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The senescence of fruit is a complex physiological process, with various cell types within the pericarp, making it highly challenging to elucidate their individual roles in fruit senescence. In this study, a single-cell expression atlas of the pericarp of pitaya ( Hylocereus undatus ) is constructed, revealing exocarp and mesocarp cells undergoing the most significant changes during the fruit senescence process. Pseudotime analysis establishes cellular differentiation and gene expression trajectories during senescence. Early-stage oxidative stress imbalance is followed by the activation of resistance in exocarp cells, subsequently senescence-associated proteins accumulate in the mesocarp cells at late-stage senescence. The central role of the early response factor HuCMB1 is unveiled in the senescence regulatory network. This study provides a spatiotemporal perspective for a deeper understanding of the dynamic senescence process in plants. Fruit senescence is a complex physiological process. Here, the authors construct a single-cell expression atlas of pitaya pericarp pitaya to provide a spatiotemporal perspective of the dynamic process of plant senescence.

Intracellular biothiols, including cysteine (Cys), glutathione (GSH), and homocysteine (Hcy), play a critical role in many physiological and pathological processes. Among them, GSH is the most abundant non-protein mercaptan (1–10 mM) in cells, and the change in GSH concentration level is closely related to the occurrence of many diseases, such as Parkinson’s disease, Alzheimer’s disease, and neurological diseases. Fluorescent probes have attracted much attention due to their advantages of high specificity, high sensitivity, high selectivity, low cost, and high quantum yield. Methods that use optical probes for selective detection of GSH in vitro and in vivo are in high demand. In this paper, we reviewed the most recent five years of research on fluorescence probes for the detection of GSH, including the specific detection of GSH, dual-channel identification of GSH and other substances, and the detection of GSH and other biothiols. According to the type of fluorophore, we classified GSH fluorescent probes into eight classes, including BODIPY, 1,8-Naphthalimide, coumarin, xanthene, rhodamine, cyanine, benzothiazoles, and others. In addition, we roundly discuss the synthesis, detection mechanism, photophysical properties, and biological applications of fluorescent probes. We hope that this review will inspire the exploration of new fluorescent probes for GSH and other related analyses.

This study investigates the degradation characteristics, pathways, and mechanisms of ochratoxin A (OTA) by CGMCC 9951 ( CGMCC 9951), as well as its detoxification effect on pulp through fermentation. The strain efficiently degraded 300 ng/mL of OTA within 72 h (98% degradation) under optimal conditions of 37 °C, pH 5.0, and 180 rpm. Active degradation substances were primarily localized in the cell-free supernatant (CF). The degradation activity was significantly inhibited by heat treatment, proteinase K, EDTA, Cu , and organic reagents, suggesting an enzymatic mechanism. UHPLC-MS and MS/MS analysis indicated that OTA appears to be degraded to a product consistent with ochratoxin α (OTα). Based on homology to known OTA-degrading carboxypeptidases, the gene encoding WGU28473.1 was selected, expressed in , and confirmed to possess OTA-degrading activity. Molecular docking suggested potential interactions between the enzyme and OTA. Under optimal conditions, co-fermentation with pulp contaminated with 300 ng/mL OTA for 96 h resulted in a 74% degradation of OTA. The fermentation process increased the pulp's sugar content and ABTS free radical scavenging capacity, reduced acidity, and improved the safety of the pulp. These findings demonstrate that CGMCC 9951 efficiently degrades OTA and improves pulp quality, highlighting its potential as a starter culture for detoxifying OTA-contaminated food.

Probiotics, known for regulating gut microbiota, may aid those with overweight or obesity, but their mechanisms require more research. This study involved 75 overweight or obese young adults, randomly assigned to either a Bifidobacterium breve BBr60 (BBr60) group or a placebo group. Both groups received diet guidance and took either BBr60 (1 × 1010 CFU/day) or a placebo for 12 weeks. Researchers analyzed body composition, serum glucose, lipids, liver and kidney function, comprehensive metabolome, and intestinal homeostasis before and after the intervention. After 12 weeks, BBr60 significantly reduced weight and BMI compared to pretreatment levels and outperformed the placebo. The BBr60 group also showed improved blood biochemistry, with notably lower fasting blood glucose (FBG) levels than the placebo group (p < 0.05). Additionally, BBr60 influenced vital serum and fecal metabolites related to three amino acid metabolic pathways and regulated the bacteria Dialister, Klebsiella, and Bacteroides, which correlated strongly with serum metabolites. These findings indicate that BBr60 can safely and effectively regulate BMI, body weight, serum glucose, lipids, and liver function markers, which may involve BBr60’s impact on key gut bacteria, which influence metabolites related to the valine, leucine, and isoleucine biosynthesis; glycine, serine, and threonine metabolism; and alanine, aspartate, and glutamate metabolism.

