Rab25 is involved in hypospadias via the ß1 integrin/EGFR pathway.

BACKGROUND: Hypospadias is a common congenital abnormality of the penile. Abnormal regulation of critical genes involved in urethral development leads to hypospadias. We used the Rab25-/- mice and foreskin fibroblasts transfected with lentivirus in vitro and in vivo to investigate the role of Rab25 in hypospadias. METHODS: The expression levels of various molecules in tissue samples and foreskin fibroblasts were confirmed using molecular biology methods (western blotting, PCR, immunohistochemistry, etc.). A scanning electron microscope (SEM) was used to visualize the external morphology of genital tubercles (GTs) of gestation day (GD) 18.5 male wild-type (WT) and Rab25-/- mice. RESULTS: An expanded distal cleft and V-shaped urethral opening were observed in GD 18.5 Rab25-/- mice. We demonstrated that Rab25 mediated hypospadias through the ß1 integrin/EGFR pathway. In addition, silencing Rab25 inhibited cell proliferation and migration and promoted apoptosis in the foreskin fibroblasts; Ki-67- and TUNEL-positive cells were mainly concentrated near the urethral seam. CONCLUSION: These findings suggest that Rab25 plays an essential role in hypospadias by activation of ß1 integrin/EGFR pathway, and Rab25 is a critical mediator of urethral seam formation in GD18.5 male fetal mice.

Screening of a potential probiotic Lactiplantibacillus plantarum NUC08 and its synergistic effects with yogurt starter.

This study aims to identify lactic acid bacteria (LAB) isolates possessing physiological characteristics suitable for use as probiotics in yogurt fermentation. Following acid and bile salt tolerance tests, Lactiplantibacillus plantarum (NUC08 and NUC101), Lacticaseibacillus rhamnosus (NUC55 and NUC201), and Lacticaseibacillus paracasei (NUC159, NUC216, and NUC351) were shortlisted based on intraspecies distribution for further evaluation. Their physiological probiotic properties, including transit tolerance, adhesion, autoaggregation, surface hydrophobicity, biofilm formation, and antibacterial activity, were assessed. Principal component analysis indicated that Lactiplantibacillus plantarum NUC08 was the preferred choice among the evaluated strains. Subsequent investigations revealed that co-culturing Lactiplantibacillus plantarum NUC08 with 2 yogurt starter strains resulted in a cooperative and synergistic effect, enhancing the growth of mixed strains and increasing their tolerance to simulated gastric and intestinal conditions. Additionally, when Vibrio harveyi bioluminescent reporter strain was used, the 3 cocultured strains cooperated to induce the activity of a quorum sensing (QS) molecule autoinducer-2 (AI-2), hinting a potential connection between phenotypic traits and QS in the cocultured strains. Importantly, LAB viable counts were significantly higher in yogurt co-fermented with Lactiplantibacillus plantarum NUC08, consistently throughout the storage period. In conclusion, the study demonstrates that the probiotic strain Lactiplantibacillus plantarum NUC08 can be employed in synergy with yogurt starter strains, affirming its potential for use in the development of functional fermented dairy products.

2D MOF-enhanced SPR detector based on tunable supramolecular probes for direct and sensitive detection of DOX in serum.

Therapeutic drug monitoring of doxorubicin (DOX) is important to study pharmacokinetics in patients undergoing chemotherapy for reduction of side effects and improve patient survival by rationally controlling the dose of DOX. A fast and ultra-sensitive surface plasmon resonance (SPR) detector without sample pre-handling was developed for DOX monitoring. First, the two-dimensional metal-organic framework was modified on the Au film to enhance SPR, and then, the supramolecular probes with tunable cavity structure were self-assembled at the sensing interface for direct detection of DOX through specific host-guest interactions with a low detection limit of 60.24 pM. The precise monitoring of DOX in serum proved the possibility of clinical application with recoveries in the range 102.86-109.47%. The mechanisms of host-guest interactions between supramolecular and small-molecule drugs were explored in depth through first-principles calculations combined with SPR experiments. The study paves the way for designing facile and sensitive detectors and provides theoretical support and a new methodology for the specific detection of small molecules through calixarene cavity modulation.

