Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 163
Filtrar
1.
Sci Rep ; 13(1): 5938, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-37045926

RESUMO

Chemical food preservatives are extensively found in various processed food products in the human environment. Hence, this study aimed to investigate the effect of long-term exposure to five food preservatives (potassium sorbate (PS), butylated hydroxyanisole (BHA), sodium benzoate (SB), calcium propionate (CP), and boric acid (BA)) on the liver and kidney in rats and the probable underlying mechanisms. For 90 days, sixty male albino rats were orally given either water (control), 0.09 mg/kg b.wt BHA, 4.5 mg/kg b.wt PS, 0.9 mg/kg b.wt SB, 0.16 mg/kg b.wt BA, or 0.18 mg/kg b.wt CP. Liver and kidney function tests were assessed. Hepatic and renal oxidative stress biomarkers were estimated. Histologic examination analysis of liver and kidney tissues was achieved. Toll-like receptors 2 and 4 (TLR-2 and TLR-4), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) mRNA expression levels were measured. The results revealed that long-term oral dosing of the five food preservatives resulted in significant increases in alkaline phosphatase, alanine transaminase, aspartate transaminase, urea, uric acid, and creatinine levels. There were significant reductions in hepatic and renal antioxidant enzymes, an increase in MDA concentrations, and pathological alterations in renal and hepatic tissues. The mRNA levels of TLR-4, TLR-2, NF-κB, and TNF-α were elevated in the food preservatives-exposed groups. Conclusively, the current findings revealed that long-term exposure to PS, BHA, SB, CP, and BA has a negative impact on liver and kidney function. Furthermore, these negative effects could be mediated via oxidative stress induction, inflammatory reactions, and cytokine production.


Assuntos
Conservantes de Alimentos , NF-kappa B , Masculino , Conservantes de Alimentos/toxicidade , Conservantes de Alimentos/metabolismo , Fígado/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo , Transdução de Sinais , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Ratos
2.
Neurotoxicol Teratol ; 93: 107123, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36150581

RESUMO

Propionate is an effective mould inhibitor widely used as a food preservative. In this study, we used zebrafish to explore the adverse effects of long-term exposure to low concentrations of sodium propionate and the underlying molecular mechanisms (from larvae to adult). When exposed for 3 months, we found that blood glucose, total cholesterol, and triglyceride levels increased, and zebrafish developed a hyperglycaemic state. New tank test results showed depression in zebrafish reduced 5-hydroxytryptamine levels in the brain and damaged the dopamine system. At the same time, the results of the color preference test showed that zebrafish had cognitive impairments. In addition, Hypothalamic-Pituitary-Adrenal axis analysis revealed abnormal gene expression, increased cortisol levels, and reduced glucocorticoid receptor mRNA levels, which were consistent with depressive behavior. We also observed abnormal transcription of inflammatory and apoptotic factors. Overall, we found that chronic exposure to sodium propionate induces depressive symptoms. This may be related to the activation of the HPA axis by the hyperglycaemic state, thereby inducing inflammation and disrupting the dopaminergic system. In summary, this study provides theoretical and technical support for the overlap of the emotional pathogenesis associated with diabetes.


Assuntos
Hiperglicemia , Doenças do Sistema Nervoso , Animais , Glicemia/metabolismo , Colesterol , Dopamina/metabolismo , Conservantes de Alimentos/metabolismo , Conservantes de Alimentos/farmacologia , Hidrocortisona/metabolismo , Hiperglicemia/induzido quimicamente , Hiperglicemia/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Propionatos/metabolismo , Propionatos/toxicidade , RNA Mensageiro/metabolismo , Receptores de Glucocorticoides/metabolismo , Serotonina/metabolismo , Triglicerídeos/metabolismo , Triglicerídeos/farmacologia , Peixe-Zebra/metabolismo
3.
Food Funct ; 12(24): 12490-12502, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34806111

RESUMO

Food contamination with pathogenic microorganisms, such as Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus and Bacillus cereus, is a common health concern. Natural products, which have been the main source of antimicrobials for centuries, may represent a turning point in alleviating the antibiotic crisis, and plant polyphenolic compounds are considered a promising source for new antibacterial agents. Resveratrol and resveratrol-derived monomers and oligomers (stilbenoids) have been shown to exert a variegated pattern of efficacy as antimicrobials depending on both the polyphenols' structure and the nature of the microorganisms, and the bacterial cell membrane seems to be one of their primary targets.In this scenario and based on the thermodynamic information reported in the literature about cell membranes, this study aimed at the investigation of the direct interaction of selected stilbenoids with a simple but informative model cell membrane. Three complete stilbenoid "monomer/dimer/dehydro-dimer" sets were chosen according to different geometries and substitution patterns. Micro-DSC was performed on 2 : 3 DPPC : DSPC small unilamellar vesicles with incorporated polyphenols at physiological pH and the results were integrated using complementary NMR data. The study highlighted the molecular determinants and mechanisms involved in the stilbenoid-membrane interaction, and the results were well correlated with the microbiological evidence previously assessed.


