Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Int J Food Sci Nutr ; 75(1): 58-69, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37921224

RESUMO

Gut microbiota is implicated in the control of host physiology by releasing bioactive actors that could exert a direct or indirect effect on tissue. A dysfunction of the gut microbiota to tissue axis could participate in the development of pathological states such as obesity and diabetes. The aim of this study was to identify the metabolic effect of Limosilactobacillus reuteri (known as Lactobacillus reuteri) BIO7251 (L. reuteri BIO7251) isolated from Corsican clementine orange. Body weight gain, adiposity, glucose tolerance, glucose absorption and food intake were measured in mice fed a high-fat diet in response to a preventive oral administration of L. reuteri BIO7251. This strain of bacteria exerts a beneficial effect on body weight gain by decreasing the subcutaneous adipose tissue mass. The treatment with L. reuteri BIO7251 decreases glucose absorption and food intake in obese/diabetic mice. L. reuteri BIO7251 could be tested as new probiotic strain that could manage body weight during obesity.


Assuntos
Diabetes Mellitus Experimental , Resistência à Insulina , Limosilactobacillus reuteri , Probióticos , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Camundongos Obesos , Obesidade/metabolismo , Peso Corporal , Aumento de Peso , Glucose/metabolismo , Fenótipo , Tecido Adiposo/metabolismo , Sistema Nervoso/metabolismo
2.
Appl Environ Microbiol ; 85(19)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31375489

RESUMO

Oenococcus oeni is the lactic acid bacterium (LAB) that most commonly drives malolactic fermentation in wine. Although oenococcal prophages are highly prevalent, their implications on bacterial fitness have remained unexplored and more research is required in this field. An important step toward achieving this goal is the ability to produce isogenic pairs of strains that differ only by the lysogenic presence of a given prophage, allowing further comparisons of different phenotypic traits. A novel protocol for the rapid isolation of lysogens is presented. Bacteria were first picked from the center of turbid plaques produced by temperate oenophages on a sensitive nonlysogenic host. When streaked onto an agar medium containing red grape juice (RGJ), cells segregated into white and red colonies. PCR amplifications with phage-specific primers demonstrated that only lysogens underwent white-red morphotypic switching. The method proved successful for various oenophages irrespective of their genomic content and attachment site used for site-specific recombination in the bacterial chromosome. The color switch was also observed when a sensitive nonlysogenic strain was infected with an exogenously provided lytic phage, suggesting that intracolonial lysis triggers the change. Last, lysogens also produced red colonies on white grape juice agar supplemented with polyphenolic compounds. We posit that spontaneous prophage excision produces cell lysis events in lysogenic colonies growing on RGJ agar, which, in turn, foster interactions between lysed materials and polyphenolic compounds to yield colonies easily distinguishable by their red color. Furthermore, the technique was used successfully with other species of LAB.IMPORTANCE The presence of white and red colonies on red grape juice (RGJ) agar during enumeration of Oenococcus oeni in wine samples is frequently observed by stakeholders in the wine industry. Our study brings an explanation for this intriguing phenomenon and establishes a link between the white-red color switch and the lysogenic state of O. oeni It also provides a simple and inexpensive method to distinguish between lysogenic and nonlysogenic derivatives in O. oeni with a minimum of expended time and effort. Noteworthy, the protocol could be adapted to two other species of LAB, namely, Leuconostoc citreum and Lactobacillus plantarum It could be an effective tool to provide genetic, ecological, and functional insights into lysogeny and aid in improving biotechnological processes involving members of the lactic acid bacterium (LAB) family.


Assuntos
Ágar/química , Meios de Cultura/química , Sucos de Frutas e Vegetais , Lisogenia , Oenococcus/fisiologia , Vitis , Contagem de Colônia Microbiana , Oenococcus/genética , Fenótipo , Filogenia , Prófagos , Vinho/microbiologia
3.
Int J Food Microbiol ; 383: 109936, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36179497

RESUMO

Winemaking is a complex process in which numerous microorganisms, mainly yeasts and lactic acid bacteria (LAB), play important roles. After alcoholic fermentation (AF), most wines undergo malolactic fermentation (MLF) to improve their organoleptic properties and microbiological stability. Oenococcus oeni is mainly responsible for this crucial process where L-malic acid (MA) in wine converts to softer L-lactic acid. The bacterium is better adapted to the limiting conditions imposed by the wine matrix and performs MLF under regular winemaking conditions, especially in wines with a pH below 3.5. Traditionally, this process has been conducted by the natural microbiota present within the winery. However, the start, duration and qualitative impact of spontaneous MLF are unpredictable, which prompts winemakers to use pure starter cultures of selected bacteria to promote a more reliable, simple, fast and efficient fermentation. Yet, their use does not always ensure a problem-free fermentation. Spontaneous initiation of the process may prove very difficult or does not occur at all. Such difficulties arise from a combination of factors found in some wines upon the completion of AF (high ethanol concentration, low temperature and pH, low nutrient concentrations, presence of free and bound SO2). Alongside these well documented facts, research has also provided evidence that negative interactions between O. oeni and other biological entities such as yeasts may also impact MLF. Another insufficiently described, but highly significant factor inhibiting bacterial growth is connected to the presence of bacteriophages of O. oeni which are frequently associated to musts and wines. The purpose of this review is to summarize the current knowledge about the phage life cycles and possible impacts on the trajectory of the microbiota during winemaking.


