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Brazilian Journal of Microbiology :... Jun 2023For 2G ethanol production, pentose fermentation and yeast tolerance to lignocellulosic hydrolyzate components are essential to improve biorefinery yields. Generally,...
Xylose consumption and ethanol production by Pichia guilliermondii and Candida oleophila in the presence of furans, phenolic compounds, and organic acids commonly produced during the pre-treatment of plant biomass.
For 2G ethanol production, pentose fermentation and yeast tolerance to lignocellulosic hydrolyzate components are essential to improve biorefinery yields. Generally, physicochemical pre-treatment methodologies are used to facilitate access to cellulose and hemicellulose in plant material, which consequently can generate microbial growth inhibitory compounds, such as furans, weak acids, and phenolic compounds. Because of the unsatisfactory yield of wild-type Saccharomyces cerevisiae during pentose fermentation, the search for xylose-fermenting yeasts tolerant to microbial growth inhibitors has gained attention. In this study, we investigated the ability of the yeasts Pichia guilliermondii G1.2 and Candida oleophila G10.1 to produce ethanol from xylose and tolerate the inhibitors furfural, 5-hydroxymethylfurfural (HMF), acetic acid, formic acid, ferulic acid, and vanillin. We demonstrated that both yeasts were able to grow and consume xylose in the presence of all single inhibitors, with greater growth limitation in media containing furfural, acetic acid, and vanillin. In saline medium containing a mixture of these inhibitors (2.5-3.5 mM furfural and HMF, 1 mM ferulic acid, 1-1.5 mM vanillin, 10-13 mM acetic acid, and 5-7 mM formic acid), both yeasts were able to produce ethanol from xylose, similar to that detected in the control medium (without inhibitors). In future studies, the proteins involved in the transport of pentose and tolerance to these inhibitors need to be investigated.
Topics: Xylose; Furans; Ethanol; Pichia; Furaldehyde; Biomass; Saccharomyces cerevisiae; Pentoses; Fermentation; Phenols; Formates
PubMed: 36826705
DOI: 10.1007/s42770-023-00937-z -
BMC Veterinary Research Nov 2015Avian coccidiosis is a disease caused worldwide by several species of parasite Eimeria that causes significant economic losses. This disease affects chickens development...
BACKGROUND
Avian coccidiosis is a disease caused worldwide by several species of parasite Eimeria that causes significant economic losses. This disease affects chickens development and production, that most of times is controlled with anticoccidial drugs. Although efforts have been made to address this disease, they have been made to control Eimeria sporozoites, although enteric stages are often vulnerable, however; the parasite oocyst remains a problem that must be controlled, as it has a resistant structure that facilitates dispersion. Despite some commercial products based on chemical compounds have been developed as disinfectants that destroy oocysts, the solution of the problem remains to be solved.
RESULTS
In this work, we assessed in vitro anticoccidial activity of a compound(s) secreted by yeast isolated in oocysts suspension from infected chickens. The yeast was molecularly identified as Meyerozyma guilliermondii, and its anticoccidial activity against Eimeria tenella oocysts was assessed. Here, we report the damage to oocysts walls caused by M. guilliermondii culture, supernatant, supernatant extract and intracellular proteins. In all cases, a significant decreased of oocysts was observed.
CONCLUSIONS
The yeast Meyerozyma guilliermondii secretes a compound with anticoccidial activity and also has a compound of protein nature that damages the resistant structure of oocyst, showing the potential of this yeast and its products as a feasible method of coccidiosis control.
Topics: Animals; Chickens; Coccidiosis; Coccidiostats; DNA, Fungal; DNA, Ribosomal Spacer; Eimeria; Oocysts; Phylogeny; Polymerase Chain Reaction; RNA, Fungal; RNA, Ribosomal, 18S; Yeasts
PubMed: 26552648
DOI: 10.1186/s12917-015-0589-0 -
Foods (Basel, Switzerland) Mar 2022The application of -glucosidase from non- yeasts to improve wine aroma has been widely explored. However, few enzymes are active under the severe conditions of wine...