Assuntos
Conservantes de Alimentos/metabolismo , Estilbenos/química , Estilbenos/metabolismo , Calorimetria/métodos , Membrana Celular/metabolismo , Análise Espectral/métodos
4.
PLoS Genet ; 17(11): e1009872, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34762651

RESUMO

Different species can find convergent solutions to adapt their genome to the same evolutionary constraints, although functional convergence promoted by chromosomal rearrangements in different species has not previously been found. In this work, we discovered that two domesticated yeast species, Saccharomyces cerevisiae, and Saccharomyces uvarum, acquired chromosomal rearrangements to convergently adapt to the presence of sulfite in fermentation environments. We found two new heterologous chromosomal translocations in fermentative strains of S. uvarum at the SSU1 locus, involved in sulfite resistance, an antimicrobial additive widely used in food production. These are convergent events that share similarities with other SSU1 locus chromosomal translocations previously described in domesticated S. cerevisiae strains. In S. uvarum, the newly described VIIXVI and XIXVI chromosomal translocations generate an overexpression of the SSU1 gene and confer increased sulfite resistance. This study highlights the relevance of chromosomal rearrangements to promote the adaptation of yeast to anthropic environments.


Assuntos
Adaptação Biológica/genética , Anti-Infecciosos/metabolismo , Fermentação , Conservantes de Alimentos/metabolismo , Saccharomyces cerevisiae/fisiologia , Saccharomyces/fisiologia , Sulfitos/metabolismo , Proteínas de Transporte de Ânions/genética , Cromossomos Fúngicos , Humanos , Filogenia , Regiões Promotoras Genéticas , Saccharomyces/genética , Saccharomyces/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Translocação Genética
5.
Arch Microbiol ; 203(4): 1427-1437, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33388790

RESUMO

Lactic acid bacteria can be considered as natural biopreservative and good biotechnological alternative to food safety. In this study, the antilisterial compounds produced by Enterococcus isolates from the Patagonian environment and their effectiveness for the control of Listeria monocytogenes in a food model were studied. Enterococcus isolates whose cell-free supernatant presented activity against Listeria monocytogenes were identified and evaluated for their virulence factors. The activity of the antimicrobial compounds produced by Enterococcus sp. against Listeria monocytogenes Scott A in meat gravy and ground beef during refrigerated storage was tested. The results indicated that ten Enterococcus isolates presented activity against Listeria monocytogenes and none of the selected strains presented virulence factors. L. monocytogenes in the food models containing the antilisterial compounds produced by Enterococcus sp. has decreased over the days, indicating that these compounds and cultures are an alternative to control the growth of L. monocytogenes in foods.


Assuntos
Antibacterianos/farmacologia , Conservantes de Alimentos/farmacologia , Lactobacillales/metabolismo , Listeria monocytogenes/crescimento & desenvolvimento , Carne/microbiologia , Animais , Antibacterianos/metabolismo , Bovinos , Enterococcus/isolamento & purificação , Enterococcus/metabolismo , Microbiologia de Alimentos , Conservantes de Alimentos/metabolismo , Armazenamento de Alimentos , Lactobacillales/isolamento & purificação , Listeria monocytogenes/efeitos dos fármacos
6.
Food Chem ; 337: 127770, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32795858

RESUMO

Sorbic acid and its potassium and calcium salts used as food preservatives and sorbic chloride were submitted to thermal analysis in order to characterize their thermal behavior on heating and cooling processes, using TG/DTG/DTA, TG-MS, DSC, hot stage microscopy and DRX analysis. Sorbic acid melted and decomposed under dynamic heating. Under isothermal it sublimated without decomposition before melting (T < 134 °C). The potassium salt presented a solid-solid phase transition before decomposition. Both potassium and calcium salts decomposed in temperatures higher than the acid without melting, producing the respective carbonates and oxides as final residues. Sorbic chloride evaporate without condensation, on dynamic heating.


