RESUMO
The purpose of this study is to evaluate the effect of the bioconversion products of Oenanthe javanica extract fermented by Lactiplantibacillus plantarum (OEFL) on relieving hangovers and improving liver function. In addition, the bioactive substance of the OEFL, which alleviates hangover and ethanol-induced liver damage, was identified and its bioactive property was verified through in vivo experiments. In major substances analysis using high-performance liquid chromatography, OEFL produced 9.5-fold higher p-coumaric acid than the O. Javanica extract (OE). In addition, considering that quinic acid, which is not present in the OE, was produced in the OEFL it was confirmed that chlorogenic acid was decomposed into quinic acid by bioconversion. In the in vivo experiment using Sprague-Dawley rats, the OEFL and p-coumaric acid diets reduced blood ethanol, acetaldehyde, GPT, and ALP concentrations, increasing blood albumin concentrations compared to ethanol-administered groups, demonstrating that OEFL and p-coumaric acid, the main substance in the OEFL, improved ethanol-induced liver damage. Furthermore, the OEFL and its main bioactive substance, p-coumaric acid, alleviated liver fibrosis by downregulating TGF-ß, SMAD-2, SMAD-4, α-SMA, and upregulating MMP-1. Therefore, OEFL is expected to be used as a functional food or pharmaceutical material as it has been confirmed to effectively relieve hangovers, prevent liver damage, and delay liver fibrosis in ethanol-induced liver damages.
Assuntos
Intoxicação Alcoólica/tratamento farmacológico , Ácidos Cumáricos , Etanol/toxicidade , Lactobacillaceae/crescimento & desenvolvimento , Cirrose Hepática Alcoólica , Oenanthe/química , Extratos Vegetais , Intoxicação Alcoólica/metabolismo , Animais , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacologia , Cirrose Hepática Alcoólica/tratamento farmacológico , Cirrose Hepática Alcoólica/metabolismo , Masculino , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
Postbiotic RS5, produced by Lactiplantibacillus plantarum RS5, has been identified as a promising alternative feed supplement for various livestock. This study aimed to lower the production cost by enhancing the antimicrobial activity of the postbiotic RS5 by improving the culture density of L. plantarum RS5 and reducing the cost of growth medium. A combination of conventional and statistical-based approaches (Fractional Factorial Design and Central Composite Design of Response Surface Methodology) was employed to develop a refined medium for the enhancement of the antimicrobial activity of postbiotic RS5. A refined medium containing 20 g/L of glucose, 27.84 g/L of yeast extract, 5.75 g/L of sodium acetate, 1.12 g/L of Tween 80 and 0.05 g/L of manganese sulphate enhanced the antimicrobial activity of postbiotic RS5 by 108%. The cost of the production medium was reduced by 85% as compared to the commercially available de Man, Rogosa and Sharpe medium that is typically used for Lactobacillus cultivation. Hence, the refined medium has made the postbiotic RS5 more feasible and cost-effective to be adopted as a feed supplement for various livestock industries.
Assuntos
Anti-Infecciosos/metabolismo , Meios de Cultura/química , Lactobacillus plantarum/crescimento & desenvolvimento , Meios de Cultura/análise , Meios de Cultura/síntese química , Fermentação , Lactobacillaceae/crescimento & desenvolvimento , Lactobacillaceae/metabolismo , Lactobacillales/crescimento & desenvolvimento , Lactobacillales/metabolismo , Lactobacillus plantarum/metabolismoRESUMO
The objective of this study was to investigate prebiotic potential, chemical composition, and antioxidant capacity of spice extracts. Seven culinary spices including black pepper, cayenne pepper, cinnamon, ginger, Mediterranean oregano, rosemary, and turmeric were extracted with boiling water. Major chemical constituents were characterized by RP-HPLC-DAD method and antioxidant capacity was determined by measuring colorimetrically the extent to scavenge ABTS radical cations. Effects of spice extracts on the viability of 88 anaerobic and facultative isolates from intestinal microbiota were determined by using Brucella agar plates containing serial dilutions of extracts. A total of 14 phenolic compounds, a piperine, cinnamic acid, and cinnamaldehyde were identified and quantitated. Spice extracts exhibited high antioxidant capacity that correlated with the total amount of major chemicals. All spice extracts, with the exception of turmeric, enhanced the growth of Bifidobacterium spp. and Lactobacillus spp. All spices exhibited inhibitory activity against selected Ruminococcus species. Cinnamon, oregano, and rosemary were active against selected Fusobacterium strains and cinnamon, rosemary, and turmeric were active against selected Clostridium spp. Some spices displayed prebiotic-like activity by promoting the growth of beneficial bacteria and suppressing the growth of pathogenic bacteria, suggesting their potential role in the regulation of intestinal microbiota and the enhancement of gastrointestinal health. The identification and quantification of spice-specific phytochemicals provided insight into the potential influence of these chemicals on the gut microbial communities and activities. Future research on the connections between spice-induced changes in gut microbiota and host metabolism and disease preventive effect in animal models and humans is needed.
