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1.
Food Chem ; 334: 127428, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32688173

RESUMO

Aspergillus quadrilineatus endo-ß-mannanase effectively degraded konjac glucomannan (66.09% w/v), copra meal (38.99% w/v) and locust bean galactomannan (20.94% w/v). High performance liquid chromatography (HPLC) analysis of KG hydrolysate indicated its mannooligosaccharides (MOS) content (656.38 mg/g) with high amounts of DP 5 oligosaccharide. Multi-scale characterization of mannan hydrolysate was done using FTIR and 13C NMR which revealed α and ß form of galactose or glucose in MOS, respectively. CM and LBG hydrolysates (1 mg/mL) have shown cytotoxic effect and reduced cell viability of Caco-2 cells by 45% and 62%, respectively. MOS DP (1-4) derived from LBG supported better Lactobacilli biofilm formation as compared to KG hydrolysate containing high DP MOS (5-7). Lactobacilli effectively fermented MOS to generate acetate and propionate as main short chain fatty acids. Lactobacilli produced leucine, isoleucine and valine as branched chain amino acids when grown on LBG hydrolysate.


Assuntos
Mananas/química , Oligossacarídeos/farmacologia , Prebióticos , beta-Manosidase/metabolismo , Aspergillus/enzimologia , Biofilmes , Células CACO-2 , Fermentação , Humanos , Hidrólise , Lactobacillus/crescimento & desenvolvimento , Espectroscopia de Ressonância Magnética , Mananas/metabolismo , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , beta-Manosidase/química
2.
Food Chem ; 336: 127616, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32763733

RESUMO

This study is an example of apple by-products (AP) recycling through a designed fermentation by selected autochthonous Lactobacillus plantarum AFI5 and Lactobacillus fabifermentans ALI6 used singly or as binary cultures with the selected Saccharomyces cerevisiae AYI7. Compared to Raw-, Unstarted- and Chemically Acidified-AP, Fermented-AP promoted the highest levels of total and insoluble dietary fibers, DPPH scavenging capacity, and free phenolics. The binary culture of L. plantarum AFI5 and S. cerevisiae AYI7 had the best effect on the bioavailability phenolic compounds as resulted by the LC-MS/MS validated method. The accumulation of phenolic acids derivatives highlighted the microbial metabolism during AP fermentation. Bio-converted phenolics were likely responsible for the increased DPPH scavenging capacity. The potential health-promoting effects of Fermented-AP were highlighted using Caco-2 cells. With variations among single and binary cultures, fermented-AP counteracted the inflammatory processes and the effects of oxidative stress in Caco-2 cells, and preserved the integrity of tight junctions.


Assuntos
Suplementos Nutricionais/análise , Malus/química , Fenóis/química , Anti-Inflamatórios/análise , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Técnicas de Cultura Celular por Lotes , Células CACO-2 , Cromatografia Líquida de Alta Pressão , Humanos , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Malus/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/análise , Fenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Espectrometria de Massas em Tandem
3.
Int J Food Microbiol ; 333: 108798, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32771821

RESUMO

Biopreservation of dairy products by acid lactic bacteria appears as a promising alternative to either replace or reduce the use of chemical preservatives. This study aimed at the identification of bacteria preventing fungal spoilers growth in dairy products, and, at the understanding of their antifungal activity. First, antifungal activity of eighteen Lactobacillus strains was tested against five molds and four yeasts leading to selection of L. casei 7006 which had an activity against seven fungal targets. Then, challenge tests against C. lusistaniae 3668 in a cheese-mimicking matrix have been performed demonstrating that this strain was able to reduce strongly this yeast growth after 14 and 21 days storages at 7 °C. Antifungal compounds produced in cheese-mimicking matrix containing L. casei 7006 strain were quantified, then compared to the one prepared with an inactive strain (L. casei 6960) or without Lactobacillus strain. Three compounds were differently produced between cheeses with or without Lactobacillus strain after 21 days at 7 °C: lactic acid, benzoic acid and diacetyl. However, lactic acid concentrations were similar between the three cheeses after 14 days at 7 °C, but an antifungal activity was only associated to L. casei 7006 presence. Benzoic acid concentrations between cheese with L. casei 7006 and negative control L. casei 6960 were also the same. Among the antifungal molecules retrieved from these analyses, diacetyl was the most significantly overproduced in cheese containing L. casei 7006, thus this volatile was associated to the antifungal activity of this strain.


