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Archives of Microbiology Mar 2024The present study focuses on investigating 60 strains of yeast isolated from the natural fermentation broth of Vitis labruscana Baily × Vitis vinifera L. These...
Recovery and characterization of β-glucosidase-producing non-Saccharomyces yeasts from the fermentation broth of Vitis labruscana Baily × Vitis vinifera L. for investigation of their fermentation characteristics.
The present study focuses on investigating 60 strains of yeast isolated from the natural fermentation broth of Vitis labruscana Baily × Vitis vinifera L. These strains underwent screening using lysine culture medium and esculin culture medium, resulting in the identification of 27 local non-Saccharomyces yeast strains exhibiting high β-glucosidase production. Subsequent analysis of their fermentation characteristics led to the selection of four superior strains (Z-6, Z-11, Z-25, and Z-58) with excellent β-glucosidase production and fermentation performance. Notably, these selected strains displayed a dark coloration on esculin medium and exhibited robust gas production during Duchenne tubules' fermentation test. Furthermore, all four non-Saccharomyces yeast strains demonstrated normal growth under specific conditions including SO mass concentration ranging from 0.1 to 0.3 g/L, temperature between 25 and 30 °C, glucose mass concentration ranging from 200 to 400 g/L, and ethanol concentration at approximately 4%. Molecular biology identification confirmed that all selected strains belonged to Pichia kudriavzevii species which holds great potential for wine production.
Topics: Vitis; Saccharomyces cerevisiae; Fermentation; beta-Glucosidase; Esculin; Yeasts; Wine; Pichia
PubMed: 38493436
DOI: 10.1007/s00203-024-03878-9 -
Journal of Bioscience and Bioengineering Jun 2024The aim of this study was to evaluate the physiology of 13 yeast strains by assessing their kinetic parameters under anaerobic conditions. They included Saccharomyces...
The aim of this study was to evaluate the physiology of 13 yeast strains by assessing their kinetic parameters under anaerobic conditions. They included Saccharomyces cerevisiae CAT-1 and 12 isolated yeasts from different regions in Brazil. The study aimed to enhance understanding of the metabolism of these strains for more effective applications. Measurements included quantification of sugars, ethanol, glycerol, and organic acids. Various kinetic parameters were analyzed, such as specific substrate utilization rate (q), maximum specific growth rate (μ), doubling time, biomass yield, product yield, maximum cell concentration, ethanol productivity (P), biomass productivity, and CO concentration. S. cerevisiae CAT-1 exhibited the highest values in glucose for μ (0.35 h), q (3.06 h), and P (0.69 gEth L h). Candida parapsilosis Recol 37 did not fully consume the substrate. In fructose, S. cerevisiae CAT-1 stood out with higher values for μ (0.25 h), q (2.24 h), and P (0.60 gEth L h). Meyerozyma guilliermondii Recol 09 and C. parapsilosis Recol 37 had prolonged fermentation times and residual substrate. In sucrose, only S. cerevisiae CAT-1, S. cerevisiae BB9, and Pichia kudriavzevii Recol 39 consumed all the substrate, displaying higher P (0.72, 0.51, and 0.44 gEth L h, respectively) compared to other carbon sources.
Topics: Fructose; Glucose; Sucrose; Fermentation; Anaerobiosis; Saccharomyces cerevisiae; Carbon; Biomass; Ethanol; Yeasts; Kinetics; Glycerol; Brazil
PubMed: 38493064
DOI: 10.1016/j.jbiosc.2024.02.003 -
European Journal of Clinical... May 2024This study investigates how surfactants affect the in-vitro anti-infective efficacy of micafungin, caspofungin, anidulafungin, and amphotericin B in treating pulmonary...
PURPOSE
This study investigates how surfactants affect the in-vitro anti-infective efficacy of micafungin, caspofungin, anidulafungin, and amphotericin B in treating pulmonary mycoses.
METHODS
MIC values for antifungal agents were determined against Candida krusei (now Pichia kudriavzevii) ATCC 6258, Candida albicans ATCC 90028, and 18 clinical isolates using the broth microdilution method in RPMI medium, following EUCAST recommendations. MIC assays included testing with and without Curosurf® surfactant at 1 mg/mL for C. krusei ATCC 6258 and all C. krusei isolates. Subsequent Time-kill studies in Sabouraud broth involved testing both C. albicans ATCC 90028 and C. krusei ATCC 6258 strains at concentrations equal their respective MIC values, with and without surfactant, using all four antifungals. CFU/mL were assessed at multiple time points up to 24 h. TKCs with different surfactant concentrations for C. krusei ATCC 6258 and mini-TKCs at various concentrations relative to the MIC of C. krusei isolates and the reference strain were conducted with micafungin, anidulafungin, and caspofungin.
