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1.
Food Res Int ; 159: 111604, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35940798

RESUMO

There has been a growing interest in developing co-inoculum of Oenococcus oeni and Saccharomyces cerevisiae/non-Saccharomyces for simultaneous malolactic fermentation (MLF) and alcoholic fermentation (AF) of wines. This study sought to elucidate the effects of two crucial factors (inoculation timing and paired yeast) on the fermentation performance and aroma production of Merlot wine. O. oeni used for MLF was concurrently or sequentially inoculated with two yeast cultures (i.e., single S. cerevisiae and mixed S. cerevisiae /Pichia fermentans H5Y-28) used for AF. Inoculation timing determined the overall vinification duration, and conditioned the production of principle higher alcohols, terpene and O. oeni-mediated volatiles. In contrast, paired yeast improved O. oeni viability, and showed significant effect on aromatic esters and volatile fatty acids. Possibly due to lower ethanol stress, co-inoculum allowed O. oeni to initiate MLF during AF, resulting in 45% reduction of total fermentation time. Meanwhile, O. oeni growth was stimulated by P. fermentans, with 1.7-fold of the maximum population higher than that in co-fermentation without P. fermentans. Such stimulation of O. oeni growth also occurred in sequential fermentation where P. fermentans had been replaced by S. cerevisiae. Only in sequential inoculum, P. fermentans induced high levels of 3-methylbutyl acetate, ethyl 3-methylbutanoate, ethyl hexanoate and ethyl octanoate, which may result in enhanced fresh fruity trait of wines. These findings suggested a positive effect of P. fermentans H5Y-28 on O. oeni and MLF. This work provides an alternative approach to improve wine MLF and aroma outcomes using friendly non-Saccharomyces yeast with appropriate inoculation strategy.


Assuntos
Vinho , Fermentação , Odorantes , Oenococcus , Pichia , Saccharomyces cerevisiae , Vinho/análise
2.
Food Microbiol ; 106: 104038, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35690442

RESUMO

Malolactic fermentation is essential for the quality of red wines and some other wine styles. Spontaneous malolactic fermentation is often driven by Oenococcus oeni, and commercial starters for this purpose are also often of this species. The increasing number of microbial species and inoculation strategies in winemaking has prompted a growing interest in microbial interactions during wine fermentation. Among other interaction mechanisms, extracellular vesicles have been hypothesized to play a role in this context. Extracellular vesicles have already been described and analysed for several wine yeast species. In this work, the production of extracellular vesicles by O. oeni is reported for the first time. The protein content of these extracellular vesicles is also characterised. It shows differences and similarities with the recently described protein content of Lactiplantibacillus plantarum, a bacterial species also capable of performing malolactic fermentation of wine (and used sometimes as an alternative starter). This work further contributes to the development of the field of extracellular vesicles in food biotechnology.


Assuntos
Vesículas Extracelulares , Oenococcus , Vinho , Vesículas Extracelulares/metabolismo , Fermentação , Malatos/metabolismo , Oenococcus/genética , Oenococcus/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/análise
3.
Pol J Microbiol ; 71(2): 279-292, 2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35716166

RESUMO

Oenococcus oeni is an important microorganism in wine-making-related engineering, and it improves wine quality and stability through malolactic fermentation. Although the genomes of more than 200 O. oeni strains have been sequenced, only a few include completed genome maps. Here, the genome sequence of O. oeni SD-2a, isolated from Shandong, China, has been determined. It is a fully assembled genome sequence of this strain. The complete genome is 1,989,703 bp with a G+C content of 37.8% without a plasmid. The genome includes almost all the essential genes involved in central metabolic pathways and the stress genes reported in other O. oeni strains. Some natural competence-related genes, like comEA, comEC, comFA, comG operon, and comFC, suggest that O. oeni SD-2a may have natural transformation potential. A comparative genomics analysis revealed 730 gene clusters in O. oeni SD-2a homologous to those in four other lactic acid bacteria species (O. oeni PSU-1, O. oeni CRBO-11381, Lactiplantibacillus plantarum UNQLp11, and Pediococcus pentosaceus KCCM40703). A collinearity analysis showed poor collinearity between O. oeni SD-2a and O. oeni PSU-1, indicating great differences in their evolutionary histories. The results provide general knowledge of O. oeni SD-2a and lay the foundation for specific gene function analyses.


