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Yeast (Chichester, England) Jan 2021In many yeast species, the three genes at the centre of the galactose catabolism pathway, GAL1, GAL10 and GAL7, are neighbours in the genome and form a metabolic gene...
In many yeast species, the three genes at the centre of the galactose catabolism pathway, GAL1, GAL10 and GAL7, are neighbours in the genome and form a metabolic gene cluster. We report here that some yeast strains in the genus Torulaspora have much larger GAL clusters that include genes for melibiase (MEL1), galactose permease (GAL2), glucose transporter (HGT1), phosphoglucomutase (PGM1) and the transcription factor GAL4, in addition to GAL1, GAL10, and GAL7. Together, these eight genes encode almost all the steps in the pathway for catabolism of extracellular melibiose (a disaccharide of galactose and glucose). We show that a progenitor 5-gene cluster containing GAL 7-1-10-4-2 was likely present in the common ancestor of Torulaspora and Zygotorulaspora. It added PGM1 and MEL1 in the ancestor of most Torulaspora species. It underwent further expansion in the T. pretoriensis clade, involving the fusion of three progenitor clusters in tandem and the gain of HGT1. These giant GAL clusters are highly polymorphic in structure, and subject to horizontal transfers, pseudogenization and gene losses. We identify recent horizontal transfers of complete GAL clusters from T. franciscae into one strain of T. delbrueckii, and from a relative of T. maleeae into one strain of T. globosa. The variability and dynamic evolution of GAL clusters in Torulaspora indicates that there is strong natural selection on the GAL pathway in this genus.
Topics: Galactose; Genes, Fungal; Melibiose; Metabolic Networks and Pathways; Multigene Family; Torulaspora
PubMed: 33141945
DOI: 10.1002/yea.3532 -
Brazilian Journal of Microbiology :... Dec 2022In recent years, ample research has focused on applying wild (especially non-Saccharomyces) yeasts in producing alcoholic beverages. Common characteristics of wild yeast...
In recent years, ample research has focused on applying wild (especially non-Saccharomyces) yeasts in producing alcoholic beverages. Common characteristics of wild yeast strains include simultaneous high production of fruity and floral aroma compounds and low ethanol production. In this study, mead starter cultures were selected based on preliminary screening of wild yeast strains from a Brazilian culture collection (n = 63) for their ability to produce aroma-active compounds. The selected strains included one strain of Saccharomyces cerevisiae and three non-Saccharomyces strains (Pichia jadinii, Torulaspora delbrueckii, and Kluyveromyces lactis). These strains were used to ferment honey must prepared with Aroeira honey, adjusted to 24°Brix, which took 36 days to complete. Single culture fermentations and co-fermentations with S. cerevisiae and non-Saccharomyces strains were carried out. The quality of the produced beverages was evaluated by sugar consumption and production of alcohols and organic acids, analyzed with high-performance liquid chromatography. The volatile organic compound composition was analyzed with gas chromatography-mass spectrometry. Meads with various ethanol amounts (4.7-11.0% v/v) and residual sugar contents (70.81-160.25 g l) were produced. In addition, in both single-strain fermentation and co-fermentation with S. cerevisiae, meads produced with either Torulaspora delbrueckii or Kluyveromyces lactis had a roughly three-fold higher content of honey-aroma compound phenethyl acetate and a higher hedonic impression score than meads produced with only S. cerevisiae. These results demonstrated non-Saccharomyces yeasts' ability to increase aroma complexity and improve the sensory quality of low-alcoholic meads.