Assuntos
Extratos Vegetais/química , Prebióticos/análise , Especiarias/análise , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Capsicum/química , Cromatografia Líquida de Alta Pressão , Cinnamomum zeylanicum/química , Curcuma/química , Humanos , Lactobacillaceae/efeitos dos fármacos , Lactobacillaceae/crescimento & desenvolvimento , Origanum/química , Fenóis/análise , Extratos Vegetais/farmacologia , Especiarias/intoxicaçãoRESUMO
Buckwheat sourdoughs supplemented with molasses as natural sucrose source were fermented with levan-producing Gluconobacter (G.) albidus TMW 2.1191 and Kozakia (K.) baliensis NBRC 16680. Cell growth, concomitant levan and low-molecular-weight metabolite production were monitored. Sourdough breads were prepared with different sourdoughs from both strains (24, 30 and 48 h fermentation, respectively) and analyzed with respect to bread volume, crumb hardness and sensory characteristics. During fermentation, levan, acetic and gluconic acids were increasingly produced, while spontaneously co-growing lactic acid bacteria additionally formed acetic and lactic acids. Sourdoughs from both strains obtained upon 24 h of fermentation significantly improved the bread sensory and quality, including higher specific volume as well as lower crumb hardness. Buckwheat doughs containing isolated levan, with similar molecular size and mass compared to in situ produced levan in the sourdough at 48 h, verified the positive effect of levan on bread quality. However, the positive effects of levan were masked to a certain extent by the impact from the natural acidification during fermentations. While levan-producing acetic acid bacteria are a promising alternative for the development of clean-label gluten-free breads without the need of additives, an appropriate balance between acidification and levan production (amount and structure) must be reached.
Assuntos
Ácido Acético/metabolismo , Acetobacteraceae/metabolismo , Pão/microbiologia , Fagopyrum/microbiologia , Frutanos/biossíntese , Gluconobacter/metabolismo , Acetobacteraceae/crescimento & desenvolvimento , Antineoplásicos , Bactérias/metabolismo , Pão/análise , Fermentação , Farinha/microbiologia , Microbiologia de Alimentos , Frutanos/metabolismo , Gluconobacter/crescimento & desenvolvimento , Glutens , Lactobacillaceae/crescimento & desenvolvimento , Lactobacillaceae/metabolismoRESUMO
The meat industry is seeking new strategies to reduce the sodium content of meat products without shortening their shelf-life. Natural seasonings as salt alternatives are more appreciated than chemical preservatives and also enable the incorporation of interesting nutrients. The present work studies the potential of a new red wine pomace seasoning (RWPS), derived from wine pomace, to inhibit spoilage growth in beef patties with different salt levels (2%, 1.5% and 1%) held in storage at 4°C. The use of RWPS (2% w/w) improved the microbial stability of the patties, delaying total aerobic mesophilic, and lactic acid bacteria growth, especially in samples with low salt levels. Satisfactory results were obtained in modified-atmosphere and air-packaged patties. RWPS also enabled the incorporation of fiber and phenolic compounds, and increased potassium and calcium levels. In summary, RWPS presented an interesting potential as a seasoning in meat products, enabling salt reduction without compromising their microbial stability.