Assuntos
Oenococcus , Vinho , Fermentação , Genômica , Oenococcus/genética , Vinho/análise , Vinho/microbiologia
4.
Food Res Int ; 157: 111235, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761547

RESUMO

Oenococcus oeni and Lactiplantibacillus plantarum are major wine-associated lactic acid bacteria that positively influence wine by carrying out malolactic fermentation. O. oeni is the most widely used commercial starter in winemaking because of its fast and efficient malate metabolism capacity under harsh wine conditions. To date, very little is known about the specific molecular mechanism underlying the differences in malate metabolism between O. oeni and L. plantarum under harsh wine conditions. Therefore, in this study, the functions of genes encoding malic enzyme (ME) and malolactic enzyme (MLE) under acid stress in O. oeni and L. plantarum, previously described to have the ability to direct malate metabolism, were comparatively verified through genetic manipulation in L. plantarum. Results showed that the MLE was the only enzyme responsible for direct malate metabolism under acid stress in O. oeni and L. plantarum. In addition, the MLEs in O. oeni and L. plantarum were positively related to acid tolerance by metabolizing malate and increasing the medium pH. Furthermore, the MLE in O. oeni exhibited significantly higher malate metabolism activity than that in L. plantarum under acid stress.


Assuntos
Oenococcus , Vinho , Ácidos , Concentração de Íons de Hidrogênio , Malatos/metabolismo , Oenococcus/genética , Oenococcus/metabolismo , Vinho/análise
5.
Int J Food Microbiol ; 375: 109726, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35635990

RESUMO

Climate change is generating several problems in wine technology. One of the main ones is lack of acidity and difficulties performing malolactic fermentation to stabilize wines before bottling. Among the different available acidity management technologies, such as direct acid addition, ion exchange resins, electro-membrane treatments, or vineyard management, the microbiological option is reliable and deeply studied. The main approach is the increase in malic acid content because of the metabolism of specific Saccharomyces strains and to increase lactic acid because of the metabolism of Lachancea genus. Other non-Saccharomyces yeasts, such as Starmerella bacillaris or Candida stellata can also acidify significantly because of the production of pyruvic or succinic acid. Wine industry needs the removal of malic acid in most red wines before bottling to achieve wine stability. Oenococus oeni performs the malolactic fermentation of red wines on most conditions because of the metabolization of malic acid into lactic acid. However, modern oenology challenges such as high ethanol concentrations, high pH or low levels of malic acid have made researchers to look for other options to reduce potential risks of deviation. Other wine-related microorganisms able to de-acidify malic acid have appeared as interesting alternatives for specific difficult scenarios. Lactiplantibacillus plantarum and Schizosaccharomyces genus make up nowadays the main studied alternatives.


Assuntos
Oenococcus , Schizosaccharomyces , Vinho , Etanol/metabolismo , Fermentação , Ácido Láctico/metabolismo , Malatos/metabolismo , Oenococcus/metabolismo , Schizosaccharomyces/metabolismo , Vinho/microbiologia
7.
Int J Food Microbiol ; 369: 109617, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35290839

RESUMO

Oenococcus oeni is the most resistant lactic acid bacteria species to the environmental stresses encountered in wine, particularly the acidity, presence of ethanol and phenolic compounds. Indigenous strains develop spontaneously following the yeast-driven alcoholic fermentation and may perform the malolactic fermentation whereby improving taste, aroma, and the microbial stability of wine. However, spontaneous fermentation is sometimes delayed, prolonged or incomplete. In order to better control its timing and quality, O. oeni strains are selected and developed to be used as malolactic starters. They are prepared under proprietary manufacturing processes to survive direct inoculation and are predominantly provided as freeze-dried preparations. In this study, we have investigated the physiological and molecular alterations occurring in O. oeni cells prepared by an industrial process that consists of preconditioning protocols and freeze-drying, and compared them to the same strain grown in a grape juice medium. We found that compared to cultured cells, the industrial production process improved survival under extreme conditions, i. e. at low pH or high tannin concentrations. In contrast, cultured cells resumed active growth more quickly and strongly than freeze-dried preparations in standard pH wines. A proteomic analysis showed that during the industrial production most non-essential metabolic processes are shut down and components of the general and the stringent stress response are upregulated. The presence of major components of the stress response facilitates protein homeostasis and physiological changes that further ensure the integrity of cells.


