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1.
Biomed Res Int ; 2021: 1057531, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34435040

RESUMO

Nowadays, production of functional foods has become very essential. Inulin is one of the most functional hydrocolloid compounds used in such products. In the present study, the production of a synbiotic yogurt containing 1, 2.5, and 5% (w/v) inulin has been investigated. The yogurt was fermented with Lactobacillus brevis PML1 derived from Tarkhineh, an Iranian cereal-dairy fermented food. Furthermore, the physicochemical properties, antioxidant activity, sensory attributes, and microbial viability properties were investigated on the 0th, 7th, and 14th days of storage after fermentation. The viable cells of L. brevis PML1 reached 108 CFU/g, and the product resisted to simulated digestive juices. Moreover, the synbiotic yogurt impressively increased the production of antimicrobial compounds and had the most profound antimicrobial effect on S. typhimurium. The physiochemical properties were in the normal range, and the fat content of the synbiotic yogurt was reduced remarkably. The antioxidant capacity of the fermented yogurt was significantly increased (p < 0.05), which was equal to those of DPPH (69.18 ± 1.00%) and BHA (89.16 ± 2.00%). The viability of L. brevis PML1 was increased during storage. Sensory analysis showed that there were significant differences in terms of the impressive parameters between the samples and the control (p < 0.05). Addition of 2.5% inulin not only improved the physical properties but also retained the viability of the probiotic after 14 days of storage, in addition to the viability of L. brevis with a viability count above 6 log CFU/g in the yogurt. Therefore, a novel synbiotic product containing L. brevis PML1, which can exert the desired properties, can be used as a suitable carrier for the delivery of the probiotic strain, exerting its beneficial health effects.


Assuntos
Laticínios/microbiologia , Grão Comestível/microbiologia , Lactobacillus brevis/metabolismo , Simbióticos/análise , Iogurte/microbiologia , Antioxidantes/análise , Fermentação , Inulina/análise , Irã (Geográfico) , Lactobacillus brevis/crescimento & desenvolvimento , Lactobacillus brevis/isolamento & purificação , Viabilidade Microbiana , Iogurte/análise
2.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33805468

RESUMO

The aim of this study was to investigate the effect of Lactobacillus brevis-fermented γ-aminobutyric acid (LB-GABA) on sleep behaviors in invertebrate and vertebrate models. In Drosophila melanogaster, LB-GABA-treated group showed an 8-9%-longer sleep duration than normal group did. LB-GABA-treated group also showed a 46.7% lower level of nighttime activity with a longer (11%) sleep duration under caffeine-induced arousal conditions. The LB-GABA-mediated inhibition of activity was confirmed as a reduction of total movement of flies using a video tracking system. In the pentobarbital-induced sleep test in mice, LB-GABA (100 mg/kg) shortened the time of onset of sleep by 32.2% and extended sleeping time by 59%. In addition, mRNA and protein level of GABAergic/Serotonergic neurotransmitters were upregulated following treatment with LB-GABA (2.0%). In particular, intestine- and brain-derived GABAA protein levels were increased by sevenfold and fivefold, respectively. The electroencephalography (EEG) analysis in rats showed that LB-GABA significantly increased non-rapid eye movement (NREM) (53%) with the increase in theta (θ, 59%) and delta (δ, 63%) waves, leading to longer sleep time (35%), under caffeine-induced insomnia conditions. LB-GABA showed a dose-dependent agonist activity on human GABAA receptor with a half-maximal effective concentration (EC50) of 3.44 µg/mL in human embryonic kidney 293 (HEK293) cells.


Assuntos
Sono/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia , Animais , Cafeína/farmacologia , Proteínas de Drosophila/genética , Drosophila melanogaster , Eletroencefalografia , Fermentação , Agonistas de Receptores de GABA-A/farmacologia , Células HEK293 , Humanos , Hipnóticos e Sedativos/farmacologia , Lactobacillus brevis/metabolismo , Locomoção/efeitos dos fármacos , Masculino , Camundongos Endogâmicos ICR , Neurotransmissores/metabolismo , Pentobarbital/farmacologia , Ratos Sprague-Dawley , Receptores de GABA-A/metabolismo , Receptores de Neurotransmissores/genética , Receptores de Neurotransmissores/metabolismo , Sono/fisiologia , Distúrbios do Início e da Manutenção do Sono/induzido quimicamente , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Ácido gama-Aminobutírico/metabolismo
3.
J Sci Food Agric ; 101(10): 4332-4341, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33417239

