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Open Forum Infectious Diseases Jan 2023Fungal species have undergone and continue to undergo significant nomenclatural change, primarily due to the abandonment of dual species nomenclature in 2013 and the... (Review)
Review
Fungal species have undergone and continue to undergo significant nomenclatural change, primarily due to the abandonment of dual species nomenclature in 2013 and the widespread application of molecular technologies in taxonomy allowing correction of past classification errors. These have effected numerous name changes concerning medically important species, but by far the group causing most concern are the yeasts. Among common species, , , , , and have been changed to , , , , and , respectively. There are currently no guidelines for microbiology laboratories on implementing changes, and there is ongoing concern that clinicians will dismiss or misinterpret laboratory reports using unfamiliar species names. Here, we have outlined the rationale for name changes across the major groups of clinically important fungi and have provided practical recommendations for managing change.
PubMed: 36632423
DOI: 10.1093/ofid/ofac559 -
Food Microbiology Aug 2022Specialty coffee can be developed by the application of explicit microorganisms or starters to obtain desired fermentation. In the present study, natural fermentation...
Specialty coffee can be developed by the application of explicit microorganisms or starters to obtain desired fermentation. In the present study, natural fermentation (NF) of Arabica coffee was carried out spontaneously, the other set was inoculated with Pichia kudriavzevii (Y) starter culture (isolated, identified and mass cultured). The effect of microbial fermentation, metagenomics, production of functional metabolites, volatiles and their sensorial aspects were studied. The bioprocess illustrated cohesive interface of coffee nutrients and microbial communities like Mycobacterium, Acinetobacter, Gordonia, etc., in NF, Lactobacillus and Leuconostoc were prevailing in Y. The Pichia and Rhodotorula dominated in both the groups. The bioactivity of bacteria and fungi induced complex changes in physicochemical features like pH (4.2-5.2), Brix° (9.5-3.0), and metabolic transition in sugar (3.0-0.7%), alcohol (1.4-2.7%), organic acids modulating flavour precursors and organoleptics in the final brew. In the roasted bean, Y exhibited higher sugar (42%), protein (25%), polyphenol (3.5%), CGA (2.5%), caffeine (17.2%), and trigonelline (2.8%) than NF. The volatile profile exhibited increased flavour molecules like furans, ketones, and pyrazines in Y, besides lactone complexes. The organoleptics in Y were highlighted with honey, malt and berry notes. P. kudriavzevii coffee fermentation could be beneficial in specialty coffee production and enhancement of distinct characteristic flavours.
Topics: Coffee; Fermentation; Flavoring Agents; Pichia; Sugars
PubMed: 35473973
DOI: 10.1016/j.fm.2022.104012 -
International Journal of Environmental... Mar 2022A variety of flocculants have been used to aggregate colloidal substances. However, recently, owing to the adverse effects and high costs of conventional flocculants,...
A variety of flocculants have been used to aggregate colloidal substances. However, recently, owing to the adverse effects and high costs of conventional flocculants, natural flocculants such as microbial flocculants are gaining attention. The aim of the study was to produce and characterize a bioflocculant from MH545928.1 and apply it in wastewater treatment. A mixture of butanol and chloroform (5:2 /) was used to extract the bioflocculant. Phenol-sulphuric acid, Bradford and Carbazole assays were utilized for the identification of carbohydrates, proteins and uronic acid, respectively. Scanning electron microscopy (SEM) and elemental detector were employed to determine the surface morphology and elemental compositions. The removal efficiencies were 73%, 49% and 47% for BOD, COD and P, respectively. The bioflocculant (2.836 g/L) obtained showed the presence of carbohydrates (69%), protein (11%) and uronic acid (16%). The bioflocculant displayed a cumulus-like structure and the elemental composition of C (16.92%), N (1.03%), O (43:76%), Na (0.18%), Mg (0.40%), Al (0.80%), P (14.44%), S (1.48%), Cl (0.31%), K (0.34%) and Ca (20.35). It showed the removal efficiencies of 43% (COD), 64% (BOD), 73% (P) and 50% (N) in coal mine wastewater. This bioflocculant is potentially viable to be used in wastewater treatment.