COMPASS core subunits MpSet1 and MpSwd3 regulate Monascus pigments synthesis in Monascus purpureus.

In eukaryotes, methylation of histone H3 at lysine 4 (H3K4me) catalyzed by the complex of proteins associated with Set1 (COMPASS) is crucial for the transcriptional regulation of genes and the development of organisms. In Monascus, the functions of COMPASS in establishing H3K4me remain unclear. This study first identified the conserved COMPASS core subunits MpSet1 and MpSwd3 in Monascus purpureus and confirmed their roles in establishing H3K4me2/3. Loss of MpSet1 and MpSwd3 resulted in slower growth and development and inhibited the formation of cleistothecia, ascospores, and conidia. The loss of these core subunits also decreased the production of extracellular and intracellular Monascus pigments (MPs) by 94.2%, 93.5%, 82.7%, and 82.5%, respectively. In addition, RNA high-throughput sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) showed that the loss of MpSet1 and MpSwd3 altered the expression of 2646 and 2659 genes, respectively, and repressed the transcription of MPs synthesis-related genes. In addition, the ΔMpset1 and ΔMpswd3 strains demonstrated increased sensitivity to cell wall stress with the downregulation of chitin synthase-coding genes. These results indicated that the COMPASS core subunits MpSet1 and MpSwd3 help establish H3K4me2/3 for growth and development, spore formation, and pigment synthesis in Monascus. These core subunits also assist in maintaining cell wall integrity.

Evidence for a causal effect of major depressive disorder, anxiety on prostatitis risk: A univariate and multivariate Mendelian randomization study.

BACKGROUND: Observational studies have shown an association between major depressive disorder (MDD), anxiety, and prostatitis. However, the causal relationship between MDD, anxiety, and prostatitis remains controversial. Therefore, we aimed to use two-sample Mendelian randomization (MR) to assess the causal effects of MDD and anxiety on prostatitis. METHODS: We conducted univariable and multivariable MR analyses using summary statistics from publicly available genome-wide association studies to estimate the causal relationships between MDD, anxiety, and prostatitis risk. In the main MR analysis, the inverse-variance weighted (IVW) method was used, while secondary methods included the weighted median, weighted mode, MR-Egger regression, and MR pleiotropy residual and outlier (MR-PRESSO) tests to detect and correct for the presence of pleiotropy. RESULTS: MDD had 97 independent instrumental variables (IVs) and anxiety had 15 IVs. Univariable MR analysis showed that genetically determined MDD had a detrimental causal effect on prostatitis (IVW: odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.12-1.92, p = 0.005), while no causal relationship was found between anxiety and prostatitis (IVW: OR = 0.25, 95% CI = 0.02-2.82, p = 0.26). More convincingly, after adjusting for confounding factors such as body mass index, alcohol consumption, and smoking, the genetic liability for MDD remained associated with prostatitis risk, with no strong evidence of anxiety affecting prostatitis incidence. CONCLUSION: This study supports the notion that MDD has a detrimental effect on prostatitis risk, and strategies focused on addressing MDD may be one of the cornerstones for treating prostatitis. The potential preventive value of treating MDD for prostatitis should be further investigated in future research.

Modeling and calibration of micro/nano FBG temperature probe for scanning probe microscopy.

