 cytokines: IL-4 levels were reduced by 71%, 90%, and 86%, and IL-13 levels by 75%, 79%, and 90% in the Diosgenin 3mg/kg and 30 mg/kg groups, and Tofacitinib 60 mg/kg group respectively. Diosgenin markedly suppressed colonic pSTAT3 expression, with reductions of 92% and 99%, in the Diosgenin 3mg/kg and 30 mg/kg groups and >90% in the Tofacitinib 60 mg/kg group.ConclusionThese findings suggest Diosgenin offers substantial protection against Oxazolone-induced colitis via cytokine modulation and pSTAT3 inhibition, highlighting its potential as a natural anti-inflammatory agent for colitis management.
Shiga toxin producing Escherichia coli (STEC) is a zoonotic pathogen associated with diarhoeal disease and severe complications in children, yet its epidemiology in pastoral settings of Tanzania remains insufficiently characterized. This study determined the prevalence, virulence gene profiles and antibiotic susceptibility patterns of STEC among children aged 6‍-59 months with diarhoea in Longido District, northern Tanzania. A hospital based cross-sectional‍ study was conducted between July and August 2025, enrolling 150 participants from four health facilities. Stool samples were collected and analyzed using culture, serological conformation and multiplex polymerase chain reaction targeting five genes; rfbE, stx1, stx2, eaeA and hlyA. STEC was operationally defined by detection of stx1 and/or stx2. Antibiotic susceptibility was assessed using the Kirby-Bauer disk diffusion method. The prevalence of STEC was‍ 13.3% (20/‍150). All stx2 positive isolates co-occurred with stx1. Virulence genes showed a heterogeneous but significantly clustered distribution, with rfbE (20.0%) and stx1 (13.3%) predominating. Significant co-occurrence was observed‍ between stx1 and eae and between stx1 and hlyA (p < .001). Animal contact, raw milk consumption and use of untreated water were significantly associated with STEC infection. Firth penalized logistic regression confirmed these exposures as independent predictors. Antibiotic susceptibility profiles were uniform, with complete susceptibility to ciprofloxacin,‍ gentamicin, cefotaxime and ceftazidime while ampicillin and trimethoprim showed complete resistance. These findings indicate that STEC transmission in pastoral communities is strongly driven by zoonotic and environmental exposures, characterized by clustered virulence determinants and consistent antibiotic profiles. Limitations include the cross-sectional design and short sampling period, which may not capture seasonal variation. Strengthened surveillance and integrated One Health interventions are needed to reduce disease burden.
Cannabis sativa L. roots have been less studied than aboveground organs, despite their key role in plant physiology, metabolism, and interactions with biotic and abiotic factors. Metabolomic and phytochemical analyses reveal that roots synthesize a diverse array of bioactive compounds with antimicrobial, anti-inflammatory, antioxidant, and cytotoxic properties, highlighting their biotechnological potential. Root exudation patterns and interactions with endophytic microorganisms modulate rhizosphere microbial networks that support nutrient uptake, stress tolerance, pathogen resistance, and whole-plant physiology. Root-derived phytohormones and other signalling molecules may participate in coordinating biochemical pathways between belowground and aboveground tissues, with potential effects on secondary metabolism in aerial tissues. Recent advances in metabolomics, transcriptomics, microfluidic rhizosphere systems, and root-specific genetic engineering now enable detailed investigation of root metabolism in Cannabis sativa L. This review synthesises current knowledge on the metabolic roles of Cannabis sativa L. roots, their interactions with the rhizosphere microbiome, and root-derived systemic signalling. It emphasises aspects of root biology that are central to fundamental plant processes and to the development of sustainable strategies for optimising phytochemical yields. By placing roots at the forefront, this synthesis underscores the need to expand research beyond aerial tissues to fully understand and harness the biotechnological potential of Cannabis species. KEY POINTS: • Root metabolism and signalling regulate whole-plant-metabolic pathways • Root-associated microbiomes influence nutrient dynamics and phytochemical profiles • Root culture systems provide a scalable platform for biotechnological manipulation aimed at the production of bioactive compounds.