Assuntos
Conservantes de Alimentos/análise , Lactobacillaceae/crescimento & desenvolvimento , Produtos da Carne/microbiologia , Cloreto de Sódio/análise , Vitis/química , Animais , Bovinos , Cor , Conservação de Alimentos , Produtos da Carne/análise , Fenóis/análise , Extratos Vegetais/análise , Resíduos/análise , Vinho/análiseRESUMO
The present study investigated the effect of feeding bovine colostrum (BC) to piglets in comparison with feeding a milk replacer (MR) and conventional rearing by the sow on the intestinal immune system and number of enterotoxigenic Escherichia coli (ETEC) colonising the intestinal tissue. Piglets (23-d-old) were allocated to one of the following four groups: (1) killed at the beginning of the experiment (Base); (2) separated from the sow and fed BC (BC-fed); (3) separated from the sow and fed a MR (MR-fed); (4) kept with the sow (Sow-Milk). Blood was sampled on days 1 and 8, and faecal samples were collected on days 1, 3, 5 and 8. On day 8, piglets were killed and gastrointestinal digesta and intestinal segments were collected. The frequency of diarrhoea was found to be higher (P≤ 0·019) in MR-fed piglets than in BC-fed and Sow-Milk piglets. Piglets from the MR-fed group had the lowest lactic acid bacteria:haemolytic E. coli ratio (P(treat)= 0·064) in the faeces. The number of E. coli colonising the intestinal tissue was higher (P< 0·001) in piglets from the MR-fed group than in those from the BC-fed and Sow-Milk groups. Piglets from the Sow-Milk group had a higher (P= 0·020) mucosal IgG concentration than those from the MR-fed group, but did not exhibit any difference when compared with piglets from the Base and BC-fed groups. Piglets from the BC-fed group exhibited a reduced (P≤ 0·037) expression level of Toll-like receptor-4 in the intestinal mucosa when compared with those from the MR-fed and Sow-Milk groups. The expression level of IL-2 was higher (P≤ 0·051) in piglets from the MR-fed group than in those from the other treatment groups. In conclusion, feeding BC rather than MR to the piglets reduced the colonisation of intestine by ETEC and modulated the intestinal immune system, whereas no differences were observed in piglets fed BC and conventionally reared by the sows.
Assuntos
Ração Animal , Colostro , Escherichia coli Enterotoxigênica/imunologia , Métodos de Alimentação/veterinária , Imunidade nas Mucosas , Mucosa Intestinal/imunologia , Sus scrofa/imunologia , Ração Animal/análise , Animais , Bile/química , Bile/imunologia , Bovinos , Colostro/química , Dinamarca , Escherichia coli Enterotoxigênica/crescimento & desenvolvimento , Escherichia coli Enterotoxigênica/isolamento & purificação , Fezes/microbiologia , Conteúdo Gastrointestinal/química , Conteúdo Gastrointestinal/microbiologia , Regulação da Expressão Gênica no Desenvolvimento , Isotipos de Imunoglobulinas/análise , Isotipos de Imunoglobulinas/metabolismo , Interleucina-2/metabolismo , Mucosa Intestinal/crescimento & desenvolvimento , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/imunologia , Intestino Delgado/metabolismo , Intestino Delgado/microbiologia , Lactobacillaceae/crescimento & desenvolvimento , Lactobacillaceae/imunologia , Lactobacillaceae/isolamento & purificação , Sus scrofa/crescimento & desenvolvimento , Sus scrofa/metabolismo , Sus scrofa/microbiologia , Técnicas de Cultura de Tecidos/veterinária , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Aumento de PesoRESUMO
Redox potential and proteolysis determine protein networks in doughs and thus dough rheology as well as the structure of baked goods. Namely, gluten-free bakery products needs structural improvements but little is known about these parameters in gluten free dough systems. In this work the influence of lactic acid bacteria (LAB) on redox status and proteolysis of buckwheat sourdoughs was investigated. An increase of free thiol groups was detected as redox potential was decreasing during fermentation. Thiol content at 8 h was higher in doughs fermented with strains with high reductive activity, such as Weissella (W.) cibaria in comparison to Pediococcus (P.) pentosaceus, which exhibited a lower reducing activity. At 24 h each fermentation showed a similar content of free thiol groups. Endogenous buckwheat proteases were characterized using various protease inhibitors in buckwheat doughs. Until pH3.1 a proteolysis increase was monitored in doughs. Employed LAB didn't show any detectable extracellular proteolytic activity. Flour proteases are thus responsible for protein breakdown, and this was demonstrated comparing free amino nitrogen (FAN) values and protein electrophoretic patterns of sourdough fermentations with chemical acidified (CA) doughs. FAN content at 24 h using P. pentosaceus, proteolytic comparative strain of Enterococcus faecalis, W. cibaria, mixed culture (containing P. pentosaceus and W. cibaria), CA and CA doughs containing glutathione (GSH) reached 45.9±1.3, 42.4±1.3, 40±1, 31±2, 29±2 and 17.8±3.9 mmol kg(-1) flour, respectively. Proteolysis was mainly influenced by pH and incubation time. The addition of GSH showed a decrease of proteolysis and of free amino acids. CA doughs showed a higher total free amino acids content than sourdough fermented with LAB indicating their metabolization. Fermentations with high FAN values exhibited lower band intensity (analyzed under reducing condition) in electrophoretic patterns. These results show that dough proteases are responsible for proteolysis in buckwheat sourdoughs and this activity is influenced from LAB metabolism. Moreover, oxidation-reduction potential (ORP) changes do not show improvements of proteolytic activity in buckwheat sourdoughs.
