Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 71
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Foods ; 13(5)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38472847

RESUMO

This study explores the potential of aerotolerant Bacteroides fragilis (B. fragilis) strains as next-generation probiotics (NGPs), focusing on their adaptability in the gastrointestinal environment, safety profile, and probiotic functions. From 23 healthy infant fecal samples, we successfully isolated 56 beneficial B. fragilis strains. Notably, the SNBF-1 strain demonstrated superior cholesterol removal efficiency in HepG2 cells, outshining all other strains by achieving a remarkable reduction in cholesterol by 55.38 ± 2.26%. Comprehensive genotype and phenotype analyses were conducted, including sugar utilization and antibiotic sensitivity tests, leading to the development of an optimized growth medium for SNBF-1. SNBF-1 also demonstrated robust and consistent antioxidant activity, particularly in cell-free extracts, as evidenced by an average oxygen radical absorbance capacity value of 1.061 and a 2,2-diphenyl-1-picrylhydrazyl scavenging ability of 94.53 ± 7.31%. The regulation of carbohydrate metabolism by SNBF-1 was assessed in the insulin-resistant HepG2 cell line. In enzyme inhibition assays, SNBF-1 showed significant α-amylase and α-glucosidase inhibition, with rates of 87.04 ± 2.03% and 37.82 ± 1.36%, respectively. Furthermore, the cell-free supernatant (CFS) of SNBF-1 enhanced glucose consumption and glycogen synthesis in insulin-resistant HepG2 cells, indicating improved cellular energy metabolism. This was consistent with the observation that the CFS of SNBF-1 increased the proliferation of HepG2 cells by 123.77 ± 0.82% compared to that of the control. Overall, this research significantly enhances our understanding of NGPs and their potential therapeutic applications in modulating the gut microbiome.

2.
Appl Microbiol Biotechnol ; 108(1): 223, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38376614

RESUMO

Pork backfat (PB) contains excessive saturated fatty acids (SFAs), but lacks polyunsaturated fatty acids (PUFAs). Excessive SFAs can be used as a substrate for the growth of certain microorganisms that convert them into PUFAs and monounsaturated fatty acids (MUFAs), and the added value of PB can be enhanced. In this study, Mucor circinelloides CBS 277.49 and Lactiplantacillus plantarum CGMCC 24189 were co-cultured for conversion of PB into fermented pork backfat (FPB) with high level of PUFAs. Our results showed that the content of γ-linolenic acid (GLA) and linoleic acid (LA) in the surface of FPB reached 9.04 ± 0.14 mg/g and 107.31 ± 5.16 mg/g for 7-day fermentation, respectively. To convert the internal SFAs of PB, ultrasound combined with papain was used to promote the penetrative growth of M. circinelloides into the internal PB, and the GLA level in the third layer of fat reached 2.58 ± 0.31 mg/g FPB. The internal growth of M. circinelloides in PB was promoted by adjusting the oxygen rate and ventilation rate through the wind velocity sensor. When the oxygen rate is 2 m/s and the ventilation rate is 18 m3/h, the GLA level in the third layer of fat reached 4.13 ± 1.01 mg/g FPB. To further improve the level of PUFAs in PB, FPB was produced by M. circinelloides at 18 °C. The GLA content on the surface of FPB reached 15.73 ± 1.13 mg/g FPB, and the GLA yield in the second and third layers of fat reached 8.68 ± 1.77 mg/g FPB and 6.13 ± 1.28 mg/g FPB, the LA yield in the second and third layers of fat reached 105.45 ± 5.01 mg/g FPB and 98.46 ± 4.14 mg/g FPB, respectively. These results suggested that excessive SFAs in PB can be converted into PUFAs and provided a new technique for improving PUFAs in FPB. KEY POINTS: • This article achieved the conversion of PUFAs in pork backfat by Mucor circinelloides CBS 277.49 and Lactiplantacillus plantarum CGMCC 24189. • This article solved the internal growth of M. circinelloides CBS277.49 in pork backfat by ultrasound combined with papain. • This article proposed an innovative of promoting the internal growth of M. circinelloides and increasing the PUFAs production by oxygen ventilation in pork backfat.