This study investigated the effects of replacing soybean meal (SBM) with black soldier fly larvae meal (BSFL) on the performance, carcass yield, blood biochemistry, hematology, and organ histology of broiler chickens. A total of 250 one-day-old Ross chicks were randomly allocated into five dietary treatments, with 5 replicates of 10 birds each, according to the following experimental design: a control group fed a basal diet (T1), and four groups with dietary replacement of SBM by 25% BSFL (T2), 50% BSFL (T3), 75% BSFL (T4), and 100% BSFL (T5). All groups were maintained under identical management and environmental conditions. At the end of the 35-day experimental period, the broilers were slaughtered, dressed, and weighed. The results showed that the 25% substitution level (T2) gave the best results, significantly improving body weight, weight gain, and the feed conversion ratio (FCR) with normal feed intake. The 50% group (T3) maintained a stable carcass weight similar to the control but showed lower feed intake. In contrast, higher levels (75% and 100%) decreased growth performance and carcass quality due to the high chitin content in the insect exoskeleton. Blood profiles and liver enzymes (ALT and AST) remained normal in most groups, confirming that the diet was safe. However, the 100% group (T5) showed higher cholesterol and HDL levels, and a lower albumin-to-globulin (A/G) ratio. Tissue analysis revealed only mild, non-pathogenic immune responses in the liver and lymphoid organs. Furthermore, BSFL did not alter the cecal microbial balance, maintaining normal Lactobacillus spp. and coliform counts, and all groups remained Salmonella-free. In conclusion, these findings indicate that BSFL can safely replace up to 50% of dietary SBM without compromising broiler health, development, or physiological status. This establishes BSFL as a viable, sustainable alternative protein source capable of reducing reliance on traditional soybean meal in poultry production, provided inclusion rates are optimized to prevent nutritional imbalances at higher substitution levels.
Although conventional microbial detection approaches for water samples are widely applied, they still suffer from prolonged assay durations (24-72 h), low sensitivity, and the absence of real-time monitoring capacity. Artificial intelligence (AI) has demonstrated conditional advantages in specific experimental environments, such as achieving a sensitivity of 99% for detecting Cryptosporidium and Giardia in low turbidity water (based on approximately 12,000 annotated images, using fivefold cross validation, completed under laboratory conditions); however, such advantages tend to diminish or vanish in high-turbidity water matrices or when training datasets are insufficient. This review critically evaluates four categories of AI-driven approaches: image-based analysis, spectroscopic techniques, genome, and metagenomic sequencing, as well as predictive pollution modeling. While AI helps boost detection efficiency, precision, and analytical capacity, a set of long-standing obstacles restrict its real-world deployment. The main issues involve non-standardized datasets, low model interpretability, weak generalization over various water substrates, and a substantial gap between lab-based performance and on-site operational outcomes. In summary, to fully exploit the capabilities of AI in aquatic microbial detection, greater emphasis should be placed on on-site validation, unified data specifications, and practical performance benchmarks, rather than further algorithmic innovation. This review seeks to provide practical references for scholars and practitioners working in the fields of microbiology, AI and water quality monitoring and management. KEY POINTS: • AI shows favorable performance for microbial detection under lab conditions. • Model performance declines greatly in complex water with many practical barriers. • Standardized data and validation will advance real-world application.
