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International Journal of Molecular... Jan 2022The objective of the current study was to examine the effects of yeasts on intestinal health and transcriptomic profiles from the distal intestine and spleen tissue of...
The objective of the current study was to examine the effects of yeasts on intestinal health and transcriptomic profiles from the distal intestine and spleen tissue of Atlantic salmon fed SBM-based diets in seawater. (CJ) and (WA) yeasts were heat-inactivated with spray-drying (ICJ and IWA) or autolyzed at 50 °C for 16 h (ACJ and AWA), followed by spray-drying. Six diets were formulated, one based on fishmeal (FM), a challenging diet with 30% soybean meal (SBM) and four other diets containing 30% SBM and 10% of each of the four yeast fractions (i.e., ICJ, ACJ, IWA and AWA). The inclusion of CJ yeasts reduced the loss of enterocyte supranuclear vacuolization and reduced the population of CD8α labeled cells present in the lamina propria of fish fed the SBM diet. The CJ yeasts controlled the inflammatory responses of fish fed SBM through up-regulation of pathways related to wound healing and taurine metabolism. The WA yeasts dampened the inflammatory profile of fish fed SBM through down-regulation of pathways related to toll-like receptor signaling, C-lectin receptor, cytokine receptor and signal transduction. This study suggests that the yeast species, and are novel high-quality protein sources with health-beneficial effects in terms of reducing inflammation associated with feeding plant-based diets to Atlantic salmon.
Topics: Animal Feed; Animals; Candida; Intestines; Saccharomycetales; Salmo salar; Glycine max; Transcriptome
PubMed: 35163597
DOI: 10.3390/ijms23031675 -
Applied Bionics and Biomechanics 2022Detection of food spoilage with simple and fast methods is an important issue in food security and safety. The present study is mainly aimed at identifying and...
Detection of food spoilage with simple and fast methods is an important issue in food security and safety. The present study is mainly aimed at identifying and quantifying four yeast species in white fresh soft cheese using an electronic nose (EN). The yeast species , , , and were used. Six concentrations of each yeast species (100, 200, 400, 600, 800, and 1000 cells/g cheese) were inoculated in 100 g of fresh soft cheese and incubated for 48 h at 25°C. The EN was used to identify and quantify different yeast species in cheese samples. It was found that EN was able to discriminate between four yeast species using principal component analysis (PCA). Moreover, EN was able to quantify in good precision three (, , and ) of the four tested yeasts presented in cheese samples using partial least squares (PLS) models. It seems that EN is a reliable tool that can be used as a fast technique to identify and quantify cheese spoilage in the cheese industry.
PubMed: 35082918
DOI: 10.1155/2022/8472661 -
AMB Express Dec 2021In total, 16 yeast were isolated from Chinese strong flavour Daqu samples and underwent RAPD analysis and identification. Totally, 11 different species were identified...
In total, 16 yeast were isolated from Chinese strong flavour Daqu samples and underwent RAPD analysis and identification. Totally, 11 different species were identified among these isolates including Saccharomyces cerevisiae, Hanseniaspora vineae, Pichia kluyveri, Trichosporon asahii, Wickerhamomyces anomalus, Kluyveromyces lactis, Yarrowia lipolytica, Wickerhamomyces mori, Galactomyces geotrichum, Dabaryomyces hansenii, and Saccharomyces kudriavzevii. To understand the impact of these yeast strains on the quality and flavour of Daqu, we then assessed volatile compounds associated with Daqu samples fermented with corresponding strains. These analyses revealed strain YE006 exhibited the most robust ability to produce ethanol via fermentation but yielded relatively low quantities of volatile compounds, whereas strain YE010 exhibited relatively poor fermentation efficiency but produced the greatest quantity of volatile compounds. These two yeast strains were then utilized in a mixed culture to produce fortified Daqu, with the optimal inoculum size being assessed experimentally. These analyses revealed that maximal fermentation, saccharifying, liquefying, and esterifying power as well as high levels of volatile compounds were achieved when using a 2% inoculum composed of YE006/YE010 at a 1:2 (v/v) ratio. When the liquor prepared using this optimized fortified Daqu was compared to unfortified control Daqu, the former was found to exhibit significantly higher levels of flavour compounds and better sensory scores. Overall, our findings may provide a reliable approach to ensuring Daqu quality and improving the consistency and flavour of Chinese strong-flavour liquor through bioaugmentation.
PubMed: 34952959
DOI: 10.1186/s13568-021-01337-y -
Computational and Structural... 2021Biological control utilizing antagonistic yeasts is an effective method for controlling postharvest diseases. Long non-coding RNAs (lncRNAs) have been found to be...