Assuntos
Conservantes de Alimentos/química , Ácido Sórbico/análogos & derivados , Cálcio/química , Conservantes de Alimentos/metabolismo , Transição de Fase , Potássio/química , Ácido Sórbico/metabolismo , Temperatura
7.
Methods Mol Biol ; 2220: 243-257, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32975780

RESUMO

This chapter describes methods used to isolate, identify, and partially characterize lactic acid bacteria (LAB) which exhibit inhibitory activity against Listeria monocytogenes from foods. Vegetal (plant based) sources are rich in naturally occurring LAB and therefore provide an easily accessible source of strains with potential antimicrobial activity for use in food-processing applications. From our previous work, the majority of LAB with inhibitory activity against L. monocytogenes were identified as generally recognized as safe (GRAS) Lactococcus lactis. Although these bacteria are most commonly known for their role in industrial dairy fermentations, they are believed to have originally derived from natural plant-based habitats. These isolates with anti-Listeria activity were all found to carry the genes involved in the production of nisin, which is an approved food-grade preservative (E234). These isolates may find various applications for in situ production of nisin allowing control of L. monocytogenes in various fermented and non-fermented foods and other environments.


Assuntos
Microbiologia de Alimentos , Lactococcus lactis/isolamento & purificação , Lactococcus lactis/fisiologia , Listeria monocytogenes/fisiologia , Interações Microbianas , Antibacterianos/metabolismo , Conservantes de Alimentos/metabolismo , Humanos , Listeriose/microbiologia , Listeriose/prevenção & controle , Nisina/metabolismo
8.
Environ Health ; 19(1): 26, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32122340

RESUMO

BACKGROUND: Parabens are synthetic chemicals commonly used in cosmetics, pharmaceuticals, food and beverage processing as antimicrobial preservatives. In experimental animals, parabens exposure was associated with adverse effects on female reproduction. Despite the widespread use of parabens little is known about their effect on female fecundity. The objective of the current analysis was to evaluate the associations of urinary parabens concentrations with parameters of ovarian reserve among women undergoing treatment in a fertility clinic. METHODS: Five hundred eleven female aged 25-39 years who attended the infertility clinic in central region of Poland for diagnostic purposes were recruited between September 2014 and February 2019. Urinary concentrations of parabens were measured by a validated gas chromatograohy ion-tap mass spectrometry method. Parameters of ovarian reserve were: antral follicle count (AFC), anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH) and estradiol (E2) levels. RESULTS: The geometric mean of specific gravity adjusted urinary concentrations of methyl (MP), ethyl (EP), propyl (PP), butyl (BP) and izobutyl paraben (iBuP) were 107.93 µg/L, 12.9 µg/L, 18.67 µg/L, 5.02 µg/L and 2.80 µg/L. Urinary concentrations of PP in the third quartile of exposure ((50-75] percentyl) were inversely associated with antral follicle count (p = 0.048), estradiol level (p = 0.03) and positively with FSH concentration (p = 0.026). MP, EP, BP and iBuP parabens were not associated any with parameters of ovarian reserve. CONCLUSIONS: Chronic exposure to PP may potentially contributing to reduced fecundity and impair fertility. As this is one of the first study to investigate the potential effect of parabens on ovarian reserve further epidemiological studies with longer duration of observation are needed.


Assuntos
Exposição Ambiental/análise , Conservantes de Alimentos/metabolismo , Reserva Ovariana/efeitos dos fármacos , Parabenos/metabolismo , Conservantes Farmacêuticos/metabolismo , Feminino , Humanos , Polônia , Adulto Jovem
9.
Int J Food Microbiol ; 322: 108574, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32151821