To accurately measure the local temperatures of the micro-nano area, we propose an optical method using a tapered fiber Bragg grating (FBG) probe with a nano tip for scanning probe microscopy (SPM). When the tapered FBG probe senses local temperature through near-field heat transfer, the intensity of the reflected spectrum decreases, along with a broadening bandwidth and a shift in the central peak position. Modeling the heat transfer between the probe and the sample shows that the tapered FBG probe is in a non-uniform temperature field when approaching the sample surface. Simulation of the probe's reflection spectrum reveals that the central peak position shifts nonlinearly with increasing local temperature. In addition, the near-field temperature calibration experiments show that the temperature sensitivity of the FBG probe increases nonlinearly from 6.2 pm/°C to 9.4 pm/°C as the sample surface temperature increases from 25.3°C to 160.4°C. The agreement of the experimental results with the theory and the reproducibility demonstrate that this method offers a promising approach for exploring micro-nano temperature.

Ligilactobacillus cholophilus sp. nov., isolated from pickled potherb mustard (Brassica juncea Coss.).

Strain BD7642T was isolated from Chinese pickled potherb mustard (Brassica juncea Coss.) purchased from a local market in Shanghai, PR China. A polyphasic approach, including 16S rRNA gene sequence, housekeeping gene, average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), G+C content and phenotypic analyses, was employed to characterize strain BD7642T. Cells of the bacterium were short round rods, Gram-stain-positive, non-spore-forming and catalase-negative. The strain grew at 30-45 °C and pH 4.0-8.0. Optimum growth occurred at 35-40 °C and pH 6.0-7.0. The strain exhibited growth with salt (NaCl) concentrations of up to 5 % (w/v). The G+C content of the strain's genomic DNA was 31.37 mol%. The major fatty acids were C16 : 0, C18 : 1 c9 and summed feature 10 (C18 : 1 c11/t9/t6). 16S rRNA gene sequencing revealed that strain BD7642T represents a member of the genus Ligilactobacillus and it had high sequence similarity to Ligilactobacillus aviarius NBRC 102162T (96.73 %), Ligilactobacillus araffinosus LGM 23560 (96.66 %) and Ligilactobacillus salivarius JCM 1231T (95.82 %). The dDDH values between strain BD7642T and its phylogenetically related species within the genus Ligilactobacillus ranged from 12.6 to 25.4 %. The ANI values between strain BD7642T and its closely related taxa were far lower than the threshold (95 %-96 %) used for species differentiation. Results of phylogenetic, physiological and phenotypic characterization confirmed that strain BD7642T represents a novel species within the genus Ligilactobacillus, for which the name Ligilactobacillus cholophilus sp. nov. is proposed. The type strain is BD7642T (=CCTCC AB 2022398T=JCM 36074T).

Inhibitory Effects of Corydalis saxicola Bunting Total Alkaloids on Macrophage Pyroptosis.

This study investigated the effect of Corydalis saxicola Bunting total alkaloids (CSBTA) on pyroptosis in macrophages (Mϕ). In the Mϕ pyroptosis model, an inverted fluorescence microscope was used to assess cell pyroptosis, while a scanning electron microscope was used to observe morphological changes in Mϕ. NLR family pyrin domain-containing 3 (NLRP3), caspase-1, and gasdermin D (GSDMD) expression levels were detected by polymerase chain reaction and western blotting, whereas interleukin-1 (IL-1) and interleukin-18 (IL-18) expression levels were measured by an enzyme-linked immunosorbent assay. After pretreatment with CSBTA or the caspase-1 inhibitor, acetyl-tyrosyl-valyl-alanyl-aspartyl-chloromethylketone (Ac-YVAD-cmk), it was discovered that NLRP3, caspase-1, and GSDMD expressions were significantly reduced at both the mRNA and protein levels, as were IL-1 and IL-18 levels. The inhibitory effects of CSBTA and Ac-YVAD-cmk did not differ significantly. These findings indicate that CSBTA blocks Porphyromonas gingivalis-lipopolysaccharide-induced Mϕ pyroptosis.

Comparison of interaction, structure, and cell proliferation of α-lactalbumin-safflower yellow complex induced by microwave heating or conventional heating.