Assuntos
Fagopyrum/microbiologia , Microbiologia de Alimentos , Lactobacillaceae/metabolismo , Aminoácidos/análise , Pão/análise , Pão/microbiologia , Fagopyrum/química , Fagopyrum/metabolismo , Fermentação , Farinha/análise , Farinha/microbiologia , Concentração de Íons de Hidrogênio , Lactobacillaceae/crescimento & desenvolvimento , Oxirredução , Proteólise , Compostos de Sulfidrila/análiseAssuntos
Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Prebióticos , Selênio/farmacologia , Chá/química , Animais , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Bacteroides/efeitos dos fármacos , Bacteroides/crescimento & desenvolvimento , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/crescimento & desenvolvimento , Clostridium/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Glucuronidase/antagonistas & inibidores , Glucuronidase/metabolismo , Humanos , Lactobacillaceae/efeitos dos fármacos , Lactobacillaceae/crescimento & desenvolvimento , RatosRESUMO
BACKGROUND: Improving the hygienic quality of forages for horse nutrition seems to be a reasonable target for decreasing the prevalence of pulmonary diseases. The aim of the experiment was to study the effects of different agricultural practices on the main aero-allergens contained in forages, including breathable dust, fungi, mycotoxins and pollens. RESULTS: Results showed that the late harvest of hay, a second crop or a haylage production provides a good alternative to increase hygienic quality by reducing fungi contamination and breathable dust content. Barn drying of hay, while having no effect on breathable dust, similarly reduced fungi contamination. In contrast, when hay was harvested at a lower dry mass content (750 g DM kg⻹ versus 850 g DM kg⻹), both breathable dust and fungi contaminations were increased, which could at least be reversed by adding propionic acid just before baling. Zearalenone was detected in different hays, and even in one case, in breathable dust. CONCLUSION: Overall, our data suggest that different approaches can be used to increase forage hygienic quality for horse feeding and thus reduce their exposure to factors involved in equine pulmonary disease.