Assuntos
Bacteriófagos , Vinho , Vinho/microbiologia , Fermentação , Bacteriófagos/metabolismo , Leveduras/metabolismo , Ácido Láctico/metabolismo , Etanol , Dinâmica Populacional
4.
Microorganisms ; 9(4)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923461

RESUMO

Oenococcus oeni is the most exploited lactic acid bacterium in the wine industry and drives the malolactic fermentation of wines. Although prophage-like sequences have been identified in the species, many are not characterized, and a global view of their integration and distribution amongst strains is currently lacking. In this work, we analyzed the complete genomes of 231 strains for the occurrence of prophages, and analyzed their size and positions of insertion. Our data show the limited variation in the number of prophages in O. oeni genomes, and that six sites of insertion within the bacterial genome are being used for site-specific recombination. Prophage diversity patterns varied significantly for different host lineages, and environmental niches. Overall, the findings highlight the pervasive presence of prophages in the O. oeni species, their role as a major source of within-species bacterial diversity and drivers of horizontal gene transfer. Our data also have implications for enhanced understanding of the prophage recombination events which occurred during evolution of O. oeni, as well as the potential of prophages in influencing the fitness of these bacteria in their distinct niches.

5.
Front Microbiol ; 11: 596541, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33519734

RESUMO

There has been little exploration of how phages contribute to the diversity of the bacterial community associated with winemaking and may impact fermentations and product quality. Prophages of Oenococcus oeni, the most common species of lactic acid bacteria (LAB) associated with malolactic fermentation of wine, have been described, but no data is available regarding phages of O. oeni with true virulent lifestyles. The current study reports on the incidence and characterization of the first group of virulent oenophages named Vinitor, isolated from the enological environment. Vinitor phages are morphologically very similar to siphoviruses infecting other LAB. Although widespread during winemaking, they are more abundant in musts than temperate oenophages. We obtained the complete genomic sequences of phages Vinitor162 and Vinitor27, isolated from white and red wines, respectively. The assembled genomes shared 97.6% nucleotide identity and belong to the same species. Coupled with phylogenetic analysis, our study revealed that the genomes of Vinitor phages are architecturally mosaics and represent unique combinations of modules amongst LAB infecting-phages. Our data also provide some clues to possible evolutionary connections between Vinitor and (pro)phages associated to epiphytic and insect-related bacteria.

6.
Viruses ; 12(11)2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33213034

RESUMO

To provide insights into phage-host interactions during winemaking, we assessed whether phenolic compounds modulate the phage predation of Oenococcus oeni. Centrifugal partition chromatography was used to fractionate the phenolic compounds of a model red wine. The ability of lytic oenophage OE33PA to kill its host was reduced in the presence of two collected fractions in which we identified five compounds. Three, namely, quercetin, myricetin and p-coumaric acid, significantly reduced the phage predation of O. oeni when provided as individual pure molecules, as also did other structurally related compounds such as cinnamic acid. Their presence was correlated with a reduced adsorption rate of phage OE33PA on its host. Strikingly, none of the identified compounds affected the killing activity of the distantly related lytic phage Vinitor162. OE33PA and Vinitor162 were shown to exhibit different entry mechanisms to penetrate into bacterial cells. We propose that ligand-receptor interactions that mediate phage adsorption to the cell surface are diverse in O. oeni and are subject to differential interference by phenolic compounds. Their presence did not induce any modifications in the cell surface as visualized by TEM. Interestingly, docking analyses suggest that quercetin and cinnamic acid may interact with the tail of OE33PA and compete with host recognition.


Assuntos
Bacteriófagos/efeitos dos fármacos , Oenococcus/virologia , Fenóis/farmacologia , Vinho/análise , Ácidos Cumáricos/química , Flavonoides/química , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Simulação de Acoplamento Molecular , Oenococcus/efeitos dos fármacos , Fenóis/química
7.
Artigo em Inglês | MEDLINE | ID: mdl-30533896

RESUMO

Oenococcus oeni is the most common species of lactic acid bacteria associated with malolactic fermentation in wine. Here, we report the genome sequence of the lytic phage OE33PA (vB_OeS_OE33PA). It has a morphotype similar to that of members of the Siphoviridae family, a linear 39,866-bp double-stranded genome with cohesive ends, and 57 predicted open reading frames.