RESUMO

Fungi are commonly identified as the cause for dairy food spoilage. This can lead to substantial economic losses for the dairy industry as well as consumer dissatisfaction. In this context, biopreservation of fermented dairy products using lactic acid bacteria, propionibacteria and fungi capable of producing a large range of antifungal metabolites is of major interest. In a previous study, extensive screening was performed in vitro and in situ to select 3 dairy fermentates (derived from Acidipropionibacterium jensenii CIRM-BIA1774, Lactobacillus rhamnosus CIRM-BIA1952 and Mucor lanceolatus UBOCC-A-109193, respectively) with antifungal activity. The aim of the present study was to determine the main compounds responsible for this antifungal activity. Fifty-six known antifungal compounds as well as volatiles were targeted using different analytical methods (conventional LC and GC, GC-MS, LC-QToF). The most abundant antifungal compounds in P. jensenii-, L. rhamnosus- and M. lanceolatus-derived fermentates corresponded to propionic and acetic acids, lactic and acetic acids, and butyric acid, respectively. Many other antifungal compounds (organic acids, free fatty acids, volatile compounds) were identified but at lower levels. In addition, an untargeted approach using nano LC-MS/MS identified a 9-amino acid peptide derived from αs2-casein in the L. rhamnosus-derived fermentate. This peptide inhibited M. racemosus and R. mucilaginosa in vitro. This study provides new insights on the molecules involved in antifungal activities of food-grade microorganism fermentates which could be used as antifungal ingredients in the dairy industry.


Assuntos
Antifúngicos/análise , Produtos Fermentados do Leite/análise , Conservantes de Alimentos/análise , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Reatores Biológicos , Produtos Fermentados do Leite/microbiologia , Fermentação , Microbiologia de Alimentos , Conservantes de Alimentos/química , Conservantes de Alimentos/metabolismo , Conservantes de Alimentos/farmacologia , Lacticaseibacillus rhamnosus/isolamento & purificação , Lacticaseibacillus rhamnosus/metabolismo , Mucor/isolamento & purificação , Mucor/metabolismo , Propionibacterium/isolamento & purificação , Propionibacterium/metabolismo , Rhodotorula/efeitos dos fármacos
10.
Int J Food Microbiol ; 322: 108545, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32109681

RESUMO

PVOH-based polymer matrices in the form of films were evaluated as carriers of living Lactococcus lactis subsp. Lactis. These lactic acid bacteria are capable of producing nisin, which is an effective antilisterial peptide. A low percentage (1:0.125 w/w) of yeast extract, gelatin, sodium caseinate, gelatin, or casein hydrolysates was incorporated in PVOH matrices with the aim of increasing the viability of bacteria in the film. The films were obtained by casting after incorporating L. lactis. Then they were evaluated for antilisterial activity in liquid medium at 37 °C for 24 h, and also at 4 °C for 21 days in order to simulate the storage of liquid foods in refrigeration conditions. The survival of the lactic acid bacteria was also evaluated at both temperatures during the experiment. L. lactis remained viable in all the films tested at 37 and 4 °C. The antimicrobial activity of the films was greater at 4 °C than at 37 °C. With regard to the effect of the film composition, the activity of the films was higher when protein hydrolysates and sodium caseinate were incorporated in the formulation. Films supplemented with protein hydrolysates or sodium caseinate inhibited growth of the pathogen during the 21 days of storage at 4 °C. At 37 °C, after 24 h the films had slowed the growth of the inoculated pathogen by between 2 and 4 log CFU/mL. Finally, as the films developed are intended to be used in the design of active packaging of foods, they were tested in pasteurized milk inoculated with 4 log CFU/mL of Listeria monocytogenes and stored at 4 °C for 21 days. The pathogen began to grow after the second day of storage with or without film, but when the films were added to the medium the growth of the pathogen was slowed down, without reaching >6 log CFU, whereas the control reached a maximum growth of 8.5 log CFU. The pH of the milk was monitored throughout the experiment, and it decreased with time. This was due to the generation of organic acids by the lactic bacteria. Buffering the food stabilized the pH without modifying the activity of the films. Thus, the current study shows that PVOH films supplemented with nutrients can act as carriers of L. lactis, and they can help to increase the safety of refrigerated dairy beverages and sauces.


Assuntos
Conservação de Alimentos/métodos , Lactobacillales/fisiologia , Listeria monocytogenes/crescimento & desenvolvimento , Leite/microbiologia , Álcool de Polivinil , Animais , Antibacterianos/metabolismo , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Conservantes de Alimentos/metabolismo , Lactobacillales/química , Lactobacillales/metabolismo , Lactococcus lactis/química , Lactococcus lactis/metabolismo , Lactococcus lactis/fisiologia , Nisina/metabolismo , Proteínas/química , Refrigeração
11.
J Biosci Bioeng ; 129(5): 558-564, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31924510

