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1.
Nano Lett ; 23(1): 124-131, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-36579734

RESUMEN

Blinking carbon dots (CDs) have attracted attention as a probe for single molecule localization microscopy (SMLM), yet quantitative analysis is limited because of inept blinking and low signal-to-noise ratio (SNR). Here we report the design and synthesis of near-infrared (NIR) blinking CDs with a maximum emission of around 750 nm by weaving a nitrogen-doped aromatic backbone with surplus carboxyl groups on the surface. The NIR-CDs allow conjugation to monovalent antibody fragments for labeling and imaging of cellular receptors as well as afford increases of 52% in SNR and 33% in localization precision over visible CDs. Analysis of fluorescent bursts allows for accurate counting of cellular receptors at the nanoscale resolution. Using NIR-CDs-based SMLM, we demonstrate oligomerization and internalization of programmed cell death-ligand 1 by a small molecule inhibitor for checkpoint blockade. Our NIR-CDs can become a generally applicable probe for quantitative nanoscopy in chemistry and biology.


Asunto(s)
Puntos Cuánticos , Puntos Cuánticos/química , Carbono/química , Parpadeo , Colorantes Fluorescentes
2.
Anal Chem ; 95(6): 3300-3308, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36716433

RESUMEN

G-protein-coupled receptor (GPCR) density at the cell surface is thought to regulate receptor function. Spatially resolved measurements of local-density effects on GPCRs are needed but technically limited by density heterogeneity and mobility of membrane receptors. We now develop a deep-learning (DL)-enhanced diffusion imaging assay that can measure local-density effects on ligand-receptor interactions in the plasma membrane of live cells. In this method, the DL algorithm allows the transformation of 100 ms exposure images to density maps that report receptor numbers over any specified region with ∼95% accuracy by 1 s exposure images as ground truth. With the density maps, a diffusion assay is further established for spatially resolved measurements of receptor diffusion coefficient as well as to express relationships between receptor diffusivity and local density. By this assay, we scrutinize local-density effects on chemokine receptor CXCR4 interactions with various ligands, which reveals that an agonist prefers to act with CXCR4 at low density while an inverse agonist dominates at high density. This work suggests a new insight into density-dependent receptor regulation as well as provides an unprecedented assay that can be applicable to a wide variety of receptors in live cells.


Asunto(s)
Aprendizaje Profundo , Agonismo Inverso de Drogas , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Membrana Celular/química , Ligandos
3.
Anal Chem ; 94(9): 3914-3921, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35188385

RESUMEN

Oligomeric organization of G protein-coupled receptors is proposed to regulate receptor signaling and function, yet rapid and precise identification of the oligomeric status especially for native receptors on a cell membrane remains an outstanding challenge. By using blinking carbon dots (CDs), we now develop a deep learning (DL)-based blinking fingerprint recognition method, named deep-blinking fingerprint recognition (BFR), which allows automatic classification of CD-labeled receptor organizations on a cell membrane. This DL model integrates convolutional layers, long-short-term memory, and fully connected layers to extract time-dependent blinking features of CDs and is trained to a high accuracy (∼95%) for identifying receptor organizations. Using deep blinking fingerprint recognition, we found that CXCR4 mainly exists as 87.3% monomers, 12.4% dimers, and <1% higher-order oligomers on a HeLa cell membrane. We further demonstrate that the heterogeneous organizations can be regulated by various stimuli at different degrees. The receptor-binding ligands, agonist SDF-1α and antagonist AMD3100, can induce the dimerization of CXCR4 to 33.1 and 20.3%, respectively. In addition, cytochalasin D, which inhibits actin polymerization, similarly prompts significant dimerization of CXCR4 to 30.9%. The multi-pathway organization regulation will provide an insight for understanding the oligomerization mechanism of CXCR4 as well as for elucidating their physiological functions.