The application of -glucosidase from non- yeasts to improve wine aroma has been widely explored. However, few enzymes are active under the severe conditions of wine aging (high ethanol concentration, low temperature, and low pH). Therefore, the application of -glucosidase in wine aging needs further research. In this study, the -glucosidases Mg-βgl and Hu-βgl extracted from NM218 and BF345 were purified and used in young Chardonnay wines aged for 50 days. The enzyme activity of the two enzymes was measured. The effects of the two enzymes and a commercial -glucosidase (An-βgl) on the volatile composition and sensory quality of the wine were also determined. The results showed that Mg-βgl and Hu-βgl had high specific activity of 1.95 U/mg and 2.11 U/mg, respectively, maintaining the activity of 70-80% at 20 °C, pH of 3.0-4.0, and 15% ethanol, corresponding to wine aging conditions. Analysis of volatiles with GC-MS showed a 65-70% increase in total terpenoids and new detection of C-norisoprenoids when the wines were treated with the three -glucosidases. In addition, wines treated with Mg-βgl and Hu-βgl had more hexanol, phenylethanol, ethyl octanoate, ethyl heptanoate, and ethyl caprate than wines treated without and with An-βgl. In sensory analysis, the judges showed a greater preference for Hu-βgl-treated wines, to which they attributed pleasant sweet, floral, honey, pomelo, and banana aromas. The results of this study not only offer a way to improve flavor complexity in wine but also provide a reference for the use of other edible sources of -glucosidase in wine aging.
PubMed: 35327274
DOI: 10.3390/foods11060852 -
Antimicrobial Agents and Chemotherapy Oct 2021Susceptibility testing is an important tool in the clinical setting; its utility is based on the availability of categorical endpoints, breakpoints (BPs), or...
Etest ECVs/ECOFFs for Detection of Resistance in Prevalent and Three Nonprevalent spp. to Triazoles and Amphotericin B and Aspergillus spp. to Caspofungin: Further Assessment of Modal Variability.
Susceptibility testing is an important tool in the clinical setting; its utility is based on the availability of categorical endpoints, breakpoints (BPs), or epidemiological cutoff values (ECVs/ECOFFs). CLSI and EUCAST have developed antifungal susceptibility testing, BPs, and ECVs for some fungal species. Although the concentration gradient strip bioMérieux Etest is useful for routine testing in the clinical laboratory, ECVs are not available for all agent/species; the lack of clinical data precludes development of BPs. We reevaluated and consolidated Etest data points from three previous studies and included new data. We defined ECOFFinder Etest ECVs for three sets of species-agent combinations: fluconazole, posaconazole, and voriconazole and 9 spp.; amphotericin B and 3 nonprevalent spp.; and caspofungin and 4 Aspergillus spp. The total of Etest MICs from 23 laboratories (Europe, the Americas, and South Africa) included (antifungal agent dependent): 17,242 Candida albicans, 244 C. dubliniensis, 5,129 C. glabrata species complex (SC), 275 C. guilliermondii (Meyerozyma guilliermondii), 1,133 C. krusei (), 933 C. kefyr (Kluyveromyces marxianus), 519 C. lusitaniae (Clavispora lusitaniae), 2,947 C. parapsilosis SC, 2,214 C. tropicalis, 3,212 Aspergillus fumigatus, 232 A. flavus, 181 A. niger, and 267 A. terreus SC isolates. Triazole MICs for 66 confirmed non-wild-type (non-WT) isolates were available ( point mutations). Distributions fulfilling CLSI ECV criteria were pooled, and ECOFFinder Etest ECVs were established for triazoles (9 spp.), amphotericin B (3 less-prevalent spp.), and caspofungin (4 Aspergillus spp.). Etest fluconazole ECVs could be good detectors of non-WT isolates (59/61 non-WT, 4 of 6 species).