Assuntos
Mucor , Carne de Porco , Carne Vermelha , Suínos , Animais , Papaína , Ácidos Graxos Insaturados , Ácido Linoleico , Oxigênio
3.
ACS Omega ; 9(1): 1643-1655, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222669

RESUMO

Conjugated linoleic acid (CLA) holds significant application prospects due to its anticancer, anti-atherosclerosis, lipid-lowering, weight-loss, and growth-promoting functions. The key to its efficient production lies in optimizing the biocatalytic performance of linoleic acid isomerase (LAI). Here, we constructed a Propionibacterium acnes mutant library and screened positive mutants with high linoleate isomerase activity. The proteomics and metabolomics were used to explore the mechanism in the regulation of linoleic acid isomerase activity. High-throughput proteomics revealed 104 differentially expressed proteins unique to positive mutant strains of linoleic acid isomerase of which 57 were upregulated and 47 were downregulated. These differentially expressed proteins were primarily involved in galactose metabolism, the phosphotransferase system, starch metabolism, and sucrose metabolism. Differential metabolic pathways were mainly enriched in amino acid biosynthesis, including glutamate metabolism, the Aminoacyl-tRNA biosynthesis pathway, and the ABC transporter pathway. The upregulated metabolites include dl-valine and Acetyl coA, while the downregulated metabolites include Glutamic acid and Phosphoenolpyruvate. Overall, the activity of linoleic acid isomerase in the mutant strain was increased by the regulation of key proteins involved in galactose metabolism, sucrose metabolism, and the phosphotransferase system. This study provides a theoretical basis for the development of high-yield CLA food.

4.
Int J Biol Macromol ; 259(Pt 1): 129176, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38181904

RESUMO

The remarkable functional characteristics of Bacillus subtilis extracellular polysaccharides (BSPS) are of great interest. Therefore, in the present study, BSPS was isolated and characterized to obtain two fractions, BSPS-1 and BSPS-2, respectively, and to investigate their biological activities. BSPS-1 contained fructose, glucose, and galactose (molar ratio: 25.27:43.37:31.36), while BSPS-2 contained fructose with only trace amounts of glucose, galactose, and mannose (molar ratio: 55.08:19.03:19.21:6.68), and their respective average molecular weights were 16.9 kDa and 202.67 kDa. With a 93.55 % clearance of ABTS•+ at a concentration of 2 mg/mL of BSPS-1, the antioxidant activity revealed that BSPS-1 had greater antioxidant activity than BSPS-2 and that both were concentration-dependent. The inhibitory effect on HepG2 cells demonstrated that BSPS-1 and BSPS-2 significantly inhibited the proliferation of HepG2 and increased the expression of apoptotic proteins, causing apoptosis. The inhibition rate on HepG2 cells was dose-dependent and reached 52.7 % and 40.3 % after 48 h of action. BSPS-2 and 800 µg/mL BSPS-1 growth was inhibited in the G1/G0 phase, while 200 and 400 µg/mL BSPS-1 growth was inhibited in the S phase. In conclusion, the study of the BSPS's structure and properties can offer a theoretical foundation for real-world industrial applications.


Assuntos
Antioxidantes , Bacillus subtilis , Antioxidantes/química , Bacillus subtilis/metabolismo , Galactose , Polissacarídeos/química , Glucose , Frutose
5.
Food Chem ; 439: 138078, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38086234

RESUMO

This study investigated the effects of ultrasound-assisted fermentation (UAF) on the preparation of antioxidant peptides (UAFP) from okara and examined their content, chemical structures, and antioxidant activity. After the optimal ultrasonic processing (time, 20 min; frequency, 45 KHz; power, 120 W/L), the peptide content yield reached the maximum of 12.36 ± 0.02 mg/mL, and their DPPH free radical scavenging rate was 65.15 ± 0.32 %. UAF increased the number of globular aggregates with deeper gullies, a looser structure, and higher porosity. The experiments conducted using the oxidative stress injury model of HepG2 cells showed that okara UAFP promoted cell growth and exerted a protective effect. Moreover, ultrasonic treatment remarkably improved the environmental stability (NaCl, glucose, sodium benzoate, temperature, pH, metal ions) and antioxidant activity of UAFP. Concisely, optimal ultrasonic processing can aid the fermentation of agroindustrial by-products to prepare antioxidant peptides, such as natural food antioxidant peptides from soybean waste.