BACKGROUND: The protein-polyphenol interaction mechanism has always been a research hotspot, but their interaction is affected by heat treatment, which is widely applied in food processing. Moreover, the effects of microwave or water-bath heating on the protein-polyphenol interaction mechanism have been not clarified. The pasteurization condition (65 °C, 30 min) was selected to compare the effects of microwave or water bath on binding behavior, structure, and cell proliferation between α-lactalbumin (α-LA) and safflower yellow (SY), thus providing a guide for the selection of functional dairy processing conditions. RESULTS: Microwave heat treatment of α-LA-SY resulted in stronger fluorescence quenching than that of conventional heat treatment. Moreover, the binding constant Ka of all α-LA-SY samples was augmented significantly after microwave or water bath treatment, and microwave-heated α-LA-SY showed the maximum Ka . Fourier transform infrared spectroscopy showed that microwave heating resulted in more ordered structures of α-LA into its disordered structures than water bath heating. However, the ferric reducing antioxidant power and chroma value of α-LA-SY were more reduced by microwave heating than by water bath heating. Moreover, microwave heating facilitated the cell proliferation of α-LA-SY compared with water bath treatment. CONCLUSION: It was demonstrated that microwave heating promoted interaction between α-LA and SY more than water bath heating did. Microwave heat treatment was a safe and effective way to enhance the binding affinity of α-LA to SY, being a potential application in food industry. © 2022 Society of Chemical Industry.

Engineered Bacillus subtilis for the de novo production of 2'-fucosyllactose.

BACKGROUND: The most abundant human milk oligosaccharide in breast milk, 2'-fucosyllactose (2'-FL), has been approved as an additive to infant formula due to its multifarious nutraceutical and pharmaceutical functions in promoting neonate health. However, the low efficiency of de novo synthesis limits the cost-efficient bioproduction of 2'-FL. RESULTS: This study achieved 2'-FL de novo synthesis in a generally recognized as safe (GRAS) strain Bacillus subtilis. First, a de novo biosynthetic pathway for 2'-FL was introduced by expressing the manB, manC, gmd, wcaG, and futC genes from Escherichia coli and Helicobacter pylori in B. subtilis, resulting in 2'-FL production of 1.12 g/L. Subsequently, a 2'-FL titer of 2.57 g/L was obtained by reducing the competitive lactose consumption, increasing the regeneration of the cofactor guanosine-5'-triphosphate (GTP), and enhancing the supply of the precursor mannose-6-phosphate (M6P). By replacing the native promoter of endogenous manA gene (encoding M6P isomerase) with a constitutive promoter P7, the 2'-FL titer in shake flask reached 18.27 g/L. The finally engineered strain BS21 could produce 88.3 g/L 2'-FL with a yield of 0.61 g/g lactose in a 3-L bioreactor, without the addition of antibiotics and chemical inducers. CONCLUSIONS: The efficient de novo synthesis of 2'-FL can be achieved by the engineered B. subtilis, paving the way for the large-scale bioproduction of 2'-FL titer in the future.

The oral histopathological and immunological characteristics of a xenogeneic mouse chronic graft-versus-host disease model.