Asunto(s)
Carbono , Aprendizaje Profundo , Puntos Cuánticos , Receptores CXCR4 , Bencilaminas/química , Bencilaminas/farmacología , Quimiocina CXCL12/agonistas , Ciclamas/química , Ciclamas/farmacología , Células HeLa , Humanos , Receptores CXCR4/química
4.
Molecules ; 26(2)2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33451119

RESUMEN

Subcritical water treatment has received considerable attention due to its cost effectiveness and environmentally friendly properties. In this investigation, Chinese quince fruits were submitted to subcritical water treatment (130, 150, and 170 °C), and the influence of treatments on the structure of milled wood lignin (MWL) was evaluated. Structural properties of these lignin samples (UL, L130, L150, and L170) were investigated by high-performance anion exchange chromatography (HPAEC), FT-IR, gel permeation chromatography (GPC), TGA, pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), 2D-Heteronculear Single Quantum Coherence (HSQC) -NMR, and 31P-NMR. The carbohydrate analysis showed that xylose in the samples increased significantly with higher temperature, and according to molecular weight and thermal analysis, the MWLs of the pretreated residues have higher thermal stability with increased molecular weight. The spectra of 2D-NMR and 31P-NMR demonstrated that the chemical linkages in the MWLs were mainly ß-O-4' ether bonds, ß-5' and ß-ß', and the units were principally G- S- H- type with small amounts of ferulic acids; these results are consistent with the results of Py-GC/MS analysis. It is believed that understanding the structural changes in MWL caused by subcritical water treatment will contribute to understanding the mechanism of subcritical water extraction, which in turn will provide a theoretical basis for developing the technology of subcritical water extraction.


Asunto(s)
Frutas/química , Lignina/química , Rosaceae/química , Purificación del Agua , Madera/química , China , Estructura Molecular , Tamaño de la Partícula
5.
Molecules ; 25(19)2020 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-33003556

RESUMEN

For screening excellent lactic acid bacteria (LAB) strains to inhibit enterotoxigenic Escherichia coli (ETEC) K88, inhibitory activities of more than 1100 LAB strains isolated from different materials, and kept in the lab, were evaluated in this study. Nine strains with inhibition zones, at least 22.00 mm (including that of a hole puncher, 10.00 mm), and good physiological and biochemical characteristics identified by 16S DNA gene sequencing and recA gene multiple detection, were assigned to Lactobacillus (L.) plantarum subsp. plantarum (5), L. fermentum (1), L. reuteri (1), Weissella cibaria (1) and Enterococcus faecalis (1), respectively. As investigated for their tolerance abilities and safety, only strain ZA3 possessed high hydrophobicity and auto-aggregation abilities, had high survival rate in low pH, bile salt environment, and gastrointestinal (GI) fluids, was sensitive to ampicillin, and resistant to norfloxacin and amikacin, without hemolytic activity, and did not carry antibiotic resistance genes, but exhibited broad spectrum activity against a wide range of microorganisms. Antibacterial substance may attribute to organic acids, especially lactic acid and acetic acid. The results indicated that the selected strain L. plantarum subsp. plantarum ZA3 could be considered a potential probiotic to inhibit ETEC K88 in weaned piglets for further research.


Asunto(s)
Escherichia coli Enterotoxigénica/efectos de los fármacos , Lactobacillus/química , Probióticos/farmacología , Destete , Ácidos/metabolismo , Animales , Ácidos y Sales Biliares/metabolismo , Biomasa , Carbohidratos/química , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Fermentación/efectos de los fármacos , Tracto Gastrointestinal/microbiología , Hemólisis/efectos de los fármacos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Lactobacillus/genética , Lactobacillus/crecimiento & desarrollo , Lactobacillus/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Filogenia , ARN Ribosómico 16S/genética , Porcinos , Pruebas de Toxicidad , Factores de Virulencia/genética
6.
Physiol Plant ; 160(2): 222-239, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28128458