Assuntos
Agricultura/métodos , Ração Animal/análise , Ração Animal/microbiologia , Contaminação de Alimentos/prevenção & controle , Doenças Transmitidas por Alimentos/veterinária , Doenças dos Cavalos/prevenção & controle , Pneumopatias/veterinária , Ração Animal/efeitos adversos , Animais , Poeira/análise , Poeira/prevenção & controle , Doenças Transmitidas por Alimentos/imunologia , Doenças Transmitidas por Alimentos/prevenção & controle , França , Fungos/crescimento & desenvolvimento , Fungos/imunologia , Fungos/isolamento & purificação , Doenças dos Cavalos/imunologia , Cavalos , Lactobacillaceae/crescimento & desenvolvimento , Lactobacillaceae/isolamento & purificação , Pneumopatias/imunologia , Pneumopatias/prevenção & controle , Pneumopatias Fúngicas/imunologia , Pneumopatias Fúngicas/prevenção & controle , Pneumopatias Fúngicas/veterinária , Viabilidade Microbiana , Micotoxinas/análise , Micotoxinas/toxicidade , Pneumoconiose/imunologia , Pneumoconiose/prevenção & controle , Pneumoconiose/veterinária , Pólen/efeitos adversos , Estações do Ano , Tempo (Meteorologia)RESUMO
In this study, four different laboratory scale gluten-free (GF) sourdoughs were developed from buckwheat or teff flours. The fermentations were initiated by the spontaneous biota of the flours and developed under two technological conditions (A and B). Sourdoughs were propagated by continuous back-slopping until the stability was reached. The composition of the stable biota occurring in each sourdough was assessed using both culture-dependent and -independent techniques. Overall, a broad spectrum of lactic acid bacteria (LAB) and yeasts species, belonging mainly to the genera Lactobacillus, Pediococcus, Leuconostoc, Kazachstania and Candida, were identified in the stable sourdoughs. Buckwheat and teff sourdoughs were dominated mainly by obligate or facultative heterofermentative LAB, which are commonly associated with traditional wheat or rye sourdoughs. However, the spontaneous fermentation of the GF flours resulted also in the selection of species which are not consider endemic to traditional sourdoughs, i.e. Pediococcus pentosaceus, Leuconostoc holzapfelii, Lactobacillus gallinarum, Lactobacillus vaginalis, Lactobacillus sakei, Lactobacillus graminis and Weissella cibaria. In general, the composition of the stable biota was strongly affected by the fermentation conditions, whilst Lactobacillus plantarum dominated in all buckwheat sourdoughs. Lactobacillus pontis is described for the first time as dominant species in teff sourdough. Among yeasts, Saccharomyces cerevisiae and Candida glabrata dominated teff sourdoughs, whereas the solely Kazachstania barnetti was isolated in buckwheat sourdough developed under condition A. This study allowed the identification and isolation of LAB and yeasts species which are highly competitive during fermentation of buckwheat or teff flours. Representatives of these species can be selected as starters for the production of sourdough destined to GF bread production.
Assuntos
Pão/microbiologia , Eragrostis/microbiologia , Fagopyrum/microbiologia , Lactobacillaceae/crescimento & desenvolvimento , Leveduras/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Fermentação , Farinha/microbiologia , Microbiologia de Alimentos , Humanos , Lactobacillaceae/classificação , Especificidade da Espécie , Leveduras/classificaçãoRESUMO
BACKGROUND: Prebiotics are a category of nutritional com-pounds grouped together, not necessarily by structural similarities, but by ability to promote the growth of spe-cific beneficial (probiotic) gut bacteria. Fructooligosaccharides (FOS) and inulin are among the most famous prebiotic compounds. In order to improve viability of probiotic bacteria during storage, fermented food should be supplemented with prebiotics. MATERIAL AND METHODS: Yoghurts were produced from skimmed milk powder and prebiotics (FOS, inulin or resistant starch), which were added at concentrations of 1%, 2% and 3%. Yoghurts were stored in +4°C for three weeks. Every week each kind of fermented drink was examined in order to check the growth of lactic acid bacteria. Apparent viscosity and texture of bio-yoghurt were determinated during refrigerated storage. RESULTS: The FOS and inulin addition to yoghurt caused an increase in the numbers of all bacteria in comparison to control yoghurt obtained without addition of prebiotics. The viable counts of Str. thermophilus, Lb. acidophilus and Bifidobacterium sp. when 1% of FOS was added to yoghurt were about 9 log cfu/g, 7.8 log cfu/g and 7.7 log cfu/g, respectively. In the presence of 1% of inulin, streptococci and bifidobacteria reached the growth at the level 8.8 log cfu/g and 7.5 respectively. Hardness and adhesiveness of yoghurt obtained with addition resistant starch increased systematically during 21 days of refrigerated storage. CONCLUSIONS: The numbers of lactic acid bacteria in obtained bio-yoghurts were sufficient in 97% of samples (10(6)-10(9) cfu/g) according to FAO/WHO protocols. Generally, viability of bacteria was sufficient for 14 days and then their numbers decreased but usually not below 10(6) cfu/g. Prebiotics as FOS and inulin added to bio-yoghurt exhibited stimulatory effect on growth Lb. acidophilus and Bifidobacterium sp. Addition of prebiotics caused an increase in apparent viscosity and hardness (in case of FOS) and decrease in syneresis of obtained bio-yoghurts.