Topics: Odorants; Saccharomyces cerevisiae; Torulaspora; Yeasts; Fermentation; Ethanol; Wine
PubMed: 36269554
DOI: 10.1007/s42770-022-00840-z -
Journal of Fungi (Basel, Switzerland) Apr 2021is the most commonly used yeast in wine, beer, and bread fermentations. However, has attracted interest in recent years due to its properties, ranging from its ability...
is the most commonly used yeast in wine, beer, and bread fermentations. However, has attracted interest in recent years due to its properties, ranging from its ability to produce flavor- and aroma-enhanced wine to its ability to survive longer in frozen dough. In this work, publicly available genomes of were explored and their annotation was improved. A total of 32 proteins were additionally annotated for the first time in the type strain CBS1146, in comparison with the previous annotation available. In addition, the annotation of the remaining three strains was performed for the first time. eggNOG-mapper was used to perform the functional annotation of the deduced coding genes, offering insights into its biological significance, and revealing 24 clusters of orthologous groups (COGs), which were gathered in three main functional categories: information storage and processing (28% of the proteins), cellular processing and signaling (27%), and metabolism (23%). Small intraspecies variability was found when considering the functional annotation of the four available genomes. A comparative study was also conducted between the genome and those from 386 fungal species, revealing a high number of homologous genes with species from the and genera, but also with and . Lastly, the phylogenetic placement of was clarified using the core homologs that were found across 204 common protein sequences of 386 fungal species and strains.
PubMed: 33920164
DOI: 10.3390/jof7040287 -
Frontiers in Bioscience (Elite Edition) Jan 2023The vineyard is a great reservoir of autochthonous yeast strains whose composition is defined by different regional (edaphology, orography or climatology) and...
BACKGROUND
The vineyard is a great reservoir of autochthonous yeast strains whose composition is defined by different regional (edaphology, orography or climatology) and anthropological factors (cultivation systems or cultural practices). Most of this yeast diversity corresponds to non- strains, some of which have potential use in winemaking.
METHODS
The oenological potential of 29 different native non- strains belonging to 4 species (, , and spp.) was evaluated, using the autochthonous XG3 strain as a control. Microfermentations with pure culture of each strain were performed in duplicate and the basic parameters and major volatiles of wines were analysed following official methodology. The best strain within each species was selected using a quantification matrix including the relevant oenological characteristics.
RESULTS
The fermentative ability of non- was lower than in all cases, but with differences among species. and showed higher fermentation rates than , whereas spp. presented a low fermentative power. At chemical level all non- strains reduced the alcoholic content, the higher alcohols and the volatile acidity of wines and increased the content of glycerol, with differences among strains within a given species. and increased the total acidity of wines. The latter and spp. strains produced lactic acid, which decreased the wine pH in the case of . According to their oenological traits the best rated strains of each species were Lt93, Td315, Mf278 and Sb474. In addition, the data obtained in pure fermentations were correlated to those chemical and aromatic compounds obtained with these non- strains in sequential fermentations.
CONCLUSIONS
Autochthonous strains of non- yeast species contribute distinctive chemical characteristics to the wines. The correlations observed between wines fermented with the different non- indigenous strains in pure and sequential fermentations suggest that their contribution to wine properties remains stable regardless of must composition or winemaking techniques.
Topics: Saccharomyces cerevisiae; Vitis; Wine; Glycerol
PubMed: 36959102
DOI: 10.31083/j.fbe1501001 -
Current Research in Food Science 2021This study evaluated the effects of yeast extracts (YE) addition (0 % and 0.25 %, w/v) on the no-volatile and volatile compounds of spent coffee grounds (SCG)...
The potential of spent coffee grounds hydrolysates fermented with and for developing an alcoholic beverage: The yeasts growth and chemical compounds modulation by yeast extracts.