RESUMO

BACKGROUND: Elemental selenium, as a new type of selenium supplement, can be prepared by microorganisms reducing inorganic selenium. In this study, Lactobacillus brevis JLD715 was incubated in broth containing different concentrations of sodium selenite (Na2 SeO3 ). RESULTS: The results showed that the bacterial biomass of L. brevis JLD715 decreased due to the inhibition of Na2 SeO3 . The cell membrane of L. brevis JLD715 treated with Na2 SeO3 was damaged, as evidenced by the reduction of intracellular ATP concentration, depolarization of cell membrane, reduction of intracellular pH and impairment of membrane integrity. In addition, we investigated the metabolism mechanism of Na2 SeO3 by L. brevis JLD715 based on transcriptome sequencing. A total of 461 genes were significantly differentially expressed under Na2 SeO3 treatment, of which 231 genes were up-regulated and 230 genes were down-regulated. These genes were involved in pathways such as pyruvate metabolism, fatty acid biosynthesis, selenocompound metabolism and nucleotide-binding oligomerization domain-like (NOD-like) receptor signaling. Meanwhile, the genes related to sulfhydryl oxidoreductase, electron carrier proteins and transmembrane transport proteins synthesis were significantly up-regulated. CONCLUSION: To sum up, the findings of this research will contribute to providing support for the application of L. brevis JLD715 in selenium-enriched functional foods. © 2021 Society of Chemical Industry.


Assuntos
Proteínas de Bactérias/genética , Lactobacillus brevis/genética , Lactobacillus brevis/metabolismo , Selenito de Sódio/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Lactobacillus brevis/crescimento & desenvolvimento , Transcriptoma
4.
J Dairy Sci ; 104(1): 78-91, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33162095

RESUMO

This study focused on the ability of adzuki bean (Vigna angularis) sprout fermented milk, which is rich in γ-aminobutyric acid (GABA), to relieve anxiety and mild depression. A high-yield GABA-producing strain, Lactobacillus brevis J1, from a healthy cow was screened, and its physiological and probiotic properties were evaluated. The effect of adzuki bean sprout fermented milk was investigated in vivo in a chronic depression mouse model. The results showed that Lb. brevis J1 had excellent probiotic properties, grew well at low pH and 3% NaCl, and adhered to the surface of HT-29 cells. The GABA-enriched (241.30 ± 1.62 µg/mL) adzuki bean sprout fermented milk prepared with Streptococcus thermophilus, Lactobacillus bulgaricus, and Lactobacillus plantarum, and Lb. brevis J1 can reduce and possibly prevent mild depression-like symptoms in mice (C57/B6) by increasing social interaction and enhancing the pleasure derived from movement. The research revealed that the GABAB-cyclic AMP-protein kinase A-cAMP-response element binding protein (GABAB-cAMP-PKA-CREB) signaling pathway was related to the depression-like symptoms and that levels of 5-hydroxytryptamine, norepinephrine, and dopamine in the hippocampus of mice increased after treatment with the adzuki bean sprout fermented milk. Our results suggest that GABA-enriched dairy products have the potential to prevent or treat mild depression-like symptoms in mice, which suggests a new approach for a dietary therapy to treat chronic social stress.


Assuntos
Depressão/dietoterapia , Leite/química , Vigna/química , Animais , Bovinos , Modelos Animais de Doenças , Feminino , Fermentação , Lactobacillus brevis/metabolismo , Lactobacillus plantarum/metabolismo , Camundongos , Leite/metabolismo , Probióticos , Streptococcus thermophilus/metabolismo , Ácido gama-Aminobutírico/metabolismo
5.
J Ind Microbiol Biotechnol ; 47(12): 1099-1108, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33221994

RESUMO

N-butanol is an important chemical and can be naturally synthesized by Clostridium species; however, the poor n-butanol tolerance of Clostridium impedes the further improvement in titer. In this study, Lactobacillus brevis, which possesses a higher butanol tolerance, was selected as host for heterologous butanol production. The Clostridium acetobutylicum genes thl, hbd, and crt which encode thiolase, ß-hydroxybutyryl-CoA dehydrogenase, and crotonase, and the Treponema denticola gene ter, which encodes trans-enoyl-CoA reductase were cloned into a single plasmid to express the butanol synthesis pathway in L. brevis. A titer of 40 mg/L n-butanol was initially achieved with plasmid pLY15-opt, in which all pathway genes are codon-optimized. A titer of 450 mg/L of n-butanol was then synthesized when ter was further overexpressed in this pathway. The role of metabolic flux was reinforced with pLY15, in which only the ter gene was codon-optimized, which greatly increased the n-butanol titer to 817 mg/L. Our strategy significantly improved n-butanol synthesis in L. brevis and the final titer is the highest achieved amongst butanol-tolerant lactic acid bacteria.