Assuntos
Suplementos Nutricionais/classificação , Lactobacillaceae/crescimento & desenvolvimento , Prebióticos/microbiologia , Probióticos/análise , Iogurte/microbiologia , Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/isolamento & purificação , Contagem de Colônia Microbiana , Fermentação , Armazenamento de Alimentos/métodos , Concentração de Íons de Hidrogênio , Inulina/análise , Inulina/metabolismo , Lactobacillaceae/isolamento & purificação , Oligossacarídeos/análise , Oligossacarídeos/metabolismo , Reologia , Streptococcus/crescimento & desenvolvimento , Streptococcus/isolamento & purificaçãoRESUMO
The use of prebiotics is a possible strategy to manage and steer the complex gut microbial community towards a health-promoting composition (Gastrointestinal Resource Management). In this study, the Simulator of the Human Intestinal Microbial Ecosystem was used to investigate the effects of two commercially-available plant polysaccharide supplements on the structure, composition and metabolism of an in vitro cultured colon microbial community. Microbial analyses showed both a bifidogenic (up to +1.3 log cfu/mL) and a lactobacillogenic (up to +0.9 log cfu/mL) effect during treatment with the dietary supplements. Quantitative PCR confirmed that the increase of Bifidobacteria spp. was statistically significant (P<0.05) in all of the colon compartments and showed a significant increase of the bacteroides-prevotella group concentration (+0.6 log cells/ml) in the compartment simulating the proximal colon. Denaturant gradient gel electrophoresis analyses and a relative ecological interpretation, in combination with sugar and short-chain fatty acids quantification, provided evidence of a positive effect of both the tested products. Overall, the treatment period was associated with (i) good and selective fermentability of the polysaccharide supplements along the entire colon; (ii) positive and selective bifidogenic effect; (iii) the possibility of enhancing species belonging to Bacteroidetes, a phylum recently associated with body weight management.
Assuntos
Suplementos Nutricionais , Trato Gastrointestinal/microbiologia , Polissacarídeos/química , Prebióticos , Bacteroides/crescimento & desenvolvimento , Bacteroides/isolamento & purificação , Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/isolamento & purificação , Ácidos Graxos Voláteis/análise , Ácidos Graxos Voláteis/metabolismo , Fermentação , Galactanos/química , Humanos , Lactobacillaceae/crescimento & desenvolvimento , Lactobacillaceae/isolamento & purificação , Gomas Vegetais/química , Plantas/químicaRESUMO
Strains of Leuconostoc mesenteroides, Lactobacillus plantarum, Weissella soli/Weissella koreensis, Enterococcus faecalis, Pediococcus pentosaceus and Lactobacillus fermentum were identified from raw carrots, French beans and marrows by partial 16S rRNA gene sequence. L. plantarum M1, Leuc. mesenteroides C1 and P. pentosaceus F4 were selected based on the rates of growth and acidification in vegetable juice media, and used as the autochthonous mixed starter for the fermentation of carrots, French beans or marrows. An allochthonous starter, consisting of the same species, was also used for fermentation. A two-step fermentation process (1 day at 25 degrees C and 7 days at 15 degrees C) in brine (1% w/v) followed by storage at room temperature in olive oil until 40 days was set up. Unstarted vegetables subjected to the same treatments were used as the controls. Cell numbers of lactic acid bacteria in the started vegetables were ca. 10,000 (autochthonous starter) and 1000 (allochthonous starter) times higher than unstarted samples throughout the process. When fermented with the autochthonous starter, carrots, French beans or marrows were characterized by the rapid decrease of pH (<4.5), marked consumption of fermentable carbohydrates, and inhibition of Enterobacteriaceae and yeasts. Fermentation with the allochthonous starter did not acidify and inhibit bacteria and yeasts so rapidly. After 40 days, carrots, French beans and marrows fermented with the autochthonous starter had significantly (P<0.05) higher total concentration of vitamin C (ascorbate+dehydroascorbate) with respect to those fermented with the allochthonous starter and, especially unstarted vegetables. The same was found for the indexes of color. Firmness of both started vegetables was higher than unstarted vegetables. Sensory analysis differentiated started vegetables. Carrots and French beans fermented with the autochthonous starter were, especially, appreciated for fragrance. Appearance was the sensory attribute that mainly distinguished marrows fermented with the autochthonous starter.