This study evaluated the effects of yeast extracts (YE) addition (0 % and 0.25 %, w/v) on the no-volatile and volatile compounds of spent coffee grounds (SCG) hydrolysates fermented with single-cultures of two non- wine yeasts, and . The added YE improved the growth of both and , especially , resulting in higher ethanol production (1.98 % vs 1.47 %, v/v) by the latter yeast. In addition, the added YE did not impact on most of the alkaloids production regardless of yeast type, while significantly decreasing the contents of chlorogenic, and caffeic acids in SCG hydrolysates fermented with . Furthermore, more odor-active compounds such as acetate esters and 2-phenylethyl alcohol were produced when YE was added, and generated significantly higher amounts of esters compared to that of . Moreover, YE addition showed a more noticeable effect on the fermentation performance of relative to that of . These findings indicated the potential of SCG hydrolysates fermented with evaluated non- yeasts and may expand the applications on utilizing SCG to develop new value-added alcoholic products.
PubMed: 34382007
DOI: 10.1016/j.crfs.2021.07.004 -
FEMS Yeast Research Feb 2022Fructans are the main sugar in agave pine used by yeasts during mezcal fermentation processes, from which Candida apicola NRRL Y-50540 and Torulaspora delbrueckii NRRL...
Identification of genes related to hydrolysis and assimilation of Agave fructans in Candida apicola NRRL Y-50540 and Torulaspora delbrueckii NRRL Y-50541 by denovo transcriptome analysis.
Fructans are the main sugar in agave pine used by yeasts during mezcal fermentation processes, from which Candida apicola NRRL Y-50540 and Torulaspora delbrueckii NRRL Y-50541 were isolated. De novo transcriptome analysis was carried out to identify genes involved in the hydrolysis and assimilation of Agave fructans (AF). We identified a transcript annotated as SUC2, which is related to β-fructofuranosidase activity, and several differential expressed genes involved in the transcriptional regulation of SUC2 such as: MIG1, MTH1, SNF1, SNF5, REG1, SSN6, SIP1, SIP2, SIP5, GPR1, RAS2, and PKA. Some of these genes were specifically expressed in some of the yeasts according to their fructans assimilation metabolism. Different hexose transporters that could be related to the assimilation of fructose and glucose were found in both the transcriptomes. Our findings provide a better understanding of AF assimilation in these yeasts and provide resources for further metabolic engineering and biotechnology applications.
Topics: Agave; Fermentation; Fructans; Gene Expression Profiling; Hydrolysis; Saccharomycetales; Torulaspora
PubMed: 35084467
DOI: 10.1093/femsyr/foac005 -
Foods (Basel, Switzerland) Jun 2021Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Besides the well-known and tested lactic acid... (Review)
Review
Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Besides the well-known and tested lactic acid bacteria, yeasts may also be probiotics. The subject of probiotic and potentially probiotic yeasts has been developing and arising potential for new probiotic products with novel properties, which are not offered by bacteria-based probiotics available on the current market. The paper reviews the first probiotic yeast var. , its characteristics, pro-healthy activities and application in functional food production. This species offers such abilities as improving digestion of certain food ingredients, antimicrobial activities and even therapeutic properties. Besides var. on this background, novel yeasts with potentially probiotic features are presented. They have been intensively investigated for the last decade and some species have been observed to possess probiotic characteristics and abilities. There are yeasts from the genera , , , , , etc. isolated from food and environmental habitats. These potentially probiotic yeasts can be used for production of various fermented foods, enhancing its nutritional and sensory properties. Because of the intensively developing research on probiotic yeasts in the coming years, we can expect many discoveries and possibly even evolution in the segment of probiotics available on the market.
PubMed: 34200217
DOI: 10.3390/foods10061306 -
International Journal of Systematic and... Dec 2022Two strains of a novel ascomycetous yeast species were isolated from rotting wood samples collected in Jiuxi Mountain Forest Park in Yunnan Province, southwest China....
Two strains of a novel ascomycetous yeast species were isolated from rotting wood samples collected in Jiuxi Mountain Forest Park in Yunnan Province, southwest China. Both strains formed one or two spherical ascospores in persistent asci. Phylogenetic analysis of the concatenated sequences of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) and the D1/D2 domain of the large subunit rRNA gene revealed that the novel strains represented a phylogenetically distinct species belonging to the genus . This novel species differed from the type strains of the closest known species, and , by 0.9 and 1.2 % nucleotide substitutions in the D1/D2 domain and 5.3 and 6 % nucleotide substitutions in the ITS region, respectively. The novel species can also be distinguished from and in terms of the ability to assimilate ribitol, succinate and citrate, and its ability to grow at 37 °C. The species name of sp. nov. is proposed with holotype CBS 16004 (Mycobank MB 844535).