BACKGROUND: Oral lesions are important clinical manifestations of chronic graft-verse-host disease (cGVHD). However, the oral characteristics of cGVHD mouse model are not yet clear. This study aims to demonstrate oral histopathological and immunological characteristics of a xenogeneic cGVHD mouse model. MATERIALS AND METHODS: 2.5 × 106 , 5.0 × 106 , 7.5 × 106 , and 10.0 × 106  human peripheral blood mononuclear cells (hPBMCs) were intravenously transplanted into NCG mice to induce cGVHD. After transplantation, clinical observations were recorded. Tissue samples from salivary glands and oral mucosa were stained with H&E, Masson Trichrome, and immunofluorescence, and the histopathology of oral tissues was scored according to our modified criteria. RESULTS: NCG mice showed signs of cGVHD onset after transplantation. The oral histopathological lesion incidences in each group were 37.50%, 50.00%, 62.50%, and 75.00%, respectively. Oral histopathological lesion incidence and histopathological scores were positively correlated with the amount of infused hPBMCs. Epithelial atrophy, epithelial cells vacuolar degeneration, and basal cells liquefaction denaturation were observed in oral mucosa, and acinar destruction and collagen deposition were observed in the salivary glands. Human CD45+ , CD4+ , CD8+ , IL-17+ , and FoxP3+ cells infiltrated into oral tissues. In the 5.0 × 106  hPBMCs group, oral histopathological changes mainly began between days 30 and 45 post-transplantation, and became more severe after day 45. The oral histopathological scores also gradually increased. CONCLUSION: Inflammation in oral mucosa epithelium and salivary glands, and CD4+ and CD8+ T cells dominating infiltration are the main oral features in the xenogeneic cGVHD mouse model. The severity of oral histopathological lesions shows a dose and time correlation. These may be helpful to oral cGVHD research.

Effect of probiotics on gingival inflammation and oral microbiota: A meta-analysis.

To evaluate the effect of probiotics on gingival inflammation and oral microbiota in patients suffering from plaque-induced gingivitis. PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were electronically searched until December 2020. The quality of included studies was assessed with the Cochrane Collaboration's Risk of Bias tool. The differences were expressed as weighted mean differences (WMD) and 95% of confidence interval (95% CI). I2 test was performed to evaluate the heterogeneity of the studies. All analyses were performed using Review Manager (version 5.3). Eleven randomized and controlled trials were included, enrolling 554 patients. All comparisons displayed that oral probiotics had no significant improvement in the Gingival Index (GI), Plaque Index (PI), and bleeding on probing (BOP) of patients with plaque-induced gingivitis. In terms of microecology, no significant difference in the volumes of gingival crevicular fluid (GCF), the concentration of IL-1ß, and the counts of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) were found between the probiotic group and the placebo group. There exists no clear evidence that oral probiotics have positive effect on gingival inflammation and oral microecological environment of patients with plaque-induced gingivitis.

Repression of Mafb promotes foreskin fibroblast proliferation through upregulation of CDK2, cyclin E and PCNA.

Mafb plays a significant role in the development and differentiation of various organs, tissues and cells. Nevertheless, its role in the control of external genital cell proliferation and function in the mechanism of hypospadias remains unknown. In this study, the expression of Mafb in foreskin fibroblasts was inhibited by siRNA. The Cell Count Kit-8 (CCK-8) assay showed cell proliferation increased after transfection, and the number of cells entered the S phase significantly increased via flow cytometry. Both mRNA and protein levels of cyclin E, cyclin-dependent kinase 2 (CDK2) and proliferating cell nuclear antigen (PCNA) were significantly upregulated in the siRNA group. Meanwhile, twenty-five prepuce tissue samples were collected from hypospadias repair surgery. These samples were divided into two groups: the severe and mild groups. Normal prepuce tissue specimens were obtained during circumcision as the normal control. The upregulated expression of cyclin E, CDK2 and PCNA and downregulated Mafb expression were observed in the hypospadias group. This study reveals for the first time that the reduction in Mafb promotes the foreskin fibroblast proliferation. Thus, downregulated Mafb expression may cause hypospadias by upregulating CDK2, cyclin E and PCNA. These findings can shed new light on the embryonic development of the urethra.

Engineering of 2D artificial nanozyme-based blocking effect-triggered colorimetric sensor for onsite visual assay of residual tetracycline in milk.