Assuntos
Antioxidantes , Peptídeos , Antioxidantes/química , Fermentação , Peptídeos/química , Aditivos Alimentares
6.
Eur J Med Chem ; 265: 116072, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38147812

RESUMO

As antibiotic-resistant bacteria and genes continue to emerge, the identification of effective alternatives to traditional antibiotics has become a pressing issue. Antimicrobial peptides are favored for their safety, low residue, and low resistance properties, and their unique antimicrobial mechanisms show significant potential in combating antibiotic resistance. However, the high production cost and weak activity of antimicrobial peptides limit their application. Moreover, traditional laboratory methods for identifying and designing new antimicrobial peptides are time-consuming and labor-intensive, hindering their development. Currently, novel technologies, such as artificial intelligence (AI) are being employed to develop and design new antimicrobial peptide resources, offering new opportunities for the advancement of antimicrobial peptides. This article summarizes the basic characteristics and antimicrobial mechanisms of antimicrobial peptides, as well as their advantages and limitations, and explores the application of AI in antimicrobial peptides prediction amd design. This highlights the crucial role of AI in enhancing the efficiency of antimicrobial peptide research and provides a reference for antimicrobial drug development.


Assuntos
Antibacterianos , Anti-Infecciosos , Antibacterianos/química , Peptídeos Antimicrobianos , Inteligência Artificial , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química
7.
J Agric Food Chem ; 71(48): 18953-18962, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37979135

RESUMO

Dajiang, a traditional Chinese condiment, is made from fermented soybeans. It is highly popular among consumers as a result of its delicious umami flavor, which mainly originates from umami peptides. To examine the mechanism of umami taste in Dajiang, we selected Dajiang samples with strong umami taste and subjected them to purification and identification analysis using ethanol precipitation, gel chromatography, reversed-phase high-performance liquid chromatography, and ultraperformance liquid chromatography-tandem mass spectrometry. Subsequently, on the basis of toxicity and umami prediction analysis, we screened, synthesized, and characterized three novel bean umami peptides in Dajiang: TLGGPTTL, 758.4174 Da; GALEQILQ, 870.4811 Da; and HSISDLQ, 911.4713 Da. Their sensory threshold values were 0.25, 0.40, and 0.17 mmol/L, respectively. Furthermore, molecular docking results showed that hydrogen-bonding and hydrophobic interactions are important interaction forces in the binding of umami peptide to taste receptors. Ser147 and Glu148 of the T1R3 taste receptor are important amino acid residues for binding of the three umami peptides. This study uncovers the mechanism of umami-peptide-driven flavor in fermented soybean products.


Assuntos
Alimentos Fermentados , Simulação de Acoplamento Molecular , Peptídeos/química , Paladar , Alimentos Fermentados/análise , Receptores Acoplados a Proteínas G/metabolismo
8.
Microb Cell ; 10(11): 233-247, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37933277

RESUMO

Microbial biofilms can cause chronic infection. In the clinical setting, the biofilm-related infections usually persist and reoccur; the main reason is the increased antibiotic resistance of biofilms. Traditional antibiotic therapy is not effective and might increase the threat of antibiotic resistance to public health. Therefore, it is urgent to study the tolerance and resistance mechanism of biofilms to antibiotics and find effective therapies for biofilm-related infections. The tolerance mechanism and host reaction of biofilm to antibiotics are reviewed, and bacterial biofilm related diseases formed by human pathogens are discussed thoroughly. The review also explored the role of biofilms in the development of bacterial resistance mechanisms and proposed therapeutic intervention strategies for biofilm related diseases.

