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Metabolites Mar 2022Kombucha is a fermented beverage obtained through the activity of a complex microbial community of yeasts and bacteria. Exo-metabolomes of kombucha microorganisms were...
Kombucha is a fermented beverage obtained through the activity of a complex microbial community of yeasts and bacteria. Exo-metabolomes of kombucha microorganisms were analyzed using FT-ICR-MS to investigate their interactions. A simplified set of microorganisms including two yeasts ( and ) and one acetic acid bacterium () was used to investigate yeast-yeast and yeast-acetic acid bacterium interactions. A yeast-yeast interaction was characterized by the release and consumption of fatty acids and peptides, possibly in relationship to commensalism. A yeast-acetic acid bacterium interaction was different depending on yeast species. With , fatty acids and peptides were mainly produced along with consumption of sucrose, fatty acids and polysaccharides. In opposition, the presence of induced mainly the decrease of polyphenols, peptides, fatty acids, phenolic acids and putative isopropyl malate and phenylpyruvate and few formulae have been produced. With all three microorganisms, the formulae involved with the yeast-yeast interactions were consumed or not produced in the presence of . The impact of the yeasts' presence on was consistent regardless of the yeast species with a commensal consumption of compounds associated to the acetic acid bacterium by yeasts. In detail, hydroxystearate from yeasts and dehydroquinate from were potentially consumed in all cases of yeast(s)-acetic acid bacterium pairing, highlighting mutualistic behavior.
PubMed: 35323678
DOI: 10.3390/metabo12030235 -
Frontiers in Microbiology 2021During a survey of trees and their parasitic fungi in Andean Patagonia (Argentina), genetically distinct strains of were obtained from the sugar-containing stromata of...
During a survey of trees and their parasitic fungi in Andean Patagonia (Argentina), genetically distinct strains of were obtained from the sugar-containing stromata of parasitic spp. Phylogenetic analyses based on the single-gene sequences (encoding rRNA and actin) or on conserved, single-copy, orthologous genes from genome sequence assemblies revealed that these strains represent a new species closely related to Additionally, delimitation of this novel species was supported by genetic distance calculations using overall genome relatedness indices (OGRI) between the novel taxon and its closest relatives. To better understand the mode of speciation in , we examined genes that were retained or lost in the novel species in comparison to its closest relatives. These analyses show that, during diversification, this novel species and its closest relatives, and , lost mitochondrial and other genes involved in the generation of precursor metabolites and energy, which could explain their slower growth and higher ethanol yields under aerobic conditions. Similarly, lost the ability to sporulate, along with genes that are involved in meiosis and mating. Based on these findings, a formal description of the novel yeast species sp. nov. is proposed, with CRUB 1602 as the holotype.
PubMed: 34367085
DOI: 10.3389/fmicb.2021.679894 -
Frontiers in Microbiology 2022Microbiological, chemical, and sensory analyses were coupled to understand the origins of kombucha organoleptic compounds and their implication in the flavor of the...
Microbiological, chemical, and sensory analyses were coupled to understand the origins of kombucha organoleptic compounds and their implication in the flavor of the kombucha beverage. By isolating microorganisms from an original kombucha and comparing it to monocultures and cocultures of two yeasts ( and ) and an acetic acid bacterium (), interaction effects were investigated during the two phases of production. 32 volatile compounds identified and quantified by Headspace-Solid Phase-MicroExtraction-Gas Chromatography/Mass Spectrometry (HS-SPME-GC/MS) were classified according to their origin from tea or microorganisms. Many esters were associated to , while alcohols were associated to both yeasts, acetic acid to , and saturated fatty acids to all microorganisms. Concentration of metabolites were dependent on microbial activity, yeast composition, and phase of production. Sensory analysis showed that tea type influenced the olfactive perception, although microbial composition remained the strongest factor. Association of and induced characteristic apple juice aroma.
PubMed: 35387069
DOI: 10.3389/fmicb.2022.836617 -
Foods (Basel, Switzerland) Feb 2022Kombucha is a traditional drink obtained from sugared tea that is transformed by a community of yeasts and bacteria. Its production has become industrialized, and the...
Kombucha is a traditional drink obtained from sugared tea that is transformed by a community of yeasts and bacteria. Its production has become industrialized, and the study of the microbial community's evolution is needed to improve control over the process. This study followed the microbial composition of black and green kombucha tea over three consecutive years in a production facility using a culture-dependent method. Microorganisms were isolated and cultivated using selective agar media. The DNA of isolates was extracted, amplified using 26S and 16S PCR, and sequenced. Identities were obtained after a comparison to the NCBI database. , and were the major yeast species, and the major bacterial genera were and . Results highlight the persistence of yeast species such as detected in 2019. Some yeasts species appeared to be sensitive towards stressful events, such as a hot period in 2019. However, they were resilient and isolated again in 2021, as was the case for . Dominance of was clear in green and black tea kombucha, but proportions in yeasts varied depending on tea type and phase (liquid or biofilm). Composition in acetic acid and lactic acid bacteria showed a higher variability than yeasts with many changes in species over time.