Assuntos
1-Butanol , Lactobacillus brevis , 1-Butanol/metabolismo , 3-Hidroxiacil-CoA Desidrogenases , Acetil-CoA C-Acetiltransferase/metabolismo , Vias Biossintéticas , Butanóis/metabolismo , Clostridium/metabolismo , Clostridium acetobutylicum/genética , Lactobacillus brevis/metabolismo
6.
Nutrients ; 12(10)2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32987850

RESUMO

Influenza virus type A (IAV) is a seasonal acute respiratory disease virus with severe symptoms, and an effective preventive measure is required. Despite many reports describing the potentially protective effects of lactic acid bacteria, few studies have investigated the effects of nutritional supplement combinations. This study reports the effect of the combined intake of heat-killed Lactobacillus brevis KB290 (KB290) and vitamin A (VA) on mice challenged with a sublethal dose of IAV. For 2 weeks, five groups of mice were fed either placebo, KB290, VA, or a combination of KB290 and VA (KB290+VA). After subsequent IAV challenge, bodyweight and general health were monitored for up to 2 weeks. Viral titres were determined in the lungs of animal subgroups euthanised at days 3, 7, and 14 after IAV challenge. A significant loss was observed in the bodyweights of IAV-infected animals from day 1 post-IAV challenge, whereas the mice fed KB290+VA did not lose any weight after IAV infection, indicating successful protection from the infection. Additionally, mice in the KB290+VA group showed the highest reduction in lung viral titres. In conclusion, the combination of KB290 and VA could be a useful food supplement relevant for protection against seasonal influenza virus infection in humans.


Assuntos
Influenza Humana/prevenção & controle , Lactobacillus brevis/metabolismo , Tretinoína/administração & dosagem , Administração Oral , Animais , Feminino , Temperatura Alta , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana , Probióticos/administração & dosagem , Carga Viral
7.
Int J Food Microbiol ; 333: 108792, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32707524

RESUMO

Gamma aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in nature and its physiological importance goes beyond its role as an inhibitory neurotransmitter of the central nervous system in mammals. Since microbial fermentation is one of the most promising methods to obtain GABA, the production of this metabolite by several strains of lactic acid bacteria isolated from quinoa and amaranth sourdoughs was investigated. Lactobacillus brevis CRL 2013 produced the highest GABA levels, reaching 265 mM when optimal culture conditions were set up. The fermentative profile showed that CRL 2013 was able to catabolize carbohydrates through the phosphoketolase pathway yielding variable amounts of lactic acid, acetate and ethanol, which depended on the type of carbon source available and the presence of external electron acceptors such as fructose. Enhanced growth parameters and low GABA synthesis were associated to pentose fermentation. This impairment on GABA production machinery was partially overpassed by the addition of ethanol to the culture media. These results support the potential use of L. brevis CRL 2013 as a starter culture for the manufacture of GABA-enriched functional foods and provide further insights to the understanding of the GAD system regulation in lactic acid bacteria.


Assuntos
Pão/microbiologia , Metabolismo dos Carboidratos/fisiologia , Fermentação/fisiologia , Lactobacillus brevis/metabolismo , Ácido gama-Aminobutírico/biossíntese , Acetatos/metabolismo , Amaranthus/microbiologia , Carboidratos , Chenopodium quinoa/microbiologia , Meios de Cultura/metabolismo , Etanol/metabolismo , Ácido Láctico/metabolismo
8.
J Appl Microbiol ; 129(5): 1309-1320, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32478894

RESUMO

AIMS: Beer is a harsh medium for bacteria to survive, however, lactic acid bacteria including Lactobacillus brevis have evolved the ability to grow in beer. Here, the influence of environmental factors such as low pH, ethanol or hop content was assessed. METHODS AND RESULTS: A transcriptomic analysis of two Lact. brevis beer-spoiling strains was performed comparing growth in nutritive media with or without the imposition of a stressor related to the beer environment. This allowed the identification of a manganese transporter encoding gene that contributes to low pH tolerance. CONCLUSIONS: We report on the importance of a manganese transporter associated with pH tolerance and beer spoilage in Lact. brevis. The importance of manganese for Lact. brevis growth in a low pH environment was highlighted. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial spoilage of beer may result in product withdrawal with concomitant economic losses for the brewing industry. A limited number of genes involved in beer spoilage have been identified but none of them are universal. It is clear that other molecular players are involved in beer spoilage. The study highlights the complexity of the genetic requirements to facilitate beer spoilage and the role of multiple key players in this process.