Assuntos
Oenococcus , Vinho , Fermentação , Malatos/metabolismo , Oenococcus/metabolismo , Proteômica , Vinho/microbiologia
8.
Food Microbiol ; 103: 103947, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35082064

RESUMO

After alcoholic fermentation, most wines undergo malolactic fermentation (MLF), driven by the lactic acid bacterium Oenococcus oeni, which improves their organoleptic properties and microbiological stability. Prophages were recently shown to be notably diverse and widely disseminated in O. oeni genomes. Such in silico predictions confirmed previous cultivation-based approaches which showed frequent lysis of strains upon treatment with the inducing agent mitomycin C. Both strategies used to assess lysogeny in the species were so far applied to a number of strains collected from distinct countries, wineries, cepages and fermentation processes. Results may not therefore be representative of the lysogenic population in natural communities driving the MLF during winemaking. Here we report the prevalence of lysogeny during winemaking in three wineries in the Bordeaux area. The dominant LAB population was collected in 11 red wines upon completion of MLF. Using VNTR and prophage typing analyses, our data confirm the presence of lysogens in the population driving the spontaneous MLF in all tested wines, although lysogeny rates varied across wineries. Higher prevalence of lysogeny was associated to a reduced diversity in VNTR profiles, the dominance of a few prophage-types and presence of some bacterial genetic backgrounds that were particularly prone to lysogenization.


Assuntos
Oenococcus , Vinho , Fermentação , Ácido Láctico , Lisogenia , Malatos , Oenococcus/genética , Prófagos/genética , Vinho/análise
9.
Food Microbiol ; 101: 103895, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34579855

RESUMO

This study aimed to investigate the behavior of Oenococcus oeni MS9 and MS46 strains in sterile grape juice (SGJ, pH 4.0) incubated at 30 °C, in terms of growth and glucose, organic acids and total phenolic compounds utilization. In addition, their antimicrobial activity and the changes in antioxidant properties of fermented juice with selected strain were evaluated. Both strains grew without lag period by ~1.40 log CFU/mL at 12 days with maximum growth rates of about 0.019 h-1. After this time the MS9 and MS46 strains counts declined by 0.6 log units and remained unchanged respectively. O. oeni MS46 was evaluated in SGJ for low inoculum size (~104 CFU/mL). In this condition it also grew without lag period by 3.11 ± 0.01 log CFU/mL with a µmax of 0.05 h-1. Glucose and L-malic and citric acids were simultaneously utilized but at different rates and extents, yielding mainly lactic acid with concomitant pH reduction. Acetic acid ranged between 11 and 19 mmol/L. Total phenolic compounds significantly decreased in fermented SGJ with strain MS9 but not MS46. In this last condition, the antioxidant activity increased by 21%. In addition, both O. oeni strains showed antibacterial properties against Escherichia coli 700, Salmonella Typhimurium and Listeria monocytogenes. O. oeni strains, especially MS46, with the ability to growth in SGJ, high malolactic potential and adequate sugars and organic acids profiles from the sensorial viewpoint may be used to ferment grape juice with safer and healthier properties than fresh juice.


Assuntos
Fermentação , Oenococcus , Vitis , Vinho , Endopeptidases , Esterases , Glucose , Oenococcus/metabolismo , Fenóis , Vitis/microbiologia , Vinho/análise , Vinho/microbiologia
10.
Food Microbiol ; 102: 103905, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809937

RESUMO

BACKGROUND: Acid stress is one of the most important environmental stresses that adversely affect the growth of lactic acid bacteria (LAB), such as Oenococcus oeni which was isolated from grape-berries and mainly used in wine fermentation. The aim of this paper is to comprehensively characterize the mechanisms of acid stress regulation in O. oeni and to provide a viable theoretical basis for breed and improvement of existing LAB. METHOD: First, six O. oeni mutants with acid-sensitive (strains b2, a1, c2) and acid-tolerant (strains b1, a3, c1) phenotypes were screened from three wild-type O. oeni, and then their genome (sequencing), transcriptome and metabolome (LC-MS/MS) were examined. RESULTS: A total of 459 genes were identified with one or more intragenic single nucleotide polymorphisms (SNPs) in these mutants, and were extensively involved in metabolism and cellular functions with a high mutation rates in purine (46%) and pyrimidine (48%) metabolic pathways. There were 210 mutated genes that cause significant changes in expression levels. In addition, 446 differentially accumulated metabolites were detected, and they were consistently detected at relatively high levels in the acid-tolerant O. oeni mutant. The levels of intracellular differentially expressed genes and differential metabolites changed with increasing culture time. CONCLUSION: The integrative pathways analysis showed that the intracellular response associated with acid regulation differed significantly between acid-sensitive and acid-tolerant O. oeni mutants, and also changed at different growth stages.