Assuntos
Antibiose/fisiologia , Queijo/microbiologia , Conservantes de Alimentos/análise , Lactobacillus/metabolismo , Antifúngicos/análise , Ácido Benzoico/análise , Diacetil/análise , Microbiologia de Alimentos , Ácido Láctico/análise , Lactobacillus/classificação , Lactobacillus/crescimento & desenvolvimento , Leveduras
4.
Food Chem ; 332: 127382, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619943

RESUMO

Sea buckthorn (Hippophaë rhamnoides L.) berries have high biological value as a rich source of phenolic compounds, fatty acids and vitamins A, C, E. Due to the high organic acid content and sour taste, the fruits are rarely used in juice production. Therefore, the study aimed to determine the metabolic activity of Lactobacillus plantarum, Lactobacillus plantarum subsp. argentoratensis and Oenococcus oeni strains along with the dynamics of changes in organic acids, sugars, phenolic compounds, and antioxidant activity during 72-h fermentation of 100% sea buckthorn and mixed with apple (1:1) juices. The strongest malolactic conversion was in mixed juices (to 75.0%). The most efficient strains were L. plantarum DSM 10492, 20174 and 6872. L. plantarum strains caused an increase in flavonols and antioxidant activity of sea buckthorn-apple juices. The results can be used to select conditions and strains in industrial-scale fermentation, to produce novel sea buckthorn products and increase their consumption.


Assuntos
Antioxidantes/química , Sucos de Frutas e Vegetais/análise , Ácido Láctico/metabolismo , Malatos/metabolismo , Fenóis/metabolismo , Açúcares/metabolismo , Fermentação , Flavonóis/química , Flavonóis/metabolismo , Frutas/química , Frutas/metabolismo , Hippophae/química , Hippophae/metabolismo , Concentração de Íons de Hidrogênio , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Malus/química , Malus/metabolismo , Oenococcus/crescimento & desenvolvimento , Oenococcus/metabolismo , Fenóis/química
5.
Oncology ; 98(9): 593-602, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32604093

RESUMO

BACKGROUND: Colorectal cancer is the second leading cause of cancer-related death worldwide. In recent years, researchers have focussed on the role of the intestinal microbiota in both the prevention and the treatment of colorectal cancer. SUMMARY: The evidence in the literature supports that there is a fragile balance between different species of bacteria in the human gut. A disturbance of this balance towards increased levels of the bacteria Fusobacterium nucleatum and Bacteroides fragilis is associated with an increased risk of colorectal cancer. The mechanisms involved include the release of toxins which activate inflammation and the regulation of specific miRNAs (with an increase in the expression of oncogenic miRNAs and a decrease in the expression of tumour suppressor miRNAs), thereby increasing cell proliferation and leading to tumorigenesis. On the other hand, Lactobacillus and Bifidobacterium have a protective effect against the development of colorectal cancer through mechanisms that involve an increase in the levels of anticarcinogenic metabolites such as butyrate and a decrease in the activity of proinflammatory pathways. Even though preliminary studies support that the use of probiotics in the prevention and management of colorectal cancer is promising, more research is needed in this field. Key Message: The association between the intestinal microbiota, diet and colorectal cancer remains an active area of research with expected future applications in the use of probiotics for the prevention and management of this significant disease.


Assuntos
Neoplasias Colorretais/dietoterapia , Neoplasias Colorretais/microbiologia , Microbioma Gastrointestinal/fisiologia , Animais , Bacteroides fragilis/crescimento & desenvolvimento , Bifidobacterium/crescimento & desenvolvimento , Neoplasias Colorretais/prevenção & controle , Fusobacterium nucleatum/crescimento & desenvolvimento , Humanos , Lactobacillus/crescimento & desenvolvimento
6.
Food Chem ; 333: 127527, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683263

RESUMO

The aim of this study was to develop a novel fermented soybean food (FSF) using selected Bacillus subtilis GD1, Bacillus subtilis N4, Bacillus velezensis GZ1, Lactobacillus delbrueckii subsp. bulgaricus and Hansenula anomala, as well as to assess its antioxidant and anti-fatigue activity. These Bacillus strains had excellent enzyme producing and soybean transformation capacity. FSF showed the highest peptide, total phenol, total flavonoid content, antioxidant activity, and suitable organic acid and biological amine content. In intense exercise mice, FSF treatment markedly increased hepatic glycogen level, decreased metabolite accumulation, improved the activities of antioxidant enzymes and decreased malondialdehyde (MDA) level in serum and liver, respectively. Furthermore, FSF treatment increased nuclear factor-erythroid 2-related factor 2 (Nrf2) and antioxidant response element (ARE)-dependent gene expression. Together, the selection of microbial starter culture and mixed culture fermentation are essential for the effective enrichment of bioactive compounds, and FSF has stronger antioxidant and anti-fatigue activity.