The reuse of polluted drainage water for irrigation is increasingly unavoidable in arid and semi-arid regions, yet it poses serious risks due to the accumulation of toxic heavy metals in soils and crops. Although biochar and plant growth-promoting rhizobacteria (PGPR) have individually shown potential to alleviate metal stress, field-scale evidence elucidating their synergistic and mechanistic effects under realistic, combined soil- and irrigation-derived contamination remains limited. This study addresses this gap by evaluating the effectiveness of PGPR-enriched biochar in mitigating lead (Pb), cadmium (Cd), and nickel (Ni) stress in canola (Brassica napus L.) grown under open-field conditions. A naturally contaminated clay soil was continuously irrigated with polluted drainage water from the Kitchener drain (Egypt), creating chronic heavy metal stress. Biochar was applied at 5 and 10 ton ha⁻¹, alone or enriched with defined PGPR consortia composed of Bacillus circulans NCAIM B.02324, Azospirillum brasiliense SARS 1001, and Pseudomonas koreensis MG209738, applied via seed inoculation. The combined application of 10 ton ha⁻¹ biochar with the three-strain consortium (10BC+PGPR3) produced the strongest responses. This treatment (10BC+PGPR3) significantly enhanced soil microbial respiration and key enzyme activities, indicating improved soil biological functioning, while reducing extractable Pb, Cd, and Ni by 55-65% relative to the untreated control. These soil-level improvements translated into marked reductions in metal uptake and translocation to shoots and seeds, alongside enhanced plant water status, membrane stability, and oxidative stress tolerance. Consequently, seed yield and oil content increased by ~ 60% and ~ 90%, respectively. Overall, this study demonstrates that PGPR-enriched biochar acts through coupled soil biochemical and plant physiological mechanisms to immobilize heavy metals and restore crop productivity under real contaminated irrigation scenarios. The findings provide robust field-based evidence supporting this integrated strategy as a practical and sustainable solution for improving soil health, crop performance, and food safety in heavy metal-affected agroecosystems.
Staphylococcus aureus is a major human commensal and pathogen, with the Panton-Valentine leukocidin (PVL) genes being associated with increased virulence. Rapid detection and molecular typing of such isolates are essential for effective epidemiological surveillance and infection control. Studies from Lithuania indicate that PVL is relatively common among S. aureus isolates, but detailed molecular typing data are still lacking. Clinical S. aureus isolates were collected from two hospitals in Vilnius in 2018-2019 and 2024, and from healthy volunteers between 2012 and 2020. Isolates were screened for PVL genes using real-time PCR. In addition, positive isolates harvested directly from the agar plate were tested for PVL production using an experimental lateral flow assay (LFA). Positive isolates were characterised using DNA-microarrays that facilitated the detection of resistance markers and virulence genes including PVL as well as an assignment to clonal complexes, strains and SCCmec types. Epidemiologically relevant isolates were subjected to whole-genome sequencing using Oxford nanopore technology. Out of 1296 S. aureus isolates, 124 yielded PVL-positive PCR results. 100 isolates were available for genotyping. Two PCR-positive isolates were negative by array and LFA, but PVL detection by DNA-microarray and lateral flow test (LF) showed complete concordance. Among PVL-positive isolates, 61.2% were methicillin-resistant S. aureus (MRSA). The most common PVL-MRSA strain (n = 43) was a Clonal Complex (CC) 8 MRSA that resembled the North American "USA300" strain but that lacked the arginine catabolic mobile element (ACME). This suggested an outbreak in one of the participating hospitals. Other common strains were PVL-positive CC30-MSSA, CC121-MSSA and CC8-MRSA-[IV+ACME] "USA300", while other lineages were represented by single isolates only. Whole-genome sequencing of two ACME-negative CC8-MRSA-IV isolates and of one local "USA300" isolate, as well as a comparison to international reference sequences, showed a very high degree of similarity in core genome and prophage content. The dominant PVL-MRSA strains were "USA300", indicating a possible importation from North America, and a locally emerged variant of "USA300" that lost the ACME-associated genes of its SCCmec element. These findings suggest that real-time PVL detection is essential for outbreak prevention. Given its clinical relevance, routine PVL screening -via PCR or lateral flow assays-in routine diagnostics should be seriously considered and surveillance of PVL-MRSA is urgently recommended.