Topics: Flocculation; Hydrogen-Ion Concentration; Pichia; Uronic Acids; Wastewater; Water Purification
PubMed: 35328836
DOI: 10.3390/ijerph19063148 -
Journal of Fungi (Basel, Switzerland) Jan 2023is an emerging non-conventional yeast which has attracted increased attention for its application in food and biotechnology areas. It is widespread in various habitats... (Review)
Review
is an emerging non-conventional yeast which has attracted increased attention for its application in food and biotechnology areas. It is widespread in various habitats and often occurs in the spontaneous fermentation process of traditional fermented foods and beverages. The contributions of in degrading organic acid, releasing various hydrolase and flavor compounds, and displaying probiotic properties make it a promising starter culture in the food and feed industry. Moreover, its inherent characteristics, including high tolerance to extreme pH, high temperature, hyperosmotic stress and fermentation inhibitors, allow it the potential to address technical challenges in industrial applications. With the development of advanced genetic engineering tools and system biology techniques, is becoming one of the most promising non-conventional yeasts. This paper systematically reviews the recent progress in the application of to food fermentation, the feed industry, chemical biosynthesis, biocontrol and environmental engineering. In addition, safety issues and current challenges to its use are discussed.
PubMed: 36836285
DOI: 10.3390/jof9020170 -
Endogenous Ethanol and Triglyceride Production by Gut , and Yeasts in Non-Alcoholic Steatohepatitis.Cells Oct 2022Nonalcoholic steatohepatitis (NASH) increases with fructose consumption and metabolic syndrome and has been recently linked with endogenous ethanol production, notably...
Nonalcoholic steatohepatitis (NASH) increases with fructose consumption and metabolic syndrome and has been recently linked with endogenous ethanol production, notably by high alcohol-producing (HiAlc Kpn). yeasts are the main causes of auto-brewery syndromes but have been neglected in NASH. Here, the fecal ethanol and microbial content of 10 cases and 10 controls were compared. Ethanol was measured by gas chromatography-mass spectrometry. Species identification was performed by MALDI-TOF MS, and triglyceride production was assessed by a colorimetric enzymatic assay. The fecal ethanol concentration was four times higher in patients with NASH (median [interquartile range]: 0.13 [0.05-1.43] vs. 0.034 [0.008-0.57], = 0.037). Yeasts were isolated from almost all cases but not from controls (9/10 vs. 0/10, = 0.0001). was the most frequent (four patients), while , and were identified in two cases each. The concentration of ethanol produced by yeasts was 10 times higher than that produced by bacteria (median, 3.36 [0.49-5.60] vs. 0.32 [0.009-0.43], = 0.0029). Using a 10% D-fructose restricted medium, we showed that NASH-associated yeasts transformed fructose in ethanol. Unexpectedly, yeasts isolated from NASH patients produced a substantial amount of triglycerides. strains produced the maximal ethanol and triglyceride levels in vitro. Our preliminary human descriptive and in vitro experimental results suggest that yeasts have been neglected. In addition to , gut and yeasts could be linked with NASH pathophysiology in a species- and strain-specific manner through fructose-dependent endogenous alcohol and triglyceride production.