RESUMEN

The plant-specific PIN-FORMED (PIN) auxin efflux proteins have been well characterized in many plant species, where they are crucial in the regulation of auxin transport in various aspects of plant development. However, little is known about the exact roles of the PIN genes during plant development in Nicotiana species. This study investigated the PIN genes in tobacco (Nicotiana tabacum) and in two ancestral species (Nicotiana sylvestris and Nicotiana tomentosiformis). Genome-wide analysis of the N. tabacum genome identified 20 genes of the PIN family. An in-depth phylogenetic analysis of the PIN genes of N. tabacum, N. sylvestris and N. tomentosiformis was conducted. NtPIN4 expression was strongly induced by the application of exogenous indole-3-acetic acid (IAA), but was downregulated by the application of ABA, a strigolactone analogue, and cytokinin, as well as by decapitation treatments, suggesting that the NtPIN4 expression level is likely positively regulated by auxin. Expression analysis indicated that NtPIN4 was highly expressed in tobacco stems and shoots, which was further validated through analysis of the activity of the NtPIN4 promoter. We used CRISPR-Cas9 technology to generate mutants for NtPIN4 and observed that both T0 and T1 plants had a significantly increased axillary bud growth phenotype, as compared with the wild-type plants. Therefore, NtPIN4 offers an opportunity for studying auxin-dependent branching processes.


Asunto(s)
Nicotiana/metabolismo , Proteínas de Plantas/metabolismo , Ácido Abscísico/farmacología , Citocininas/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/genética , Ácidos Indolacéticos/farmacología , Proteínas de Plantas/genética , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Regiones Promotoras Genéticas/efectos de los fármacos , Regiones Promotoras Genéticas/genética , Nicotiana/efectos de los fármacos , Nicotiana/genética
7.
Molecules ; 22(4)2017 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-28358319

RESUMEN

As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%. Further, the catechins, theanine, caffeine and aroma components, which determine the quality of the tea, fluctuated after SBE treatment. Compared with the uncrushed leaves, pesticide residues can more easily be removed from crushed leaves, and the practical extraction efficiency was 97%. These results indicate that SBE is a useful method to efficiently remove the bifenthrin, and as appearance is not relevant in the production process, tea leaves should first be crushed and then extracted in order that residual pesticides are thoroughly removed.


Asunto(s)
Butanos/química , Residuos de Plaguicidas/aislamiento & purificación , Piretrinas/aislamiento & purificación , Té/química , Camellia sinensis/química , Fraccionamiento Químico , Hojas de la Planta/química
8.
Molecules ; 22(2)2017 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-28157172

RESUMEN

In this study, the subcritical butane extraction process of fenugreek seed oil was optimized using response surface methodology with a Box-Behnken design. The optimum conditions for extracted oil from fenugreek seed was as follows: extraction temperature of 43.24 °C , extraction time of 32.80 min, and particle size of 0.26 mm. No significant differences were found between the experimental and predicted values. The physical and chemical properties of the oil showed that the oil could be used as edible oil. Fatty acid composition of oils obtained by subcritical butane under the optimum conditions and by accelerated solvent extraction showed negligible difference. The oils were rich in linoleic acid (42.71%-42.80%), linolenic acid (26.03%-26.15%), and oleic acid (14.24%-14.40%). The results revealed that the proposed method was feasible, and this essay shows the way to exploit fenugreek seeds by subcritical butane extraction under the scope of edible oils.


Asunto(s)
Butanos/química , Extracción Líquido-Líquido , Extractos Vegetales/química , Aceites de Plantas/química , Semillas/química , Trigonella/química , Rastreo Diferencial de Calorimetría , Ácidos Grasos/química , Extracción Líquido-Líquido/métodos , Fitoquímicos/química , Termogravimetría
9.
Molecules ; 22(4)2017 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-28346341

RESUMEN

Chinese quince seed (CQS) is an underutilized oil source and a potential source of unsaturated fatty acids and α-tocopherol-rich oil. Subcritical fluid (SCF) extraction is executed at lower pressures and temperatures than the pressures and temperatures used in supercritical fluid extraction. However, no studies on the SCF extraction of CQS oil are reported. Therefore, the objective of this study was to evaluate the use of SCF for the extraction of CQS oil and to compare the use of SCF with the classical Soxhlet (CS) and supercritical CO2 (SC-CO2) extraction methods. Response surface methodology (RSM) was used to investigate the extraction conditions: temperature (45-65 °C), time (30-50 min), and solvent/solid ratio (5-15 mL/g). The optimization results showed that the highest yield (27.78%) was obtained at 56.18 °C, 40.20 min, and 12.57 mL/g. The oil extracted by SCF had a higher unsaturated fatty acid content (86.37%-86.75%), higher α-tocopherol content (576.0-847.6 mg/kg), lower acid value (3.97 mg/g), and lower peroxide value (0.02 meq O2/kg) than extractions using CS and SC-CO2 methods. The SCF-defatted meal of oilseed exhibited the highest nitrogen solubility index (49.64%) and protein dispersibility index (50.80%), demonstrating that SCF extraction was a promising and efficient technique as an alternative to CS and SC-CO2 methods, as very mild operating conditions and an eco-friendly solvent can be used in the process with maximum preservation of the quality of the meal.