Bacterial and viral diseases continue to remain major problem in aquaculture, and the growing limitations on the use of antibiotics have intensified a growing focus on host-directed nutrition-based disease management strategies. While vitamin D3 (VD3) has been recognized for its role in calcium-phosphorus metabolism, it is now increasingly recognized to exert an immunonutrient role in fish, which includes modulation of antimicrobial peptide production, inflammatory regulation, epithelial barrier integrity, oxidative homeostasis, microbiota-associated immune interactions, and antiviral signaling. This review critically synthesizes current knowledge on VD3 metabolism and vitamin D receptor (VDR)-mediated signaling in relation to disease resilience in cultured aquatic species, with particular emphasis on antibacterial, antiviral, and functional-feed applications. Across experimental studies, VD3 supplementation has frequently been associated with enhanced phagocytic activity, lysozyme and complement function, antimicrobial peptide induction, cytokine modulation, and improved mucosal stability. Emerging evidence further implicates VD3 in type I interferon and JAK-STAT-associated antiviral pathways. However, these responses remain highly variable across species, supplementation doses, developmental stages, and environmental conditions, reflecting substantial biological and methodological heterogeneity. Importantly, the current evidence base is still frequently composed of transcriptomic and short-term laboratory studies with comparatively few studies demonstrating functional validity in form of pathogen-load reduction, histopathological protection, improvement of survival, or production level. The translation value for VD3 is still not fully understood, although it holds promise for use in integrated functional feed systems. Overall, effective application will depend on species-specific dose optimization, long-term safety assessment, and stronger field-scale validation across diverse aquaculture systems. KEY POINTS: • Vitamin D3 modulate antimicrobial peptides and innate and antibacterial immunity in fish. • VD3 activates interferon pathways and strengthens antiviral defenses. • Optimal VD3 dosing improves resilience; field validation is needed in aquaculture.
In drylands, which cover >40 % of the Earth's terra firma, anthropogenic soil compression damages biological soil crusts (biocrusts), disrupts subsurface microbial communities, and exposes destabilized mineral soil to weathering. Weathering causes dust generation and erosion, threatening human health and infrastructures. Ecological restoration aims to restore soil ecosystem services by repairing soil structural integrity and functionality. However, in arid regions, effective restoration is largely limited to biocrust seeding. To bolster biocrust-mediated restoration of powdered sandy loam soils in arid regions, extracellular polysaccharide-rich biomass of terrestrial cyanobacteria (EPS-rich cyanomass) was applied to the subsurface soil alongside surface biocrust seeding. The EPS-rich cyanomass served a functional, non-proliferating amendment intended to bind mineral particles stabilizing soil, reducing erosion, and facilitating biocrust establishment and subsurface microbial recovery. Consequently, following cyanomass application, we examined mechanical soil stability, biocrust development, and the size and cyanomass-degradation capacity of subsurface microbial communities for two years. As controls, we included biocrust-seeded unamended soil and soil treated with a synthetic polyacrylamide used for soil stabilization as well as the intact soil. We found that, following the application of 4 g/m2 of EPS-rich biomass, soil stability and biomass and enzymatic activity of subsurface microorganisms approached the levels observed in intact soil. The measured capacity for EPS consumption of subsurface microbial community after two years indicated lasting benefit of the cyanomass treatment. This proof-of-concept field study showed that the novel EPS-rich cyanomass-mediated approach of structural and functional subsoil restoration has high potential for ecological recovery of damaged soils in arid regions.