Assuntos
Ácidos , Oenococcus , Vinho , Cromatografia Líquida , Fermentação , Genoma Bacteriano , Ácido Láctico , Metaboloma , Oenococcus/genética , Oenococcus/crescimento & desenvolvimento , Espectrometria de Massas em Tandem , Transcriptoma , Vinho/análise
11.
Int J Food Microbiol ; 362: 109496, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-34895934

RESUMO

We report the fermentative traits of two Kazachstania species (K. aerobia and K. servazzii) in non-sterile red wine and the resulting chemical and sensory properties. This builds on our previous work which revealed that Kazachstania spp. increased acetate esters in sterilised white wine. In this study Kazachstania spp. were initially evaluated in laboratory-scale fermentations (500 mL) in Merlot must to assess whether similar increases in chemical/volatile compounds would occur. The impact of malolactic fermentation (MLF) by Oenococcus oeni (VP41) on aroma composition was considered and found to reduce ester profiles in Merlot wines. The sensory implications of sequential inoculation with Kazachstania spp., followed by Saccharomyces cerevisiae, were then evaluated in small-lot fermentations (7 kg) of Shiraz must. Fungal diversity was monitored during early fermentation stages and was influenced by the early implantation of Kazachstania spp., followed by the dominance of S. cerevisiae. The effect of MLF in Shiraz wines was inconclusive due to high ethanol levels providing an inhospitable environment for lactic acid bacteria. When compared to S. cerevisiae alone, Kazachstania spp. significantly increased acetate esters, particularly phenylethyl acetate and isoamyl acetate, in both Merlot and Shiraz. The Shiraz wines fermented with Kazachstania spp. had higher jammy and red fruit aroma/flavour compared to S. cerevisiae (monoculture) wines. No influence was observed on colour one-year post-bottling. Results from this study show the contribution of Kazachstania spp. to the aroma profile of red wines and demonstrate their potential as starter cultures for improving the aromatic complexity of wines.


Assuntos
Oenococcus , Saccharomycetales , Vinho , Fermentação , Odorantes/análise , Saccharomyces cerevisiae , Vinho/análise
12.
Int J Food Microbiol ; 362: 109490, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-34844030

RESUMO

Oenococcus oeni is the main agent responsible for malolactic fermentation (MLF) in wine. This usually takes place in red wines after alcoholic fermentation (AF) carried out by Saccharomyces cerevisiae. In recent years, there is an increasing interest in using non-Saccharomyces yeast, usually in combination with S. cerevisiae, to improve wine quality. Current studies report a stimulatory effect of non-Saccharomyces on MLF, generally related to a decrease in the inhibitor compounds found in wine. In this work, we followed a comparative multi-omics approach, including transcriptomic and proteomic analysis, to study the molecular adaptation of O. oeni in wines fermented with Torulaspora delbrueckii and Metschnikowia pulcherrima, two of the most frequently used non-Saccharomyces, in sequential inoculation with S. cerevisiae. We compared the results to the adaptation of O. oeni in S. cerevisiae wine to determine the main changes arising from the use of non-Saccharomyces. The duration of MLF was shortened when using non-Saccharomyces, to half the time with T. delbrueckii and to a quarter with M. pulcherrima. In this work, we observed for the first time how O. oeni responds at molecular level to the changes brought about by non-Saccharomyces. We showed a differential adaptation of O. oeni in the wines studied. In this regard, the main molecular functions affected were amino acid and carbohydrate transport and metabolism, from which peptide metabolism appeared as a key feature under wine-like conditions. We also showed that the abundance of Hsp20, a well-known stress protein, depended on the duration time. Thus, the use of non-Saccharomyces reduced the abundance of Hsp20, which could mean a less stressful wine-like condition for O. oeni.