PubMed: 35206089
DOI: 10.3390/foods11040614 -
Current Research in Food Science 2022The demand for Kombucha, a sparkling sugared tea beverage fermented by a symbiotic culture of acetic acid bacteria (AAB) and yeast is increasing worldwide. Despite the...
The demand for Kombucha, a sparkling sugared tea beverage fermented by a symbiotic culture of acetic acid bacteria (AAB) and yeast is increasing worldwide. Despite the popularity of the beverage which is mainly due to its perceived health benefits and appealing sensory properties, the microbial composition of the products at the time of consumption is unknown. Such information is important to both manufacturers and consumers. Therefore, this study characterised the dominant AAB and yeast present in six commercial Kombucha samples sold in New Zealand which comprised of three domestic and three imported samples. Acetic acid bacteria and yeast were isolated from the Kombucha samples using glucose yeast extract peptone mannitol (GYPM) and yeast extract glucose chloramphenicol (YGC) media, respectively. Phenotypic and taxonomic identification of AAB and yeast were achieved by morphological and biochemical characterisation, followed by sequence analysis of ribosomal RNA genes (16S rRNA for AAB and 26S rRNA for yeast). Viable AAB and yeast were only found in domestically produced Kombucha samples and not in the imported products. The dominant AAB species were identified as and . The yeast isolates belonged to , and The yeast communities were more complex and variable than the AAB communities in the analysed Kombucha samples.
PubMed: 35600538
DOI: 10.1016/j.crfs.2022.04.013 -
Foods (Basel, Switzerland) Feb 2024As a biological alternative to the antimicrobial action of SO, bioprotection has been proposed to winemakers as a means to limit or prevent grape musts microbial...
As a biological alternative to the antimicrobial action of SO, bioprotection has been proposed to winemakers as a means to limit or prevent grape musts microbial alteration. Competition for nitrogenous nutrients and for oxygen are often cited as potential explanations for the effectiveness of bioprotection. This study analyses the effect of a bioprotective strain on the growth of one strain and one strain. Bioprotection efficiency was observed only against inoculated at the two lowest concentrations. These results indicate a potential species-dependent efficiency of the bioprotective strain and a strong impact of the initial ratio between bioprotective and apiculate yeasts. The analysis of the consumption of nitrogen compounds revealed that leucine, isoleucine, lysine and tryptophan were consumed preferentially by all three strains. The weaker assimilation percentages of these amino acids observed in at 24 h growth suggest competition with that could negatively affects the growth of the apiculate yeast in co-cultures. The slowest rate of O consumption of strain, in comparison with , was probably not involved in the bioprotective effect. Non-targeted metabolomic analyses of and co-culture indicate that the interaction between both strains particularly impact lysin and tryptophan metabolisms.
PubMed: 38472837
DOI: 10.3390/foods13050724 -
Frontiers in Microbiology 2021A process development from a traditional grain-based fermentation to a defined water kefir fermentation using a co-culture of one lactic acid bacterium and one yeast was...
A process development from a traditional grain-based fermentation to a defined water kefir fermentation using a co-culture of one lactic acid bacterium and one yeast was elaborated as a prerequisite for an industrially scalable, controllable, and reproducible process. Further, to meet a healthy lifestyle, a low ethanol-containing product was aimed for. Five microbial strains-, , , , and -were used in pairs in order to examine their influence on the fermentation progress and the properties of the resulting water kefir products against grains as a control. Thereby, the combination of and provided the best-rated water kefir beverage in terms of taste and low ethanol concentrations at the same time. As a further contribution to harmonization and reduction of complexity, the usage of dried figs in the medium was replaced by fig syrup, which could have been proven as an adequate substitute. However, nutritional limitations were faced afterward, and thus, an appropriate supplementation strategy for yeast extract was established. Finally, comparative trials in 5-L scale applying grains as well as a defined microbial consortium showed both water kefir beverages characterized by a pH of 3.14, and lactic acid and aromatic sensory properties. The product resulting from co-culturing outperformed the grain-based one, as the ethanol level was considerably lower in favor of an increased amount of lactic acid. The possibility of achieving a water kefir product by using only two species shows high potential for further detailed research of microbial interactions and thus functionality of water kefir.
PubMed: 35910583
DOI: 10.3389/fmicb.2021.732019 -
Journal of Applied Microbiology Jul 2006To identify and describe the indigenous yeast population involved in traditional balsamic vinegar (TBV) fermentation.
AIMS
To identify and describe the indigenous yeast population involved in traditional balsamic vinegar (TBV) fermentation.