Assuntos
Cerveja/microbiologia , Homeostase , Lactobacillus brevis/metabolismo , Manganês/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cerveja/análise , Fermentação , Microbiologia de Alimentos , Perfilação da Expressão Gênica , Concentração de Íons de Hidrogênio , Lactobacillus brevis/genética , Lactobacillus brevis/crescimento & desenvolvimento , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo
9.
Food Microbiol ; 91: 103539, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32539972

RESUMO

Some beverage-spoiling lactic acid bacteria (LAB) produce capsular ß-glucans from UDP-glucose, which is accompanied by cell network formation causing viscosity increases of liquids. This feature of certain LAB is feared in breweries but could be useful for structural and nutritional improvement of baked goods, provided that these LAB are suited for the manufacture of sourdoughs. The aim of this study was to investigate the persistence and ß-glucan formation of the brewery isolates Levilactobacillus (L.) brevis TMW 1.2112 and Pediococcus (P.) claussenii TMW 2.340 in wheat and rye sourdoughs. Both the wild-type strains and the respective ß-glucan-deficient mutants were dominant in wheat and rye sourdoughs and acidified them to characteristic pH ranges. The formation of ß-glucan capsules during sourdough fermentations was stable in L. brevis TMW 1.2112 in contrast to P. claussenii TMW 2.340. Wheat sourdoughs fermented with the ß-glucan producing L. brevis TMW 1.2112 cells were significantly more viscous than doughs fermented by the P. claussenii TMW 2.340 cells and the applied mutant strains. In conclusion, L. brevis TMW 1.2112 and P. claussenii TMW 2.340 were suited and persistent wheat and rye sourdough starters, while the in situ ß-glucan formation in sourdoughs was hardly detectable in case of P. claussenii.


Assuntos
Cerveja/microbiologia , Pão/microbiologia , Lactobacillales/metabolismo , Secale , Triticum , beta-Glucanas/metabolismo , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/metabolismo , Pão/análise , Contagem de Colônia Microbiana , Fermentação , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillales/genética , Lactobacillales/crescimento & desenvolvimento , Lactobacillales/isolamento & purificação , Lactobacillus brevis/genética , Lactobacillus brevis/crescimento & desenvolvimento , Lactobacillus brevis/isolamento & purificação , Lactobacillus brevis/metabolismo , Mutação , Pediococcus/genética , Pediococcus/crescimento & desenvolvimento , Pediococcus/isolamento & purificação , Pediococcus/metabolismo , Secale/microbiologia , Triticum/microbiologia , Viscosidade , beta-Glucanas/análise
10.
Probiotics Antimicrob Proteins ; 12(4): 1542-1554, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32279232

RESUMO

Functional foods and nutraceuticals frequently contain viable probiotic strains that, at certain titers, are considered to be responsible of beneficial effects on health. Recently, it was observed that secreted metabolites might play a key role in this respect, especially in immunomodulation. Exopolysaccharides produced by probiotics, for example, are used in the food, pharmaceutical, and biomedical fields, due to their unique properties. Lactobacillus brevis CD2 demonstrated the ability to inhibit oral pathogens causing mucositis and periodontal inflammation and to reduce Helycobacter pylori infections. Due to the lack of literature, for this strain, on the development of fermentation processes that can increase the titer of viable cells and associated metabolites to industrially attractive levels, different batch and fed-batch strategies were investigated in the present study. In particular, aeration was shown to improve the growth rate and the yields of lactic acid and biomass in batch cultures. The use of an exponential feeding profile in fed-batch experiments allowed to produce 9.3 ± 0.45 × 109 CFU/mL in 42 h of growth, corresponding to a 20-fold increase of viable cells compared with that obtained in aerated batch processes; moreover, also increased titers of exopolysaccharides and lactic acid (260 and 150%, respectively) were observed. A purification process based on ultrafiltration, charcoal treatment, and solvent precipitation was applied to partially purify secreted metabolites and separate them into two molecular weight fractions (above and below 10 kDa). Both fractions inhibited growth of the known gut pathogen, Salmonella typhimurium, demonstrating that lactic acid plays a major role in pathogen growth inhibition, which is however further enhanced by the presence of Lact. brevis CD2 exopolysaccharides. Finally, the EPS produced from Lact. brevis CD2 was characterized by NMR for the first time up to date.


Assuntos
Meios de Cultura/farmacologia , Ácido Láctico/biossíntese , Lactobacillus brevis/metabolismo , Polissacarídeos Bacterianos/biossíntese , Probióticos/análise , Técnicas de Cultura Celular por Lotes/métodos , Fracionamento Químico/métodos , Meios de Cultura/química , Suplementos Nutricionais , Fermentação , Alimento Funcional , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus brevis/efeitos dos fármacos , Peso Molecular , Oxigênio/farmacologia , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento
11.
Sci Rep ; 10(1): 1347, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992761