Assuntos
Daucus carota/microbiologia , Fabaceae/microbiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Lactobacillaceae/crescimento & desenvolvimento , Ácido Ascórbico/análise , Contagem de Colônia Microbiana , Comportamento do Consumidor , Qualidade de Produtos para o Consumidor , Fermentação , Concentração de Íons de Hidrogênio , Lactobacillaceae/metabolismo , Azeite de Oliva , Óleos de Plantas , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Fatores de TempoRESUMO
AIMS: To characterize two probiotic carnobacterial isolates, Carnobacterium maltaromaticum (B26) and C. divergens (B33), derived from rainbow trout (Oncorhynchus mykiss) intestine. METHODS AND RESULTS: Both cultures, which were able to colonize the fish gut mucosal layer, comprised nonsporogenous, nonmotile, Gram-positive, catalase and oxidase-negative rods. The growth of both carnobacteria occurred between 0 and 37 degrees C, in 0-10% (w/v) NaCl and at pH 5-10. Specifically, strain B26 grew in nutrient broth supplemented with 15% (w/v) NaCl. The most abundant cellular fatty acid of both cultures was 9-octadecenoic acid (18 : 1 n-9) (B26 = 52.6%; B33 = 40.6%), which was characteristic of Carnobacterium. Both cultures were inhibitory to Aeromonas salmonicida, Aer. hydrophila, Streptococcus iniae and Vibrio anguillarum, and strain B33 inhibited Listeria monocytogenes. Both carnobacteria, which did not contain plasmids, produced inhibitory compounds against Gram-positive and Gram-negative bacteria. CONCLUSIONS: Both probiotic cultures, B26 and B33, had unique phenotypic characteristics and showed a broad spectrum of antibiotic resistance against varying pathogenic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study contribute to new information and significance of carnobacterial species.
Assuntos
Intestinos/microbiologia , Lactobacillaceae/isolamento & purificação , Oncorhynchus mykiss/microbiologia , Probióticos , Animais , Farmacorresistência Bacteriana , Ácidos Graxos/análise , Lactobacillaceae/química , Lactobacillaceae/efeitos dos fármacos , Lactobacillaceae/crescimento & desenvolvimento , Fenótipo , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genéticaRESUMO
Natural-abundance (13)C-nuclear magnetic resonance was used to probe the intracellular organic solute content of the moderately halophilic bacterium Tetragenococcus halophila. When grown in complex growth media supplemented or not with NaCl, T. halophila accumulates glycine betaine and carnitine. Unlike other moderate halophiles, T. halophila was not able to produce potent osmoprotectants (such as ectoines and glycine betaine) through de novo synthesis when cultured in defined medium under hyperosmotic constraint. Addition of 2 mM carnitine, glycine betaine, or choline to defined medium improved growth parameters, not only at high salinity (up to 2.5 M NaCl) but also in media lacking NaCl. These compounds were taken up when available in the surrounding medium. The transport activity occurred at low and high salinities and seems to be constitutive. Glycine betaine and carnitine were accumulated by T. halophila in an unmodified form, while exogenously provided choline led to an intracellular accumulation of glycine betaine. This is the first evidence of the existence of a choline-glycine betaine pathway in a lactic acid bacterium. An assay showed that the compatible solutes strikingly repressed the accumulation of glutamate and slightly increased the intracellular potassium level only at high salinity. Interestingly, osmoprotectant-treated cells were able to maintain the intracellular sodium concentration at a relatively constant level (200 to 300 nmol/mg [dry weight]), independent of the NaCl concentration of the medium. In contrast, in the absence of osmoprotectant, the intracellular sodium content increased sharply from 200 to 2,060 nmol/mg (dry weight) when the salinity of the medium was raised from 1 to 2 M. Indeed, the imported compatible solutes play an actual role in regulating the intracellular Na(+) content and confer a much higher salt tolerance to T. halophila.