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Journal of Food Science and Technology Jun 2023Kombucha is a fermented tea with a combination of yeast and bacteria. Kombucha teas may have a variable microbiota based on geographic origin and cultural conditions....
UNLABELLED
Kombucha is a fermented tea with a combination of yeast and bacteria. Kombucha teas may have a variable microbiota based on geographic origin and cultural conditions. The microbial flora of kombucha has been studied with culture-dependent methods. But, the improvement of the metataxonomic approach has broadened our perspective on fermented foods. In this study, a kombucha mother was procured from an artisanal supplier in Türkiye. High-throughput new-generation sequencing (16S rRNA and Internal Transcribed Spacer (ITS)) was carried out to investigate the microbial communities of kombucha after 7 days of fermentation in both liquid tea (L) and pellicle (P). Microbial counts, pH (4.42 ± 0.01 and 3.50 ± 0.02), and TA% (0.26 ± 0.02 and 0.60 ± 0.04) were also detected on the first and 7 days of fermentation. According to metataxonomic results, the dominant bacteria were (%21.13), an acetic acid-producing bacteria, and the dominant fungal genus was (64.35%) in L while sp. CE17 was the dominant bacteria (7%) and was also the dominant yeast in P. This study also revealed different species which were not common in kombucha including propionic acid and butyric acid-producing bacteria such as and , a butyrivibriocin producing bacteria. Accordingly, different yeast species were detected such as and .
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13197-023-05725-z.
PubMed: 37187981
DOI: 10.1007/s13197-023-05725-z -
Medical Mycology Jun 2024In response to the growing global threat of fungal infections, in 2020 the World Health Organisation (WHO) established an Expert Group to identify priority fungi and...
In response to the growing global threat of fungal infections, in 2020 the World Health Organisation (WHO) established an Expert Group to identify priority fungi and develop the first WHO fungal priority pathogen list (FPPL). The aim of this systematic review was to evaluate the features and global impact of invasive infections caused by Pichia kudriavzevii (formerly known as Candida krusei). PubMed and Web of Science were used to identify studies published between 1 January 2011 and 18 February 2021 reporting on the criteria of mortality, morbidity (defined as hospitalisation and length of stay), drug resistance, preventability, yearly incidence, and distribution/emergence. Overall, 33 studies were evaluated. Mortality rates of up to 67% in adults were reported. Despite the intrinsic resistance of P. kudriavzevii to fluconazole with decreased susceptibility to amphotericin B, resistance (or non-wild-type rate) to other azoles and echinocandins was low, ranging between 0 and 5%. Risk factors for developing P. kudriavzevii infections included low birth weight, prior use of antibiotics/antifungals, and an underlying diagnosis of gastrointestinal disease or cancer. The incidence of infections caused by P. kudriavzevii is generally low (∼5% of all Candida-like blood isolates) and stable over the 10-year timeframe, although additional surveillance data are needed. Strategies targeting the identified risk factors for developing P. kudriavzevii infections should be developed and tested for effectiveness and feasibility of implementation. Studies presenting data on epidemiology and susceptibility of P. kudriavzevii were scarce, especially in low- and middle-income countries (LMICs). Thus, global surveillance systems are required to monitor the incidence, susceptibility, and morbidity of P. kudriavzevii invasive infections to inform diagnosis and treatment. Timely species-level identification and susceptibility testing should be conducted to reduce the high mortality and limit the spread of P. kudriavzevii in healthcare facilities.
Topics: Humans; Drug Resistance, Fungal; Antifungal Agents; World Health Organization; Pichia; Incidence; Risk Factors; Candidiasis
PubMed: 38935911
DOI: 10.1093/mmy/myad132 -
Archives of Microbiology Aug 2023Recently, there has been growing interest in the characterization of native yeasts for their use in production of wines with regional characteristics. This study aimed...
Recently, there has been growing interest in the characterization of native yeasts for their use in production of wines with regional characteristics. This study aimed to investigate Saccharomyces and non-Saccharomyces yeasts present in the spontaneous fermentation of Tannat and Marselan grape musts collected from Concordia (Entre Ríos, Argentina) over 2019, 2020, and 2021 vintages. The evolution of these fermentative processes was carried out by measuring total soluble solids, total acidity, volatile acidity, pH, ethanol concentration, and total carbon content. Isolated Saccharomyces and non-Saccharomyces yeasts were identified based on colony morphology in WL medium, 5.8S-ITS-RFLP analysis, and 26S rDNA D1/D2 gene sequencing. Two hundred and ten yeast colonies were isolated and identified as Pichia kudriavzevii, Saccharomyces cerevisiae, Hanseniaspora uvarum, Metschnikowia pulcherrima, Candida albicans, Candida parapsilosis, Pichia occidentalis, Pichia bruneiensis, Hanseniaspora opuntiae, Issatchenkia terricola, and Hanseniaspora vineae. P. kudriavzevii isolated from all vintages was associated with the spontaneous fermentation of grape musts from the Concordia region.