Accurate and low-cost onsite assay of residual antibiotics in food and agriculture-related matrixes (e.g., milk) is of significant importance for evaluating and controlling food pollution risk. Herein, we employed hybrid Cu-doped-g-C3N4 nanozyme to engineer smartphone-assisted onsite visual sensor for reliable and precise reporting the levels of tetracycline (TC) residues in milk through π-π stacking-triggered blocking effect. Benefiting from the synergetic effects of Cu2+ and g-C3N4 nanosheet, Cu-doped-g-C3N4 nanocomposite exhibited an improved peroxidase-like activity, which could effectively catalyze H2O2 to oxidate colorless TMB into steel-blue product oxTMB. Interestingly, owing to the blocking effect caused by the π-π stacking interaction between TC tetraphenyl skeleton and Cu-doped-g-C3N4 nanozyme, the affinity of Cu-doped-g-C3N4 nanocomposite toward the catalytic substrates was remarkably blocked, resulting in a TC concentration-dependent fading of solution color. Using smartphone-assisted detection a simple, low-cost, reliable, and sensitive portable colorimetric sensor-based nanozyme for onsite visual monitoring the residual TC in milk was successfully developed with a detection limit of 86.27 nM. Of particular mention is that this detection limit is comparable to most other reported colorimetric methods and below most official allowable residue thresholds in milk matrixes. This work gave a novel insight to integrate two-dimensional (2D) artificial nanozymes-based π-π stacking-triggered blocking effect with smartphone-assisted detection for developing efficient and low-cost colorimetric point-of-care testing of the risk factors in food and agriculture-related matrixes.

Synthesis and Performance of Double-Chain Quaternary Ammonium Salt Glucosamide Surfactants.

A series of double-chain quaternary ammonium salt surfactants N-[N'[3-(gluconamide)] propyl-N'-alkyl]propyl-N,N-dimethyl-N-alkyl ammonium bromide (CnDDGPB, where n represents a hydrocarbon chain length of 8, 10, 12, 14 and 16) were successfully synthesized from D (+)-glucose δ-lactone, N,N-dimethyldipropylenetriamine, and bromoalkane using a two-step method consisting of a proamine-ester reaction and postquaternization. Their surface activity, adsorption, and aggregation behavior in aqueous solution were investigated via measurements of dynamic/static surface tension, contact angle, dynamic light scattering, and transmission electron microscopy. An analysis of their application performance in terms of wettability, emulsifying properties, toxicity, and antibacterial properties was conducted. The results show that with increasing the carbon chain length of the CnDDGPB surfactants, their critical micelle concentration (CMC) increased and the pC20 and efficiency in the interface adsorption of the target product gradually decreased. Moreover, the influence of the hydrophobic carbon chain length on the surface of polytetrafluoroethylene (PTFE) was even greater for the wetting effect, reducing the contact angle to 32° within the length range of C8-C14. The results of the contact angle change and the wettability experiments proved that C10DDGPB exhibited the best wettability. The liquid paraffin and soybean oil emulsification ability of CnDDGPB showed an upward trend followed by a downward trend with the growth of the carbon chain, with C12DDGPB exhibiting the best emulsification performance. The Dlong/Dshort ratio was far lower than 1, which indicates mixed-kinetic adsorption. The surfactants formed spherical micelles and showed a unique aggregation behavior in aqueous solution, which showed an increase-decrease-increase trend with the change in concentration. A cell toxicity and acute oral toxicity experiment showed that the CnDDGPB surfactants were less toxic than the commonly used surfactant dodecyldimethylbenzyl ammonium chloride (1227). In addition, at a concentration of 150 ppm, CnDDGPB exhibited the same bacteriostatic effect as 1227 at a concentration of 100 ppm. The results demonstrate that sugar-based amide cationic surfactants are promising as environmentally friendly disinfection products.

Bifidobacteria exhibited stronger ability to utilize fructooligosaccharides, compared with other bacteria in the mouse intestine.