RESUMO

The characterization of mechanisms involved in the positive effects of probiotic bacteria in various pathophysiological conditions is a prerogative for their safe and efficient application in biomedicine. We have investigated the immunological effects of live bacteria-free supernatant collected from GABA-producing Lactobacillus brevis BGZLS10-17 on Concanavalin A-stimulated mesenteric lymph node cells (MLNC), an in vitro model of activated immune cells. We have shown that GABA containing and GABA-free supernatant of Lactobacillus brevis BGZLS10-17 have strong immunoregulatory effects on MLNC. Further, GABA produced by this strain exhibit additional inhibitory effects on proliferation, IFN-γ and IL-17 production by MLNC, and the expression of MHCII and CD80 on antigen presenting cells. At the other hand, GABA-containing supernatants displayed the strongest stimulatory effects on the expression of immunoregulatory molecules, such as Foxp3+, IL-10, TGF-ß, CTLA4 and SIRP-α. By looking for the mechanisms of actions, we found that supernatants produced by BGZLS10-17 induce autophagy in different MLNC, such as CD4+ and CD8+ T lymphocytes, NK and NKT cells, as well as antigen presenting cells. Further, we showed that the stimulation of Foxp3+, IL-10 and TGF-ß expression by BGZLS10-17 produced GABA is completely mediated by the induction of ATG5 dependent autophagy, and that other molecules in the supernatants display GABA-, ATG5-, Foxp3+-, IL-10- and TGF-ß- independent, immunoregulatory effects.


Assuntos
Proteína 5 Relacionada à Autofagia/metabolismo , Autofagia , Interações Hospedeiro-Patógeno/imunologia , Imunomodulação , Lactobacillus brevis/imunologia , Ácido gama-Aminobutírico/metabolismo , Animais , Autofagia/genética , Proteína 5 Relacionada à Autofagia/genética , Meios de Cultivo Condicionados , Metabolismo Energético , Feminino , Lactobacillus brevis/metabolismo , Probióticos , Ratos , Transdução de Sinais , Ácido gama-Aminobutírico/farmacologia
12.
Appl Environ Microbiol ; 86(7)2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-31953336

RESUMO

Lactic acid bacteria often encounter a variety of multiple stresses in their natural and industrial fermentation environments. The glutamate decarboxylase (GAD) system is one of the most important acid resistance systems in lactic acid bacteria. In this study, we demonstrated that GlnR, a nitrogen regulator in Gram-positive bacteria, directly modulated γ-aminobutyric acid (GABA) conversion from glutamate and was involved in glutamate-dependent acid resistance in Lactobacillus brevis The glnR deletion strain (ΔglnR mutant) achieved a titer of 284.7 g/liter GABA, which is 9.8-fold higher than that of the wild-type strain. The cell survival of the glnR deletion strain was significantly higher than that of the wild-type strain under the condition of acid challenge and was positively correlated with initial glutamate concentration and GABA production. Quantitative reverse transcription-PCR assays demonstrated that GlnR inhibited the transcription of the glutamate decarboxylase-encoding gene (gadB), glutamate/GABA antiporter-encoding gene (gadC), glutamine synthetase-encoding gene (glnA), and specific transcriptional regulator-encoding gene (gadR) involved in gadCB operon regulation. Moreover, GABA production and glutamate-dependent acid resistance were absolutely abolished in the gadR glnR deletion strain. Electrophoretic mobility shift and DNase I footprinting assays revealed that GlnR directly bound to the 5'-untranslated regions of the gadR gene and gadCB operon, thus inhibiting their transcription. These results revealed a novel regulatory mechanism of GlnR on glutamate-dependent acid resistance in Lactobacillus IMPORTANCE Free-living lactic acid bacteria often encounter acid stresses because of their organic acid-producing features. Several acid resistance mechanisms, such as the glutamate decarboxylase system, F1Fo-ATPase proton pump, and alkali production, are usually employed to relieve growth inhibition caused by acids. The glutamate decarboxylase system is vital for GAD-containing lactic acid bacteria to protect cells from DNA damage, enzyme inactivation, and product yield loss in acidic habitats. In this study, we found that a MerR-type regulator, GlnR, was involved in glutamate-dependent acid resistance by directly regulating the transcription of the gadR gene and gadCB operon, resulting in an inhibition of GABA conversion from glutamate in L. brevis This study represents a novel mechanism for GlnR's regulation of glutamate-dependent acid resistance and also provides a simple and novel strategy to engineer Lactobacillus strains to elevate their acid resistance as well as GABA conversion from glutamate.


Assuntos
Ácidos/metabolismo , Proteínas de Bactérias/genética , Ácido Glutâmico/metabolismo , Lactobacillus brevis/genética , Transativadores/genética , Proteínas de Bactérias/metabolismo , Lactobacillus brevis/metabolismo , Transativadores/metabolismo
13.
J Food Sci ; 85(1): 165-172, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31898817