RESUMO

ε-Poly-l-lysine (ε-PL) produced as a secondary metabolite of Streptomyces albulus has long been used as a natural food preservative in a number of countries, including Japan, the United States, South Korea, and China. To date, numerous studies employing classical biotechnological approaches have been carried out to improve its productivity. Here we report a modern and rational genetic approach to enhancing metabolic flux toward ε-PL biosynthesis. Based on in silico genome analyses, we revealed that S. albulus NBRC14147 produces five antifungal polyene antibiotics-tetramycin A and B, tetrin A and B, and a trace amount of nystatin A1-concomitantly with antimicrobial ε-PL. Targeted inactivation of the biosynthetic gene cluster for tetramycins and tetrins in a nystatin A1 production-deficient mutant completely abolished the production of polyene macrolides, which in turn led to an approximately 20% improvement in ε-PL production that closely correlated with the polyene defects. The biosynthetic flux for ε-PL was thus successfully enhanced by inactivation of the concomitant secondary metabolite biosynthetic pathways. Since this elimination of concomitantly produced metabolites also allows for simpler purification after fermentation production of ε-PL, the rational strain engineering strategy we show here will improve its industrial production.


Assuntos
Macrolídeos/metabolismo , Polienos/metabolismo , Polilisina/biossíntese , Streptomyces/metabolismo , Fermentação , Conservantes de Alimentos/metabolismo , Macrolídeos/química , Polienos/química , Streptomyces/química , Streptomyces/genética
12.
Biocontrol Sci ; 24(4): 185-192, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31875610

RESUMO

Lactic Acid Bacteria (LAB) are generally recognized as safe. It has been used to increase the shelf-life of fermented products, and its antimicrobial action is based on the metabolites secretions, such as lactic acid, hydrogen peroxide, reuterin, bacteriocins and the like-bacteriocins substances. It has been proven that LAB are able to inhibit deteriorating bacteria of raw meat, but improper handling of live cultures could lead to spoilage. So, the use of their bacteriocins, small antimicrobial peptides, could be an alternative. Besides reducing the number of spoilage bacteria, it seeks to inhibit pathogenic bacteria such as Salmonella, enterohemorrhagic Escherichia coli and Listeria. The food industry uses few bacteriocins and now bacterial resistance has been reported. For that reason, the search of novel bacteriocins produced by LAB is a priority. Moreover, the natural microbiota of meat could be a reservoir of LAB.


Assuntos
Microbiologia de Alimentos , Armazenamento de Alimentos/métodos , Lactobacillales/fisiologia , Carne/microbiologia , Animais , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Bacteriocinas/toxicidade , Resistência Microbiana a Medicamentos , Contaminação de Alimentos/prevenção & controle , Conservação de Alimentos/métodos , Conservantes de Alimentos/metabolismo , Conservantes de Alimentos/farmacologia , Conservantes de Alimentos/toxicidade , Inocuidade dos Alimentos/métodos , Humanos , Produtos da Carne/microbiologia , Microbiota/fisiologia , Carne Vermelha/microbiologia
13.
J Agric Food Chem ; 67(39): 10930-10936, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31496247

RESUMO

The stability of lipids in meat products depends on the initial concentration of hydroperoxides, the catalytic involvement of metal ions and myoglobin, endogenous antioxidants, and biological and technological factors. Ground meat was treated with additives, sealed in vacuum bags, heated to 75 °C, and stored opened to air at 4 °C. S-Nitroso-N-acetylcysteine (NAC-SNO) at concentration like nitrite used by the industry prevents lipid peroxidation in the product, even after storage for 1 month at 4 °C. The same simulated treatments at different concentrations of both compounds show that NAC-SNO acts as an antioxidant ∼4-fold better than nitrite at pH 6.2 or 3.0. Ascorbic acid significantly improves nitrite antioxidant effect. NAC-SNO was found to prevent, much better than nitrite, accumulation of reactive aldehydes and hydroxynonenal protein modification. In condition like those used by the industry for meat products processing, NAC-SNO acts better than nitrite to provide antioxidant protection without the side effect of N-nitrosation, oxidation, and the loss of nutrient generated by nitrite.