Aspergillus flavus is a globally significant threat to peanut (Arachis hypogaea L.) production, causing yellow mold disease and contaminating crops with carcinogenic aflatoxins. This review synthesizes current knowledge on the origins, pathogenesis, diagnosis, and sustainable management of this disease, with a specific focus on pre-harvest interventions. The disease cycle originates from soil-borne inoculum and spreads via wind and insects. As a saprophytic opportunist, A. flavus deploys hydrolytic enzymes, with host lipids governing sporulation and aflatoxin biosynthesis. Pathogenicity is orchestrated by an intricate signalling network: GPCRs sense host oxylipins, activating cAMP/PKA and three MAPK cascades (Fus3, HOG, CWI), while the TOR pathway functions as an independent nutrient sensor; these converge on the velvet complex (VeA, VelB, LaeA) to regulate development and virulence. Diagnosis integrates visual scales, culture, chemical (TLC, HPLC-MS/MS), immunological (ELISA), and molecular tools (PCR, qPCR, LAMP). Management strategies have advanced through breeding partially resistant cultivars (leveraging defense-related genes, microRNAs, and CRISPR-based tools) and biological control using non-aflatoxigenic A. flavus strains, beneficial bacteria, microbial cell-free supernatants, and plant metabolites. However, we critically evaluate concerns that non-aflatoxigenic biocontrol strains may retain plant-pathogenic potential independent of aflatoxin production. Because complete genetic resistance remains elusive, we advocate integrated disease management combining host resistance, biocontrol, cultural practices, and climate-adaptive surveillance. Future priorities include elucidating the ecological role of sexual recombination, validating field-deployable diagnostics, implementing digital phenotyping, and developing predictive models that incorporate climate change scenarios to safeguard peanut production and global food safety.
Objectives: To assess the feasibility and reproducibility of predicting antimicrobial resistance (AMR) in Escherichia coli from MALDI-TOF mass spectrometry data using a standardized, open-source machine learning (ML) workflow, we systematically compared four ML algorithms, evaluated the impact of culture conditions, extract storage, and spectral preprocessing on model performance, and validated results through nested cross-validation with statistical significance testing. Methods: A total of 282 clinical E. coli isolates were analyzed. Two MALDI-TOF MS datasets were generated from freshly cultured extracts (T1) and recultured isolates one year later (T3), yielding 4468 spectra. A third dataset from the T1 extracts stored at -20 °C for one year (T2) was evaluated for spectral stability but excluded from primary modeling likely due to storage-induced degradation. Protein spectra (m/z 2000-15,000) were preprocessed using an in-house developed MALDI-TOF preprocessing pipeline (MTPP) comprising variance stabilization, Savitzky-Golay smoothing, SNIP baseline correction, TIC normalization, LOWESS alignment, and MAD-based peak detection (SNR ≥ 3), yielding 121 m/z features. Four classifiers-Random Forest (RF), Logistic Regression, Support Vector Machine, and Gradient Boosting-were trained to predict resistance to 11 antibiotics using nested cross-validation: outer GroupShuffleSplit (5-fold, isolate-level) for evaluation and inner GroupKFold for recursive feature elimination (RFECV) and hyperparameter tuning (RandomizedSearchCV). Classification thresholds were optimized via the precision-recall curve. Model performance was assessed using AUROC, AUPRC, F1-score, Matthews Correlation Coefficient (MCC), and bootstrap 95% confidence intervals (1000 replicates). Pairwise model comparisons were tested with McNemar's chi-squared test. Results: Among the 12 antibiotics included in the analysis (meropenem excluded for absence of resistance), resistance prevalence ranged from 1.1% (colistin) to 59.9% (amoxicillin). Colistin was subsequently also excluded from ML modeling due to insufficient resistant isolates (n = 3), leaving 11 antibiotics for prediction. The best predictive performance was observed for ciprofloxacin (AUROC 0.76 [95% CI 0.74-0.77]; F1 0.54; MCC 0.38) and ceftazidime (AUROC 0.68 [0.65-0.71]; F1 0.36; MCC 0.29), using 13 and 37 RFECV-selected features, respectively. Amoxicillin achieved the highest F1-score (0.76), driven by high recall (0.98) but modest AUROC (0.58). No meaningful predictive signal was detected for amikacin, cefepime, or tigecycline (AUROC ≤ 0.57, F1 ≤ 0.17), attributable to extreme class imbalance, and no robust multi-peak resistance signature was detected in this dataset. McNemar's test confirmed that RF significantly outperformed Logistic Regression for all antibiotics (p < 0.01), while Gradient Boosting performed comparably to RF for ciprofloxacin (p = 0.17) and ceftazidime (p = 0.28). Frozen extracts (T2) produced lower spectral similarity and were excluded from model training; the aligned T1+3 dataset yielded the most stable performance across metrics. Conclusions: Machine learning analysis of MALDI-TOF spectra enables reproducible AMR prediction for selected antibiotics in E. coli, with ciprofloxacin and ceftazidime showing the strongest signal. Nested isolate-level cross-validation, multi-model comparison with statistical testing, and open-source code provide a transparent, reproducible foundation for integrating ML-assisted MALDI-TOF analysis into diagnostic AMR surveillance. Extract storage at -20 °C degrades spectral quality and should be avoided in ML training workflows.