Assuntos
Oenococcus , Vinho , Fermentação , Malatos , Oenococcus/genética , Proteômica , Saccharomyces cerevisiae , Vinho/análise
13.
Viruses ; 15(1)2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36680056

RESUMO

The Oenococcus genus comprises four recognized species, and members have been found in different types of beverages, including wine, kefir, cider and kombucha. In this work, we implemented two complementary strategies to assess whether oenococcal hosts of different species and habitats were connected through their bacteriophages. First, we investigated the diversity of CRISPR-Cas systems using a genome-mining approach, and CRISPR-endowed strains were identified in three species. A census of the spacers from the four identified CRISPR-Cas loci showed that each spacer space was mostly dominated by species-specific sequences. Yet, we characterized a limited records of potentially recent and also ancient infections between O. kitaharae and O. sicerae and phages of O. oeni, suggesting that some related phages have interacted in diverse ways with their Oenococcus hosts over evolutionary time. Second, phage-host interaction analyses were performed experimentally with a diversified panel of phages and strains. None of the tested phages could infect strains across the species barrier. Yet, some infections occurred between phages and hosts from distinct beverages in the O. oeni species.


Assuntos
Bacteriófagos , Oenococcus , Vinho , Bacteriófagos/genética , Oenococcus/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Ecossistema , Sistemas CRISPR-Cas
14.
Appl Microbiol Biotechnol ; 105(23): 8575-8592, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34694447

RESUMO

The widespread existence of bacteriophage has been of great interest to the biological research community and ongoing investigations continue to explore their diversity and role. They have also attracted attention and in-depth research in connection to fermented food processing, in particular from the dairy and wine industries. Bacteriophage, mostly oenophage, may in fact be a 'double edged sword' for winemakers: whilst they have been implicated as a causal agent of difficulties with malolactic fermentation (although not proven), they are also beginning to be considered as alternatives to using sulphur dioxide to prevent wine spoilage. Investigation and characterisation of oenophage of Oenococcus oeni, the main species used in winemaking, are still limited compared to lactococcal bacteriophage of Lactococcus lactis and Lactiplantibacillus plantarum (formally Lactobacillus plantarum), the drivers of most fermented dairy products. Interestingly, these strains are also being used or considered for use in winemaking. In this review, the genetic diversity and life cycle of phage, together with the debate on the consequent impact of phage predation in wine, and potential control strategies are discussed. KEY POINTS: • Bacteriophage detected in wine are diverse. • Many lysogenic bacteriophage are found in wine bacteria. • Phage impact on winemaking can depend on the stage of the winemaking process. • Bacteriophage as potential antimicrobial agents against spoilage organisms.


Assuntos
Bacteriófagos , Oenococcus , Vinho , Fermentação , Lactobacillus , Vinho/análise
15.
Microbiol Spectr ; 9(2): e0115421, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34612664

RESUMO

To successfully complete malolactic fermentation (MLF), Oenococcus oeni must overcome wine stress conditions of low pH, high ethanol, and the presence of SO2. Failure to complete MLF may result in detrimental effects to the quality and stability of the resulting wines. Research efforts to date have focused on elucidating the mechanisms and genetic features that confer the ability to withstand low pH and high ethanol concentrations on O. oeni; however, the responses to SO2 stress are less well defined. This study focused on characterizing the transcriptional response of O. oeni to SO2 challenge during cultivation in a continuous system at wine-like pH (3.5). This experimental design allowed the precise discrimination of transcriptional changes linked to SO2 stress from responses associated with growth stage and cultivation parameters. Differential gene expression analysis revealed major transcriptional changes following SO2 exposure and suggested that this compound primarily interacts with intracellular proteins, DNA, and the cell envelope of O. oeni. The molecular chaperone hsp20, which has a demonstrated function in the heat, ethanol, and acid stress response, was highly upregulated, confirming its additional role in the response of this species to SO2 stress. This work also reports the first nanopore-based complete genome assemblies for O. oeni. IMPORTANCE Malolactic fermentation is an indispensable step in the elaboration of most wines and is generally performed by Oenococcus oeni, a Gram-positive heterofermentative lactic acid bacterium species. While O. oeni is tolerant to many of the wine stresses, including low pH and high ethanol concentrations, it has high sensitivity to SO2, an antiseptic and antioxidant compound regularly used in winemaking. Understanding the physiological changes induced in O. oeni by SO2 stress is essential for the development of more robust starter cultures and methods for their use. This study describes the main transcriptional changes induced by SO2 stress in the wine bacterium O. oeni and provides foundational understanding on how this compound interacts with the cellular components and the induced protective mechanisms of this species.