Assuntos
Antioxidantes/metabolismo , Bacillus/metabolismo , Alimentos e Bebidas Fermentados/análise , Lactobacillus/metabolismo , Pichia/metabolismo , Soja/metabolismo , Animais , Antioxidantes/farmacologia , Bacillus/crescimento & desenvolvimento , Nitrogênio da Ureia Sanguínea , Fadiga/metabolismo , Fadiga/patologia , Flavonoides/análise , Glicogênio/metabolismo , Lactobacillus/crescimento & desenvolvimento , Fígado/metabolismo , Masculino , Malondialdeído/sangue , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/análise , Condicionamento Físico Animal , Pichia/crescimento & desenvolvimento , Soja/química
7.
Food Chem ; 326: 126985, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32413764

RESUMO

This study aims to investigate the effects of fermentation on the phenolic components and their bioaccessibility in extruded brown rice (EBR). The saccharified solution of EBR (SS-EBR) depicted higher phenolics when fermented by single or co-culture of Lactobacillusplantarum, Lactobacillus fermentum and Saccharomyces cerevisiae for 24 h at 37 °C. The co-culture fermented SS-EBR more significantly enhanced free, conjugated and bound phenolics and flavonoids with total increment of 93.3% and 61.3%, respectively. Fermentation changed the contents and compositions of phenolics in each fraction with more than 10-fold increase in vanillic acid and quercetin contents. Ferulic, p-cumaric and chlorogenic acids were increased by 83.5%, 52.2% and 113.4%, respectively, while kaempferol and cinnamic acid were found only in fermented SS-EBR. Fermentation also improved the oxygen radical absorption capacity (ORAC) and the bioaccessible phenolics in SS-EBR. Hence, the co-culture fermented SS-EBR, can be utilized as a functional supplement to provide more bioaccessible antioxidants.


Assuntos
Lactobacillus/crescimento & desenvolvimento , Oryza/química , Fenóis/química , Saccharomyces cerevisiae/crescimento & desenvolvimento , Antioxidantes/metabolismo , Técnicas de Cultura Celular por Lotes , Flavonoides/metabolismo , Oryza/metabolismo , Fenóis/metabolismo , Quercetina/metabolismo , Saccharomyces cerevisiae/metabolismo , Ácido Vanílico/metabolismo
8.
PLoS One ; 15(4): e0228798, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330172

RESUMO

OBJECTIVE: This study aimed to investigate salivary levels of Streptococcus mutans (S. mutans) and Lactobacilli, and other salivary indices in subjects wearing clear aligners (CA) in comparison with multibrackets orthodontic appliances (MB). MATERIALS AND METHODS: A sample of 80 participants (46 males and 34 females) was included in the study: 40 subjects (aged 20.4±1.7 years) were treated with CA, and 40 (aged 21.3±1.7 years) were treated with MB. Plaque index (PI), salivary flow, buffering power of saliva, and salivary levels of S. mutans and Lactobacilli were evaluated prior to start of orthodontic treatment (t0), after 3 months (t1) and 6 months (t2). RESULTS: CA patients maintained PI at level 0 over time, while MB participants experienced a statistically significant increasing trend of PI over time. In addition, at t2, 37.5% of MB participants (15 subjects over 40) showed risky salivary levels (CFU/ml>105) of S. mutans (odds ratio = 7.40; 95% C.I. = 1.94-28.25; chi-square = 10.32; p = 0.001) as well as Lactobacilli (odds ratio = 23.40; 95% C.I. = 2.91-188.36; chi-square = 15.31; p = 0.0001). CONCLUSIONS: Comparing all the data, subjects treated with CA achieved lower salivary microbial colonization after 6 months of treatment compared with MB. Different additional strategies for plaque control and salivary microbial colonization must be triggered considering the type of orthodontic appliance.


Assuntos
Índice de Placa Dentária , Lactobacillus/fisiologia , Aparelhos Ortodônticos Fixos , Aparelhos Ortodônticos Removíveis , Saliva/microbiologia , Streptococcus mutans/fisiologia , Contagem de Colônia Microbiana , Feminino , Humanos , Lactobacillus/crescimento & desenvolvimento , Masculino , Streptococcus mutans/crescimento & desenvolvimento , Adulto Jovem
9.
Microbiol Res ; 236: 126450, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146295

RESUMO

The industrial ethanol fermentation imposes several stresses to microorganisms. However, some bacterial species are well adapted and manage to endure these harmful conditions. Lactobacillus vini is one of the most found bacteria in these environments, indicating the existence of efficient tolerance mechanisms. In view of this premise, the present study aimed to describe the tolerance of L. vini to several stressing agents encounter in industrial environments and the genetic components of the stress response. In general, L. vini showed significant tolerance to stressors commonly found in fuel-ethanol fermentations, and only doses higher than normally reached in processes restrained its growth. The lag phase and the growth rate were the most responsive kinetic parameter affected. Gene expression analysis revealed that uspII gene positively responded to all conditions tested, a typical profile of a general stress response gene. In addition, the results also revealed aspects of regulatory modules of co-expressed genes responding to different stresses, and also the similarities of response mechanism with basis in common cellular damages. Altogether, these data contribute to uncover the factors that could favour L. vini in the industrial fermentation which could be shared with other well adapted species and reports the first stress response genes in this bacterium.