Topics: Humans; Pichia; Ethanol; Non-alcoholic Fatty Liver Disease; Candida albicans; Candida glabrata; Triglycerides; Candida; Fructose
PubMed: 36359786
DOI: 10.3390/cells11213390 -
Foods (Basel, Switzerland) Sep 2022plays an important role in fermented foods and beverages. In the long domestication process of traditional fermentation, the mechanism of response to lactic acid, a...
plays an important role in fermented foods and beverages. In the long domestication process of traditional fermentation, the mechanism of response to lactic acid, a common metabolite and growth inhibitor, is currently unclear in . In this study, the tolerance to lactic acid of C-16, isolated from fermented grains, was compared with its type strain ATCC 24210. Under lactic acid stress, C-16 showed increased biomass yields and lactic acid consumption rates. Then, mRNA sequencing was used to analyze the response to lactic acid in C-16. Results showed that 92 and 96 genes were significantly upregulated, 52 and 58 genes were significantly downregulated, respectively, in C-16 cultured for 12 h and 24 h. The genes, which involved in pyruvate metabolic pathway, ABC transporter proteins, glutamate metabolic pathway, and the biosynthetic pathway of leucine and valine, were observed to be differentially expressed between the C-16 and its type strain ATCC 24210. By analyzing the production of higher alcohols, the concentrations of isobutyl alcohol and isoamyl alcohol produced by C-16 increased significantly. It was consistent with the up-regulation of genes that biosynthesized related amino acids.
PubMed: 36140854
DOI: 10.3390/foods11182725 -
Biological Trace Element Research Feb 2021The cadmium and lead binding capacities and antioxidant activities of Lactobacillus plantarum and Pichia kudriavzevii were evaluated in vitro and in vivo. Lactic acid...
The cadmium and lead binding capacities and antioxidant activities of Lactobacillus plantarum and Pichia kudriavzevii were evaluated in vitro and in vivo. Lactic acid bacteria and yeasts obtained from fermenting cassava mash and maize slurry were screened for tolerance to cadmium and lead at 500-1050 mg ml screened for probiotic potentials and antioxidant activities such as 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant properties. The in vivo studies were carried out in male Wistar rats. The strains identified as Lactobacillus plantarum ML05 and Pichia kudriavzevii FY05 demonstrated the best probiotic potentials and antioxidant activities. Alterations in antioxidant capacities were positive in the treatment groups. The histopathology displayed positive changes in the renal tubules and glomeruli, hypertrophy, with normal capsular spaces without inflammation in the kidney, while the liver sinusoids appear normal in the rats administered with L. plantarum ML05 and P. kudriavzevii FY05 while the infected and not treated showed cell necrosis induced by toxicities. Our results provided new evidence that Lactobacillus plantarum and Pichia kudriavzevii have different biological actions on the heavy metals binding capacities and antioxidant activities in experimental animals. This study suggests that these microorganisms can be considered dietary therapeutics against cadmium and lead toxicities.
Topics: Animals; Antioxidants; Cadmium; Lactobacillus plantarum; Lead; Male; Pichia; Probiotics; Rats; Rats, Wistar
PubMed: 32436065
DOI: 10.1007/s12011-020-02164-1 -
Food Chemistry Apr 2024This study is the first to demonstrate the yeast Pichia kudriavzevii can effectively deliver Se and investigate the distribution and species of Se in Se-enriched P....
This study is the first to demonstrate the yeast Pichia kudriavzevii can effectively deliver Se and investigate the distribution and species of Se in Se-enriched P. kudriavzevii. Results showed that P. kudriavzevii can accumulate Se and convert 84.883% of absorbed Se into organic forms, of which 78.338% was incorporated into protein, 1.978% combined with polysaccharides, and 0.456% bound to nucleic acid. Besides, water-soluble, salt-soluble, and alkali-soluble proteins account for 49.398%, 1.867%, and 20.628% of selenoprotein, respectively. The dominant Se species were SeCys2 and MeSeCys. Additionally, Se-enrichment enhanced nutritional value of P. kudriavzevii by increasing the levels of amino acids, iron, and zinc. The activity of key rate-limiting enzyme sephosphate synthetase involved in Se biotransformation was improved after Se enrichment. The extracellular pH results suggest that Se enrichment ability can be further enhanced by elevating pH. These results suggest P. kudriavzevii holds great promise as an effective vehicle for delivering Se.