RESUMO

Sufu is a form of food derived from traditional Chinese fermented soybean. It has a unique flavor and contains abundant nutrients. With demands for healthy food on the rise, a higher level of sufu functionality is required. In fermentation of soybean-derived products, lactic acid bacteria (LAB) are widely used as an adjunct culture, which provides health benefits and enhances flavor of food. Among LAB, Lactobacillus brevis has the potential to generate γ-aminobutyric acid (GABA), which is well-known for its physiological functions. In this study, L. brevis was added to bacteria-fermented sufu to evaluate its impacts on sufu quality. Sufu was produced via co-inoculation with Bacillus subtilis and L. brevis (group A sufu) or a single inoculation with B. subtilis (group B sufu). Metabolite changes in the two groups during fermentation were investigated and physicochemical changes were observed. The results indicated that the addition of L. brevis increased the concentration of GABA and decreased the concentrations of histamine and serotonin. The concentrations of volatile compounds, such as esters and acids, especially 2-methyl-butanoic acid ethyl ester, as well as the concentrations of phenylethyl alcohol and 3-methyl-butanol were significantly higher in group A. Inoculation of L. brevis changed the metabolite profile of sufu and improved its functionality and safety of edibility. The current study explored the potential of applying L. brevis to the manufacture of bacteria-fermented sufu.


Assuntos
Bacillus subtilis/metabolismo , Aromatizantes/análise , Lactobacillus brevis/metabolismo , Alimentos de Soja/microbiologia , Ésteres/metabolismo , Fermentação , Aromatizantes/metabolismo , Alimentos de Soja/análise , Soja/química , Soja/metabolismo , Soja/microbiologia , Ácido gama-Aminobutírico/análise , Ácido gama-Aminobutírico/metabolismo
14.
Colloids Surf B Biointerfaces ; 186: 110734, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31865119

RESUMO

Recently, silver nanoparticles gain significant attention due to their applications in various fields. The aim of present study was to develop the eco-friendly, cost effective, and simple method to biosynthesized the silver nanoparticle using sliver nitrate as precursor. In this study, we investigated the physical characterization and biotechnological applications of biosynthesized silver nanoparticle using exopolysaccharide of probiotic Lactobacillus brevis MSR104 isolated from Chinese koumiss. Biosynthesized silver nanoparticles were characterized using the fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, and elemental analyzer. The achieved results indicate that silver nanoparticles varied in sized with an average size of 45 nm. The X-ray diffraction analysis results showed that the silver nanoparticles have a crystalline nature. The results of antimicrobial assay indicated that the silver nanoparticles exhibited outstanding antimicrobial activity in dose dependent manner against both Gram's negative as well as Gram's positive. The antioxidant results indicate that the silver nanoparticles showed excellent scavenging rate against DPPH free radicals (81.4 ±â€¯1.2%) and nitric oxide free radicals (75.06 ±â€¯0.4%). Furthermore, the results of MTT assay revealed that the AgNPs significantly reduced the percentage of live HT-29 cells at higher concentration. This study concluded that the newly synthesized silver nanoparticles have antibacterial, antioxidant, and anticancer applications in agricultural and food industries.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Kumis/microbiologia , Lactobacillus brevis/metabolismo , Polissacarídeos/farmacologia , Antibacterianos/biossíntese , Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Compostos de Bifenilo/antagonistas & inibidores , China , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Lactobacillus brevis/química , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Picratos/antagonistas & inibidores , Polissacarídeos/biossíntese , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Prata/química , Prata/metabolismo , Propriedades de Superfície
15.
Biotechnol Lett ; 42(2): 241-248, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31760528

RESUMO

OBJECTIVE: To evaluate whether the surface layer (S-layer) protein of Lactobacillus brevis serves as a self-aggregating protein tag for cost-effective separation of human and yeast D-amino acid oxidases (hDAAO and yDAAO) expressed in E. coli. RESULTS: In aqueous two-phase (PEG-phosphate) system, the S-layer:DAAO fusion proteins (shDAAO and syDAAO) were separated at the interface with a recovery of 82 ± 10.6% for shDAAO and 95 ± 1.9% for syDAAO. Some shDAAO proteins were separated as precipitates with a recovery of 41 ± 0.5% in phosphate (9%, w/w) using PEG 3000 and PEG 4000 (16%, w/w), while some syDAAO proteins were also isolated as precipitates with a recovery of 75 ± 17.5% in phosphate (9%, w/w) using PEG 4000 and PEG 8000 (16%, w/w). CONCLUSIONS: The S-layer of L. brevis was applied to a self-assembled protein tag to enable cost-effective separation of human and yeast D-amino acid oxidases expressed in E. coli cells. Because of the self-assembling properties of S-layer proteins, human and yeast D-amino acid oxidases fused with S-layer proteins could be easily separated by aggregates at the interface and/or in a few conditions by precipitates to the bottom of the PEG-phosphate aqueous system.