BACKGROUND: Fructooligosaccharides (FOS) have been identified as important prebiotics. Previous studies have found that they can significantly promote the proliferation of Bifidobacterium pseudolongum in the mouse intestine. However, it is still unclear which other bacteria in the mouse intestine can utilize FOS, and the differences in the ability to utilize FOS. In this study, the bacteria capable of utilizing FOS were isolated from mice feces and their ability to utilize FOS was compared. Draft genome sequencing was also applied to explain the differences in FOS utilization at the gene levels. RESULTS: A total of 15 species were isolated from mouse feces and 13 species were able to utilize fructofuranosylnystose (GF2). Eleven species could utilize nistose (GF3), but not Enterococcus hirae and Lactobacillus reuteri. In contrast, 1-kestose (GF4) was hardly utilized. The enzyme activity determination and draft genome sequencing-based analyses revealed that all isolated species used the phosphotransferase system or permease system to transport FOS into the cells before hydrolysis by ß-fructofuranosidase. Although ß-fructofuranosidase exists in all strains, there are big differences in the corresponding coding genes between bifidobacteria and non-bifidobacteria. CONCLUSION: Compared with the other isolates, Bifidobacterium species exhibited higher enzyme activity and shorter generation time, leading to a stronger ability to utilize FOS. © 2021 Society of Chemical Industry.

Effects of fructooligosaccharides (FOS) on the composition of cecal and fecal microbiota and the quantitative detection of FOS-metabolizing bacteria using species-specific primers.

BACKGROUND: Fructooligosaccharides (FOS) are a kind of prebiotic. Previous studies concerning the effect of FOS on intestinal microbiota have focused on Bifidobacterium and Lactobacillus. However, the presence of other FOS-utilizing bacteria makes it necessary to investigate the quantitative changes in these bacterial species in the intestine after FOS intake. In this study, the composition of cecal and fecal microbiota was analyzed using MiSeq sequencing, and the abundance of FOS-utilizing bacteria was detected using quantitative polymerase chain reaction after the oral administration of FOS. RESULTS: Species-specific primers for FOS-utilizing bacteria were designed with superior amplification efficiency for quantification. After FOS intervention, the relative abundance of Bifidobacterium pseudolongum in feces increased to 17.37% and the abundance reached 2.28 × 1010 CFU g-1 . The abundance of Bifidobacterium longum and Bifidobacterium breve did not change significantly. Whereas the abundance of Ligilactobacillus murinus decreased, that of Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, and Lacticaseibacillus rhamnosus remained at approximately 104 CFU g-1 . CONCLUSION: Species-specific primers for FOS-utilizing bacteria were successfully developed, and we confirmed that FOS significantly increased the relative abundance and the abundance of B. pseudolongum in mice, while decreasing the proportion of Lactobacillus. The detection of these species using 16S ribosomal DNA sequencing and quantitative polymerase chain reaction showed the same results. Further investigations are needed to reveal the response of the intestinal microbiota to different FOS compositions. These techniques will contribute to future studies about the composition and dynamics of the intestinal microflora. © 2022 Society of Chemical Industry.

Levan from Leuconostoc citreum BD1707: production optimization and changes in molecular weight distribution during cultivation.

BACKGROUND: Levan is a well-known homopolymer of fructose composed predominantly of ß-(2, 6) fructofuranosyl linkages in the backbone with occasional ß-(2, 1) linkages in the branch chains with varied applications. However, high production cost due to low yield of microbial levan has become a bottleneck for its practical applications. Furthermore, factors affecting the molecular mass of the synthesized levan by Leuconostoc spp. during prolonged cultivation is not fully elucidated. METHODS: The cultivation condition for Leuconostoc citreum BD1707 to synthesize levan was optimized by single-factor experiments and subsequently with response surface methodology (RSM). The average molecular weight (Mw) of levan synthesized by the strain L.citreum BD1707 under the optimized cultivation conditions was monitored by high-performance size exclusion chromatography (HPSEC). Finally, the enzyme with levan-degrading activity was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The levan yield of BD1707 reached 34.86 g/L with a corresponding productivity of 7.47 g/L/d under the optimal cultivation conditions deduced by RSM, i.e., cultivation at 26 °C and 200 rpm for 112 h in tomato juice supplemented with 172 g/L sucrose with an initial pH value of 6.12. The Mw of levan reached a peak value of 2.320 × 107 Da at 6 h of cultivation under the optimized cultivation conditions and then gradually decreased to 8.809 × 106 Da after 120 h of cultivation. CONCLUSION: The levan yield of the strain L.citreum BD1707 could be sufficiently enhanced via cultivation condition optimization. The decrease in molecular mass of the synthesized levan was attributed predominantly to the hydrolytic activity of levansucrase secreted by L.citreum BD1707 during cultivation, with an estimated Mw of 130 KD by SDS-PAGE, while the effect of acid hydrolysis could be nearly neglected.