9.
Biochim Biophys Acta Rev Cancer ; 1878(6): 188989, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37742727

RESUMO

Inflammatory bowel disease (IBD) is associated with complex complications that may lead to tumors. However, research on the mechanisms underlying susceptibility to chronic immune diseases and cancer pathogenesis triggered by the inflammatory environment remains limited. An imbalance in the host gut microbiota often accompanies intestinal inflammation. The delayed recovery of the dysregulated intestinal microbiota may exacerbate systemic inflammatory responses, multiorgan pathology, and metabolic disorders. This delay may also facilitate bacterial translocation. This review examined the relationship between gut barrier disruption and unbalanced microbial translocation and their impact on the brain, liver, and lungs. We also explored their potential roles in tumor initiation. Notably, the role of the intestinal microbiota in the development of inflammation is linked to the immune surveillance function of the small intestine and the repair status of the intestinal barrier. Moreover, adherence to a partially anti-inflammatory diet can aid in preventing the malignant transformation of inflammation by repairing the intestinal barrier and significantly reducing inflammation. In conclusion, enhancing intestinal barrier function may be a novel strategy for preventing and treating chronic malignancies in the intestine and other body areas.


Assuntos
Doenças Inflamatórias Intestinais , Neoplasias , Humanos , Inflamação , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/microbiologia , Dieta , Fígado/metabolismo
10.
Nat Commun ; 14(1): 3967, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37407565

RESUMO

Downsizing electrode architectures have significant potential for microscale energy storage devices. Asymmetric micro-supercapacitors play an essential role in various applications due to their high voltage window and energy density. However, efficient production and sophisticated miniaturization of asymmetric micro-supercapacitors remains challenging. Here, we develop a maskless ultrafast fabrication of multitype micron-sized (10 × 10 µm2) micro-supercapacitors via temporally and spatially shaped femtosecond laser. MXene/1T-MoS2 can be integrated with laser-induced MXene-derived TiO2 and 1T-MoS2-derived MoO3 to generate over 6,000 symmetric micro-supercapacitors or 3,000 asymmetric micro-supercapacitors with high-resolution (200 nm) per minute. The asymmetric micro-supercapacitors can be integrated with other micro devices, thanks to the ultrahigh specific capacitance (220 mF cm-2 and 1101 F cm-3), voltage windows in series (52 V), energy density (0.495 Wh cm-3) and power density (28 kW cm-3). Our approach enables the industrial manufacturing of multitype micro-supercapacitors and improves the feasibility and flexibility of micro-supercapacitors in practical applications.

11.
ACS Appl Mater Interfaces ; 15(15): 18569-18589, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37037009

RESUMO

The decreased number of viable bacteria and the ability of Bifidobacterium to adhere to and colonize the gut in the gastrointestinal environment greatly limit their efficacy. To solve this problem, thiolated carboxymethyl cellulose sodium (CMC) probiotic double-layered multinucleated microcapsules with Bifidobacterium adolescentis FS2-3 in the inner layer and Bacillus subtilis SN15-2 embedded in the outer layers were designed. First, the viable counts and release rates of microcapsules were examined by in vitro simulated digestion assays, and it was found that microcapsules were better protected from gastrointestinal digestion than the controls. Compared with free Bifidobacterium strains, double-layered multinucleated microcapsules have higher viable bacterial survival rates and storage stability. Second, through in vitro rheology, tensile tests, isotherm titration calorimetry, and adhesion tests, it was observed that thiolated CMC could enhance the strong interaction of Bifidobacterium with intestinal mucus and significantly promote the proliferation and growth of probiotics. Finally, double-layered multinucleated microcapsules containing B. adolescentis FS2-3 and B. subtilis SN15-2 modified with sulfhydryl-modified CMC were studied in the intestine. Alleviation of Escherichia coli O157:H7 induced intestinal inflammation. The results showed that microencapsulation could significantly increase the colon content of Bifidobacterium, relieve intestinal inflammation symptoms in mice with bacterial enteritis, and repair the intestinal microbiota disorder caused by inflammation. The probiotic double-layered multinucleated microcapsules prepared in this study can improve the survival rate of probiotics and promote proliferation, adhesion, and colonization of probiotics.


