-
World Journal of Microbiology &... Jan 2021The role of the yeast community in Chinese strong-flavor baijiu fermentation was investigated by culture-independent and culture-dependent methods based on 26S rDNA...
The role of the yeast community in Chinese strong-flavor baijiu fermentation was investigated by culture-independent and culture-dependent methods based on 26S rDNA sequence analysis. 92 yeast species belonging to 54 genera were found by Illumina sequencing during the fermentation of strong-flavor baijiu "Wuliangye" and 306 strains belonging to 28 species, which covered all species with more than 1% of relative abundance, were isolated and identified. Kazachstania exigua, Geotrichum silvicola, Pichia kudriavzevii, Saccharomyces cerevisiae, Zyosaccharomyces bailii, and K. humilis were found to be the first six dominant species, and their proportion varied with different fermentation stages. K. exigua was the most important yeast species responsible for the production of ethanol with the assistance of P. kudriavzevii and Z. bailii in the vigorous stage and P. kudriavzevii and G. silvicola in the continuous fermentation stage. Higher alcohols were mainly produced by K. exigua, P. kudriavzevii, S. cerevisiae, and Z. bailii in the vigorous fermentation stage, which was stimulated by more oxygen in the grains of the upper strata. K. exigua, P. kudrizevii, S. cerevisiae, Z. bailii, G. silvicola, and Trichosporon ovoides promoted the formation of ethyl alcohol. The results revealed the key roles of K. exigua, G. silvicola, and P. kudriavzevii in the fermentation of strong-flavor baijiu. The functions of these species should be confirmed by a further study based on the fermentation characteristics of isolated yeast strains gathered in this study. Distribution and function of dominant yeast species in the fermentation of strong flavor baijiu.
Topics: Basidiomycota; Candida; Ethanol; Fermentation; Flavoring Agents; Geotrichum; Phylogeny; Pichia; Saccharomyces cerevisiae; Saccharomycetales; Taste
PubMed: 33427975
DOI: 10.1007/s11274-020-02988-y -
Journal of Dairy Science Oct 2022Bovine mastitis, a major infectious disease affecting milking cows, leads to reduced milk yield and quality, reduced animal welfare, and an increased need for culling....
Bovine mastitis, a major infectious disease affecting milking cows, leads to reduced milk yield and quality, reduced animal welfare, and an increased need for culling. Although its major causative agents are bacteria, yeast species and achlorophyllous algae of the Prototheca genus are well known as causative agents of bovine refractory mastitis. Nevertheless, few studies have analyzed specific yeasts and Prototheca in this context. Herein, we present survey data of yeast species and Prototheca species isolated from bulk tank milk in the Tokachi district of Japan from April 2020 through March 2021. The species of 276 isolates were determined. Yeast species accounted for 184 isolates, of which Pichia kudriavzevii was the most prevalent species. Regarding Prototheca species, only Prototheca bovis was isolated (92 isolates). Prototheca bovis and Pichia kudriavzevii were detected throughout the year and were detected repeatedly on the same farm. Kluyveromyces marxianus was the second most frequently isolated yeast species after Pichia kudriavzevii. Candida parapsilosis, the fourth most frequently isolated yeast species, was found discontinuously. Analysis of monthly data indicated that Kluyveromyces marxianus and Candida parapsilosis were mainly found during the winter and summer months, respectively. Candida akabanensis and Pichia cactophila were the third and fifth most frequently isolated yeast species, respectively. They were detected repeatedly in bulk tank milk samples from the same farms. Results obtained from bulk tank milk underscore the prevalence of these species. These study results are expected to contribute to the elucidation of problematic yeast and Prototheca species.
Topics: Animals; Cattle; Cattle Diseases; Female; Japan; Kluyveromyces; Mastitis, Bovine; Milk; Phylogeny; Pichia; Prototheca
PubMed: 35965121
DOI: 10.3168/jds.2022-21781 -
Foods (Basel, Switzerland) Feb 2023This study explored the effect of the combination of yeast, non- yeast (), and during cider fermentation on physicochemical properties, antioxidant activities, flavor...
This study explored the effect of the combination of yeast, non- yeast (), and during cider fermentation on physicochemical properties, antioxidant activities, flavor and aroma compounds, as well as sensory qualities. Ciders fermented with the triple mixed-cultures of these three species showed lower acid and alcohol content than those fermented with the single-culture of . The antioxidant activities were enhanced by the triple mixed-culture fermentation, giving a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate and total antioxidant capacity; specifically, the SPL5 cider showed the highest DPPH radical scavenging rate (77.28%), while the SPL2 gave the highest total antioxidant capacity (39.57 mmol/L). Additionally, the triple mixed-culture fermentation resulted in improved flavor and aroma with a lower acidity (L-malic acid) and higher aroma compounds (Esters), when compared with the single-culture fermented ciders (); more specifically, the SPL4 cider resulted in the highest total flavor and aroma compounds. In addition, sensory evaluation demonstrated that ciders produced using the triple mixed-cultures gained higher scores than those fermented using the single-culture of , giving better floral aroma, fruity flavor, and overall acceptability. Therefore, our results indicated that the triple mixed-cultures (, , and ) were found to make up some enological shortages of the single fermented cider. This study is believed to provide a potential strategy to enhance cider quality and further give a reference for new industrial development protocols for cider fermentation that have better sensory qualities with higher antioxidant properties.