RESULTS
MIC results showed that 1 µg/mL surfactant reduced killing of micafungin and anidulafungin against C. krusei, while caspofungin was unaffected. Amphotericin B's MIC decreased by half. TKCs demonstrated significant effects of surfactant on micafungin and anidulafungin against C. krusei, with complete abolition of anidulafungin's activity against C. albicans.
CONCLUSION
This in-vitro study highlights the concentration-dependent inhibitory effect of surfactant on antifungal activity against C. krusei and, to some extent, C. albicans, necessitating further clinical validation for invasive lung mycoses treatment.
Topics: Antifungal Agents; Microbial Sensitivity Tests; Humans; Pulmonary Surfactants; Candida albicans; Candida; Micafungin; Candidiasis; Amphotericin B; Echinocandins; Caspofungin
PubMed: 38483681
DOI: 10.1007/s10096-024-04799-7 -
Microbiology Spectrum Apr 2024Azole drugs are the main therapeutic drugs for invasive fungal infections. However, azole-resistant strains appear repeatedly in the environment, posing a major threat...
Azole drugs are the main therapeutic drugs for invasive fungal infections. However, azole-resistant strains appear repeatedly in the environment, posing a major threat to human health. Several reports have shown that mitochondria are associated with the virulence of pathogenic fungi. However, there are few studies on the mechanisms of mitochondria-mediated azoles resistance. Here, we first performed mitochondrial proteomic analysis on multiple species (, , and ) and analyzed the differentially expressed mitochondrial proteins (DEMPs) between azole-sensitive and azole-resistant species. Subsequently, we performed Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, gene ontology analysis, and protein-protein interaction network analysis of DEMPs. Our results showed that a total of 417, 165, and 25 DEMPs were identified in resistant , and , respectively. These DEMPs were enriched in ribosomal biogenesis at cytosol and mitochondria, tricarboxylic acid cycle, glycolysis, transporters, ergosterol, and cell wall mannan biosynthesis. The high activations of these cellular activities, found in and (at low scale), were mostly opposite to those observed in two fermenter species- and . Several transcription factors including Rtg3 were highly produced in resistant that experienced a complex I activation of mitochondrial electron transport chain (ETC). The reduction of mitochondrial-related activities and complex IV/V of ETC in and was companying with the reduced proteins of Tor1, Hog1, and Snf1/Snf4.IMPORTANCE spp. are common organisms that cause a variety of invasive diseases. However, spp. are resistant to azoles, which hinders antifungal therapy. Exploring the drug-resistance mechanism of pathogenic spp. will help improve the prevention and control strategy and discover new targets. Mitochondria, as an important organelle in eukaryotic cells, are closely related to a variety of cellular activities. However, the role of mitochondrial proteins in mediating azole resistance in spp. has not been elucidated. Here, we analyzed the mitochondrial proteins and signaling pathways that mediate azole resistance in spp. to provide ideas and references for solving the problem of azole resistance. Our work may offer new insights into the connection between mitochondria and azoles resistance in pathogenic fungi and highlight the potential clinical value of mitochondrial proteins in the treatment of invasive fungal infections.
Topics: Humans; Candida; Azoles; Antifungal Agents; Proteomics; Drug Resistance, Fungal; Candida albicans; Signal Transduction; Mitochondria; Invasive Fungal Infections; Mitochondrial Proteins; Microbial Sensitivity Tests
PubMed: 38442003
DOI: 10.1128/spectrum.04042-23 -
Journal of Agricultural and Food... Mar 2024Geraniol is an attractive natural monoterpene with significant industrial and commercial value in the fields of pharmaceuticals, condiments, cosmetics, and bioenergy....
Geraniol is an attractive natural monoterpene with significant industrial and commercial value in the fields of pharmaceuticals, condiments, cosmetics, and bioenergy. The biosynthesis of monoterpenes suffers from the availability of key intermediates and enzyme-to-substrate accessibility. Here, we addressed these challenges in by a plasma membrane-anchoring strategy and achieved sustainable biosynthesis of geraniol using bagasse hydrolysate as substrate. On this basis, a remarkable 2.4-fold improvement in geraniol titer was achieved by combining spatial and temporal modulation strategies. In addition, enhanced geraniol transport and modulation of membrane lipid-associated metabolism effectively promoted the exocytosis of toxic monoterpenes, significantly improved the resistance of the engineered strain to monoterpenes and improved the growth of the strains, resulting in geraniol yield up to 1207.4 mg L at shake flask level. Finally, 1835.2 mg L geraniol was obtained in a 5 L bioreactor using undetoxified bagasse hydrolysate. Overall, our study has provided valuable insights into the plasma membrane engineering of for the sustainable and green production of valuable compounds.