Assuntos
Adaptação Fisiológica/genética , Microbiologia Industrial , Lactobacillus , Estresse Fisiológico/genética , Etanol , Fermentação , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Concentração de Íons de Hidrogênio , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Temperatura , Transcriptoma
10.
Int J Food Microbiol ; 321: 108551, 2020 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-32078867

RESUMO

Sourdough is a very interesting natural preservation system to prolong mould free shelf-life of bread. Numerous studies have reported that the antifungal activity of sourdough is mainly correlated with the presence of lactic (LA) and acetic acid (AA), but very few information is available on the effect of undissociated acid concentrations in the aqueous phase of bread (CHA; mmole/L). This study was conducted to provide additional information about the mode of action of the acids in sourdough bread, enabling a better shelf-life prediction. This study was divided into two parts. In part 1, three industrial biological sourdoughs were characterized (dough yield, pH, aw, fermentation quotient, microbiota). During 7 weeks, a shelf-life test with natural flora was conducted with daily checks of visible mould growth (21 °C). In part 2, the effect of the acids present in the antifungal active sourdough breads was validated in chemically acidified wheat breads. Complete growth inhibition was observed in full-baked sourdough bread (30 g/100 g dough) containing Lactobacillus sanfranciscensis and Saccharomyces cerevisiae as dominant sourdough micro-organisms, whereas in control bread the shelf-life was limited to 4.4-9.2 days. These full-baked sourdough breads contained 36 mmole undissociated LA/L and 220 mmole undissociated AA/L. The data were used to make General Linear Regression models for shelf-life prediction and resulted in a fit of R2 = 0.79 when expressing the shelf-life in function of CHA,LA and CHA,AA. In acidified breads, the role of lactic acid was not significant and only impacted shelf-life indirectly through acidification. No difference between antifungal activity of sourdough breads and chemically acidified bread with comparable CHA,AA concentrations was observed. Shelf-life increased when 150-200 mmole undissociated AA/L aqueous phase in bread was present. To conclude, this study showed the importance of the undissociated acid fraction of acetic acid in relation to bread shelf-life, together with bread pH and moisture content.


Assuntos
Ácido Acético/farmacologia , Antifúngicos/farmacologia , Pão/análise , Conservação de Alimentos/métodos , Ácido Láctico/farmacologia , Ácido Acético/análise , Antifúngicos/análise , Pão/microbiologia , Fermentação , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Ácido Láctico/análise , Lactobacillus/efeitos dos fármacos , Lactobacillus/crescimento & desenvolvimento , Triticum/microbiologia , Água/análise
11.
Animal ; 14(6): 1156-1166, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32026796

RESUMO

To further understand the contribution of feedstuff ingredients to gut health in swine, gut histology and intestinal bacterial profiles associated with the use of two high-quality protein sources, microbially enhanced soybean meal (MSBM) and Menhaden fishmeal (FM) were assessed. Weaned pigs were fed one of three experimental diets: (1) basic diet containing corn and soybean meal (Negative Control (NEG)), (2) basic diet + fishmeal (FM; Positive Control (POS)) and (3) basic diet + MSBM (MSBM). Phase I POS and MSBM diets (d 0 to d 7 post-wean) included FM or MSBM at 7.5%, while Phase II POS and MSBM diets (d 8 to d 21) included FM or MSBM at 5.0%. Gastrointestinal tissue and ileal digesta were collected from euthanised pigs at d 21 (eight pigs/diet) to assess gut histology and intestinal bacterial profiles, respectively. Data were analysed using Proc Mixed in SAS, with pig as the experimental unit and pig (treatment) as the random effect. Histological and immunohistochemical analyses of stomach and small intestinal tissue using haematoxylin-eosin, Periodic Acid Schiff/Alcian blue and inflammatory cell staining did not reveal detectable differences in host response to dietary treatment. Ileal bacterial composition profiles were obtained from next-generation sequencing of PCR generated amplicons targeting the V1 to V3 regions of the 16S rRNA gene. Lactobacillus-affiliated sequences were found to be the most highly represented across treatments, with an average relative abundance of 64.0%, 59.9% and 41.80% in samples from pigs fed the NEG, POS and MSBM diets, respectively. Accordingly, the three most abundant Operational Taxonomic Units (OTUs) were affiliated to Lactobacillus, showing a distinct abundance pattern relative to dietary treatment. One OTU (SD_Ssd_00001), most closely related to Lactobacillus amylovorus, was found to be more abundant in NEG and POS samples compared to MSBM (23.5% and 35.0% v. 9.2%). Another OTU (SD_Ssd_00002), closely related to Lactobacillus johnsonii, was more highly represented in POS and MSBM samples compared to NEG (14.0% and 15.8% v. 0.1%). Finally, OTU Sd_Ssd-00011, highest sequence identity to Lactobacillus delbrueckii, was found in highest abundance in ileal samples from MSBM-fed pigs (1.9% and 3.3% v. 11.3, in POS, NEG and MSBM, respectively). There was no effect of protein source on bacterial taxa to the genus level or diversity based on principal component analysis. Dietary protein source may provide opportunity to enhance presence of specific members of Lactobacillus genus that are associated with immune-modulating properties without altering overall intestinal bacterial diversity.