Butyrate, a short-chain fatty acid derived from the gut microbiota, has been linked to depression through correlational studies; however, whether it might act as a sufficient downstream mediator of the antidepressant effects of a probiotic remains poorly understood. To explore this, a chronic unpredictable mild stress (CUMS) rat model was established to evaluate the potential antidepressant effects of Weizmannia coagulans BC99. Behavioral assessments included the sucrose preference test (SPT), forced swim test (FST), tail suspension test (TST), and open field test (OFT). In addition, 16S rRNA sequencing, serum metabolomics, and short-chain fatty acid (SCFA) profiling were performed. Levels of inflammatory cytokines (IL-1β, IL-6, IL-4, and LPS) and brain-derived neurotrophic factor (BDNF) were measured in serum, hippocampus, and colon by ELISA. An independent sodium butyrate supplementation experiment was conducted to test functional sufficiency, and hippocampal BDNF/TrkB/CREB signaling was assessed by Western blotting. Treatment with BC99 was associated with alleviation of CUMS-induced depressive-like behaviors, increased butyrate levels, reduced neuroinflammation (IL-1β, IL-6, LPS, and IL-4), and restored hippocampal BDNF levels. BC99 also enriched butyrate-producing bacterial taxa (e.g., Lactobacillus, Bifidobacterium, Faecalibaculum) and normalized tryptophan and sphingolipid metabolism. Notably, sodium butyrate alone recapitulated several of the behavioral and anti-inflammatory effects observed with BC99 and, as shown by Western blot, partially restored hippocampal BDNF/TrkB/CREB signaling, which was impaired in CUMS rats. Together, these findings suggest that butyrate may be associated with the antidepressant effects of W. coagulans BC99, potentially acting through suppression of neuroinflammation and activation of the BDNF pathway. Our results support further investigation of butyrate-enhancing strategies as a nutritional approach for depression.

Oenococcus oeni β-glucosidase can significantly improve food flavor, but its catalytic activity and stability performance need to be enhanced. In this study, the two dominant mutants III and IV were obtained by site-directed mutation of key amino acid residues in the catalytic pocket of Oenococcus oeni β-glucosidase. Compared with the wild-type enzyme, the activities of mutants III and IV were increased by 2.81 and 3.18 times, respectively. Their thermal stability was also significantly improved. Mutants III and IV showed a significant increase in affinity for the standard substrate p-NPG, with the Km value decreasing by 18.2% and 33.3%, respectively. Molecular docking analysis indicated that hydrogen bonding and π–π aromatic interactions were the primary factors influencing the changes in enzyme properties, with F133 and N181 identified as key amino acids affecting catalytic activity and stability. This research is of great significance for enhancing food flavor and expands the potential industrial applications of Oenococcus oeni β-glucosidase.

This study aimed to evaluate the safety profile and beneficial effects of Heyndrickxia coagulans strain BC99 (BC99) for potential use in functional foods and pharmaceuticals. We began with whole genome sequencing of BC99, followed by a comprehensive safety assessment comprising genome analysis, hemolysis, cytotoxicity, antibiotic susceptibility tests, and cell adhesion and tolerance studies, along with acute and subacute oral toxicity studies in animal models. BC99 was isolated from a well-characterized collection originating from the feces of a healthy infant. Our results indicated no hemolytic activity on Columbia blood agar plates and broad antibiotic sensitivity, including to gentamicin, ampicillin, chloramphenicol, ciprofloxacin, and others. Cytotoxicity testing confirmed no adverse effects on HT-29 cells and significant adhesive properties to intestinal epithelial cells. Tolerance tests demonstrated over 90% viability of BC99 under simulated gastrointestinal conditions. In vivo studies in mice and rats confirmed the absence of adverse effects following oral administration. Collectively, these findings support BC99’s robust tolerance to gastrointestinal environments, strong adhesion capabilities, and a broad spectrum of antibiotic resistance, underlining its potential as a safe and effective agent for gut microbiota modulation and host health enhancement.