Topics: Acyclic Monoterpenes; Metabolic Engineering; Monoterpenes; Pichia
PubMed: 38408332
DOI: 10.1021/acs.jafc.3c09651 -
Current Medical Mycology Jun 2023The increasing rate of opportunistic infections caused by and other yeasts is becoming a major health concern worldwide. However, systematic data on the epidemiology...
BACKGROUND AND PURPOSE
The increasing rate of opportunistic infections caused by and other yeasts is becoming a major health concern worldwide. However, systematic data on the epidemiology and the yeast species infections in Malaysia is still limited. In this regard, the present research aimed to identify pathogenic yeasts utilizing an economically practical and easily available molecular technique and evaluate the prevalence of pathogenic yeasts in a Malaysian tertiary care hospital.
MATERIALS AND METHODS
Yeast isolates were collected from Sultan Abdul Halim Hospital, Kedah, Malaysia, from October 2020 to October 2021. Molecular identification of the isolates was performed by one enzyme-based polymerase chain reaction-restriction fragment length polymorphism method.
RESULTS
was the most prevalent species, accounting for 120 isolates (59%) in total. The most prevalent non- species were (n=33, 16%), (Pichia kudriavzevii) (n=12, 5.8%), (n=12, 5.8%), and (n=6, 3%). Other unusual species were (2), (2), (1), (1), (1), (1), (1), and (1). Moreover, (1), (1), (3), and (1) were among the other yeasts identified.
CONCLUSION
The Molecular technique used in this study identified 96% of isolates, including mixed species. According to the findings, the most prevalent species are , , , and .
PubMed: 38375519
DOI: 10.18502/cmm.2023.345062.1432 -
ACS Synthetic Biology Mar 2024is an industrial yeast with excellent multistress resistance. However, due to the diploid genome and the lack of meiosis and screening markers, its molecular genetic...
is an industrial yeast with excellent multistress resistance. However, due to the diploid genome and the lack of meiosis and screening markers, its molecular genetic operation is limited. Here, a gene editing system using the toxin-antitoxin pair from the type II toxin-antitoxin system in as a screening marker was constructed. The RelBE complex can specifically and effectively regulate cell growth and arrest through a conditionally controlled toxin RelE switch, thereby achieving the selection of positive recombinants. The constructed editing system achieved precise gene deletion, replacement, insertion, and gene episomal expression in . Compared with the traditional amino acid deficiency complementation editing system, this editing system produced higher biomass and the gene deletion efficiency was increased by 3.5 times. Using this system, the production of 2-phenylethanol by was increased by 11.5-13.5% through metabolic engineering and tolerance engineering strategies. These results suggest that the stable gene editing system based on toxin-antitoxin pairs can be used for gene editing of to modify metabolic pathways and promote industrial applications. Therefore, the constructed gene editing system is expected to provide a promising strategy for polyploid industrial microorganisms lacking gene manipulation methods.
Topics: Gene Editing; Antitoxins; Bacterial Toxins; Phenylethyl Alcohol; Escherichia coli; Pichia
PubMed: 38365187
DOI: 10.1021/acssynbio.3c00640 -
Wiadomosci Lekarskie (Warsaw, Poland :... 2023The aim: To investigate the epidemiology and microbiology of vulvovaginal candidiasis (VVC) after gynecological surgeries, and adverse pregnancy outcomes in Ukraine.
OBJECTIVE
The aim: To investigate the epidemiology and microbiology of vulvovaginal candidiasis (VVC) after gynecological surgeries, and adverse pregnancy outcomes in Ukraine.
PATIENTS AND METHODS
Materials and methods: Multicenter prospective cohort study was conducted from January 2020 to December 2022 and recruited pregnant and non-pregnant women aged 15-65 years who had sought medical help for vaginal dysbiosis the seven medical clinic from five regions of Ukraine.