Topics: Selenium; Pichia; Biotransformation; Zinc
PubMed: 37976881
DOI: 10.1016/j.foodchem.2023.137966 -
Mycopathologia Aug 2022Revealing the phylogenetic relationships of Candida krusei strains (sexual form Pichia kudriavzevii) is a prerequisite for understanding the evolution of its...
Revealing the phylogenetic relationships of Candida krusei strains (sexual form Pichia kudriavzevii) is a prerequisite for understanding the evolution of its virulence-associated mechanisms and ecological lifestyles. Molecular phylogenetic analyses based on entire internal transcribed spacer region (ITS) and multilocus sequence typing (MLST) data were carried out with sequences available in public databases and Hungarian isolates from animals obtained for the study. The ITS haplotype network yielded a high frequency haplotype at the centre of the network (H1; n = 204) indicating that various selective pressure might resulted in population expansion from H1. MLST analysis identified three new genotypes among animal-derived isolates, therefore overall 203 sequence types were investigated to determine the population structure of C. krusei. The most commonly encountered sequence types were ST 17 and ST 67. Phylogenetic analyses showed diverse genetic construction of C. krusei population. Evidence of potential recombination events were also observed that might play some role in high intraspecies genetic variability among strains, however, the limited data of C. krusei genotypes from different countries prevented us to identify accurate evolutionary routes of commensal and pathogenic strains or species-specific lineages. Further expansion of C. krusei MLST database may promote the better understanding of the mixed evolutionary history of this species.
Topics: Candida; Multilocus Sequence Typing; Phylogeny; Pichia
PubMed: 35689765
DOI: 10.1007/s11046-022-00640-x -
Journal of the Science of Food and... Mar 2023Microencapsulated yeasts are a novel alternative as a delivery matrix for microbiological starters. This technology aims to protect the active compounds from adverse...
BACKGROUND
Microencapsulated yeasts are a novel alternative as a delivery matrix for microbiological starters. This technology aims to protect the active compounds from adverse environmental conditions and prolong their useful life and could also improve the conditions of the starters for cocoa fermentation. The present study established the effective dose to apply the microencapsulated yeast Pichia kudriavzevii as a microbiological starter of fermentation and biotechnological strategy for promoting the biochemical dynamics and sensory expression of the cocoa variety CCN-51. For this, 0.5%, 1%, 2%, and 3% of microencapsulated P. kudriavzevii yeast insolated from the artisanal fermentation process of cocoa was added to the cocoa mass to be fermented and studied on a laboratory scale.
RESULTS
The partial least squares regression of fermentation was related in four quartiles, comprising the hedonic judgments of the sensory evaluation with the biochemical traits of the cocoa liquor, finding a high correlation between the physicochemical variables total phenols, percentage of insufficiently fermented grains, and percentage of total acidity, with a level of bitterness and defects found in liquors with the addition of 0.5% of microencapsulated starter. The treatments with the addition of 2% and 3% of the inoculum showed a high correlation between the variables pH, total anthocyanins, cocoa, fruity and floral aromas, sweet taste, and general aroma perception.
CONCLUSION
The higher presence of volatile compounds such as 2,3-butanediol associated with cocoa aroma and 1-phenyl-2-ethanol and acetophenone associated with aromatic descriptors of fruity and floral series allowed establishment in 2% of microencapsulated P. kudriavzevii yeast, comprising the effective dose for promoting the biochemical dynamics of laboratory-scale fermentation and the development of cocoa, as well as the fruity and floral aromas of cocoa CCN-51 liquor. The microencapsulation is suitable for cocoa starters. © 2023 Society of Chemical Industry.
Topics: Cacao; Fermentation; Saccharomyces cerevisiae; Anthocyanins; Genotype
PubMed: 36606570
DOI: 10.1002/jsfa.12433