Objectives: Constipation is one of the most prevalent gastrointestinal disorders worldwide. Recent studies have demonstrated that probiotics may alleviate constipation by restoring gut microbiota balance. Methods: This study investigated the effects of Weizmannia coagulans BC99 (formerly Bacillus coagulans BC99) on gut microbiota and intestinal function in a loperamide-induced mouse model of functional constipation. BALB/c mice were randomly divided into six groups: control, model, phenolphthalein, BC99-L (2 × 107 CFU/day), BC99-M (2 × 108 CFU/day), and BC99-H (2 × 109 CFU/day). After 14 days of supplementation, constipation was induced in mice via loperamide administration. Results: BC99 significantly increased fecal water content, gastrointestinal transit rate, microbial metabolic activity, and butyric acid production, while decreasing the abundance of inflammation-related metabolic pathways. Moreover, BC99 improved levels of gastrointestinal regulatory peptides, including motilin and somatostatin. The Firmicutes-to-Bacteroidetes ratio was elevated in the BC99-M and the BC99-H group compared to the model group, indicating that BC99 effectively modulated gut microbiota composition and host biosynthetic pathways. Conclusions:  Weizmannia coagulans BC99 alleviated and prevented loperamide-induced functional constipation in mice by enhancing intestinal peristalsis and restoring gut microbial homeostasis.

Background: An imbalance in the immune system, stress response, and gut microbiota can contribute to the onset and progression of anxiety and depression. This pilot study aimed to explore the effect of Weizmannia coagulans BC99 on anxiety and depression through the gut microbiota–brain axis. Methods: A total of 79 participants with Hamilton Depression Rating Scale (HAMD-17) ≥ 8 or Hamilton Anxiety Rating Scale (HAMA-14) ≥ 7 were included and completed the study. The participants were randomly assigned to either the placebo group or the BC99 intervention group. The intervention lasted 8 weeks, with participants receiving either dextrin (3 g/day) or BC99 probiotics (3 g/day, 5 × 109 CFU) daily. Pre- and post-intervention comparisons were made on HAMD and HAMA scores, inflammatory cytokines, neurotransmitters, gut microbiota, and short-chain fatty acids. Results: Results showed that after 8 weeks, BC99 and placebo intervention were effective in reducing HAMD and HAMA scores, and HAMD and HAMA scores in BC99 group were reduced by 2.40 and 5.53 points compared the placebo group, and the response and remission rates were also higher than that of the placebo, but there was no significant difference. BC99 also could regulate the levels of inflammatory cytokines IL-17 and IL-10, and increase neurotransmitter levels of γ-GABA and NO. Moreover, compared with the placebo group, BC99 also enhanced the abundance of beneficial bacteria such as Faecalibactrium, Megamonas, Dialister, and Agathobacter, which were closely associated with clinical indicators of mental disorders, and increased the production of short-chain fatty acids. Conclusions: These preliminary findings suggested that BC99 might alleviate anxiety and depression symptoms by regulating the level of neurotransmitters or the change of microbiota, which needed further verification in subsequent animal or clinical experiments.

Aspergillus flavus, a common food contaminant, poses health and economic risks. Previous research showed that recombinant Puroindoline B protein (rPINB) inhibited A. flavus by disrupting its cell wall, membrane, nuclear function, mitochondrial activity, and oxidative stress. This study used transcriptome technology to explore the impact of rPINB on A. flavus gene expression and created gene deletion strains to test the sensitivity to rPINB. RNA-Seq identified the differentially expressed genes (DEGs) affecting cell wall synthesis, membrane transport, oxidative stress, spore formation, and aflatoxin production. The MFS transporter genes AFLA_106900 (mfs1) and AFLA_106910 (mfs2) were crucial for an inhibitory effect of rPINB. The mutants exhibited reduced sensitivity to rPINB-mediated inhibition, indicating lower growth, sunken conidia, and shriveled hyphae, compared to the wild-type strain. The results also demonstrated decreased sensitivity to the stress agents affecting cell membranes, osmotic balance, and oxidation, alongside a significant reduction in AFB1 production in gene-deleted strains. These results suggested that mfs1 and mfs2 were essential for rPINB protein’s inhibition of A. flavus growth, laying the groundwork for the mold control strategies using plant proteins.