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Journal of Applied Microbiology Dec 2023The antifungal effect of the yeast species Kluyveromyces marxianus, Meyerozyma caribbica, and Wickerhamomyces anomalus was evaluated against two Fusarium graminearum...
AIMS
The antifungal effect of the yeast species Kluyveromyces marxianus, Meyerozyma caribbica, and Wickerhamomyces anomalus was evaluated against two Fusarium graminearum strains (FRS 26 and FSP 27) in vitro and on corn seeds.
METHODS AND RESULTS
The antifungal effect of the yeasts against F. graminearum was evaluated using scanning electron microscopy and extracellular chitinase and glucanase production to further elucidate the biocontrol mode of action. In addition, the germination percentage and vigor test were investigated after applying yeast on corn seeds. All the yeast strains inhibited fungal growth in vitro (57.4%-100.0%) and on corn seeds (18.9%-87.2%). In co-culture with antagonistic yeasts, F. graminearum showed collapsed hyphae and turgidity loss, which could be related to the ability of yeasts to produce chitinases and glucanases. The three yeasts did not affect the seed corn germination, and W. anomalus and M. caribbica increased corn seed growth parameters (germination percentage, shoot and root length, and shoot dry weight).
CONCLUSION
Meyerozyma caribbica and W. anomalus showed satisfactory F. graminearum growth inhibition rates and did not affect seed growth parameters. Further studies are required to evaluate the application of these yeasts to the crop in the field.
Topics: Antifungal Agents; Zea mays; Yeasts; Fusarium; Plant Diseases
PubMed: 38049375
DOI: 10.1093/jambio/lxad296 -
Frontiers in Microbiology 2022Salami is a kind of fermented meat product with rich nutrition and unique flavor. Because it is rich in fat, it is easy to oxidize to produce bad flavor. Compared with...
Salami is a kind of fermented meat product with rich nutrition and unique flavor. Because it is rich in fat, it is easy to oxidize to produce bad flavor. Compared with the way of adding artificial or natural antioxidants to reduce the degree of sausage oxidation, the antioxidant characteristics of developing the starter itself deserve more attention. In this study, firstly the antioxidant activities of 5 strains of yeast were measured , and then the mixture of yeast and Lactobacillus rhamnosus YL-1 was applied to fermented sausage model. The effect of the starter in the sausage model was investigated through physicochemical parameters, degree of fat oxidation, free fatty acid content, and though volatile flavor compound analysis, sensory evaluation and various indexes after storage were observed. Metagenomics was used to explore metabolic pathways, functional genes and key enzymes related to lipid oxidizing substances in sausage in yeast. The results showed that Wickerhamomyces anomalus Y12-3 and Y12-4 had strong tolerance to H2O2, and had higher SOD and CAT enzyme activities. The addition of yeast effectively reduced the material value of peroxidation value and active thiobarbiturate in salami. In flavor analysis, the content of flavor compounds associated with lipid oxidation, such as hexanal, heptanal, nonanal and (E)-2-decenal were significantly lower with the use of Debaryomyces hansenii Y4-1 and Y12-3. Meanwhile, the possible pathways of yeast metabolism of flavor substances related to lipid oxidation (mainly aldehydes) were discussed with the help of metagenomic techniques. According to the results of metagenomics, fatty acid degradation (ko00071) metabolic pathway was related to the degradation of aldehydes through aldehyde dehydrogenase, which was the potential key enzyme.
PubMed: 36726562
DOI: 10.3389/fmicb.2022.1113848 -
Journal of the Science of Food and... Jan 2022To improve the aroma of kiwi wine through the utilization of Wickerhamomyces anomalus, kiwi juice was fermented using a selected W. anomalus strain in pure culture and...
Assessment of chemical constitution and aroma properties of kiwi wines obtained from pure and mixed fermentation with Wickerhamomyces anomalus and Saccharomyces cerevisiae.
BACKGROUND
To improve the aroma of kiwi wine through the utilization of Wickerhamomyces anomalus, kiwi juice was fermented using a selected W. anomalus strain in pure culture and mixed fermentations with Saccharomyces cerevisiae, which was inoculated simultaneously and sequentially. The physicochemical indices, volatile compounds and aroma properties of the kiwi wines were assessed.
RESULTS
The study suggested that the ethanol, color indices and organic acids of the wines were closely related to the method of inoculation. Compared with the pure S. cerevisiae fermentation, the mixed fermentations produced more varieties and concentrations of volatiles. The sequential fermentations increased the concentrations of esters and terpenes, improving the flower and sweet fruit notes of the wines. The simultaneous inoculation enhanced the contents of esters and aldehydes, intensifying the flower, sweet and sour fruit of the wines. Partial least-squares regression analysis showed that esters and terpenes contributed greatly to the flower and sweet fruit aroma, whereas aldehydes were the major contributors to the sour note.
CONCLUSION
Based on our results, the mixed fermentations not only enriched the types and concentrations of volatiles, but also had better sensory properties. © 2021 Society of Chemical Industry.
Topics: Actinidia; Ethanol; Fermentation; Fruit; Humans; Odorants; Saccharomyces cerevisiae; Saccharomycetales; Taste; Volatile Organic Compounds; Wine
PubMed: 34061382
DOI: 10.1002/jsfa.11344 -
World Journal of Microbiology &... May 2015Pichia anomala (Wickerhamomyces anomalus) WRL-076 was discovered by a visual screening bioassay for its antagonism against Aspergillus flavus. The yeast was shown to...
Pichia anomala (Wickerhamomyces anomalus) WRL-076 was discovered by a visual screening bioassay for its antagonism against Aspergillus flavus. The yeast was shown to significantly inhibit aflatoxin production and the growth of A. flavus. P. anomala is a potential biocontrol agent for reduction of aflatoxin in the food chain. Maintaining the viability of biocontrol agents in formulated products is a great challenge for commercial applications. Four media, NYG, NYGS, NYGT and NYGST are described which support good growth of yeast cells and were tested as storage formulations. Post growth supplement of 5 % trehalose to NYGST resulted in 83 % viable yeast cells after 12 months in cold storage. Intracellular sorbitol and trehalose concentrations were determined by HPLC analysis at the beginning of the storage and at the end of 12 month. Correlation of cell viability to both trehalose and sorbitol suggested a synergistic effect. Bonferroni (Dunn) t Test, Tukey's Studentized Range (HSD) Test and Duncan's Multiple Range Test, all showed that yeast cell viability in samples with both intracellular trehalose and sorbitol were significantly higher than those with either or none, at a 95 % confidence level. DiBAC4(5) and CFDA-AM were used as the membrane integrity fluorescent stains to create a two-color vital staining scheme with red and green fluorescence, respectively. Yeast cells stored in formulations NYG and NYGS with no detectable trehalose, displayed mostly red fluorescence. Yeast cells in NYGST+5T showed mostly green fluorescence.
Topics: Aflatoxins; Aspergillus flavus; Chromatography, High Pressure Liquid; Culture Media; Microbial Viability; Pest Control, Biological; Pichia; Preservation, Biological; Sorbitol; Time Factors; Trehalose
PubMed: 25700743
DOI: 10.1007/s11274-015-1824-3 -
Animal Science Journal = Nihon Chikusan... 2020To investigate the yeast population dynamics during air exposure in total mixed ration (TMR) silage containing sweet potato residue. TMR were ensiled in laboratory silos...
To investigate the yeast population dynamics during air exposure in total mixed ration (TMR) silage containing sweet potato residue. TMR were ensiled in laboratory silos (1 kg) with or without two lactic acid bacteria strains, Lactobacillus plantarum (LP), and Lactobacillus amylovorus (LA). Fermentation characteristics were measured and yeast population was investigated by ITS1 region gene sequencing using Illumina MiSeq platform. All treatments were well ensiled, and L. amylovorus improved aerobic stability. During aerobic exposure, Pichia kudriavzevii was detected with increased relative abundance in all treatments and more relative abundant in LP. Pichia fermentans was more relative abundant in control. Higher relative abundance of Pichia anomala was detected in deteriorating LP. The relative abundance of Pichia ohmeri increased during later aerobic exposure in the control and LA, with a significant increase in the count of yeast population. Despite Cryptococcus was detected more relative abundant during early stage of aerobic exposure, the yeast population was below the detection limit. Aerobic deterioration was characterized by an increase in operational taxonomic units of Pichia. High relative abundance of P. anomala and P. kudriavzevii made aerobic deterioration easier. Inhibition of P. fermentans might be an effective strategy for improving the aerobic stability to some instance.
Topics: Aerobiosis; Air; Bioreactors; Cryptococcus; Diet; Fermentation; Food Microbiology; Food Quality; High-Throughput Nucleotide Sequencing; Ipomoea batatas; Lactobacillus acidophilus; Lactobacillus plantarum; Pichia; Silage
PubMed: 32484290
DOI: 10.1111/asj.13397 -
International Journal of Molecular... Jan 2022The objective of the current study was to examine the effects of yeasts on intestinal health and transcriptomic profiles from the distal intestine and spleen tissue of...
The objective of the current study was to examine the effects of yeasts on intestinal health and transcriptomic profiles from the distal intestine and spleen tissue of Atlantic salmon fed SBM-based diets in seawater. (CJ) and (WA) yeasts were heat-inactivated with spray-drying (ICJ and IWA) or autolyzed at 50 °C for 16 h (ACJ and AWA), followed by spray-drying. Six diets were formulated, one based on fishmeal (FM), a challenging diet with 30% soybean meal (SBM) and four other diets containing 30% SBM and 10% of each of the four yeast fractions (i.e., ICJ, ACJ, IWA and AWA). The inclusion of CJ yeasts reduced the loss of enterocyte supranuclear vacuolization and reduced the population of CD8α labeled cells present in the lamina propria of fish fed the SBM diet. The CJ yeasts controlled the inflammatory responses of fish fed SBM through up-regulation of pathways related to wound healing and taurine metabolism. The WA yeasts dampened the inflammatory profile of fish fed SBM through down-regulation of pathways related to toll-like receptor signaling, C-lectin receptor, cytokine receptor and signal transduction. This study suggests that the yeast species, and are novel high-quality protein sources with health-beneficial effects in terms of reducing inflammation associated with feeding plant-based diets to Atlantic salmon.
Topics: Animal Feed; Animals; Candida; Intestines; Saccharomycetales; Salmo salar; Glycine max; Transcriptome
PubMed: 35163597
DOI: 10.3390/ijms23031675 -
Frontiers in Microbiology 2023Ethanol tolerance is crucial for the oenological yeasts. Tratt, a Rosaceae plant native to China, is rich in nutritional and medicinal ingredients. In this study,...
Ethanol tolerance is crucial for the oenological yeasts. Tratt, a Rosaceae plant native to China, is rich in nutritional and medicinal ingredients. In this study, ethanol-tolerant non- yeasts were screened, and their oenological properties were further evaluated. Three ethanol-tolerant yeast strains (designated as C6, F112, and F15), which could tolerate 12% (v/v) ethanol treatment, were isolated from , and identified as , , and , respectively. The winemaking condition tolerances of these ethanol-tolerant yeast strains were similar to those of X16. However, their growth, sugar metabolic performance and sulphureted hydrogen activities, were different. The β-glucosidase production ability of strain F15 was lower than that of X16, and strains of C6 and F112 were similar to X16. Electronic sensory properties of the wines fermented using ethanol-tolerant yeasts together with showed no significant differences. However, the mixed inoculation of the ethanol-tolerant yeast strains with could regulate the volatile aroma characteristics of the fermented wine, enriching and enhancing the aroma flavor. Therefore, the selected ethanol-tolerant yeasts have the potential for application in the production of unique wine.
PubMed: 37323890
DOI: 10.3389/fmicb.2023.1202440 -
Journal of Agricultural and Food... Jul 20172-Furfurylthiol is an important aroma compound with characteristic sesame flavor. It was recently identified as the representative aroma compound of Chinese...
2-Furfurylthiol is an important aroma compound with characteristic sesame flavor. It was recently identified as the representative aroma compound of Chinese sesame-flavored Baijiu. But its formation mechanism is unclear. In this study, the dominant yeast species Saccharomyces cerevisiae, Pichia kudriavzevii, and Wickerhamomyces anomalus were isolated from samples of Chinese sesame-flavored fermentation and were screened for the capacity of 2-furfurylthiol biosynthesis. Some isolates were found to be capable of generating 2-furfurylthiol using furfural and l-cysteine as precursors, among which S. cerevisiae G20 exhibited the strongest capacity with a yield of 3.03 mg/L. Furthermore, the genes STR3 and CYS3 from S. cerevisiae were cloned and overexpressed in the reference strain S. cerevisiae S288c and the isolate strain G20, respectively, which resulted in a significant increase in 2-furfurylthiol release in the two strains. Moreover, inactivation of STR3 gene in S288c and G20 led to obvious reduction in 2-furfurylthiol production, demonstrating that STR3 got involved in 2-furfurylthiol biosynthesis in S. cerevisiae. It is the first time that the yeast isolates with high capacity of 2-furfurylthiol biosynthesis were found during Chinese sesame-flavored Baijiu fermentation and confirmed that the genes STR3 and CYS3 were closely relevant to 2-furfurylthiol biosynthesis.
Topics: China; Fermentation; Flavoring Agents; Fungal Proteins; Furans; Sesamum; Sulfhydryl Compounds; Yeasts
PubMed: 28603986
DOI: 10.1021/acs.jafc.7b01359 -
FEMS Yeast Research Feb 2022Non-Saccharomyces yeasts have been suggested for use in wine production for lowering alcohol content. In this study, 23 non-Saccharomyces yeasts were investigated in...
Non-Saccharomyces yeasts have been suggested for use in wine production for lowering alcohol content. In this study, 23 non-Saccharomyces yeasts were investigated in laboratory-scale trials using previously frozen grape must. Both aerated and standard fermentation conditions were investigated and the fermentations were co-inoculated with a commercial Saccharomyces cerevisiae reference yeast strain. Sugar consumed for percentage alcohol formed was calculated from sugar and alcohol measurements. The non-Saccharomyces yeasts showed greater variability in sugar consumption compared with the S. cerevisiae reference yeast. Two of the yeast strains (Starmerella bacillaris and Wickerhamomyces anomalus) consumed more sugar than the S. cerevisiae reference yeast under the same conditions. These two strains were subsequently used in a small-scale wine production trial following a similar aeration and standard fermentation strategy. The wine production trials using aeration compared with the standard strategy showed shorter fermentation times, increased biomass formation and more sugar utilized for alcohol produced, but reduced wine quality. The same yeasts under standard fermentation conditions also showed increased use of sugar, but neutral or positive effects on wine quality. The S. bacillaris strain showed the most potential for use in wine production for lowering alcohol content.
Topics: Ethanol; Fermentation; Saccharomyces cerevisiae; Sugars; Vitis; Wine
PubMed: 35134915
DOI: 10.1093/femsyr/foac002 -
Microbial Cell Factories Mar 2015A key pathway for ester biosynthesis in yeast is the condensation of an alcohol with acetyl-CoA by alcohol-O-acetyltransferase (AATase). This pathway is also prevalent...
BACKGROUND
A key pathway for ester biosynthesis in yeast is the condensation of an alcohol with acetyl-CoA by alcohol-O-acetyltransferase (AATase). This pathway is also prevalent in fruit, producing short and medium chain volatile esters during ripening. In this work, a series of six AATases from Saccharomyces and non-Saccharomyces yeasts as well as tomato fruit were evaluated with respect to their activity, intracellular localization, and expression in Saccharomyces cerevisiae and Escherichia coli cell hosts. The series of AATases includes Atf1 and Atf2 from S. cerevisiae, as well as AATases from S. pastorianus, Kluyveromyces lactis, Pichia anomala, and Solanum lycopersicum (tomato).
RESULTS
When expressed in S. cerevisiae, Atf1, Atf2, and an AATase from S. pastorianus localized to lipid droplets, while AATases from non-Saccharomyces yeasts and tomato fruit did not localize to intracellular membranes and were localized to the cytoplasm. All AATases studied here formed intracellular aggregates when expressed in E. coli, and western blot analysis revealed that expression levels in E. coli were upwards of 100-fold higher than in S. cerevisiae. Fermentation and whole cell lysate activity assays of the two most active AATases, Atf1 from S. cerevisiae and an AATase from tomato fruit, demonstrated that the aggregates were enzymatically active, but with highly reduced specific activity in comparison to activity in S. cerevisiae. Activity was partially recovered at lower expression levels, coinciding with smaller intracellular aggregates. In vivo and in vitro activity assays from heterologously expressed Atf1 from S. cerevisiae, which localizes to lipid droplets under homologous expression, demonstrates that its activity is not membrane dependent.
CONCLUSIONS
The results of these studies provide important information on the biochemistry of AATases under homologous and heterologous expression with two common microbial hosts for biochemical processes, S. cerevisiae and E. coli. All studied AATases formed aggregates with low enzymatic activity when expressed in E. coli and any membrane localization observed in S. cerevisiae was lost in E. coli. In addition, AATases that were found to localize to lipid droplet membranes in S. cerevisiae were found to not be membrane dependent with respect to activity.
Topics: Acetyltransferases; Blotting, Western; Escherichia coli; Fungal Proteins; Green Fluorescent Proteins; Intracellular Space; Kluyveromyces; Lipid Droplets; Solanum lycopersicum; Microscopy, Fluorescence; Pichia; Plant Proteins; Proteins; Recombinant Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Species Specificity
PubMed: 25880435
DOI: 10.1186/s12934-015-0221-9