Asunto(s)
Aceites de Plantas/química , Rosaceae/química , Semillas/química , Presión Atmosférica , Ácidos Grasos Insaturados/análisis , Temperatura , alfa-Tocoferol/análisis
10.
J Sci Food Agric ; 97(6): 1894-1903, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27528006

RESUMEN

BACKGROUND: Red pepper seeds account for 450-500 g kg-1 of the total pepper weight and are often discarded as waste. In this study, process optimization and characterization of fragrant oil from roasted red pepper seed extracted by subcritical butane extraction were carried out. RESULTS: The optimal conditions of extraction were a temperature of 74.61 °C, a time of 68.65 min and a liquid/solid ratio of 30.24:1. The oil had a refractive index (25 °C) of 1.471, a relative density of 0.900, an acid value of 1.421 mg g-1 oil, an iodine value of 127.035 g per 100 g, a saponification value of 184.060 mg KOH g-1 , an unsaponifiable matter content of 12.400 g kg-1 , a peroxide value of 2.465 meq. O2 kg-1 and a viscosity of 52.094 cP. The main fatty acids in the oil were linoleic acid (72.95%) followed by palmitic acid (11.43%) and oleic acid (10.00%). The oil showed desirable thermal and oxidative stability. A total of 19 volatile compounds, mostly aldehydes and alkenes, were identified from the oil. CONCLUSION: The results indicated that the method is appropriate for the preparation of fragrant red pepper seed oil, and the oil is suitable for used as edible oil. © 2016 Society of Chemical Industry.


Asunto(s)
Capsicum/química , Fraccionamiento Químico/métodos , Aceites de Plantas/química , Aceites de Plantas/aislamiento & purificación , Semillas/química , Butanos/química , Fraccionamiento Químico/instrumentación , Oxidación-Reducción
11.
Int J Biol Macromol ; 258(Pt 2): 129034, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38151080

RESUMEN

The impacts of four extraction techniques, including hot water, ultrasonic-assisted, complex enzyme-assisted and acid-assisted methods, on the morphological, physicochemical properties and bioactivities of Asparagus cochinchinensis (poly)saccharides (EACP, WACP, UACP, and AACP) were investigated and compared. The four samples were mainly composed of glucose, fructose, and galactose with molar ratios of 50.8:22.7:4.4 for WACP, 53.9:26.0:5.3 for UACP, 35.6:14.1:21.4 for AACP and 45.0:15.6:9.0 for EACP, respectively. The rheological result showed that ACPs were non-Newtonian fluids. EACP with high purity (97.65 %) had good DPPH, O2- and ABTS+ radical scavenging activities, and significantly promoted the proliferation of the RAW264.7 cells at low concentration. UACP had good Fe2+ chelating ability, radical (DPPH, O2- and OH) scavenging activities, which might be attributed to the existence of triple-helix structure. AACP had high yield, molecular weight (17,477.2 Da), high crystallinity (23.33 %), and good radical (OH and ABTS+) scavenging activities. All four significantly stimulated the transcript expression levels of TNF-α, IL-1ß and IL-6, as determined by RT-PCR. These results suggest that the exploitation and utilization of non-inulin (poly)saccharides extracted by ultrasonic-assisted, complex enzyme-assisted and acid-assisted extraction methods are potentially valuable as effective and natural immune adjuvants and antioxidants.