Topics: Torulaspora; Wood; Phylogeny; DNA, Ribosomal Spacer; China; DNA, Fungal; Sequence Analysis, DNA; Mycological Typing Techniques; Base Composition; RNA, Ribosomal, 16S; DNA, Bacterial; Bacterial Typing Techniques; Fatty Acids; Saccharomycetales; Ascomycota
PubMed: 36748467
DOI: 10.1099/ijsem.0.005629 -
International Journal of Food... Aug 2019The use of non-Saccharomyces yeasts in dough fermentation has become increasingly popular because of their effects on product composition, texture and flavour. These...
The use of non-Saccharomyces yeasts in dough fermentation has become increasingly popular because of their effects on product composition, texture and flavour. These yeasts are co-cultured with Saccharomyces cerevisiae. In this study, the characteristics of dough fermentation with combined Torulaspora delbrueckii Y22 and S. cerevisiae Y10 were investigated. In the dough containing co-cultures, S. cerevisiae Y10 cell populations increased rapidly and reached approximately 8.5 Log CFU/g wet dough, which is comparable to the monoculture after 24 h of fermentation. However, the cell number of T. delbrueckii Y22 did not significantly change throughout the dough fermentation (p > 0.05). When co-culture was used, the gas holding capacity and CO production profile of the dough improved, and a high maltose concentration reaching 5.93 mg/g dry dough was observed after 12 h of dough fermentation. The mixed inocula of S. cerevisiae Y10 and T. delbrueckii Y22 enhanced the production of succinic acid, acetic acid and essential amino acids in the fermented dough. These results revealed the synergistic behaviour between S. cerevisiae Y10 and T. delbrueckii Y22 during dough fermentation and suggested the potential use of mixed yeast cultures in dough fermentation for steamed bread making.
Topics: Bread; Coculture Techniques; Fermentation; Saccharomyces cerevisiae; Steam; Torulaspora
PubMed: 31136955
DOI: 10.1016/j.ijfoodmicro.2019.05.009 -
Parkinsonism & Related Disorders Feb 2022Gut fungal composition and its metabolites have not been assessed simultaneously in Parkinson's disease (PD) despite their potential pathogenic contribution.
BACKGROUND
Gut fungal composition and its metabolites have not been assessed simultaneously in Parkinson's disease (PD) despite their potential pathogenic contribution.
OBJECTIVE
To evaluate the faecal metabolome and mycobiome in PD by assessing volatile organic compounds (VOCs) and fungal rRNA.
METHODS
Faecal VOCs from 35 PD patients and two control groups (n = 35; n = 15) were assessed using gas chromatography and mass spectrometry. DNA was extracted from 44 samples: 18S rRNA gene amplicons were prepared and sequenced. Metabolomics, mycobiome and integrated analyses were performed.
RESULTS
Several VOCs were more abundant and short chain fatty acids were less abundant in PD. Hanseniaspora, Kazachstania, uncultured Tremellaceae and Penicillium genera were more abundant, and Saccharomyces less abundant in PD (FDR<0.0007). Torulaspora was associated with PD and two VOCs.
CONCLUSION
PD patients had a distinct metabolome and mycobiome suggesting that fungal dysbiosis may contribute to PD pathogenesis.
Topics: Gas Chromatography-Mass Spectrometry; Gastrointestinal Microbiome; Humans; Metabolome; Mycobiome; Parkinson Disease
PubMed: 35045378
DOI: 10.1016/j.parkreldis.2022.01.005