Assuntos
Bactérias/crescimento & desenvolvimento , Proteínas na Dieta/análise , Suínos/microbiologia , Ração Animal/análise , Animais , Dieta/veterinária , Feminino , Trato Gastrointestinal/microbiologia , Íleo/microbiologia , Lactobacillus/crescimento & desenvolvimento , Masculino , RNA Ribossômico 16S/genética , Soja , Suínos/crescimento & desenvolvimento , Suínos/fisiologia , Desmame , Zea mays
12.
J Sci Food Agric ; 100(6): 2554-2567, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31975408

RESUMO

BACKGROUND: Carapax Trionycis is the shell of the soft-shelled turtle. It is rich in minerals, amino acid, peptides, and other nutrients. Current processing and consumption of soft-shelled turtle leads to the waste of huge quantities of Carapax Trionycis in the form of spent materials. In this study, the bioavailability, prebiotic activity, and physicochemical properties of Carapax Trionycis using different processing methods were investigated. The vinegar-quenched Carapax Trionycis (V-CT), fine powders (D0.18, D0.10), and superfine powders (D0.05, D0.025) of Carapax Trionycis were prepared by the vinegar-quenching method, common grinding, and the superfine grinding method. RESULTS: The average particle sizes of D0.18, D0.10, D0.05, and D0.025 were 147.82, 77.35, 36.65, and 2.24 µm, respectively. Superfine grinding changed the surface morphology of Carapax Trionycis and promoted the release of active ingredients. D0.025 had the highest polypeptide (8.15%), polysaccharide (1.21%), total free amino acid (232.36 mg 100 g-1 ) and water-soluble extract content (10.74%), and showed the highest calcium release rate (55.64%) after in vitro digestion. The apparent permeability (PAPP ) of the resulting Carapax Trionycis samples in the dialysis tubing model and the everted intestinal sac model increased significantly with the decrease in the Carapax Trionycis particle sizes. Furthermore, the five Carapax Trionycis samples significantly stimulated the growth of the tested probiotics and increased lactic acids production after 48 h fermentation compared to the control. The Carapax Trionycis powder prepared by superfine grinding displayed better prebiotic activity than other samples as it significantly induced a greater proliferation of probiotic bacteria and higher production of lactic acid, as well as greater release of free calcium. CONCLUSIONS: The results showed that Carapax Trionycis superfine powder D0.025 had the highest active ingredient content, calcium bioavailability, and prebiotic activity. Our approach of developing Carapax Trionycis superfine powder as natural calcium supplement or potential prebiotic would therefore broaden the scope of soft-shelled turtle processing waste utilization in an eco-friendly, cost-effective, and sustainable approach in the future. © 2020 Society of Chemical Industry.


Assuntos
Exoesqueleto/química , Disponibilidade Biológica , Prebióticos/análise , Tartarugas , Animais , Cálcio/química , Digestão , Resíduos Industriais , Absorção Intestinal , Lactobacillus/crescimento & desenvolvimento , Masculino , Tamanho da Partícula , Pós/química , Probióticos , Ratos Sprague-Dawley
13.
J Food Sci ; 85(2): 289-297, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31968403