The livestock industry faces growing constraints due to antimicrobial resistance, particularly in poultry systems that have historically relied on antibiotic use. These challenges are exacerbated in free-range production, where restrictions on antimicrobial interventions coincide with heightened exposure to infectious diseases, leading to increased mortality and reduced productivity. On-farm disease outbreaks cannot be reproduced in high ethics standards approved animal houses, where they can be modeled to recognize some patterns of pathogen dynamics. While laboratory settings enable rigorous control and monitoring, they lack the environmental, management, production, pathogen pressures and complexity found on industrial farms and therefore cannot realistically recreate disease progression. Here, we present a field study in a layer flock that experienced three disease outbreaks of spotty liver disease (SLD) and fowl cholera (FC). The treatment group was supplemented with a precision biotic, a synthetic glycan product, while weekly performance measures and responses of microbial populations across major gut sections were observed. The precision biotic supplemented birds showed higher cumulative mortality but also higher egg output. However, as this was an unreplicated field study, these differences should be interpreted as descriptive associations. The intestinal microbial community responded differently to supplementation under concurrent environmental and disease pressures. This study provides large-scale field observations during concurrent outbreaks of SLD and FC, offering real-world insights that may inform future controlled studies of disease dynamics and performance management. KEY POINTS: • Free-range systems increase disease risk, reducing health and productivity in layer flocks. • Precision biotics were associated with higher egg output and higher cumulative mortality in hens. • Gut microbiota and liver congestion differed between precision biotic supplemented and control groups.
Exposure to cadmium (Cd), a toxic heavy metal, is a severe threat to organismal health, causing a wide range of pathological alterations in various tissues and organs. Alterations in the composition and function of the gut microbiome have been indicated across numerous animals exposed to Cd. However, the impact of Cd inhalation exposure on the pulmonary microbiome has not been well investigated yet. Therefore, in this study, we investigated the effects of exposure to CdONPs and its clearance on both colonic and pulmonary microbiomes in mice. The diversity of both colonic and pulmonary microbiomes of exposed mice was significantly affected after 9 weeks of CdONPs inhalation. The effects of CdONPs exposure on bacterial composition and function were more pronounced in the colonic microbiome than in the pulmonary microbiome. The clearance was more efficient in the restoration of gut microbiome composition in comparison to the lung microbiome. Moreover, we evaluated a bidirectional interaction between Cd exposure and gut microbiota. Duncaniella, Odoribacter, and Pontibacter were the prominent biomarkers that significantly positively correlated with dysregulated functions in the colonic microbiome of exposed mice. Based on the PICRUSt2 prediction analysis, our results suggested that perturbations in the gut microbiota balance due to Cd exposure were associated with the increase in the proportion level of bacteria with excessive membrane transporters, which may potentially augment the absorption of this metal by intestinal microbiota thereby leading to the accumulation of Cd in intestinal bacteria and the potential alleviation of the Cd toxicity effect. Furthermore, genes related to metal chelators were consistent with the colonic microbiome of exposed mice, suggesting possible promotion of Cd excretion and its eventual fecal elimination. However, these observations derived from 16S rRNA profiling and PICRUSt2 predictions would need to be verified experimentally to establish any functional or mechanistic implications. This could be considered a key factor in determining the intestinal bacterial species able to minimize the toxicity of heavy metals in future therapeutic approaches. KEY POINTS: • Inhalation of CdO nanoparticles significantly alters both gut and pulmonary microbiome composition and diversity in mice. • Microbiome changes are more pronounced in the gut than in the lungs following inhalation exposure. • Partial recovery of microbiome composition occurs after the clearance period, with greater restoration in the gut than in the lung. • Predicted functional profiles indicate shifts in microbial metabolic potential associated with Cd exposure. • The findings support a potential interaction between inhaled Cd exposure and the gut microbiome, highlighting the relevance of the gut-lung axis.