Assuntos
Escherichia coli O157 , Probióticos , Animais , Camundongos , Carboximetilcelulose Sódica , Cápsulas/química , Bifidobacterium , Probióticos/uso terapêutico , Sódio
12.
Compr Rev Food Sci Food Saf ; 22(4): 2773-2801, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37082778

RESUMO

The characteristic flavor of fermented foods has an important impact on the purchasing decisions of consumers, and its production mechanisms are a concern for scientists worldwide. The perception of food flavor is a complex process involving olfaction, taste, vision, and oral touch, with various senses contributing to specific properties of the flavor. Soy-based fermented products are popular because of their unique flavors, especially in Asian countries, where they occupy an important place in the dietary structure. Microorganisms, known as the souls of fermented foods, can influence the sensory properties of soy-based fermented foods through various metabolic pathways, and are closely related to the formation of multisensory properties. Therefore, this review systematically summarizes the core microbiome and its interactions that play an active role in representative soy-based fermented foods, such as fermented soymilk, soy sauce, soybean paste, sufu, and douchi. The mechanism of action of the core microbial community on multisensory flavor quality is revealed here. Revealing the fermentation core microbiome and related enzymes provides important guidance for the development of flavor-enhancement strategies and related genetically engineered bacteria.


Assuntos
Alimentos Fermentados , Microbiota , Alimentos de Soja , Fermentação , Alimentos Fermentados/microbiologia , Alimentos de Soja/análise , Redes e Vias Metabólicas
13.
Zhongguo Zhen Jiu ; 43(2): 203-6, 2023 Feb 12.
Artigo em Chinês | MEDLINE | ID: mdl-36808516

RESUMO

The paper presents professor WU Han-qing's experience in treatment of lumbar disc herniation (LDH) with "sinew-bone three needling technique" of Chinese medicine. Based on the theory of meridian sinew, the points are located by "three-pass method" in terms of the distribution of meridian sinew and syndrome/pattern differentiation. The cord-like muscles and adhesion are relieved by relaxing technique to work directly on the affected sites and alleviate the local compression to the nerve root. The needle technique is operated flexibly according to the affected regions involved, due to which, the needling sensation is increased while the safety ensured. As a result, the meridian qi is enhanced, the mind and qi circulation is regulated; and the clinical effect is improved.


Assuntos
Terapia por Acupuntura , Deslocamento do Disco Intervertebral , Meridianos , Humanos , Medicina Tradicional Chinesa , Deslocamento do Disco Intervertebral/terapia , Terapia por Acupuntura/métodos , Procedimentos Cirúrgicos Vasculares , Pontos de Acupuntura
14.
Food Chem X ; 17: 100581, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36845482

RESUMO

Mature milk, as a nutrient-rich endogenous metabolite, has various beneficial effects on the human body. In order to investigate the specific nutrients provided by different dairy products to humans, we used UHPLC-Q-TOF MS to analyze the highly significantly differentially expressed metabolites in 13 species of mammalian mature milk, which were grouped into 17 major metabolite classes with 1992 metabolites based on chemical classification. KEGG shows that 5 pathways in which differentially significant metabolites are actively involved are ABC transporters, Purine metabolism, Pyrimidine metabolism, Phosphotransferase system, Galactose metabolism. The study found that pig milk and goat milk are closer to human milk and contain more nutrients that are beneficial to human health, followed by camel milk and cow milk. In the context of dairy production, the development of goat milk is more likely to meet human needs and health.

15.
Food Res Int ; 163: 112291, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36596196

RESUMO

Thermosonication (TS) is a novel and viable technique employed to replace conventional thermal processing. TS treatment combined with pasteurization was used to kill the residual heat-resistant Bacillus in pasteurized milk and extend the shelf life of pasteurized milk and compared with High Temperture Shoort Time (HTST) pasteurization to study its decontamination effect on Bacillus subtilis and the quality of treated milk. The results showed that after 40 kHz, 240 W, 25 min ultrasonic treatment and 50 °C heating decontamination treatment, the number of B. subtilis in the medium and milk medium decreased by 4.17 log CFU/mL and 4.09 log CFU/mL respectively. The results of cell membrane permeability showed that the leakage of DNA and protein in the HTST-TS group increased by 52.3 % and 34 %, respectively, when compared to that in the HTST group. In addition, transmission electron microscopy (TEM) analysis showed that the bacterial cell membrane of the HTST-TS group swelled up, the cell wall was ruptured, and the cell content was accumulated in the cells. The results showed that HTST-TS treatment significantly inhibited the activities of ATPase (47 %), succinate dehydrogenase (SDH) (68.6 %), and malate dehydrogenase (MDH) (54.4 %). The physical and chemical sensory evaluation of milk treated with HTST-TS showed that HTST-TS treatment could improve the L* value (2.24 %), zeta potential (64.19 %), and colloidal particle size (14.49 %) of milk but had no significant effect on oral sensitivity. In conclusion, this study provides new insights, which may be helpful in implementing this new combined decontamination method in the dairy industry to improve the quality of pasteurized milk and extend the its shelf life.