RESUMO

The purpose of the study was to investigate the effect of a reduced pH value (5.1 instead of 5.5 to 5.6) on the properties of highly perishable, spreadable raw fermented sausages (onion mettwurst) with or without the addition of homopolysaccharide (HoPS)-producing lactic acid bacteria (LAB). Hence, sausages with HoPS-producing LAB and a pH value of 5.1 were produced and compared to sausages (pH 5.1) produced with a non-exopolysaccharide (EPS)-forming strain (Lactobacillus sakei TMW 1.2037). Microbial growth and pH values were monitored during processing (24 °C for 48 hr, 10 °C for 24 hr) and storage (14 days at 0 to 2 °C). Furthermore, fat (Weibull-Stoldt) and EPS contents were determined in the final products. Sausages were characterized using texture profile and sensory analysis. The fat contents ranged from 16% to 19% and the determined EPS concentrations ranged from 0.17 to 0.59 g/kg for L. sakei TMW 1.411 and Lactobacillus curvatus TMW 1.1928 and from 0.67 to 1.58 g/kg for L. curvatus TMW 1.51. The strains L. sakei TMW 1.411 and L. curvatus TMW 1.51 reduced the hardness of the samples significantly (P < 0.05) compared to the control samples. Regarding spreadability and mouthfeel, sausages containing an EPS-forming culture were rated slightly better than the control samples and the taste was not negatively influenced. PRACTICAL APPLICATION: This study clearly demonstrated that it is promising to apply HoPS-producing LAB to maintain the spreadability of pH-reduced (pH 5.1) spreadable raw fermented onion mettwurst, which may prospectively give the opportunity to increase the safety of this highly perishable product.


Assuntos
Alimentos e Bebidas Fermentados/microbiologia , Lactobacillus/metabolismo , Produtos da Carne/microbiologia , Polissacarídeos/metabolismo , Animais , Fermentação , Alimentos e Bebidas Fermentados/análise , Aditivos Alimentares/análise , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Produtos da Carne/análise , Suínos , Paladar
14.
J Dairy Sci ; 103(2): 1269-1275, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31837788

RESUMO

Control of Listeria monocytogenes in queso fresco and other fresh cheeses continues to be a challenge in the United States. These cheese types are particularly challenging due to their high moisture and high pH, which provide favorable conditions for the growth of L. monocytogenes. Protective cultures (i.e., viable strains of lactic acid bacteria that inhibit other microorganisms) have been investigated in foods such as meat as an alternative, clean-label control strategy for L. monocytogenes. However, the efficacy of protective cultures can vary by food matrix. In this study, we were interested in whether protective cultures used to control L. monocytogenes in meats could be applied to control the pathogen in queso fresco. We selected 4 commercially available bacterial cultures used for the control of L. monocytogenes in meat: Lactobacillus curvatus, Lactobacillus sakei, Pediococcus acidilactici, and Leuconostoc carnosum. We incorporated these cultures into batches of queso fresco during manufacturing and evaluated them for their ability to inhibit the growth of surface-applied L. monocytogenes at levels of 1 × 102 and 1 × 104 cfu/g. We stored the queso fresco at 6 and 21°C for up to 21 d. After 14 d, Listeria was able to grow to 1 × 107 cfu/g on the cheese. Our data show that the bacterial cultures did not significantly inhibit the growth of L. monocytogenes in queso fresco. The results from this study highlight the complexity of antagonistic bacterial interactions and their potential variability across food matrices. Protective cultures represent an important, clean-label tool for the control of L. monocytogenes in foods, but each strain must be evaluated in the food environment it is intended for to ensure its efficacy.


Assuntos
Queijo/microbiologia , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Listeria monocytogenes/crescimento & desenvolvimento , Carne/microbiologia , Animais , Lactobacillus/crescimento & desenvolvimento , Leuconostoc/crescimento & desenvolvimento
15.
J Perinat Med ; 48(2): 179-183, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31874102

RESUMO

Background To meet the nutritional needs of preterm infants, multicomponent nutrient fortifiers are added to human milk. The fortified human milk (FHM) product changes the physical and biochemical characteristics of the milk. We questioned whether such physical-chemical changes in the milk would alter intrinsic probiotic bacterial activity. The objective of the study was to evaluate the effect of osmolality and pH on the growth of probiotic bacterial species intrinsic to human milk. Methods Human milk samples (n = 26) were collected from mothers in the neonatal intensive care unit (NICU) and stored at -20°C until analyzed. The samples were thawed and divided into three portions. Human milk fortifiers (HMFs) were added to two portions to prepare concentrations of FHM. The remaining portion was the unfortified control sample. Each sample was then divided into two parts. One part (baseline) was used to measure the osmolality and pH and plated on selective agar to enumerate the growth of lactobacilli and bifidobacteria species. The remaining part was incubated at 37°C for 24 h to further test bacterial integrity (post-incubation) and then the same measurements were made (osmolality, pH, bacterial colony counts). Results When compared with unfortified milk at baseline, osmolality increased and pH decreased significantly after the addition of HMFs. Lactobacilli and bifidobacteria colony counts did not differ among the groups pre-incubation. Post-incubation lactobacilli and bifidobacteria increased in all the groups. Conclusion The appropriate addition of HMFs differentially affected the osmolality and pH of the milk. These physical changes did not affect the growth of probiotic bacterial species.