Dietary fibre may influence bile acid (BA) metabolism via interactions with gut microbiota. We hypothesised that dietary fibres with distinct fermentative properties, resistant starch (RS) and polydextrose (PD), would differentially alter BA profiles in plasma and faeces through gut microbiota-mediated mechanisms. BA profiles were analysed by ultra-performance liquid chromatography mass spectrometry in plasma (n = 74) and faeces (n = 50) from a double-blind, randomised, placebo-controlled 2 × 2 factorial trial. Healthy participants consumed 23 g/day Hi-maize®260 (type 2 RS) and/or 12 g/day Litesse®Ultra™ (PD) for 50 days. The intervention effects of RS and PD on BA profile were investigated using general linear models and beta regression models. Genus abundances derived from 16 S rRNA gene sequencing were used to investigate fibre-specific microbial correlations with BA profiles. Supplementation with RS, but not PD, increased a range of conjugated BAs and deoxycholic acid (FDR < 0.05). Concentrations of taurochenodeoxycholic acid (FDR = 0.027) and taurine conjugated BAs (FDR = 0.049) in plasma correlated positively with Akkermansia abundance in response to RS. Although neither RS nor PD altered BA concentrations in faeces, RS decreased (p = 0.032) and PD increased (p = 0.012) faecal proportions of primary BAs. PD reduced secondary BA transformation ratios (p < 0.05), along with shifts in related microbial associations. There were negative correlations between plasma primary conjugated BAs and faecal secondary BAs in response to RS specifically (p < 0.05). RS increased plasma BAs, particularly conjugated BAs, whereas PD reduced faecal secondary BA transformation. The distinct impacts of RS and PD on BA profiles and fibre-specific microbial associations may underlie their differential metabolic effects. Trail registration The DISC Study was registered with https://clinicaltrials.gov/ (Identifier NCT01214681) in 2010.
Biological hydrogen (H₂) production is a promising alternative to fossil-based energy processes, and strategies capable of improving H₂ yields are required to enhance its industrial feasibility. In this study, iron nanoparticles supported on carbon black (Fe/CB) were evaluated, for the first time, alone and in combination with electro-stimulated fermentation (EF), to enhance H₂ production by Clostridium pasteurianum DSMZ 525. Suspended Fe/CB and Fe/CB immobilized on the anode were employed and compared with traditional fermentation (TF) and EF. Under TF conditions, suspended and immobilized Fe/CB increased H₂ production by 16.7% and 62.5%, respectively, while increasing organic acid concentrations by 3.6- and 4.7-fold. The highest H₂ concentration (129.82 mmol L⁻1) and H₂ yield were achieved under EF (0.4 V) without Fe/CB. Under this condition, organic acid and cell biomass concentrations decreased by 83% and twofold, respectively. In contrast, the addition of suspended or immobilized Fe/CB during EF decreased H₂ production by 29% and 24%, respectively, while substantially increasing organic acid concentrations. Overall, Fe/CB enhanced H₂ production during TF, particularly when immobilized on the anode, whereas EF alone proved to be the most effective strategy for maximizing H₂ production. These findings demonstrate that electro-stimulation can redirect microbial metabolism toward H₂ evolution, while Fe/CB supplementation may be more suitable for promoting the formation of value-added fermentation products. The results provide new insights into the combined use of conductive materials and electro-fermentation for controlling product selectivity in Clostridium-based bioprocesses. KEY POINTS: Suspended iron nanoparticles increase hydrogen production by 16.7% in fermentation.While immobilized iron nanoparticles increase hydrogen production by 62.5%.Electro-stimulation yields more hydrogen than iron-assisted electro-stimulation.