Assuntos
Regulação Bacteriana da Expressão Gênica/genética , Malatos/metabolismo , Oenococcus/genética , Oenococcus/metabolismo , Sulfitos/metabolismo , Membrana Celular/metabolismo , Dano ao DNA/genética , Etanol/análise , Fermentação , Genoma Bacteriano/genética , Proteínas de Choque Térmico HSP20/metabolismo , Concentração de Íons de Hidrogênio , Ácido Láctico/metabolismo , Estresse Fisiológico/fisiologia , Transcrição Genética/genética , Transcriptoma/genética , Vinho/microbiologia
16.
BMC Complement Med Ther ; 21(1): 183, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210310

RESUMO

BACKGROUND: In recent years, researchers are interested in the discovery of active compounds from traditional remedies and natural sources, as they reveal higher therapeutic efficacies and improved toxicological profiles. Among the various traditional treatments that have been widely studied and explored for their potential therapeutic benefits, kefir, a fermented beverage, demonstrates a broad spectrum of pharmacological properties, including antioxidant, anti-inflammation, and healing activities. These health-promoting properties of kefir vary among the kefir cultures found at the different part of the world as different media and culture conditions are used for kefir maintenance and fermentation. METHODS: This study investigated the microbial composition and readily found bioactive compounds in water kefir fermented in Malaysia using 16S rRNA microbiome and UHPLC sequencing approaches. The toxicity effects of the kefir water administration in BALB/c mice were analysed based on the mice survival, body weight index, biochemistry profile, and histopathological changes. The antioxidant activities were evaluated using SOD, FRAP, and NO assays. RESULTS: The 16S rRNA amplicon sequencing revealed the most abundant species found in the water kefir was Lactobacillus hilgardii followed by Lactobacillus harbinensis, Acetobacter lovaniensis, Lactobacillus satsumensis, Acetobacter tropicalis, Lactobacillus zeae, and Oenococcus oeni. The UHPLC screening showed flavonoid and phenolic acid derivatives as the most important bioactive compounds present in kefir water which has been responsible for its antioxidant activities. Subchronic toxicity study showed no toxicological signs, behavioural changes, or adverse effects by administrating 10 mL/kg/day and 2.5 mL/kg/day kefir water to the mice. Antioxidants assays demonstrated enhanced SOD and FRAP activities and reduced NO level, especially in the brain and kidney samples. CONCLUSIONS: This study will help to intensify the knowledge on the water kefir microbial composition, available phytochemicals and its toxicological and antioxidant effects on BALB/c mice since there are very limited studies on the water kefir grain fermented in Malaysia.


Assuntos
Kefir/microbiologia , Metagenoma , Microbiologia da Água , Acetobacter/genética , Animais , Encéfalo/metabolismo , Cromatografia Líquida de Alta Pressão , Rim/metabolismo , Lactobacillus/genética , Fígado/metabolismo , Espectrometria de Massas , Camundongos Endogâmicos BALB C , Microbiota , Óxido Nítrico/metabolismo , Oenococcus/genética , RNA Ribossômico 16S , Baço/metabolismo , Superóxido Dismutase/metabolismo , Testes de Toxicidade Subcrônica
17.
Appl Microbiol Biotechnol ; 105(12): 5053-5066, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34106310

RESUMO

The two most commonly used wine microorganisms, Saccharomyces cerevisiae yeast and Oenococcus oeni bacteria, are responsible for completion of alcoholic and malolactic fermentation (MLF), respectively. For successful co-inoculation, S. cerevisiae and O. oeni must be able to complete fermentation; however, this relies on compatibility between yeast and bacterial strains. For the first time, quantitative trait loci (QTL) analysis was used to elucidate whether S. cerevisiae genetic makeup can play a role in the ability of O. oeni to complete MLF. Assessment of 67 progeny from a hybrid S. cerevisiae strain (SBxGN), co-inoculated with a single O. oeni strain, SB3, revealed a major QTL linked to MLF completion by O. oeni. This QTL encompassed a well-known translocation, XV-t-XVI, that results in increased SSU1 expression and is functionally linked with numerous phenotypes including lag phase duration and sulphite export and production. A reciprocal hemizygosity assay was performed to elucidate the effect of the gene SSU1 in the SBxGN background. Our results revealed a strong effect of SSU1 haploinsufficiency on O. oeni's ability to complete malolactic fermentation during co-inoculation and pave the way for the implementation of QTL mapping projects for deciphering the genetic bases of microbial interactions. KEY POINTS: • For the first time, QTL analysis has been used to study yeast-bacteria interactions. • A QTL encompassing a translocation, XV-t-XVI, was linked to MLF outcomes. • S. cerevisiae SSU1 haploinsufficiency positively impacted MLF by O. oeni.