Assuntos
Alimentos Fortificados/microbiologia , Leite Humano/microbiologia , Probióticos , Bifidobacterium/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Lactobacillus/crescimento & desenvolvimento , Leite Humano/química , Concentração Osmolar
16.
Int J Food Microbiol ; 313: 108379, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31675541

RESUMO

Lactobacillus algidus is a meat spoilage bacterium often dominating the bacterial communities on chilled, packaged meat. Yet, L. algidus strains are rarely recovered from meat, and only few studies have focused on this species. The main reason limiting detailed studies on L. algidus is related to its poor growth on the media routinely used for culturing food spoilage bacteria. Thus, our study sought to develop reliable culture media for L. algidus to enable its recovery from meat, and to allow subculturing and phenotypic analyses of the strains. We assessed the growth of meat-derived L. algidus strains on common culture media and their modifications, and explored the suitability of potential media for the recovery of L. algidus from meat. Moreover, we determined whether 12 meat-derived L. algidus strains selected from our culture collection produce biogenic amines that may compromise safety or quality of meat, and finally, sequenced de novo and annotated the genomes of two meat-derived L. algidus strains to uncover genes and metabolic pathways relevant for phenotypic traits observed. MRS agar supplemented with complex substances (peptone, meat and yeast extract, liver digest) supported the growth of L. algidus, and allowed the recovery of new L. algidus isolates from meat. However, most strains grew poorly on standard MRS agar and on general-purpose media. In MRS broth, most strains grew well but a subset of strains required supplementation of MRS broth with additional cysteine. Supplementation of MRS broth with catalase allowed growth in aerated cultures suggesting that the strains produced hydrogen peroxide when grown aerobically. The strains tested (n = 12) produced ornithine from arginine and putrescine from agmatine, and two strains produced tyramine from tyrosine. Our findings reveal that L. algidus populations are underestimated if routine culture protocols are applied, and prompt concerns that L. algidus may generate tyramine or putrescine in meat or fermented meat products.


Assuntos
Lactobacillus/crescimento & desenvolvimento , Produtos da Carne/microbiologia , Animais , Aminas Biogênicas/análise , Aminas Biogênicas/metabolismo , Bovinos , Meios de Cultura/metabolismo , Fermentação , Lactobacillus/metabolismo , Produtos da Carne/análise , Putrescina/análise , Putrescina/metabolismo , Suínos
17.
J Agric Food Chem ; 67(50): 13969-13977, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31747272

RESUMO

Various ß-galactosidase enzymes catalyze the trans-glycosylation reaction with lactose. The resulting galactooligosaccharide (GOS) mixtures are widely used in infant nutrition to stimulate growth of beneficial gut bacteria. GOS consists mainly of compounds with a degree of polymerization (DP) varying from 2-8 and with diverse glycosidic linkages. In recent years, we have elucidated in detail the composition of several commercial GOS mixtures in terms of DP and the structural identity of the individual compounds. In this work, 13 (single) probiotic strains of gut bacteria, belonging to 11 different species, were grown to stationary phase with a Vivinal GOS-derived sample purified to remove lactose and monosaccharides (pGOS). Growth among the probiotic strains varied strongly between 30 and 100% of OD600nm relative to positive controls with glucose. By identifying the components of the pGOS mixture that remain after growth, we showed that strains varied in their consumption of specific GOS compounds. All strains commonly used most of the GOS DP2 pool. Lactobacillus salivarius W57 also utilized the DP3 branched compound ß-d-Galp-(1 → 4)-[ß-d-Galp-(1 → 2)]-d-Glc. Bifidobacterial strains tended to use GOS with higher DP and branching than lactobacilli; Bifidobacterium breve DSM 20091, Lactobacillus acidophilus W37, and Bifidobacterium infantis DSM 20088 were exceptional in using 38, 36, and 35 compounds, respectively, out of the 40 different structures identified in pGOS. We correlated these bacterial GOS consumption profiles with their genomic information and were able to relate metabolic activity with the presence of genome-encoded transporters and carbohydrate-active enzymes. These detailed insights may support the design of synbiotic combinations pairing probiotic bacterial strains with GOS compounds that specifically stimulate their growth. Such synbiotic combinations may be of interest in food/feed and/or pharmacy/medicine applications.