PubMed: 36766182
DOI: 10.3390/foods12030655 -
New Biotechnology Jul 2022Oleaginous yeasts offer an interesting possibility for renewable lipid production, since the single cell oil accumulated can be based on a wide range of cheap,...
Oleaginous yeasts offer an interesting possibility for renewable lipid production, since the single cell oil accumulated can be based on a wide range of cheap, waste-derived carbon sources. Here, several short chain carboxylic acids and sugars commonly found in these substrates were assessed as carbon sources for Apiotrichum brassicae and Pichia kudriavzevii. While both strains were able to utilize all carbon sources employed, high volumetric lipid productivities (0.4 g/Lh) and lipid contents (68%) could be reached particularly with acetic acid as carbon source. Odd-numbered volatile fatty acids led to lower productivities and lipid contents, but the lipids contained unusually high proportions of odd-numbered fatty acids (up to 80% of total fatty acids). These fatty acids are rather uncommon in nature and might offer the possibility for various high value applications. In conclusion both strains are able to utilize a wide range of substrates potentially present in waste-derived substrates. Lipid content and volumetric lipid productivity strongly depend on the carbon source, with even-numbered volatile fatty acids resulting in the highest values. For volatile fatty acids in particular, the carbon source also strongly influences the composition of the lipids produced by the yeast strains.
Topics: Basidiomycota; Biofuels; Carbon; Fatty Acids; Fatty Acids, Volatile; Pichia; Yeasts
PubMed: 35182781
DOI: 10.1016/j.nbt.2022.02.003 -
ELife Apr 2021Bacterial members of the infant gut microbiota and bacterial-derived short-chain fatty acids (SCFAs) have been shown to be protective against childhood asthma, but a...
Bacterial members of the infant gut microbiota and bacterial-derived short-chain fatty acids (SCFAs) have been shown to be protective against childhood asthma, but a role for the fungal microbiota in asthma etiology remains poorly defined. We recently reported an association between overgrowth of the yeast in the gut microbiota of Ecuadorian infants and increased asthma risk. In the present study, we replicated these findings in Canadian infants and investigated a causal association between early life gut fungal dysbiosis and later allergic airway disease (AAD). In a mouse model, we demonstrate that overgrowth of within the neonatal gut exacerbates features of type-2 and -17 inflammation during AAD later in life. We further show that growth and adherence to gut epithelial cells are altered by SCFAs. Collectively, our results underscore the potential for leveraging inter-kingdom interactions when designing putative microbiota-based asthma therapeutics.
Topics: Animals; Asthma; Bacteria; Bacterial Physiological Phenomena; Case-Control Studies; Child; Child, Preschool; Gastrointestinal Microbiome; Humans; Infant; Mice, Inbred C57BL; Pichia; Specific Pathogen-Free Organisms; Mice
PubMed: 33876729
DOI: 10.7554/eLife.67740 -
Food Microbiology Sep 2022White colony-forming yeasts (WCFYs) have been reported to form a white colony on the surface of kimchi, resulting in the deterioration of kimchi sensory quality....
White colony-forming yeasts (WCFYs) have been reported to form a white colony on the surface of kimchi, resulting in the deterioration of kimchi sensory quality. However, toxicity of WCFY has rarely been studied. Thus, to evaluate the safety of WCFY (i.e., Kazachstania servazzii, Candia sake, and Pichia kudriavzevii), we conducted cell and animal experiments as well as genomic analysis. In vitro studies indicated that WCFY did not induce cytotoxic responses such as lactate dehydrogenase release, excessive oxidative stress, and mitochondrial damage at concentrations of up to 2.5 × 10 CFU/mL in human intestinal and liver cells. In animal studies using rats (single-dose and 14-day repeated-dose oral toxicity studies), WCFY did not induce death, clinical signs of toxicity, histological alterations of the liver, or increases in the expression of pro-inflammatory cytokines nor cytochrome P450-2E1 in liver tissue at concentrations of up to 5 × 10 CFU/head/day. Genomic analysis revealed that P. kudriavzevii did not harbor genes related to toxicity and antimicrobial resistance. Taken together, our data suggest that exposure to WCFY through kimchi intake did not induce toxic response in the Caco-2, HepG2, and Sprague-Dawley rats. The current work provides evidence for the safety of accidental major WCFY ingestion via kimchi.