Assuntos
Oenococcus , Vinho , Fermentação , Determinismo Genético , Malatos , Locos de Características Quantitativas , Saccharomyces cerevisiae/genética , Vinho/análise
18.
Food Microbiol ; 99: 103839, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34119090

RESUMO

The use of non-Saccharomyces yeast together with S. cerevisiae in winemaking is a current trend. Apart from the organoleptic modulation of the wine, the composition of the resulting yeast lees is different and may thus impact malolactic fermentation (MLF). Yeasts of Saccharomyces cerevisiae, Torulaspora delbrueckii and Metschnikowia pulcherrima were inactivated and added to a synthetic wine. Three different strains of Oenococcus oeni were inoculated and MLF was monitored. Non-Saccharomyces lees, especially from some strains of T. delbrueckii, showed higher compatibility with some O. oeni strains, with a shorter MLF and a maintained bacterial cell viability. The supplementation of lees increased nitrogen compounds available by O. oeni. A lower mannoprotein consumption was related with longer MLF. Amino acid assimilation by O. oeni was strain specific. There may be many other compounds regulating these yeast lees-O. oeni interactions apart from the well-known mannoproteins and amino acids. This is the first study of MLF with different O. oeni strains in the presence of S. cerevisiae and non-Saccharomyces yeast lees to report a strain-specific interaction between them.


Assuntos
Malatos/metabolismo , Oenococcus/metabolismo , Vinho/microbiologia , Leveduras/metabolismo , Meios de Cultura/metabolismo , Fermentação , Filogenia , Leveduras/classificação , Leveduras/genética
19.
Enzyme Microb Technol ; 148: 109814, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34116760

RESUMO

The ß-glucosidase derived from microorganisms has attracted worldwide interest for their industrial applications, but studies on ß-glucosidases from Oenococcus oeni are rare. In this paper, catalytic mechanism of a novel ß-glucosidase BGL0224 of Oenococcus oeni SD-2a was explored for the first time by kinetic parameters determination, fluorescence spectroscopy and quenching mechanism analysis, molecular dynamics simulation. The results indicated that BGL0224 had universal catalytic effect on different types of glycoside substrates, but the catalytic efficiencies were different. Fluorescence quenching analysis results suggested that the quenching processes between BGL0224 and seven kinds of substrates were predominated by the static quenching mechanism. A reasonable three-dimensional model of BGL0224 was obtained using the crystal structure of E.coli BglA as a template. The analysis results of molecular simulation (RMSD, Rg, RMSF and hydrogen bonding) showed that the composite system 'BGL0224-pNPG' was very stable after 40 ns. The catalytic process of BGL0224 acting on 'p-Nitrophenyl ß-d-glucopyranoside' conformed to the double displacement mechanism. Two glutamic acid residues 'Glu178 and Glu377' played a vital role in the whole catalytic process. Overall, this study gave specific insights on the catalytic mechanism of BGL0224, which was of great significance for developing its potential applications in food industry.


Assuntos
Oenococcus , beta-Glucosidase , Catálise , Cinética , Simulação de Acoplamento Molecular , Oenococcus/metabolismo , beta-Glucosidase/metabolismo
20.
J Agric Food Chem ; 69(9): 2906-2918, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33587641

RESUMO

Oenococcus oeni plays a key role in inducing malolactic fermentation in wine. Acid stress is often encountered under wine conditions. However, the lack of systematic studies of acid resistance mechanisms limits the downstream fermentation applications. In this study, the acid responses of O. oeni were investigated by combining transcriptome, metabolome, and genome-scale metabolic modeling approaches. Metabolite profiling highlighted the decreased abundance of nucleotides under acid stress. The gene-metabolite bipartite network showed negative correlations between nucleotides and genes involved in ribosome assembly, translation, and post-translational processes, suggesting that stringent response could be activated under acid stress. Genome-scale metabolic modeling revealed marked flux rerouting, including reallocation of pyruvate, attenuation of glycolysis, utilization of carbon sources other than glucose, and enhancement of nucleotide salvage and the arginine deiminase pathway. This study provided novel insights into the acid responses of O. oeni, which will be useful for designing strategies to address acid stress in wine malolactic fermentation.


Assuntos
Oenococcus , Vinho , Fermentação , Ácido Láctico , Oenococcus/genética
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