Assuntos
Bacillus , Animais , Leite/química , Subtilisina/análise , Descontaminação , Pasteurização/métodos
16.
Crit Rev Biotechnol ; 43(5): 753-769, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35658758

RESUMO

Polyunsaturated fatty acids (PUFAs) have beneficial roles in a variety of human pathologies and disorders. Owing to the limited source of PUFAs in animals and plants, microorganisms, especially fungi, have become a new source of PUFAs. In fungi, fatty acid desaturases (F-FADS) are the main enzymes that convert saturated fatty acids (SFAs) into PUFAs. Their catalytic activities and substrate specificities, which are directly dependent on the structure of the FADS proteins, determine their efficiency to convert SFAs to PUFAs. Catalytic mechanisms underlying F-FADS activities can be determined from the findings of the relationship between their structure and function. In this review, the advances made in the past decade in terms of catalytic activities and substrate specificities of the fungal FADS cluster are summarized. The relationship between the key domain(s) and site(s) in F-FADS proteins and their catalytic activity is highlighted, and the FADS cluster is analyzed phylogenetically. In addition, subcellular localization of F-FADS is discussed. Finally, we provide prospective crystal structures of F-FADSs. The findings may provide a reference for the resolution of the crystal structures of F-FADS proteins and facilitate the increase in fungal PUFA production for human health.


Assuntos
Ácidos Graxos Dessaturases , Ácidos Graxos Insaturados , Animais , Humanos , Estudos Prospectivos , Ácidos Graxos Insaturados/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos , Plantas/metabolismo
17.
Crit Rev Food Sci Nutr ; 63(5): 569-584, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35647734

RESUMO

Horizontal gene transfer (HGT) has contributed significantly to the adaptability of bacteria, yeast and mold in fermented foods, whose evidence has been found in several fermented foods. Although not every HGT has biological significance, it plays an important role in improving the quality of fermented foods. In this review, how HGT facilitated microbial domestication and adaptive evolution in fermented foods was discussed. HGT can assist in the industrial innovation of fermented foods, and this adaptive evolution strategy can improve the quality of fermented foods. Additionally, the mechanism underlying HGT in fermented foods were analyzed. Furthermore, the critical bottlenecks involved in optimizing HGT during the production of fermented foods and strategies for optimizing HGT were proposed. Finally, the prospect of HGT for promoting the industrial innovation of fermented foods was highlighted. The comprehensive report on HGT in fermented foods provides a new trend for domesticating preferable starters for food fermentation, thus optimizing the quality and improving the industrial production of fermented foods.


Assuntos
Alimentos Fermentados , Transferência Genética Horizontal , Bactérias/genética , Alimentos
18.
Food Chem ; 404(Pt A): 134583, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36257274

RESUMO

Umami peptides are an important taste substance in fermented foods. However, in the absence of known microbiota-derived umami peptides, the understanding of the umami mechanism remains unclear. Tetragenococcus halophilus, a dominant fermentation bacteria, may be an important source of umami peptides. Accordingly, T. halophilus fermentation broth was fractioned by ethanol precipitation, gel chromatography, and reverse phase-high performance liquid chromatography. The isolated peptide fraction with the most intense umami taste was screened by amino acid composition and sensory analyses. Finally, three novel microbiota-derived peptides (DFE, LAGE, and QLQ) were identified, synthesized, and characterized for taste. Among them, only DFE had umami and umami-enhancing abilities improving multiple tastes. Molecular docking studies indicated that DEF binds to T1R1/T1R3 receptors through hydrogen bonding and electrostatic interactions involving receptor residues Ser332, Ser256, ASN41, His125, etc. This study highlights the critical role of microbiota-derived peptides in the umami taste of fermented foods.