Topics: Animals; Caco-2 Cells; Fermented Foods; Genomics; Humans; Rats; Rats, Sprague-Dawley; Yeasts
PubMed: 35690449
DOI: 10.1016/j.fm.2022.104057 -
Food Research International (Ottawa,... Feb 2020Guangxi Suansun (Guangxi SS) and Guangxi Suancai (Guangxi SC) are two kinds of traditionally fermented vegetables consumed as cooking ingredients in Guangxi Province,... (Comparative Study)
Comparative Study
Guangxi Suansun (Guangxi SS) and Guangxi Suancai (Guangxi SC) are two kinds of traditionally fermented vegetables consumed as cooking ingredients in Guangxi Province, China, for thousands of years. However, little is known about their microbial communities as well as the differences between them. Thus, this study was aimed to investigate and compare the physicochemical indexes as well as the bacterial and fungal profiles of Guangxi SS and Guangxi SC. Results showed that the titratable acidity, lactic acid and acetic acid content in SS were significantly higher than those in SC, while the salinity of SS was significantly lower than that in SC, and the nitrite contents in all samples were are far lower than the limit of nitrite contents in fermented vegetables. Firmicutes, Proteobacteria, Ascomycota and Basidiomycota were the main phyla observed in both SS and SC samples. Lactobacillus, Serratia, Stenotrophomonas and Lactococcus were the major bacterial genera in both SS and SC samples, the predominant fungal genera in SS group were Kazachstania, Debaryomyces and Pichia, while the major genera in SC group were Kazachstania, Debaryomyces and Nakaseomyces. At the species level, Lactobacillus acetotolerans, Pichia kudriavzevii, Debaryomyces hansenii, Pichia norvegensis, Kazachstania exigua and Kazachstania humilis were the major species observed in SS, while L. delbrueckii, L. fermentum, L. aviarius, and Pichia kudriavzevii and Debaryomyces hansenii were the predominant species in SC. Salinity was found to be more strongly correlated to the bacterial and fungal communities of both SS and SC than other physicochemical factors (pH, the titratable acidity, lactic acid and acetic acid content). This study provided detailed insight into the microbial communities of Guangxi SS and Guangxi SC, and the findings may help understand the microbial structures of Chinese traditional fermented vegetables.
Topics: Debaryomyces; Fermentation; Fermented Foods; Food Microbiology; Lactobacillus; Microbiota; Pichia; Saccharomycetales; Salinity; Vegetables; Zygosaccharomyces
PubMed: 31955789
DOI: 10.1016/j.foodres.2019.108755 -
Microbiology Spectrum Dec 2022In recent decades, the incidence of infections has increased in immunocompromised patients. This multicenter study aimed to evaluate antifungal activities of 8...
In recent decades, the incidence of infections has increased in immunocompromised patients. This multicenter study aimed to evaluate antifungal activities of 8 antifungal agents against the species isolated from 10 university hospitals in Iran. During the period from Dec 2019 to Dec 2021, species were collected from clinical samples of patients. The isolates were identified by PCR restriction fragment length polymorphism and sequencing methods. The antifungal susceptibility tests of each isolate to eight antifungal agents were performed according to the microdilution CLSI M27, M59, and M60 standard methods. A total of 598 strains were isolated from clinical samples. The most commonly isolated species was C. albicans, followed by C. glabrata, C. parapsilosis, Debaryomyces hansenii (Candida famata), C. tropicalis, (Candida krusei), C. orthopsilosis, Meyerozyma guilliermondii (Candida guilliermondii), Kluyveromyces marxianus (Candida kefyr), and Clavispora lusitaniae (Candida lusitaniae). MIC values in all species were as follows: 0.25 μg/mL for caspofungin and voriconazole; 0.5 μg/mL for amphotericin B and isavuconazole; 2 μg/mL for itraconazole, luliconazole, and posaconazole; and 16 μg/mL for fluconazole. Although 30/285 C. albicans, 15/31 3/12 , 67/125 C. glabrata, 5/15 , 6/60 C. parapsilosis, and 5/23 C. tropicalis isolates were multiazole resistant with resistance to 2 to 4 azoles, pan-azole resistance was not observed. According to our data, Candida albicans and C. glabrata were the most frequent species isolated from clinical samples in Iran. Caspofungin and voriconazole, with lower MIC values, are the most effective than other antifungal agents for the treatment of infections in this region. species cause severe invasive infections of the heart, brain, eyes, bones, and other parts of the body. Knowledge of regional distributions of causative agents and their antifungal susceptibility patterns can help to monitor resistance to antifungal agents of various species and support local and national surveillance programs. In the present study, C. albicans and C. glabrata were the most frequently isolated species from clinical samples in Iran. Increasing rates of non- isolates from the Iranian population should be looked at as alarming due to various levels of intrinsic MIC values or resistance to various antifungal drugs. Caspofungin and voriconazole are recommended over fluconazole for the treatment of infections in the study region. However, amphotericin B and isavuconazole are also active against the most common species isolated from patients. Pan azole-resistant species were not observed in the present study.