Asunto(s)
Antioxidantes , Benzotiazoles , Antioxidantes/química , Ácidos Sulfónicos , Peso Molecular , Polisacáridos/química
12.
Toxins (Basel) ; 15(9)2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37755996

RESUMEN

The overuse of antibiotics and the emergence of multiple-antibiotic-resistant pathogens are becoming a serious threat to health security and the economy. Reducing antimicrobial resistance requires replacing antibiotic consumption with more biocontrol strategies to improve the immunity of animals and humans. Probiotics and medicinal plants have been used as alternative treatments or preventative therapies for a variety of diseases caused by bacterial infections. Therefore, we reviewed some of the anti-virulence and bacterial toxin-inhibiting strategies that are currently being developed; this review covers strategies focused on quenching pathogen quorum sensing (QS) systems, the disruption of biofilm formation and bacterial toxin neutralization. It highlights the probable mechanism of action for probiotics and medicinal plants. Although further research is needed before a definitive statement can be made on the efficacy of any of these interventions, the current literature offers new hope and a new tool in the arsenal in the fight against bacterial virulence factors and bacterial toxins.

13.
Toxins (Basel) ; 15(5)2023 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-37235364

RESUMEN

Mycotoxins, secondary metabolites of fungi, are a major obstacle to the utilization of animal feed for various reasons. Wheat straw (WS) is hollow, and miscellaneous bacteria can easy attach to its surface; the secondary fermentation frequency after silage is high, and there is a risk of mycotoxin poisoning. In this study, a storage fermentation process was used to preserve and enhance fermentation quality in WS through the addition of Artemisia argyi (AA), which is an effective method to use WS resources and enhance aerobic stability. The storage fermentation of WS treated with AA had lower pH and mycotoxin (AFB1 and DON) values than the control due to rapid changes in microbial counts, especially in the 60% AA groups. Meanwhile, the addition of 60% AA improved anaerobic fermentation profiles, showing higher lactic acid contents, leading to increased efficiency of lactic acid fermentation. A background microbial dynamic study indicated that the addition of 60% AA improved the fermentation and aerobic exposure processes, decreased microbial richness, enriched Lactobacillus abundance, and reduced Enterobacter and Aspergillus abundances. In conclusion, 60% AA treatment could improve the quality by increase fermentation quality and improve the aerobic stability of WS silage by enhancing the dominance of desirable Lactobacillus, inhibiting the growth of undesirable microorganisms, especially fungi, and reducing the content of mycotoxins.


Asunto(s)
Microbiota , Micotoxinas , Animales , Ensilaje/análisis , Triticum/metabolismo , Fermentación , Lactobacillus/metabolismo , Hongos/metabolismo , Micotoxinas/metabolismo , Ácido Láctico/metabolismo
14.
Int J Syst Evol Microbiol ; 62(Pt 10): 2383-2387, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22140166

RESUMEN

Characterization and identification of strain CW 1 ( = JCM 17161) isolated from corn silage were performed. Strain CW 1 was a Gram-positive, catalase-negative and homofermentative rod that produced the DL-form of lactic acid. This strain exhibited more than 99.6% 16S rRNA gene sequence similarity and greater than 82% DNA-DNA reassociation with type strains of Lactobacillus kimchii, L. bobalius and L. paralimentarius. To clarify the taxonomic positions of these type strains, phenotypic characterization, 16S rRNA gene sequencing, ribotyping and DNA-DNA relatedness were examined. The three type strains displayed different L-arabinose, lactose, melibiose, melezitose, raffinose and N-acetyl-ß-glucosaminidase fermentation patterns. Phylogenetic analysis showed that L. paralimentarius is a closer neighbour of L. kimchii and L. bobalius, sharing 99.5-99.9% 16S rRNA gene sequence similarity, which was confirmed by the high DNA-DNA relatedness (≥82%) between L. paralimentarius JCM 10415(T), L. bobalius JCM 16180(T) and L. kimchii JCM 10707(T). Therefore, it is proposed that L. kimchii and L. bobalius should be reclassified as later synonyms of L. paralimentarius.