METHODS AND RESULTS
Using the restriction analysis of the ribosomal region 5.8S (5.8S rRNA) and the internal transcribed spacers 1 and 2 (5.8S-ITS region) we were able to group 133 strains isolated from 17 cooked grape must samples into 10 different yeast species, included into 4 genera. Moreover, we sequenced the D1/D2 domains of the 26S rRNA and confirmed the reliability of each identification at species level. Most strains belonged to the genus Zygosaccharomyces. In particular, Zygosaccharomyces bailii was found in 41% of the samples, followed by Saccharomyces cerevisiae, Zygosaccharomyces pseudorouxii and Candida stellata. Strains belonging respectively to Zygosaccharomyces mellis, Zygosaccharomyces bisporus, Zygosaccharomyces rouxii, Hanseniaspora valbyensis, Hanseniaspora osmophila and Candida lactis-condensi species were also detected. Despite the great number of species recovered, the mtDNA restriction profiles showed low variability at strain level. Saccharomyces cerevisiae isolates with an higher degree of intraspecific variance were considered an exception.
CONCLUSIONS
Many different indigenous yeast species were recovered and TBV yeasts population seems to be far more complex than what was reported in previous literature.
SIGNIFICANCE AND IMPACT OF THE STUDY
This study has allowed us to gain a better understanding of the indigenous yeast species of TBV cooked must.
Topics: Acetic Acid; Base Sequence; Ecosystem; Fermentation; Food Microbiology; Genes, Fungal; Humans; Molecular Sequence Data; Mycological Typing Techniques; RNA, Fungal; Yeasts
PubMed: 16834592
DOI: 10.1111/j.1365-2672.2006.02906.x -
Applied and Environmental Microbiology Nov 2020The application of starter is a common practice to accelerate and steer the pomegranate wine fermentation process. However, the use of starter needs a better...
The application of starter is a common practice to accelerate and steer the pomegranate wine fermentation process. However, the use of starter needs a better understanding of the effect of the interaction between the starter and native microorganisms during alcoholic fermentation. In this study, high-throughput sequencing combined with metabolite analysis was applied to analyze the effect of commercial inoculation on the native fungal community interaction and metabolism during pomegranate wine fermentation. Results showed that there were diverse native fungi in pomegranate juice, including , , , , and Based on ecological network analysis, we found that inoculation transformed the negative correlations into positive correlations among the native fungal communities and decreased the Granger causalities between native yeasts and volatile organic compounds. This might lead to decreased contents of isobutanol, isoamylol, octanoic acid, decanoic acid, ethyl laurate, ethyl acetate, ethyl hexadecanoate, phenethyl acetate, and 2-phenylethanol during fermentation. This study combined correlation and causality analysis to gain a more integrated understanding of microbial interaction and the fermentation process. It provided a new strategy to predict certain behaviors between inoculated and selected microorganisms and those coming directly from the fruit. Microbial interactions play an important role in flavor metabolism during traditional food and beverage fermentation. However, we understand little about how selected starters influence interactions among native microorganisms. In this study, we found that inoculation changed the interactions and metabolisms of native fungal communities during pomegranate wine fermentation. This study not only suggests that starter inoculation should take into account the positive features of starters but also characterizes the microbial interactions established among the starters and the native communities. It may be helpful to select appropriate starter cultures for winemakers to design different styles of wine.
Topics: Disaccharides; Fermentation; Fungi; Glucuronates; High-Throughput Nucleotide Sequencing; Mycobiome; Pomegranate; Saccharomyces cerevisiae; Solid Phase Extraction; Wine
PubMed: 33036987
DOI: 10.1128/AEM.01847-20 -
Journal of Bacteriology Jul 1968The mannose-containing polysaccharides formed by species of Nadsonia, Hanseniaspora, Kloeckera, and Saccharomycodes were extracted with hot aqueous alkali and purified...
The mannose-containing polysaccharides formed by species of Nadsonia, Hanseniaspora, Kloeckera, and Saccharomycodes were extracted with hot aqueous alkali and purified by precipitation as their copper complexes. N. fulvescens and N. elongata formed galactomannans, while Hanseniaspora and Kloeckera species and S. ludwigii formed mannans. H. valbyensis, H. uvarum, and K. apiculata were a group which formed mannans which had identical H-1 regions in their proton magnetic resonance (PMR) spectra, and H. osmophila, K. africana, and K. magna mannas formed another group based on similar spectra. K. javanica formed a mannan with an H-1 spectral region which resembled that of the H. valbyensis group in some respects and that of the H. osmophila group in others. The H-1 portion of the PMR spectrum of S. lugwigii mannan was very complex and was unlike that of any other apiculate yeast studied.
Topics: Chromatography, Paper; Magnetic Resonance Spectroscopy; Polysaccharides; Yeasts
PubMed: 5663567
DOI: 10.1128/jb.96.1.180-183.1968