Assuntos
Microbiota , Paladar , Simulação de Acoplamento Molecular , Peptídeos/química , Aminoácidos , Receptores Acoplados a Proteínas G/metabolismo
19.
J Sci Food Agric ; 103(2): 738-749, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36053948

RESUMO

BACKGROUND: Exopolysaccharide biopolymers produced by microorganisms are crucial to the environment. They contribute to areas such as the health and bionanotechnology sectors, food and cosmetic industries as gelling agents, and environmental sector as flocculants owing to their biodegradability and non-toxic nature. The current study aimed to isolate the fraction of released exopolysaccharide (rEPS) by Bacillus velezensis SN-1 from Chinese Da-Jiang. RESULTS: The weighted average molecular weight of the major isolated component, rEPS-2, was 202 kDa, and its monosaccharide composition included mannose, glucose, and galactose at a molar ratio of 0.38:0.30:0.32. Further, the rEPS-2 was characterized using methylation analysis and one-dimensional/two-dimensional nuclear magnetic resonance (1D/2D NMR) spectroscopy. In vivo hepatoprotective effects indicated that rEPS-2 could alleviate carbon tetrachloride (CCl4 )-induced liver injury in mice by lowering the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the malondialdehyde (MDA) levels. Furthermore, rEPS-2 can increase the expression of antioxidant genes HO-1, GCLC and NQO1 in the Nrf2/ARE signaling pathway, thereby increasing the activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and reduced catalase (CAT) in liver cells. Furthermore, the rEPS-2 can be used and modulate the gut microbiota of mice with liver injury caused by CCl4 . CONCLUSIONS: These results suggest that rEPS-2 has promising potential to serve as hepatoprotective agents. © 2022 Society of Chemical Industry.


Assuntos
Antioxidantes , Doença Hepática Induzida por Substâncias e Drogas , Camundongos , Animais , Antioxidantes/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Tetracloreto de Carbono/farmacologia , Tetracloreto de Carbono/toxicidade , Aspartato Aminotransferases/metabolismo , Alanina Transaminase/metabolismo , Fígado/metabolismo , Estresse Oxidativo
20.
J Sci Food Agric ; 103(6): 2960-2969, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36534037

RESUMO

BACKGROUND: Mold-ripened cheeses have low levels of unsaturated fatty acids (UFAs). Geotrichum candidum is an adjunct culture for the development of Geotrichum-ripened cheese but has a low ability to produce high levels of UFAs. Δ12 fatty acid desaturase (FADS12) is a pivotal enzyme that converts oleic acid (OA) to linoleic acid (LA) and plays a vital role in UFA biosynthesis. By investigating FADS12 catalytic activity from various species with OA substrates, we found that FADS12 from Mucor circinelloides (McFADS12) had the highest catalytic activity for OA. RESULTS: In the current study, a plasmid harboring McFADS12 was constructed and overexpressed in G. candidum. Our results showed that LA production increased to 31.1 ± 1.4% in engineered G. candidum - three times higher than that in wild-type G. candidum. To enhance LA production, an exogenous substrate (OA) was supplemented, and the yield of LA was increased to 154 ± 6 mg L-1 in engineered G. candidum. Engineered G. candidum was used as an adjunct culture for Geotrichum-ripened cheese production. The LA level reached 74.3 ± 5.4 g kg-1 cheese, whereas the level of saturated fatty acids (SFAs) decreased by 9.9 ± 0.5%. In addition, the soybean byproduct (okara) was introduced into the engineered G. candidum growth and the level of LA increased to 126 ± 4 g kg-1 cheese and the percentage of UFAs:SFAs increased from 0.8:1 to 1.3:1. CONCLUSION: This study offers a suitable technology for converting SFAs to UFAs in Geotrichum-ripened cheeses and provides a novel trend for converting soybean waste into a value-added product. © 2022 Society of Chemical Industry.


Assuntos
Queijo , Ácidos Graxos Dessaturases , Geotrichum , Farinha , Ácido Linoleico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...