Topics: Amphotericin B; Antifungal Agents; Aspergillus; Candida; Caspofungin; Disk Diffusion Antimicrobial Tests; Drug Resistance, Fungal; Kluyveromyces; Microbial Sensitivity Tests; Pichia; Saccharomycetales; Triazoles
PubMed: 34370582
DOI: 10.1128/AAC.01093-21 -
Pathogens (Basel, Switzerland) Apr 2021The study aimed to compare the yeast species diversity in the specific environment of dishwashers, taking into account the potential risk for users. Yeasts were isolated...
The study aimed to compare the yeast species diversity in the specific environment of dishwashers, taking into account the potential risk for users. Yeasts were isolated from ten dishwashers and from tap water supplied to the appliances. Samples were collected for mycological analyses at the beginning of each month, from February to May 2016. Four dishwasher sites (rubber seals, detergent dispensers, sprinklers, and water drains) were analyzed. The microfungi were identified by the standard procedures applied in mycological diagnostics. To confirm species identification, molecular analysis was performed based on the sequences of the D1/D2 region. The presence of microfungi was detected in 70% of the investigated appliances. Rubber seals, detergent dispensers, and water drains were the most frequently colonized elements. Thirty-five yeast strains were isolated in this study, of which twenty-seven were obtained from dishwashers and eight from tap water. The strains belonged to six genera and six species (, and ). Most of the strains came from rubber seals. In this way, it was demonstrated that the dishwashers' condition is sufficient as an ecological niche for microfungi.
PubMed: 33917934
DOI: 10.3390/pathogens10040446 -
Beilstein Journal of Organic Chemistry 2015Three new depsidones, botryorhodines E-G (1-3), and two new isoindolinones, meyeroguillines A and B (7 and 9), along with five known compounds were isolated from an...
Three new depsidones, botryorhodines E-G (1-3), and two new isoindolinones, meyeroguillines A and B (7 and 9), along with five known compounds were isolated from an endophytic fungus Meyerozyma guilliermondii, derived from the mangrove plant Kandelia obovata. Their structures were elucidated by 1D and 2D NMR spectroscopy and high resolution mass spectrometry (HREIMS). Compounds 1-6 exhibited strong α-glucosidase inhibitory activity with IC50 values ranging from 2.1 to 13.3 μM. Moreover, kinetic studies of compounds 2 and 6 showed that both of them were noncompetitive inhibitors of α-glucosidase.
PubMed: 26425177
DOI: 10.3762/bjoc.11.133 -
Gut Microbes Nov 2020Alcohol abuse and alcoholic liver diseases (ALD) have been worldwide spread. Chronic alcoholism-induced overgrowth of intestinal bacteria and fungi together with the...
Alcohol abuse and alcoholic liver diseases (ALD) have been worldwide spread. Chronic alcoholism-induced overgrowth of intestinal bacteria and fungi together with the enteric dysbiosis are important pathogenic mechanisms in ALD. We demonstrated that the water-insoluble polysaccharides (WIP) from effectively ameliorated the hepatic inflammatory injury and fat accumulation through modulating gut microbiota in mice with alcoholic hepatic steatosis (AHS). Oral administration of WIP significantly enhanced the ratio of Firmictues to Proteobacteria, increased the abundance of Lachnospiraceae including Ruminoclostridum and unidentified_clostridials, and inhibited the ethanol-induced fungal overgrowth. Treatment with WIP activated the PPAR-γ signaling and reduced the inflammation in the colonic epithelia cell, facilitating a hypoxic state that suppresses the overgrowth of fungi and Proteobacteria in the gut. In addition, we found an overwhelming increase of the commensal fungus in the feces of mice with AHS by culturing and ITS sequencing. Inoculation of into fungi-free mice aggravated the features of AHS. was found to generate PGE by biotransformation of arachidonic acid. Furthermore, the gut fungi ()-induced PGE production in the liver was confirmed as one of the mechanisms in the chronic AHS. The current study supports the manipulation of the gut microbiota (bacteria and fungi) as an effective and alternative strategy for alleviating ALD.