RESULTS
Results: Between 2020 and 2022, 2,341 women were followed in gynecological practices, and 1,056 (41.5%) women were diagnosed with VVC during the same period. Of the total VVC cases, 31.9% were in non-pregnant and 68.1% in pregnant women. The use of antibiotics (OR=3.48), use hormonal contracep¬tives (OR=2.75) and pregnancy (OR=1.13) were associated with an increase in the risk of VVC diagnosis. Diabetes mellitus (OR=0.44) were additional risk factors. The most common pathogen of VVC was C. albicans, Nakaseomyces glabratus (C. glabrata), followed by Pichia kudriavzevii (C. krusei), C. parapsilosis, C. tropicalis, C. kefyr, C. guillieromondii, C. lusitaniae, and C. rugosa. We found no significant difference in adverse pregnancy outcomes between Candida-positive and Candida-negative women.
CONCLUSION
Conclusions: Vulvovaginal candidiasis after gynecological surgeries in Ukraine is a common medical problem in women that is associated with significant morbidity, and hence frequent medical visits. High prevalence rate of vulvovaginal candidiasis in the present study warrants, the importance of conducting continuous epidemiological surveys to measure changes in species distribution from C. albicans to non-albicans Candida species in Ukraine.
Topics: Female; Humans; Pregnancy; Candida; Candida albicans; Candidiasis, Vulvovaginal; Gynecologic Surgical Procedures; Pregnancy Outcome; Prospective Studies; Ukraine; Adolescent; Young Adult; Adult; Middle Aged; Aged
PubMed: 38290017
DOI: 10.36740/WLek202312102 -
Medical Mycology Jan 2024Candida krusei also known as Pichia kudriavzevii is a potentially multidrug-resistant yeast because it is intrinsically resistant to fluconazole and develops acquired...
Candida krusei also known as Pichia kudriavzevii is a potentially multidrug-resistant yeast because it is intrinsically resistant to fluconazole and develops acquired resistance to echinocandins and polyenes. Here, we aim to provide a better understanding of the epidemiology and transmission modes of C. krusei infections by comparing invasive bloodstream (n = 35) and non-invasive vaginal (n = 20) C. krusei isolates. The genetic relatedness of the isolates was assessed using a newly described short tandem repeat (STR) analysis and their sensitivity to eight antifungal compounds was evaluated by antifungal susceptibility testing using the CLSI microbroth dilution method. All C. krusei isolates revealed unique STR genotypes, indicating the absence of clonal transmission in the study group. Furthermore, no drug-resistant or non-wild-type isolates were identified. Our findings demonstrated high resolution of STR genotyping for the detection and simultaneous genetic analysis of multiple C. krusei strains in clinical samples and excellent in vitro activity of common antifungal agents against invasive strains.
Topics: Female; Animals; Antifungal Agents; Turkey; Candida; Drug Resistance, Fungal; Molecular Typing; Microbial Sensitivity Tests; Pichia
PubMed: 38289726
DOI: 10.1093/mmy/myae005 -
Food Science & Nutrition Jan 2024Iron deficiency anemia is highly prevalent in developing countries due to the consumption of cereal-based foods rich in phytate that chelates minerals such as iron and...
Iron deficiency anemia is highly prevalent in developing countries due to the consumption of cereal-based foods rich in phytate that chelates minerals such as iron and zinc making them unavailable for absorption by humans. The aim of the present study was to degrade phytic acid in composite flour (wheat/cassava/sorghum) bread by the addition of phytase-producing yeasts in the baking process to achieve a phytate-to-iron molar ratio <1 and a phytate-to-zinc molar ratio <15, ratios needed to achieve an enhanced absorption by humans. The high-phytase (HP)-producing yeasts were two (YD80 and BY80) that have been genetically modified by a directed mutagenesis strategy, and TY13 isolated from a Tanzanian lactic fermented maize gruel () and selected as naturally HP yeast. To further improve the phytase production by the yeasts, four different brands of phytase-promoting yeast extracts were added in the baking process. In addition, two yeast varieties were preincubated for 1 h at 30°C to initiate phytase biosynthesis. The phytate content was measured by high-performance ion chromatography (HPIC) and the mineral content by ion chromatography (HPIC). The results showed that all three HP yeasts improved the phytate degradation compared with the composite bread with no added HP yeast. The composite bread with preincubated BY80 or TY13 plus Bacto yeast extract resulted in the lowest phytate content (0.08 μmol/g), which means a 99% reduction compared with the phytate content in the composite flour. With added yeast extracts from three of the four yeast extract brands in the baking process, all composite breads had a phytate reduction after 2-h fermentation corresponding to a phytate: iron molar ratio between 1.0 and 0.3 and a phytate: zinc molar ratio <3 suggesting a much-enhanced bioavailability of these minerals.
PubMed: 38268898
DOI: 10.1002/fsn3.3754