8.
Viruses ; 10(1)2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29337868

RESUMO

The Gluconobacter phage GC1 is a novel member of the Tectiviridae family isolated from a juice sample collected during dry white wine making. The bacteriophage infects Gluconobacter cerinus, an acetic acid bacterium which represents a spoilage microorganism during wine making, mainly because it is able to produce ethyl alcohol and transform it into acetic acid. Transmission electron microscopy revealed tail-less icosahedral particles with a diameter of ~78 nm. The linear double-stranded DNA genome of GC1 (16,523 base pairs) contains terminal inverted repeats and carries 36 open reading frames, only a handful of which could be functionally annotated. These encode for the key proteins involved in DNA replication (protein-primed family B DNA polymerase) as well as in virion structure and assembly (major capsid protein, genome packaging ATPase (adenosine triphosphatase) and several minor capsid proteins). GC1 is the first tectivirus infecting an alphaproteobacterial host and is thus far the only temperate tectivirus of gram-negative bacteria. Based on distinctive sequence and life-style features, we propose that GC1 represents a new genus within the Tectiviridae, which we tentatively named "Gammatectivirus". Furthermore, GC1 helps to bridge the gap in the sequence space between alphatectiviruses and betatectiviruses.


Assuntos
Ácido Acético/metabolismo , Gluconobacter/virologia , Tectiviridae/classificação , Vinho/microbiologia , Replicação do DNA , DNA Viral/genética , Genoma Viral , Gluconobacter/metabolismo , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA , Tectiviridae/genética , Tectiviridae/isolamento & purificação , Vírion/genética
9.
Int J Food Microbiol ; 257: 138-147, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-28651079

RESUMO

Oenophages have so far been mostly isolated from red wines under malolactic fermentation (MLF), and correspond to temperate or ex-temperate phages of Oenococcus oeni. Their genomes are clustered into 4 integrase gene sequence groups, which are also related to the chromosomal integration site. Our aims were to survey the occurrence of oenophages in a broader and more diverse collection of samples than those previously explored. Active phages were isolated from 33 out of 166 samples, which mostly originated from must and MLF. Seventy one phage lysates were produced and 30% were assigned to a novel group with unusual genomic characteristics, called unk. All unk members produced similar RAPD and DNA restriction patterns, were negative by PCR for the signature sequences previously identified in the integrase and endolysin genes of oenophages, and lacked any BamHI restriction site in their genome. The data support that development of additional and novel signature genes for assessing oenophage diversity is now required.


Assuntos
Bacteriófagos/genética , Integrases/genética , Oenococcus/virologia , Vinho/microbiologia , Vinho/virologia , Tipagem de Bacteriófagos , Bacteriófagos/classificação , Sequência de Bases , DNA Viral/genética , Fermentação , Genômica , Consórcios Microbianos/genética , Oenococcus/genética , Reação em Cadeia da Polimerase , Técnica de Amplificação ao Acaso de DNA Polimórfico
10.
Int J Food Microbiol ; 166(2): 331-40, 2013 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-23994162

RESUMO

Temperate bacteriophages are a contributor of the genetic diversity in the lactic acid bacterium Oenococcus oeni. We used a classification scheme for oenococcal prophages based on integrase gene polymorphism, to analyze a collection of Oenococcus strains mostly isolated in the area of Bordeaux, which represented the major lineages identified through MLST schemes in the species. Genome sequences of oenococcal prophages were clustered into four integrase groups (A to D) which were related to the chromosomal integration site. The prevalence of each group was determined and we could show that members of the intB- and intC-prophage groups were rare in our panel of strains. Our study focused on the so far uncharacterized members of the intD-group. Various intD viruses could be easily isolated from wine samples, while intD lysogens could be induced to produce phages active against two permissive O. oeni isolates. These data support the role of this prophage group in the biology of O. oeni. Global alignment of three relevant intD-prophages revealed significant conservation and highlighted a number of unique ORFs that may contribute to phage and lysogen fitness.


Assuntos
Bacteriófagos/classificação , Bacteriófagos/fisiologia , Variação Genética , Integrases/genética , Oenococcus/virologia , Bacteriófagos/enzimologia , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Sequência de Bases , Genoma Viral/genética , Dados de Sequência Molecular , Filogenia , Prófagos/genética , Alinhamento de Sequência , Vinho/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA