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Food Chemistry: X Jun 2023Mixed fermentation using saccharomyces cerevisiae and non- has become one of the main research strategies to improve wine aroma. Hence, this study applied the mixed...
Mixed fermentation using saccharomyces cerevisiae and non- has become one of the main research strategies to improve wine aroma. Hence, this study applied the mixed fermentation technique using and to brew Cabernet Sauvignon wine and to investigate the effects of inoculation timing and inoculation ratio on the polyphenolics, antioxidant activity and aroma of the resulting wine. The results showed that mixed fermentation significantly improved the amounts of flavan-3-ols. In particular, S1:5 had the highest amounts of (-)-catechin and procyanidin B1 (73.23 mg/L and 46.59 mg/L), while S1:10 had the highest (-)-epicatechin content (57.95 mg/L). Meanwhile, S1:10 showed the strongest FRAP, CUPRAC and ABTS + activities (31.46 %, 25.38 % and 13.87 % higher than that of CK, respectively). In addition, mixed fermentation also increased the amounts of phenylethanol, isoamyl alcohol and ethyl esters, which enhanced the rose-like and fruity flavor of wine. This work used a friendly non- alongside appropriate inoculation strategies to provide an alternative approach for improved wine aroma and phenolic profile.
PubMed: 37131849
DOI: 10.1016/j.fochx.2023.100685 -
Microorganisms Apr 2023There is an expanding market for beer of different flavors. This study aimed to prepare a craft Belgian-style pale ale with a non- yeast. 4A was used as a sole starter...
There is an expanding market for beer of different flavors. This study aimed to prepare a craft Belgian-style pale ale with a non- yeast. 4A was used as a sole starter culture, and malted barley as the only substrate. The ingredients and brewing process were carefully monitored to ensure the quality and innocuousness of the beverage. During fermentation, the yeast consumed 89.7% of total sugars and produced 13.8% / of ethanol. The product was fermented and then aged for 8 days, adjusted to 5% / alcohol, and analyzed. There were no traces of mycotoxins, lead, arsenic, methanol, or microbiological contamination that would compromise consumer health. According to the physicochemical analysis, the final ethanol concentration (5.2% /) and other characteristics complied with national and international guidelines. The ethyl acetate and isoamyl alcohol present are known to confer sweet and fruity flavors. The sensory test defined the beverage as refreshing and as having an apple and pear flavor, a banana aroma, and a good level of bitterness. The judges preferred it over a commercial reference sample of Belgian-style pale ale made from . Hence, 4A has the potential for use in the beer industry.
PubMed: 37110400
DOI: 10.3390/microorganisms11040977 -
Food Microbiology Aug 2023Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize...
Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize their succession in white-brined cheese during a shelf-life of 52 weeks. White-brined cheeses added herbs (WBC1) or sundried tomatoes (WBC2) were produced at a Danish dairy and incubated at 5 °C and 10 °C. An increase in yeast counts was observed for both products within the first 12-14 weeks of incubation and stabilized afterwards varying in a range of 4.19-7.08 log CFU/g. Interestingly, higher incubation temperature, especially in WBC2, led to lower yeast counts, concurrently with higher diversity of yeast species. Observed decrease in yeast counts was, most likely, due to negative interactions between yeast species leading to growth inhibition. In total, 469 yeast isolates from WBC1 and WBC2 were genotypically classified using the (GTG)-rep-PCR technique. Out of them, 132 representative isolates were further identified by sequencing the D1/D2 domain of the 26 S rRNA gene. Predominant yeast species in WBCs were Candida zeylanoides and Debaryomyces hansenii, while Candida parapsilosis, Kazachstania bulderi, Kluyveromyces lactis, Pichia fermentans, Pichia kudriavzevii, Rhodotorula mucilaginosa, Torulaspora delbrueckii, and Wickerhamomyces anomalus were found in lower frequency. Heterogeneity of yeast species in WBC2 was generally larger compared to WBC1. This study indicated that, along with contamination levels, taxonomic heterogeneity of yeasts is an important factor influencing yeast cell counts, as well as product quality during storage.
Topics: Cheese; Yeasts; Polymerase Chain Reaction
PubMed: 37098422
DOI: 10.1016/j.fm.2023.104266 -
Veterinary World Feb 2023Probiotic supplementation can assist with manipulating the rumen microbial ecosystem. Lactic acid bacteria and yeast from fermented fish (Budu) as the indigenous food...
BACKGROUND AND AIM
Probiotic supplementation can assist with manipulating the rumen microbial ecosystem. Lactic acid bacteria and yeast from fermented fish (Budu) as the indigenous food from West Sumatra, Indonesia, are potential probiotics for livestock. This study aims to select the best candidate lactic acid bacteria and yeast strains from fermented fish as ruminant probiotics and evaluate the effect of their supplementation on the characteristics of rumen fermentation, feed digestion, and total gas production .
MATERIALS AND METHODS
This study used nine treatments, performed in triplicate, in a completely randomized design. The substrate ratio comprised of 70% forage and 30% concentrate. Five lactic acid bacteria and three yeast isolates were used in this study. Treatments were as follows: T0: control (basal diet); T1: T0 + strain 3347; T2: T0 + strain 5296; T3: T0 + JCM 16178; T4: T0 + strain LH991; T5: T0 + strain 6902; T6: T0 + strain B-5P; T7: T0 + strain CBS 5147; and T8: T0 + commercial yeast (). The lactic acid bacteria inoculum contained 1.02 × 10 colony-forming unit (CFU)/mL, while the yeast inoculum contained 1.5 × 10 CFU/mL.
RESULTS
The results showed that four lactic acid bacteria and three yeast produced a higher total gas yield (104-183.33 mL) compared to the control (103 mL). Supplementation with lactic acid bacteria in the rumen fermentation showed dry matter digestibility of 63%-70% and organic matter digestibility (OMD) of 64%-71%. We observed that total volatile fatty acid (VFA) production in all treatments was significantly higher (86-121 mM) compared to the control (81 mM). The concentration of NH production was higher in all treatments (12.33-16.83 mM) than in the control (12.25 mM). Meanwhile, the probiotic supplementation did not cause a significant change in the rumen pH (6.86-7.12). Supplementation with the lactic acid bacteria strain LH991 consistently demonstrated the best results from the parameters of dry and OMD (70.29% and 71.16%, respectively), total VFA (121.67 mM), NH (16.83 mM), and total gas production (149.17 mL). The best results were observed from the yeast candidate strain B-5P, where the results were dry and OMD (67.64% and 69.55% respectively), total VFA (96.67 mM), NH (13.42 mM), and total gas production (183.33 mL).
CONCLUSION
Based on the obtained results, lactic acid bacteria strain LH991 and yeast strain B-5P are attractive candidates to be utilized as probiotics for ruminants based on their potential to improve rumen fermentation . This probiotic supplementation can increase the digestibility of feed ingredients, production of total VFA and NH, and total gas produced.
PubMed: 37041999
DOI: 10.14202/vetworld.2023.395-402 -
Medical Mycology Apr 2023Time-to-positivity (TTP) may assist in predicting the outcome of candidaemia. We analysed a candidaemia dataset collected prospectively in Australia over 1 year...
Time-to-positivity (TTP) may assist in predicting the outcome of candidaemia. We analysed a candidaemia dataset collected prospectively in Australia over 1 year (2014-2015). TTP was defined as the period from blood culture sampling to the blood culture flagging positive. Of 415 candidaemia episodes, overall, 30-day mortality was 29% (120/415); mortality with Candida albicans was 35% (59/169), C. glabrata complex, 37% (43/115), C. tropicalis, 43% (10/23), Pichia kudriavzevii 25% (3/12), and C. parapsilosis complex 7% (5/71). Each day of increased TTP multiplied the odds ratio (OR) of survival at 30 days by a factor of 1.32 [95% confidence interval (CI) 1.06-1.69]. Shorter TTP was associated with increased mortality, with 1-day TTP associated with 30-day mortality 37% (41/112) (95%CI: 28%-46%) and 5-day TTP 11% (2/18) (95%CI: 2%-36%).
Topics: Animals; Candida; Prognosis; Candidemia; Candida glabrata; Candida albicans; Candida tropicalis; Candida parapsilosis; Antifungal Agents
PubMed: 37019819
DOI: 10.1093/mmy/myad028 -
Microorganisms Mar 2023In recent years, research on yeasts as probiotics has gained more and more interest, which will allow the development of "new" products in the probiotics market. In this...
In recent years, research on yeasts as probiotics has gained more and more interest, which will allow the development of "new" products in the probiotics market. In this context, seventeen yeast strains isolated from , a traditional beer produced in Burkina Faso, were assessed for their probiotic attributes. The yeast identification was performed by molecular methods, including PCR-RFLP and 5.8S-ITS region sequencing. (14 strains) was the predominantly identified species, followed by (2 strains) and (1 strain). Except for , all yeast strains grew well at human temperature. The yeast strains showed high resistance when they were exposed to simulated gastrointestinal conditions. Auto-aggregation ability was between 70.20 ± 10.53% and 91.82 ± 1.96%, while co-aggregation with ranged from 24.92 ± 3.96% to 80.68 ± 9.53% and with Typhimurium from 40.89 ± 8.18% to 74.06 ± 7.94%. Furthermore, the hydrophobicity of isolated strains toward n-hexane was in the range from 43.17 ± 5.07% to 70.73 ± 2.42%. All yeast strains displayed high antioxidant capabilities, and the strains did not show hemolysis halos, such that they can be considered safe. Additionally, strains strongly inhibited the growth of foodborne pathogens. This is the first preliminary study to identify and characterize the yeast strains isolated from with interesting probiotic properties.
PubMed: 36985375
DOI: 10.3390/microorganisms11030802 -
Microorganisms Mar 2023The supplementation of animal feed with microbial additives remains questioning for the traditional or quality label raw milk cheeses with regard to microbial transfer...
The supplementation of animal feed with microbial additives remains questioning for the traditional or quality label raw milk cheeses with regard to microbial transfer to milk. We evaluated the effect of dietary administration of live yeast on performance and microbiota of raw milk, teat skin, and bedding material of dairy cows. Two balanced groups of cows (21 primiparous 114 ± 24 DIM, 18 multiparous 115 ± 33 DIM) received either a concentrate supplemented with CNCM I-1077 (1 × 10 CFU/d) during four months (LY group) or no live yeast (C group). The microbiota in individual milk samples, teat skins, and bedding material were analysed using culture dependent techniques and high-throughput amplicon sequencing. The live yeast supplementation showed a numerical increase on body weight over the experiment and there was a tendency for higher milk yield for LY group. A sequence with 100% identity to that of the live yeast was sporadically found in fungal amplicon datasets of teat skin and bedding material but never detected in milk samples. The bedding material and teat skin from LY group presented a higher abundance of reaching 53% ( < 0.05) and 10% ( < 0.05) respectively. A significant proportion of bacterial and fungal ASVs shared between the teat skin and the milk of the corresponding individual was highlighted.
PubMed: 36985246
DOI: 10.3390/microorganisms11030673 -
Current Research in Food Science 2023In this research, the LAB and yeast isolations and identifications of homemade traditional sourdoughs were investigated. Both LAB and yeasts were identified by the PCR...
In this research, the LAB and yeast isolations and identifications of homemade traditional sourdoughs were investigated. Both LAB and yeasts were identified by the PCR method and used in the production of sourdough bread (SDB). Twelve types of SDB were produced from combinations of isolated LAB and yeasts. Eleven LAB and yests were identified from 36 sourdoughs. The most frequently isolated LAB species were (45.0%), (20.0%) and (18.3%) while other LAB species were isolated by only 1.7-3.5%. On the other hand, 27.5% of the isolates were , which was followed by (25.0%) and (12.5%). The total titratable acidity and pH of the sourdough ranged from 3.10 to 34.45% and from 4.05 to 4.80 respectively. High acceptable loaf height (7.2 cm), moisture (30.05%), dry matter (69.95%), volume (1370 cm), specific volume (4.35 cm g ) and sensory value (62 scores) were determined for SDB12. Isolated LAB is mainly composed of heterofermentative species (75%). Among the bread produced with the combination of LAB and yeasts, the SDB12 was the most preferred SDB in terms of sensory analysis and other quality characteristics. The use of homofermentative and heterofermentative LAB and yeast combinations provided high-quality SDB. This would be due to the symbiotic growth of these microorganisms. The use of by and by other species resulted in high-quality SDB.
PubMed: 36969566
DOI: 10.1016/j.crfs.2023.100479 -
Frontiers in Immunology 2023Neutropenia is a common complication in the treatment of hematological diseases and the most common predisposing factor for invasion by fungi, such as . Recent studies...
Neutropenia is a common complication in the treatment of hematological diseases and the most common predisposing factor for invasion by fungi, such as . Recent studies have shown that , a life-threatening pathogen, has developed resistance to amphotericin B (AMB). However, the mechanisms that led to the rapid emergence of this AMB-resistant phenotype are unclear. In this study, we found the sensitivity for AMB could be promoted by inhibiting histone acyltransferase activity and western blot analysis revealed differences in the succinylation levels of isolated from immunocompromised patients and of the corresponding AMB-resistant mutant. By comparative succinyl-proteome analysis, we identified a total of 383 differentially expressed succinylated sites in with 344 sites in 134 proteins being upregulated in the AMB-resistant mutant, compared to 39 sites in 23 proteins in the wild-type strain. These differentially succinylated proteins were concentrated in the ribosome and cell wall. The critical pathways associated with these proteins included those involved in glycolysis, gluconeogenesis, the ribosome, and fructose and mannose metabolism. In particular, AMB resistance was found to be associated with enhanced ergosterol synthesis and aberrant amino acid and glucose metabolism. Analysis of whole-cell proteomes, confirmed by parallel reaction monitoring, showed that the key enzyme facilitating lysine acylation was significantly upregulated in the AMB-resistant strain. Our results suggest that lysine succinylation may play an indispensable role in the development of AMB resistance in Our study provides mechanistic insights into the development of drug resistance in fungi and can aid in efforts to stifle the emergence of AMB-resistant pathogenic fungi.
Topics: Amphotericin B; Antifungal Agents; Candida; Lysine; Microbial Sensitivity Tests; Fungi; Protein Processing, Post-Translational
PubMed: 36936926
DOI: 10.3389/fimmu.2023.1148681 -
Microbiology Spectrum Mar 2023Multispecies communities participate in the fermentation of Chinese strong-flavor Baijiu (CSFB), and the metabolic activity of the dominant and keystone taxa is key to...
Multispecies communities participate in the fermentation of Chinese strong-flavor Baijiu (CSFB), and the metabolic activity of the dominant and keystone taxa is key to the flavor quality of the final product. However, their roles in metabolic function and assembly processes are still not fully understood. Here, we identified the variations in the metabolic profiles of dominant and keystone taxa and characterized their community assembly using 16S rRNA and internal transcribed spacer (ITS) gene amplicon and metatranscriptome sequencing. We demonstrate that CSFB fermentations with distinct metabolic profiles display distinct microbial community compositions and microbial network complexities and stabilities. We then identified the dominant taxa (Limosilactobacillus fermentum, Kazachstania africana, Saccharomyces cerevisiae, and Pichia kudriavzevii) and the keystone ecological cluster (module 0, affiliated mainly with Thermoascus aurantiacus, Weissella confusa, and Aspergillus amstelodami) that cause changes in metabolic profiles. Moreover, we highlight that the alpha diversity of keystone taxa contributes to changes in metabolic profiles, whereas dominant taxa exert their influence on metabolic profiles by virtue of their relative abundance. Additionally, our results based on the normalized stochasticity ratio (NST) index and the neutral model revealed that stochastic and deterministic processes together shaped CSFB microbial community assemblies. Stochasticity and environmental selection structure the keystone and dominant taxa differently. This study provides new insights into understanding the relationships between microbial communities and their metabolic functions. From an ecological perspective, keystone taxa in microbial networks with high connectivity have crucial roles in community assembly and function. We used CSFB fermentation as a model system to study the ecological functions of dominant and keystone taxa at the metabolic level. We show that both dominant taxa (e.g., those taxa that have the highest relative abundances) and keystone taxa (e.g., those taxa with the most cooccurrences) affected the resulting flavor profiles. Moreover, our findings established that stochastic processes were dominant in shaping the communities of keystone taxa during CSFB fermentation. This result is striking as it suggests that although the controlled conditions in the fermentor can determine the dominant taxa, the uncontrolled rare keystone taxa in the microbial community can alter the resulting flavor profiles. This important insight is vital for the development of potential manipulation strategies to improve the quality of CSFB through the regulation of keystone species.
PubMed: 36916915
DOI: 10.1128/spectrum.05103-22