Voltammetric Determination of 5-Hydroxymethyl-2-furfural in Processed Cheese Using an Easy-Made and Economic Integrated 3D Graphene-like Electrode.

The concentration of 5-hydroxymethyl-2-furfural (HMF) is an important quality-related index in milk and milk products. Fast, cost-effective and environmentally friendly determination of HMF is of great significance in milk products control. In this study, a three-dimensional (3D) graphene-like surface (3DGrls) was successfully prepared within 5 min by an electrochemical amperometric pretreatment on a pencil graphite electrode (PGE). The fast-obtained 3D graphene-like surface increased the electrode surface area and enhanced the electron transfer capability without the addition of any harmful chemicals. The morphology and chemical composition of the obtained electrode were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). The results found that the electrochemical response to HMF at the prepared 3DGrls/PGE was 34 times higher than that at PGE. The modified electrode showed a good linear response to HMF in a concentration range of 0.35~116 µM with a low limit of detection (LOD) of 0.099 µM. The integrated electrode also exhibited excellent stability and wonderful antifouling property. Furthermore, the 3DGrls/PGE was successfully applied for the determination of HMF in three processed cheese samples with satisfactory results.

Effect of fermented milk on upper respiratory tract infection in adults who lived in the haze area of Northern China: a randomized clinical trial.

CONTEXT: Upper respiratory tract infection (URTI) is the most common illness in humans. Fermented milk containing probiotics can mitigate URTI symptoms. OBJECTIVE: This study tests the effect of fermented milk (Qingrun), a yogurt supplemented with Bifidobacterium animalis subsp. lactis Bl-04, on adults with URTIs who live in a haze-covered area in a randomized clinical trial. MATERIALS AND METHODS: A total of 136 subjects were enrolled in the study at the baseline and randomized to consume either control yogurt or Qingrun yogurt (250 g) once daily for 12 weeks. The duration and severity of URTI were evaluated by the Wisconsin Upper Respiratory Symptom Survey-24. Blood and faecal samples were collected at the baseline and post-intervention, to determine the changes of immune biomarkers. RESULTS: Qingrun yogurt significantly reduced the incidence of the common cold (OR, 0.38; 95% CI, 0.17-0.81; p = 0.013) and influenza-like illness (OR, 0.32; 95% CI, 0.11-0.97; p = 0.045). Compared to the control yogurt, Qingrun yogurt significantly reduced the duration (1.23 ± 2.73 vs. 4.78 ± 5.09 d) and severity score (3.58 ± 7.12 vs. 11.37 ± 11.73) of URTI. In addition, the post-intervention levels of interferon-γ (139.49 ± 59.49 vs. 113.45 ± 65.12 pg/mL) and secretory immunoglobulin A (529.19 ± 91.70 vs. 388.88 ± 53.83 mg/dL) significantly increased in the Qingrun group, compared with those in the control group. CONCLUSIONS: Qingrun yogurt showed a protective effect against URTI in adults, suggesting that the use of yogurt with probiotics could be a promising dietary supplement for mitigating URTI.