Asunto(s)
Lactobacillus/clasificación , Filogenia , Ensilaje/microbiología , ADN Bacteriano/genética , Fermentación , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Ribotipificación , Análisis de Secuencia de ADN
15.
Microorganisms ; 10(3)2022 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-35336105

RESUMEN

This study assessed the effects of Enterococcus faecalis (E. faecalis) in combination with protease on fermentation characteristics and microbial communities during ensiling and aerobic exposure phases of soybean meal (SBM). In this study, response surface methodology (RSM) was used to optimize the optimal growth conditions of E. faecalis ZZUPF95, which produced protease, and fermented SBM under the optimal fermentation conditions. The fermentation test was divided into four groups as follows: CK (Control check), ZZUPF95, Protease and ZZUPF95+Protease groups. Results showed that the best medium ratio of ZZUPF95 was glucose 1%, peptone 2%, inorganic salt 1.47%; fermentation time 36 h, inoculation amount 10%, ratio of material to water 1:1 is the optimal fermentation scheme; after fermentation and aerobic exposure treatment, ZZUPF95 and ZZUPF95 + Protease group can reduce the pH of feed, improve the content of lactic acid in the fermentation system, and have the effect of inhibiting the reproduction of pathogenic bacteria, increasing the content of crude protein and ether extract, and degrading crude fiber; the microbial community of SBM were changed after fermentation and aerobic exposure. This study explored the changes of fermentation quality of SBM, which has certain theoretical value to improve the fermentation mode and storage of SBM.

16.
Front Microbiol ; 13: 1004495, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36439818

RESUMEN

Whole-crop wheat silage (WCWS) is an excellent feed material for ruminants. However, microbial fermentation during silage production consumes valuable nutrients, decreasing the quality of silage. The main objective of this study was to assess how the addition of increasing amounts of Artemisia argyi (AA) affected fermentation quality, microbial composition, and mycotoxin production in whole-crop wheat at dough stage (WCWD) silage during ensiling to aerobic exposure compared with Lactiplantibacillus buchneri (LB). The addition of 20% AA, resulted in a lower pH and higher lactic acid content, was found in silage treated with 20% AA, and an obvious increase in the relative abundance of Lactobacillus was detected in silages treated with LB and 20% AA, respectively. Meanwhile, inoculation with 20% AA decreased the abundance of harmful microorganisms, including Acinetobacter, Enterobacter, and Aspergillus. It also reduced the contents of mycotoxins, Aflatoxin B1 (AFB1), and deoxynivalenol (DON) during ensiling and aerobic exposure. These results confirmed that WCWD treated with 20% AA could improve the fermentation quality and enhance the aerobic stability of silage.

17.
Toxins (Basel) ; 14(5)2022 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-35622595

RESUMEN

Silage, especially whole crop corn silage (WCCS), is an important part of ruminant diets, with its high moisture content and rich nutrient content, which can easily cause contamination by mold and their toxins, posing a great threat to ruminant production, food safety and human health. The objective of this study was to examine effects of lactic acid bacteria (LAB) Lactiplantibacillus (L.) plantarum subsp. plantarum ZA3 and Artemisia argyi (AA) on the fermentation characteristics, microbial community and mycotoxin of WCCS during 60 days (d) ensiling and subsequent 7 d aerobic exposure. The results showed that WCCS treated with LAB and AA both had lower pH value and ammonia nitrogen (NH3-N) contents, and higher lactic and acetic acids concentration compared with other groups after 60 d ensiling. In addition, for microbial communities, Acetobacter and Enterobacter were inhibited in all AA group, while higher abundance of Lactobacilli was maintained; besides, Candida, Pichia and Kazachstania abundances were decreased in both 6% and 12% AA groups. The content of five kinds of mycotoxins were all significantly lower after 7 d of aerobic exposure. As for the total flavonoid (TF), which is significantly higher in all AA treated groups, it was positively correlated with Paenibacillus, Weissella and Lactobacilli, and negatively with Acetobacter, Enterobacteria, Kazachstania and Pichia.