Assuntos
Bifidobacterium/metabolismo , Lactobacillus/metabolismo , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Lactobacillus/crescimento & desenvolvimento , Lactobacillus acidophilus/crescimento & desenvolvimento , Lactobacillus acidophilus/metabolismo , Prebióticos/análise , Probióticos/metabolismo
18.
Food Funct ; 10(12): 7828-7843, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31778135

RESUMO

Rhamnogalacturonan-I (RG-I)-enriched pectin (WRP) was recovered from citrus processing water by sequential acid and alkaline treatments in a previous study. RG-I-enriched pectin was proposed as a potential supplement for functional food and pharmaceutical development. However, previous studies illustrated that favorable modulations of gut microbiota by RG-I-enriched pectin were based on in vitro changes in the overall microbial structure and the question of whether there is a structure-dependent modulation of gut microbiota remains largely enigmatic. In the present study, modulations of gut microbiota by commercial pectin (CP), WRP and its depolymerized fraction (DWRP) with different RG-I contents and Mw were compared in vivo. It was revealed by 16s rRNA high-throughput sequencing that WRP and DWRP mainly composed of RG-I modulated the gut microbiota in a positive way. DWRP significantly increased the abundance of prebiotic such as Bifidobacterium spp., Lactobacillus spp., while WRP increased SCFAs producers including species in Ruminococcaceae family. By maintaining a more balanced gut microbiota composition and enriching some SCFA producers, dietary WRP and DWRP also elevated the SCFA content in the colon. Collectively, our findings offer new insights into the structure-activity correlation of citrus pectin and provide impetus towards the development of RG-I-enriched pectin with small molecular weight for specific use in health-promoting prebiotic ingredients and therapeutic products.


Assuntos
Bactérias/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Lactobacillus/crescimento & desenvolvimento , Pectinas/farmacologia , Extratos Vegetais/farmacologia , Animais , Bactérias/efeitos dos fármacos , Bifidobacterium/efeitos dos fármacos , Citrus/química , Faecalibacterium/efeitos dos fármacos , Faecalibacterium/crescimento & desenvolvimento , Fermentação , Lactobacillus/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Pectinas/análise , Extratos Vegetais/análise , Prebióticos/análise
19.
Biomed Res Int ; 2019: 1083952, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662964

RESUMO

Globe artichoke is an intriguing source of indigestible sugar polymers such as inulin-type fructans. In this study, the effect of ultrasound in combination with ethanol precipitation to enhance the extraction of long chain fructans from artichoke wastes has been evaluated. The inulin-type fructans content both from bracts and stems was measured using an enzymatic fructanase-based assay, while its average degree of polymerization (DP) was determined by HPLC-RID analysis. Results show that this method provides artichoke extracts with an inulin-type fructans content of 70% with an average DP between 32 and 42 both in bracts and in stems. The prebiotic effect of long chain inulins from artichoke extract wastes was demonstrated by its ability to support the growth of five Lactobacillus and four Bifidobacterium species, previously characterized as probiotics. Besides, we considered the possibility to industrialize the process developing a simpler method for the production of inulin-type fructans from the artichoke wastes so that the artichoke inulin preparation could be suitable for its use in synbiotic formulations in combination with different probiotics for further studies including in vivo trials.


Assuntos
Cynara scolymus/química , Frutanos/isolamento & purificação , Microbioma Gastrointestinal/efeitos dos fármacos , Inulina/isolamento & purificação , Extratos Vegetais/farmacologia , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/crescimento & desenvolvimento , Glicosídeo Hidrolases , Hidroxibenzoatos/isolamento & purificação , Lactobacillus/efeitos dos fármacos , Lactobacillus/crescimento & desenvolvimento , Extratos Vegetais/química , Polimerização , Prebióticos , Proteínas/análise , Ondas Ultrassônicas
20.
Nat Med ; 25(10): 1500-1504, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31591599

RESUMO

We report the results of a first exploratory study testing the use of vaginal microbiome transplantation (VMT) from healthy donors as a therapeutic alternative for patients suffering from symptomatic, intractable and recurrent bacterial vaginosis (ClinicalTrials.gov NCT02236429 ). In our case series, five patients were treated, and in four of them VMT was associated with full long-term remission until the end of follow-up at 5-21 months after VMT, defined as marked improvement of symptoms, Amsel criteria, microscopic vaginal fluid appearance and reconstitution of a Lactobacillus-dominated vaginal microbiome. One patient presented with incomplete remission in clinical and laboratory features. No adverse effects were observed in any of the five women. Notably, remission in three patients necessitated repeated VMT, including a donor change in one patient, to elicit a long-standing clinical response. The therapeutic efficacy of VMT in women with intractable and recurrent bacterial vaginosis should be further determined in randomized, placebo-controlled clinical trials.


Assuntos
Lactobacillus/crescimento & desenvolvimento , Microbiota , Vagina/microbiologia , Vaginose Bacteriana/terapia , Adulto , Feminino , Humanos , Lactobacillus/genética , Microbiota/genética , Pessoa de Meia-Idade , Probióticos/uso terapêutico , Indução de Remissão , Doadores de Tecidos , Vagina/patologia , Vaginose Bacteriana/microbiologia , Vaginose Bacteriana/patologia
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