Topics: Animals; Bacteria; Dinoprostone; Fungi; Gastrointestinal Microbiome; Humans; Liver; Liver Diseases, Alcoholic; Male; Mice; Mice, Inbred C57BL; Polysaccharides; Wolfiporia
PubMed: 33106075
DOI: 10.1080/19490976.2020.1830693 -
World Journal of Microbiology &... Mar 2024Probiotic microorganisms are used to improve the health and wellness of people and the research on this topic is of current relevance and interest. Fifty-five yeasts,...
Probiotic microorganisms are used to improve the health and wellness of people and the research on this topic is of current relevance and interest. Fifty-five yeasts, coming from honeybee's ecosystem and belonging to Candida, Debaryomyces, Hanseniaspora, Lachancea, Metschnikowia, Meyerozyma, Starmerella and Zygosacchromyces genera and related different species, were evaluated for the probiotic traits. The resistance to gastrointestinal conditions, auto-aggregation, cell surface hydrophobicity or biofilm formation abilities as well as antimicrobial activity against common human pathogenic bacteria were evaluated. The safety analysis of strains was also carried out to exclude any possible negative effect on the consumer's health. The influence of proteinase treatment of living yeasts and their adhesion to Caco-2 cells were also evaluated. The greatest selection occurred in the first step of survival at the acidic pH and in the presence of bile salts, where more than 50% of the strains were unable to survive. Equally discriminating was the protease test which allowed the survival of only 27 strains belonging to the species Hanseniaspora guilliermondii, Hanseniaspora uvarum, Metschnikowia pulcherrima, Metschnikowia ziziphicola, Meyerozyma caribbica, Meyerozyma guilliermondii, Pichia kluyveri, Pichia kudriavzevii and Pichia terricola. An integrated analysis of the results obtained allowed the detection of seven yeast strains with probiotic aptitudes, all belonging to the Meyerozyma genus, of which three belonging to M. guillermondii and four belonging to M. caribbica species.
Topics: Bees; Animals; Humans; Ecosystem; Caco-2 Cells; Yeasts; Candida; Probiotics
PubMed: 38538981
DOI: 10.1007/s11274-024-03941-z -
Revista Argentina de Microbiologia 2019
Topics: Agrobacterium tumefaciens; Biofilms; Endophytes; Microbial Interactions; Models, Biological; Saccharomycetales
PubMed: 30651186
DOI: 10.1016/j.ram.2018.09.006 -
Microorganisms Nov 2021Durum wheat production is seriously threatened by Fusarium head blight (FHB) attacks in Tunisia, and the seed coating by bio-agents is a great alternative for chemical...
Durum wheat production is seriously threatened by Fusarium head blight (FHB) attacks in Tunisia, and the seed coating by bio-agents is a great alternative for chemical disease control. This study focuses on evaluating, under field conditions, the effect of seed coating with , and their combination on (i) FHB severity, durum wheat grain yield and TKW in three crop seasons, and (ii) on physiological parameters and the carbon and nitrogen content and isotope composition in leaves and grains of durum wheat. The results indicated that the treatments were effective in reducing FHB severity by 30 to 70% and increasing grain yield with an increased rate ranging from 25 to 68%, compared to the inoculated control. The impact of treatments on grain yield improvement was associated with higher NDVI and chlorophyll content and lower canopy temperature. Furthermore, the treatments mitigated the FHB adverse effects on N and C metabolism by resulting in a higher δCgrain (C/Cgrain) and δNgrain (N/Ngrain). Overall, the combination outperformed the other seed treatments by producing the highest grain yield and TKW. The high potency of seed coating with the combination suggests that the two microorganisms have synergetic or complementary impacts on wheat.
PubMed: 34946012
DOI: 10.3390/microorganisms9122410