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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 -
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 -
Microorganisms Apr 2022Microbial administration has been used successfully to improve host health. However, the positive effects of endogenous microbials are still underexplored. This study...
Microbial administration has been used successfully to improve host health. However, the positive effects of endogenous microbials are still underexplored. This study investigated the effects of bovine Lactic acid bacteria and yeast on the milk production, quality and digestive tract microbiome of dairy cows. Y9, T7 and isolated from high-yielding dairy cows were selected to feed low-yielding Holstein cows. T7 could significantly increase milk yield, meanwhile, T7 and B14 could obviously reduce the number of somatic cell counts (SCC). However, slight differences were found in milk fat, protein, lactose and SNF (solids not fat) percentage. High throughput sequencing showed that the dominant bacteria were and in rumen and feces, respectively, and the dominant fungi were , and in both samples, before and after feeding the microbial addition. Nonetheless, microbial addition changed the abundance and structure of the microbiome in the digestive tract. Our data showed bovine yeast and LAB were beneficial for improving performance and regulating the microbial structure of dairy cows. This study was expected to enrich the knowledge of the digestive tract microbiome in dairy cows and provide a feasible strategy for the further utilization of bovine microorganisms.
PubMed: 35630288
DOI: 10.3390/microorganisms10050842 -
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 -
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 -
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 -
Frontiers in Microbiology 2022Heterotrophic nitrification is a process of organic nitrogen degradation completed by the participation of heterotrophic nitrifying microorganisms, which can accelerate...
Heterotrophic nitrification is a process of organic nitrogen degradation completed by the participation of heterotrophic nitrifying microorganisms, which can accelerate the nitrogen transformation process. However, the current research mainly focuses on heterotrophic nitrifying bacteria and their ammonium degradation capacities. And there is little accumulation of research on fungi, the main force of heterotrophic nitrification, and their capacities to transform organic nitrogen. In this study, novel heterotrophic nitrifying fungus (XTY1) and bacterium (GS2) were screened and isolated from upland soil, and the strains were identified and registered through GenBank comparison. After 24 h single nitrogen source tests and N labeling tests, we compared and preliminarily determined the heterotrophic nitrification capacities and pathways of the two strains. The results showed that XTY1 and GS2 had different transformation capacities to different nitrogen substrates and could efficiently transform organic nitrogen. However, the transformation capacity of XTY1 to ammonium was much lower than that of GS2. The two strains did not pass through NHOH and NO during the heterotrophic nitrification of organic nitrogen, and mainly generated intracellular nitrogen and low NO. Other novel organic nitrogen metabolism pathways may be existed, but they remain to be further validated.
PubMed: 36569078
DOI: 10.3389/fmicb.2022.1038599 -
AMB Express May 2018The yeast strain SJP-SNU was investigated as a probiotic and was characterized with respect to growth temperature, bile salt resistance, hydrogen sulfide reducing...
The yeast strain SJP-SNU was investigated as a probiotic and was characterized with respect to growth temperature, bile salt resistance, hydrogen sulfide reducing activity, intestinal survival ability and chicken embryo pathogenicity. In addition, we determined the complete genomic and mitochondrial sequences of SJP-SNU and conducted comparative genomics analyses. SJP-SNU grew rapidly at 37 °C and formed colonies on MacConkey agar containing bile salt. SJP-SNU reduced hydrogen sulfide produced by Salmonella serotype Enteritidis and, after being fed to 4-week-old chickens, could be isolated from cecal feces. SJP-SNU did not cause mortality in 10-day-old chicken embryos. From 13 initial contigs, 11 were finally assembled and represented 10 chromosomal sequences and 1 mitochondrial DNA sequence. Comparative genomic analyses revealed that SJP-SNU was a strain of Pichia kudriavzevii. Although SJP-SNU possesses pathogenicity-related genes, they showed very low amino acid sequence identities to those of Candida albicans. Furthermore, SJP-SNU possessed useful genes, such as phytases and cellulase. Thus, SJP-SNU is a useful yeast possessing the basic traits of a probiotic, and further studies to demonstrate its efficacy as a probiotic in the future may be warranted.
PubMed: 29774473
DOI: 10.1186/s13568-018-0609-0 -
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 -
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