Asunto(s)
Artemisia , Lactobacillales , Microbiota , Fermentación , Humanos , Lactobacillus , Ensilaje/análisis , Zea mays/microbiología
18.
Foods ; 11(5)2022 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-35267342

RESUMEN

Lactic acid bacteria (LAB), which are characterized by producing various functional metabolites, including antioxidants, organic acids, and antimicrobial compounds, are widely used in the food industry to improve gut health and prevent the growth of spoilage microorganisms. With the continual incidence of foodborne disease and advocacy of consumers for gut health, LAB have been designated as vital biopreservative agents in recent years. Therefore, LAB with excellent antimicrobial properties and environmental tolerance should be explored further. In this study, we focus on screening the LAB strains from a specialty pig (Bamei pig) feces of the Tibetan plateau region and determine their antimicrobial properties and environmental tolerance to evaluate their potential probiotic values. A total of 116 LAB strains were isolated, from which the LAB strain Qinghai (QP)28-1 was identified as Lactiplantibacillus (L.) plantarum subsp. plantarum using 16S rDNA sequencing and recA amplification, showing the best growth capacity, acid production capacities, environmental tolerance, hydrophobicity, antibiotic susceptibility, and bacteriocin production capacity. Furthermore, this strain inhibited the growth of multiple pathogens by producing organic acids and bacteriocin. These bacteriocin-encoding genes were identified using PCR amplification, including plnS, plnN, and plnW. In conclusion, bacteriocin-producing L. plantarum subsp. plantarum QP28-1 stands out among these 116 LAB strains, and was considered to be a promising strain used for LAB-related food fermentation. Moreover, this study provides a convenient, comprehensive, and shareable profile for screening of superior functional and bacteriocin-producing LAB strains, which can be used in the food industry.

19.
Foods ; 11(6)2022 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-35327218

RESUMEN

This study evaluated the effects of Lactiplantibacillus plantarum subsp. plantarum ZA3, Artemisia argyi and their combination, on the fermentation characteristics, microbial community, mycotoxins and crude flavonoids content of fermented soybean meal during fermentation (under anaerobic conditions) and aerobic exposure (under aerobic conditions). The results showed that ZA3, Artemisia argyi and ZA3+ Artemisia argyi groups had lower pH values and higher lactic acid concentrations compared with controls, and additives increased the abundance of Lactiplantibacillus and decreased those of Acetobacter and Enterobacter; in particular, Artemisia argyi and ZA3+ Artemisia argyi reduced the abundance of fungi, such as Aspergillus, Pichia, Fusarium, Cladosporium and Xeromyces. Meanwhile, the contents of mycotoxins were lower in treated groups, and even mycotoxins in the control were significantly reduced after 30 d (p < 0.05). Crude flavonoids that were correlated positively with Lactococcus and negatively with Bacillus, Aspergillus, Enterobacter and Kazachstania were significantly higher in the Artemisia argyi and ZA3+ Artemisia argyi groups (p < 0.05).

20.
Animals (Basel) ; 11(6)2021 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-34207593

RESUMEN

Enterotoxigenic Escherichia coli (ETEC), which expresses K88 is the principal microorganism responsible for bacterial diarrhea in pig husbandry, and the indiscriminate use of antibiotics has caused many problems; therefore, antibiotics need to be replaced in order to prevent diarrhea caused by ETEC K88. The objective of this study was to screen excellent lactic acid bacteria (LAB) strains that inhibit ETEC K88 and explore their effects as probiotic supplementation on reproduction, growth performance, diarrheal incidence, and antioxidant capacity of serum in sows and weaned piglets. Three LAB strains, P7, P8, and P15, screened from 295 LAB strains and assigned to Lactobacillus (L.) reuteri, L. amylovorus, and L. johnsonii with high inhibitory activity against ETEC K88 were selected for a study on feeding of sows and weaned piglets. These strains were chosen for their good physiological and biochemical characteristics, excellent exopolysaccharide (EPS) production capacity, hydrophobicity, auto-aggregation ability, survival in gastrointestinal (GI) fluids, lack of hemolytic activity, and broad-spectrum activity against a wide range of microorganisms. The results indicate that LAB strains P7, P8, and P15 had significant effects on improving the reproductive performance of sows and the growth performance of weaned piglets, increasing the activity of antioxidant enzymes and immune indexes in both.

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