Wastewater-based surveillance has emerged as a powerful approach for population-level monitoring of pathogen circulation in a timely and non-invasive manner. In this study, shotgun metagenomic sequencing was applied to wastewater samples collected from a hospital (HP), a university campus (UN), and a wastewater treatment plant (WTP). Viral sequences were taxonomically classified using Kraken2. Specifically, HP samples showed the highest viral richness, followed by WTP and UN samples (HP vs. UN, p = 0.0003; WTP vs. UN, p = 0.0018). Using Jaccard distance, significant differences were observed between WTP and UN (R2 = 0.181, p < 0.001), WTP and HP (R2 = 0.159, p < 0.001), and UN and HP (R2 = 0.223, p < 0.001), and similarly, for Sørensen-Dice dissimilarity: WTP vs. UN (R2 = 0.238, p < 0.001), WTP vs. HP (R2 = 0.212, p < 0.001), and UN vs. HP (R2 = 0.307, p < 0.001). Human-associated viral families were detected across all sources, predominantly Poxviridae, Orthoherpesviridae, Polyomaviridae and Circoviridae. Furthermore, the taxonomic composition of indirectly associated viruses, mainly Anelloviridae and Crassvirales, was examined. Overall, these findings support the potential of wastewater metagenomics as a reliable tool for monitoring viral diversity within environmental and public health contexts, although further research is needed to establish its operational utility for routine surveillance applications within a One Health framework.
Kimchi-derived lactic acid bacteria (LAB) have gained increasing attention as functional microorganisms with potential roles in metabolic health. This study aimed to screen and characterize LAB isolated from kimchi for probiotic potential, with a focus on their antioxidant and antidiabetic activities. Three LAB strains with promising functional properties were tentatively identified by partial 16S rRNA gene sequencing as Levilactobacillus brevis KB042-STR, Leuconostoc lactis KH007-STR and Weissella cibaria KH017-STR. Lb. brevis KB042-STR exhibited the strongest antidiabetic activity, with α-glucosidase and α-amylase inhibition of approximately 72% and 64%, respectively (p ≤ 0.05). This strain also demonstrated antioxidant activity, as indicated by high total phenolic content (4.20 ± 0.01 mg GAE/g), strong 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacities. Both Lb. brevis KB042-STR and W. cibaria KH017-STR tolerated simulated gastric conditions (pH 2.0; survival > 50%), while all LAB strains maintained high viability in the presence of bile salts (0.6%), with viable populations remaining above 9 log CFU/mL. In addition, the isolates exhibited high cell surface hydrophobicity and auto-aggregation ability. Notably, Lb. brevis KB042-STR showed significantly greater co-aggregation with pathogens and the strongest adhesion to Caco-2 cells (p ≤ 0.05). All strains were non-haemolytic and susceptible to commonly used antibiotics. These findings expand current knowledge of kimchi-associated LAB and highlight Lb. brevis KB042-STR as a promising multifunctional probiotic candidate, supporting its potential application in functional food or nutraceutical development.