Assuntos
Acetilcisteína/análogos & derivados , Antioxidantes/análise , Conservantes de Alimentos/análise , Mucosa Gástrica/metabolismo , Produtos da Carne/análise , Acetilcisteína/análise , Acetilcisteína/metabolismo , Animais , Antioxidantes/metabolismo , Conservantes de Alimentos/metabolismo , Temperatura Alta , Peroxidação de Lipídeos , Nitritos/análise , Oxirredução , Perus
14.
Pol J Microbiol ; 68(2): 269-280, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257793

RESUMO

Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R 2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R 2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Conservantes de Alimentos/metabolismo , Glucose/metabolismo , Lactococcus lactis/crescimento & desenvolvimento , Nisina/metabolismo , Probióticos/metabolismo , Ácido Acético/metabolismo , Biomassa , Fermentação/fisiologia , Concentração de Íons de Hidrogênio , Ácido Láctico/metabolismo
16.
Arch Microbiol ; 201(9): 1249-1258, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31197409

RESUMO

This work was aimed to screen bacteriocin-producing LAB from freshwater fish, select a prominent strain and evaluate its safety, characterise the bacteriocin produced, and evaluate its potential to be used as biopreservatives. Isolate 3MT showed the ability to produce bacteriocin-like substances and was identified as Lactococcus lactis subsp. lactis. This strain proved to be free from virulence factors as well as biogenic amine production and antibiotic resistance patterns. The bacteriocin produced displayed high resistance to heat, pH, detergents, and its partial purification led to a 4.35-fold increase in specific activity. Moreover, this bacteriocin showed the ability to inhibit the growth of Vibrio sp. 1T1 in fish pâté stored at 10 °C for 20 days, without altering its sensory properties. The bacteriocin can be used successfully as a preservative to improve the hygienic quality and enhance the shelf life of fish paté in particular and food products in general. Lactococcus lactis subsp. lactis strain 3MT can also be safely used as a protective culture.


Assuntos
Bacteriocinas/metabolismo , Ciclídeos/microbiologia , Conservantes de Alimentos/metabolismo , Lactococcus lactis/metabolismo , Alimentos Marinhos/microbiologia , Animais , Água Doce/microbiologia , Lactococcus lactis/isolamento & purificação , Vibrio/crescimento & desenvolvimento
17.
J Microbiol Biotechnol ; 29(7): 1033-1042, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31216789

RESUMO

Bacillus velezensis BS2 was isolated from meongge (common sea squirt) jeotgal, a Korean fermented seafood, and produces a bacteriocin, BacBS2, which strongly inhibits Listeria monocytogenes and Bacillus cereus. BacBS2 was partially purified by Q-Sepharose column chromatography after ammonium sulfate precipitation of the culture supernatant, then further purified by Sephadex G-50 column chromatography. Partially purified BacBS2 was estimated to be 6.5 kDa in size by Tricine-SDS PAGE and activity detection by gel-overlay. Enzyme treatment and FT-IR spectrum of partially purified BacBS2 confirmed its proteinaceous nature. BacBS2 was fully stable at pH 4-9, and half of activity was retained at pH 1-3. Full activity was retained after exposure to 80°C for 15 min, but half of the activity was retained upon exposure to 90°C for 15 min or 100°C for 10 min. BacBS2 inhibited L. monocytogenes by bactericidal mode of action. B. velezensis BS2 and its BacBS2 seem useful as biopreservatives for fermented foods such as jeotgal.


Assuntos
Antibacterianos/metabolismo , Bacillus/metabolismo , Bacteriocinas/isolamento & purificação , Bacteriocinas/metabolismo , Alimentos Fermentados/microbiologia , Conservantes de Alimentos/metabolismo , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antibiose , Bacillus/crescimento & desenvolvimento , Bacillus/fisiologia , Bacillus cereus/efeitos dos fármacos , Bacteriocinas/química , Bacteriocinas/farmacologia , Meios de Cultura , Conservantes de Alimentos/química , Conservantes de Alimentos/isolamento & purificação , Conservantes de Alimentos/farmacologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Listeria monocytogenes/efeitos dos fármacos , Peso Molecular , Estabilidade Proteica
18.
Food Microbiol ; 82: 160-170, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027770