Topics: Vitis; Fermentation; Yeasts; Wine; Saccharomyces cerevisiae; DNA, Ribosomal
PubMed: 37550458
DOI: 10.1007/s00203-023-03646-1 -
Current Microbiology Mar 2023Arsenic (As) exists widely in the environment and its strong toxicity endangers human health, causing widespread concern. Microbial adsorption technology plays an...
Arsenic (As) exists widely in the environment and its strong toxicity endangers human health, causing widespread concern. Microbial adsorption technology plays an important role in As removal due to its advantages of high safety, low pollution, and low cost. The removal of As by active microorganisms requires not only good accumulation characteristics but also high As tolerance. The effect of salt preincubation on arsenate [As(V)] tolerance and bioaccumulation of Pichia kudriavzevii A16 and the possible mechanisms were studied. Salt preincubation improved the As(V) tolerance and bioaccumulation ability of the yeast. After NaPO preincubation, the proportion of dead cells and cells with high reactive oxygen species (ROS) accumulation decreased from 50.88% and 16.54% to 14.60% and 5.24%, respectively. In addition, the As removal rate significantly increased from 26.20% to 57.98%. The preincubated cells showed stronger As(V) tolerance and removal ability. The potential of use in complex environment to remove As(V) as well as the mechanisms involved in As(V) tolerance by yeast will be discussed.
Topics: Humans; Arsenic; Saccharomyces cerevisiae; Sodium Chloride; Pichia
PubMed: 36862180
DOI: 10.1007/s00284-023-03216-0 -
Journal of Applied Microbiology Feb 2024To assess the capability of Pichia kudriavzevii strains isolated from wine, cider, and natural environments in North Patagonia to produce ciders with reduced malic acid...
AIMS
To assess the capability of Pichia kudriavzevii strains isolated from wine, cider, and natural environments in North Patagonia to produce ciders with reduced malic acid levels.
METHODS AND RESULTS
Fermentation kinetics and malic acid consumption were assessed in synthetic media and in regional acidic apple musts. All P. kudriavzevii strains degraded malic acid and grew in synthetic media with malic acid as the sole carbon source. Among these strains, those isolated from cider exhibited higher fermentative capacity, mainly due to increased fructose utilization; however, a low capacity to consume sucrose present in the must was also observed for all strains. The NPCC1651 cider strain stood out for its malic acid consumption ability in high-malic acid Granny Smith apple must. Additionally, this strain produced high levels of glycerol as well as acceptable levels of acetic acid. On the other hand, Saccharomyces cerevisiae ÑIF8 reference strain isolated from Patagonian wine completely consumed reducing sugars and sucrose and showed an important capacity for malic acid consumption in apple must fermentations.
CONCLUSIONS
Pichia kudriavzevii NPCC1651 strain isolated from cider evidenced interesting features for the consumption of malic acid and fructose in ciders.
Topics: Malus; Fructose; Wine; Saccharomyces cerevisiae; Fermentation; Acetic Acid; Sucrose; Malates; Pichia
PubMed: 38268424
DOI: 10.1093/jambio/lxae019 -
Current Opinion in Biotechnology Dec 2016Succinic acid (SA) has been recognized as one of the most important bio-based building block chemicals due to its numerous potential applications. For the economical... (Review)
Review
Succinic acid (SA) has been recognized as one of the most important bio-based building block chemicals due to its numerous potential applications. For the economical bio-based production of SA, extensive research works have been performed on developing microbial strains by metabolic engineering as well as fermentation and downstream processes. Here we review metabolic engineering strategies applied for bio-based production of SA using representative microorganisms, including Saccharomyces cerevisiae, Pichia kudriavzevii, Escherichia coli, Mannheimia succiniciproducens, Basfia succiniciproducens, Actinobacillus succinogenes, and Corynebacterium glutamicum. In particular, strategies employed for developing engineered strains of these microorganisms leading to the best performance indices (titer, yield, and productivity) are showcased based on the published papers as well as patents. Those processes currently under commercialization are also analyzed and future perspectives are provided.
Topics: Bacteria; Fermentation; Fungi; Metabolic Engineering; Phylogeny; Succinic Acid
PubMed: 26990278
DOI: 10.1016/j.copbio.2016.02.034 -
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