Topics: Humans; Amphotericin B; Antifungal Agents; Azoles; Candida; Candida albicans; Candida glabrata; Candidiasis; Caspofungin; Drug Resistance, Fungal; Fluconazole; Iran; Microbial Sensitivity Tests; Tertiary Care Centers; Voriconazole
PubMed: 36445122
DOI: 10.1128/spectrum.02453-22 -
American Journal of Physiology.... Apr 2022The gut microbiome has the capacity to regulate bone mass. The aim of this study was to develop a nutritional synbiotic dietary assemblage at an optimal dose to maintain...
The gut microbiome has the capacity to regulate bone mass. The aim of this study was to develop a nutritional synbiotic dietary assemblage at an optimal dose to maintain bone mass in ovariectomized (Ovx) mice. We performed genomic analyses and in vitro experiments in a large collection of bacterial and fungal strains (>4,000) derived from fresh fruit and vegetables to identify candidates with the synergistic capacity to produce bone-protective short-chain fatty acids (SCFA) and vitamin K2. The candidate SBD111-A, composed of , , , , and together with prebiotic dietary fibers, produced high levels of SCFA in vitro and protected against Ovx-induced trabecular bone loss in a dose-dependent manner in mice. Metagenomic sequencing revealed that SBD111-A changed the taxonomic composition and enriched specific pathways for synthesis of bone-protective SCFA, vitamin K2, and branched-chain amino acids in the gut microbiome. We performed genomic analyses and in vitro experiments in a collection of bacterial and fungal strains. We identified a combination (SBD111-A) that produced high levels of SCFA in vitro and protected against ovariectomy-induced bone loss in a dose-dependent manner in mice. Metagenomic sequencing revealed that SBD111-A changed the taxonomic composition and function of the gut microbiome and enriched pathways for synthesis of bone-protective SCFA, vitamin K2, and branched-chain amino acids.
Topics: Amino Acids, Branched-Chain; Animals; Bacteria; Cancellous Bone; Fatty Acids, Volatile; Female; Humans; Mice; Ovariectomy; Synbiotics; Vitamin K 2
PubMed: 35156423
DOI: 10.1152/ajpendo.00366.2021 -
Journal of Insect Science (Online) May 2024The black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae), is commonly used for organic waste recycling and animal feed production. However, the often...
The black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae), is commonly used for organic waste recycling and animal feed production. However, the often inadequate nutrients in organic waste necessitate nutritional enhancement of black soldier fly larvae, e.g., by fungal supplementation of its diet. We investigated the amino acid composition of two fungi, Candida tropicalis (Castell.) Berkhout (Saccharomycetales: Saccharomycetaceae) and Pichia kudriavzevii Boidin, Pignal & Besson (Saccharomycetales: Pichiaceae), from the black soldier fly gut, and commercial baker's yeast, Saccharomyces cerevisiae Meyen ex E.C. Hansen (Saccharomycetales: Saccharomycetaceae), and their effects on larval growth and hemolymph metabolites in fifth-instar black soldier fly larvae. Liquid chromatography-mass spectrometry was used to study the effect of fungal metabolites on black soldier fly larval metabolism. Amino acid analysis revealed significant variation among the fungi. Fungal supplementation led to increased larval body mass and differential metabolite accumulation. The three fungal species caused distinct metabolic changes, with each over-accumulating and down-accumulating various metabolites. We identified significant alteration of histidine metabolism, aminoacyl-tRNA biosynthesis, and glycerophospholipid metabolism in BSF larvae treated with C. tropicalis. Treatment with P. kudriavzevii affected histidine metabolism and citrate cycle metabolites, while both P. kudriavzevii and S. cerevisiae treatments impacted tyrosine metabolism. Treatment with S. cerevisiae resulted in down-accumulation of metabolites related to glycine, serine, and threonine metabolism. This study suggests that adding fungi to the larval diet significantly affects black soldier fly larval metabolomics. Further research is needed to understand how individual amino acids and their metabolites contributed by fungi affect black soldier fly larval physiology, growth, and development, to elucidate the interaction between fungal nutrients and black soldier fly physiology.
Topics: Animals; Larva; Diptera; Hemolymph; Pichia; Saccharomyces cerevisiae; Amino Acids; Diet; Saccharomycetales; Animal Feed; Candida
PubMed: 38713543
DOI: 10.1093/jisesa/ieae050