RESUMO

In the context of a demand for "preservative-free" food products, biopreservation appears as a promising alternative to either replace or reduce the use of chemical preservatives. The purpose of this study was to evaluate the antifungal activity of a collection of lactic acid bacteria (n = 194), and then to evaluate the applicability and efficacy of selected ones used as bioprotective cultures against mold spoilers in dairy and bakery products. First, lactic acid bacteria were isolated from various Algerian raw milk samples and Amoredj, a traditional fermented product. Secondly, in vitro screening tests against Mucor racemosus UBOCC-A-109155, Penicillium commune UBOCC-A-116003, Yarrowia lipolytica UBOCC-A-216006, Aspergillus tubingensis AN, Aspergillus flavus T5 and Paecilomyces formosus AT allowed for the selection of 3 active strains, namely Lactobacillus plantarum CH1, Lactobacillus paracasei B20 and Leuconostoc mesenteroides L1. In situ tests were then performed to validate their activity in actual products (sour cream and sourdough bread) challenged with fungal spoilers. These tests showed that antifungal LAB could slow the fungal target growth and could be candidates of interest for industrial applications. Finally, organic acids and various antifungal compounds produced in sour cream and sourdough bread by the selected LAB, and thus potentially supporting the observed antifungal activity, were identified and quantified by HPLC and LC-QTOF.


Assuntos
Antifúngicos/farmacologia , Laticínios/microbiologia , Microbiologia de Alimentos , Conservantes de Alimentos/farmacologia , Lactobacillales/fisiologia , Animais , Antibiose , Antifúngicos/metabolismo , Pão/microbiologia , Alimentos Fermentados/microbiologia , Conservantes de Alimentos/metabolismo , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Lactobacillales/isolamento & purificação , Lactobacillales/metabolismo , Leite/microbiologia
19.
J Agric Food Chem ; 67(16): 4397-4417, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30844263

RESUMO

Terpenoids and polyphenols are high-valued plant secondary metabolites. Their high antimicrobial activities demonstrate their huge potential as natural preservatives in the food industry. With the rapid development of metabolic engineering, it has become possible to realize large-scale production of non-native terpenoids and polyphenols by using the generally recognized as safe (GRAS) strain, Saccharomyces cerevisiae, as a cell factory. This review will summarize the major terpenoid and polyphenol compounds with high antimicrobial properties, describe their native metabolic pathways as well as antimicrobial mechanisms, and highlight current progress on their heterologous biosynthesis in S. cerevisiae. Current challenges and perspectives for the sustainable production of terpenoid and polyphenol as natural food preservatives via S. cerevisiae will also be discussed.


Assuntos
Conservantes de Alimentos/metabolismo , Polifenóis/biossíntese , Saccharomyces cerevisiae/metabolismo , Terpenos/metabolismo , Engenharia Metabólica , Saccharomyces cerevisiae/genética
20.
J Microbiol Immunol Infect ; 52(3): 409-417, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28863970

RESUMO

BACKGROUND/PURPOSE: Lactic acid bacteria (LAB) are used in a variety of bio-industrial processes, including milk fermentation, and have been reported to have bactericidal activities. We previously isolated Lactobacillus plantarum NTU 102 from homemade Korean-style cabbage pickles. The aims of this work were to perform a screen of the antimicrobial substances produced by L. plantarum NTU 102 and to characterize it. METHODS: In this study, we investigated the bactericidal activity of this LAB strain and demonstrated that the cell-free supernatant of L. plantarum NTU 102 had antimicrobial activity. RESULTS: The antibacterial activity was significantly decreased by proteolytic enzymes, including pepsin, proteinase K, and trypsin, suggesting that the antimicrobial substance had proteinaceous properties. Additionally, this activity was heat stable and not affected by alterations in the pH from 1.0 to 4.0. The antibacterial substance produced by L. plantarum NTU 102, which we named LBP102, exhibited a broad inhibitory spectrum. The active compound was identified by nuclear magnetic resonance (NMR) techniques (1H NMR and 13C NMR). The IUPAC name was 2-(2-1 mino-1-hydroxyethoxy) ethyl 2-methylpropanoate. The substance showed antibacterial activity against Vibrio parahaemolyticus, and completely inhibited the growth of V. parahaemolyticus on agar plates at a concentration of 75 µg/mL. CONCLUSION: The proposed antimicrobial substance, LBP102 was found to be effective against V. parahaemolyticus BCRC 12864 and Cronobacter sakazakii BCRC 13988. The remarkable effects of LBP102 against this and other pathogens indicated its potential as a natural preservative/food additive.


Assuntos
Anti-Infecciosos/farmacologia , Conservantes de Alimentos/farmacologia , Lactobacillus plantarum/metabolismo , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Meios de Cultivo Condicionados/análise , Conservantes de Alimentos/química , Conservantes de Alimentos/metabolismo , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Peptídeo Hidrolases/metabolismo , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...