Assuntos
D-Aminoácido Oxidase/isolamento & purificação , Lactobacillus brevis/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas Recombinantes de Fusão/isolamento & purificação , Cromatografia de Afinidade/economia , D-Aminoácido Oxidase/genética , DEAE-Dextrano , Proteínas Fúngicas/isolamento & purificação , Humanos , Glicoproteínas de Membrana/genética , Saccharomyces cerevisiae/metabolismo , Especificidade da Espécie
16.
Int J Food Microbiol ; 316: 108426, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-31722270

RESUMO

Aiming at meeting recent consumers requirements in terms of high nutritional value and functional foods, the cereal food industry has proposed the use of legumes as wheat substitutes due to the high contents of proteins with high biological value and dietary fibers. Nevertheless, legumes contain several anti-nutritional factors which may limit the bio-availability of several nutrients. In this study, an integrate biotechnological approach, combining a thermal treatment ("gelatinization") and fermentation with selected lactic acid bacteria, was set-up in order to improve the functional and nutritional quality of red and yellow lentils, white and black beans, chickpeas and peas flours. Gelatinization carried out at pilot-plant level on legume grains before milling, affected the nutritional properties of the flours by the increase of protein digestibility, resistant starch formation, the decrease of trypsin inhibitors, although negatively affecting the antioxidant activity. Fermentation with Lactobacillus plantarum MRS1 and Lactobacillus brevis MRS4 further enhanced the nutritional properties of processed legume flours through the increase of free amino acids concentration and protein digestibility, the degradation of phytic acid, condensed tannins and raffinose, and the decrease of the trypsin inhibitory activity and starch hydrolysis index. Moreover, fermentation also contributed to the increase of the radical scavenging activity of both raw and processed legumes.


Assuntos
Fabaceae/química , Farinha/análise , Manipulação de Alimentos/métodos , Lactobacillales/metabolismo , Carboidratos/química , Fermentação , Farinha/microbiologia , Lactobacillus brevis/metabolismo , Lactobacillus plantarum/metabolismo , Valor Nutritivo , Proteínas/química , Proteínas/metabolismo
17.
Sci Rep ; 9(1): 16323, 2019 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-31704943

RESUMO

Metabolic and neuroactive metabolite production represents one of the mechanisms through which the gut microbiota can impact health. One such metabolite, gamma-aminobutyric acid (GABA), can modulate glucose homeostasis and alter behavioural patterns in the host. We previously demonstrated that oral administration of GABA-producing Lactobacillus brevis DPC6108 has the potential to increase levels of circulating insulin in healthy rats. Therefore, the objective of this study was to assess the efficacy of endogenous microbial GABA production in improving metabolic and behavioural outcomes in a mouse model of metabolic dysfunction. Diet-induced obese and metabolically dysfunctional mice received one of two GABA-producing strains, L. brevis DPC6108 or L. brevis DSM32386, daily for 12 weeks. After 8 and 10 weeks of intervention, the behavioural and metabolic profiles of the mice were respectively assessed. Intervention with both L. brevis strains attenuated several abnormalities associated with metabolic dysfunction, causing a reduction in the accumulation of mesenteric adipose tissue, increased insulin secretion following glucose challenge, improved plasma cholesterol clearance and reduced despair-like behaviour and basal corticosterone production during the forced swim test. Taken together, this exploratory dataset indicates that intervention with GABA-producing lactobacilli has the potential to improve metabolic and depressive- like behavioural abnormalities associated with metabolic syndrome in mice.


Assuntos
Comportamento Animal , Depressão/complicações , Lactobacillus brevis/metabolismo , Síndrome Metabólica/microbiologia , Síndrome Metabólica/psicologia , Ácido gama-Aminobutírico/biossíntese , Tecido Adiposo/patologia , Animais , Peso Corporal , Colesterol/metabolismo , Corticosterona/metabolismo , Depressão/metabolismo , Depressão/fisiopatologia , Modelos Animais de Doenças , Trânsito Gastrointestinal , Glucose/metabolismo , Resistência à Insulina , Intestino Delgado/metabolismo , Intestino Delgado/microbiologia , Lactobacillus brevis/fisiologia , Aprendizagem em Labirinto , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Metabolômica , Camundongos
18.
J Med Microbiol ; 68(9): 1359-1366, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31364964

RESUMO

Methodology. Biochemical and molecular methods were used to identify 100 lactobacilli isolated from rectal swabs. Among these, L. paracasei ssp. paracasei LP5 and L. brevis LP9 showed significant antibacterial activity against S. agalactiae and L. monocytogenes. Accordingly, characterization of their bacteriocins, BacLP5 and BacLP9, was conducted to obtain information on their kinetic production, sensitivity to chemico-physical parameters and molecular weight. To investigate the possible use of the two Lactobacillus strains as probiotics, their gastrointestinal resistance, cellular adhesiveness and sensitivity to antibiotics were also studied.Results. The obtained data show that BacLP5 and BacLP9 most likely belong to class II bacteriocins and both have a molecular weight of approximately 3 kDa. The production of BacLP5 and BacLP9 started after 4 h (40 and 80 AU ml-1), respectively. Both of the Lactobacillus strains survived gastric and intestinal juices well and showed adhesive capability on HEp-2 cells.Conclusion. Due to their peculiar antimicrobial characteristics, L. paracasei ssp. paracasei LP5 and L. brevis LP9 are suitable for use in the treatment of vaginal disorders, through both oral and transvaginal administration.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Lactobacillus brevis/metabolismo , Lactobacillus paracasei/metabolismo , Antibacterianos/química , Antibacterianos/isolamento & purificação , Aderência Bacteriana , Bacteriocinas/química , Bacteriocinas/isolamento & purificação , Ácidos e Sais Biliares/farmacologia , Linhagem Celular , Fenômenos Químicos , Suco Gástrico/metabolismo , Humanos , Lactobacillus brevis/classificação , Lactobacillus brevis/isolamento & purificação , Lactobacillus paracasei/classificação , Lactobacillus paracasei/isolamento & purificação , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Peso Molecular , Probióticos , Reto/microbiologia , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/crescimento & desenvolvimento
19.
J Microbiol Biotechnol ; 29(11): 1745-1748, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31434366

RESUMO

Gamma-aminobutyric acid (GABA) plays important roles in host physiology. However, the effects of GABA are greatly restricted due to its low bioavailability in the human body. Here, a high acid-tolerance GABA-producing strain, Lactobacillus brevis Bmb5, was isolated from kimchi. Bmb5 converted glutamate to GABA (7.23 ± 0.68 µg/µl) at a rate of 72.3%. The expression of gadB gene, encoding the enzyme involved in the decarboxylation of glutamate to GABA, was decreased upon incubation. Our findings indicate GABA production in Bmb5 is not directly correlated with gadB gene expression, providing new insight into the mechanisms underlying GABA production in Lactobacillus.


Assuntos
Lactobacillus brevis/metabolismo , Glutamato de Sódio/metabolismo , Ácido gama-Aminobutírico/metabolismo , Ácidos/metabolismo , Proteínas de Bactérias/genética , Alimentos e Bebidas Fermentados/microbiologia , Expressão Gênica , Glutamato Descarboxilase/genética , Concentração de Íons de Hidrogênio , Lactobacillus brevis/enzimologia , Lactobacillus brevis/genética , Lactobacillus brevis/crescimento & desenvolvimento , Proteínas de Membrana Transportadoras/genética
20.
Food Res Int ; 123: 115-124, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31284959

RESUMO

Selenium (Se), which is present as SeCys in seleno-proteins, is involved in cancer prevention, thyroid functioning, and pathogen inhibition. Se is incorporated in the diet through Se-containing foods. Some lactic acid bacteria (LAB) can biotransform selenite (toxic) into Se-nanoparticles (SeNPs) and Se-amino acids. To exert their beneficial properties in the host, bacteria should survive the harsh conditions of the gastrointestinal tract and during food storage. We evaluated whether selenization of LAB influenced bacterial growth and survival during gastrointestinal digestion and after storage when present in a fermented fruit juice-milk (FJM) beverage. Lactobacillus brevis CRL 2051 and Fructobacillus tropaeoli CRL 2034 were grown in MRS with and without selenite, and used to inoculate the FJM matrix. Selenization had no effect on LAB growth (9.54-9.9 log CFU/mL) in the FJM drink. The presence of SeNPs was confirmed for both selenized strains in the FJM beverage; however, the highest Se concentration (100 µg/L) was detected for the fermented beverage with selenized L. brevis. Under storage conditions 1.1 log CFU/ml decrease in cell count of selenized cells of L. brevis was observed, while no effect on cell viability was detected for non-selenized L. brevis or both selenized and control cells of F. tropaeoli. Resistance of L. brevis during digestion of the fermented FJM beverage was not affected by selenization. Contrarily, an increase (1 log CFU/mL) in the resistance of F. tropaeoli was observed when cells were selenized. After digestion, Se was detected in the soluble fraction of the beverage fermented by both strains, being higher for L. brevis (23.6 µg/L). Although selenization did not exert a drastic effect on strains´ survival during storage and digestion, microbial selenization previous to food fermentation could be an interesting tool for Se enrichment avoiding thus the addition of toxic Se salts.


Assuntos
Digestão , Fermentação , Lactobacillales/metabolismo , Selênio/metabolismo , Animais , Bebidas/microbiologia , Alimentos e Bebidas Fermentados/microbiologia , Armazenamento de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillus brevis/isolamento & purificação , Lactobacillus brevis/metabolismo , Leuconostocaceae/isolamento & purificação , Leuconostocaceae/metabolismo , Nanopartículas Metálicas/química , Microscopia Eletrônica de Varredura , Leite/microbiologia , Modelos Biológicos
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