Biological control utilizing antagonistic yeasts is an effective method for controlling postharvest diseases. Long non-coding RNAs (lncRNAs) have been found to be involved in a variety of plant growth and development processes, including those associated with plant disease resistance. In the present study, the yeast antagonist, , was found to strongly inhibit postharvest blue mold () and gray mold () decay of kiwifruit. Additionally, lncRNA high-throughput sequencing and bioinformatic analysis was used to identify lncRNAs in -treated wounds in kiwifruit and predict their function based on putative target genes. Our results indicate that lncRNAs may be involved in increasing ethylene (ET), jasmonic acid (JA), abscisic acid (ABA), and auxin (IAA) levels, as well as activating signal transduction pathways that regulate the expression of several transcription factors (, , ). These transcription factors (TFs) then mediate the expression of downstream, defense-related genes (, , ) and the synthesis of secondary metabolites, thus, potentially enhancing disease resistance. Notably, by stimulating the accumulation of antifungal compounds, such as phenols and lignin, disease resistance in kiwifruit was enhanced. Our study provides new information on the mechanism underlying the induction of disease resistance in kiwifruit by , as well as a new disease resistance strategy that can be used to enhance the defense response of fruit to pathogenic fungi.
PubMed: 34849193
DOI: 10.1016/j.csbj.2021.09.037 -
Frontiers in Microbiology 2021is an emerging pathogen, which has been associated with clonal outbreaks and poor clinical outcomes. Despite being an important emerging yeasts species, our...
Investigation of the Emerging Nosocomial Infections at a Chinese Tertiary Teaching Hospital and a Systemic Review: Clinical Manifestations, Risk Factors, Treatment, Outcomes, and Anti-fungal Susceptibility.
is an emerging pathogen, which has been associated with clonal outbreaks and poor clinical outcomes. Despite being an important emerging yeasts species, our understanding concerning the microbiological and clinical characteristics of infections due to this species is limited. Herein, we are reporting a retrospective analysis of fungemia patients with from a 2,100-bed hospital in Shanghai during 2014-2016. Moreover, we conducted an extensive literature review to gain a deeper clinical and microbiological insights. Detailed clinical data were recorded. Antifungal susceptibility testing (AFST) followed CLSI M27-A3, and isolates were identified using MALDI-TOF MS. In total, 13 patients were identified with a mortality rate of 38.5% (5/13). Central venous catheter (CVC), broad-spectrum antibiotic therapy, total parenteral nutrition (TPN), surgery, and mechanical ventilation were the most frequently observed risk factors. Eight patients (61.5%) experienced mixed bacterial/Candida bloodstream infections, and four patients developed mixed candidemia (MC). isolates showed high minimum inhibitory concentrations (MICs) against all azoles tested and flucytosine, while AMB showed the highest activity. Azoles were used for 84.6% (11/13) of the cases, while 36.4% (4/11) of them died. When combining with the AFST data and the literature review, our study highlights the poor efficacy of azoles and optimal efficacy of AMB and LAMB against infections caused by . In conclusion, our study highlights the emerging threat of affecting both neonates and adults. Furthermore, our results advocate the use of AMB formulations rather than azoles among patients infected with . Future studies are warranted to reach a definitive consensus regarding the utility of echinocandins among such patients.
PubMed: 34690991
DOI: 10.3389/fmicb.2021.744502 -
Toxins Sep 2021strain F17.12 is a yeast with an antiplasmodial property based on the production of a killer toxin. For its symbiotic association with mosquitoes, it has been proposed...
strain F17.12 is a yeast with an antiplasmodial property based on the production of a killer toxin. For its symbiotic association with mosquitoes, it has been proposed for the control of malaria. In an applied view, we evaluated the yeast formulation by freeze-drying F17.12. The study was carried out by comparing yeast preparations stored at room temperature for different periods, demonstrating that lyophilization is a useful method to obtain a stable product in terms of cell growth reactivation and maintenance of the killer toxin antimicrobial activity. Moreover, cytotoxic assays on human cells were performed, showing no effects on the cell viability and the proinflammatory response. The post-formulation effectiveness of the killer toxin and the safety tests indicate that F17.12 is a promising bioreagent able to impair the malaria parasite in vector mosquitoes.
Topics: Biological Control Agents; Cell Survival; Freeze Drying; HaCaT Cells; Humans; Microbial Viability; Saccharomycetales; Toxins, Biological
PubMed: 34678969
DOI: 10.3390/toxins13100676 -
Mikrobiyoloji Bulteni Oct 2021Fungal peritonitis is less commonly seen than bacterial peritonitis in patients undergoing peritoneal dialysis (PD), but it is a serious complication with high morbidity...
Fungal peritonitis is less commonly seen than bacterial peritonitis in patients undergoing peritoneal dialysis (PD), but it is a serious complication with high morbidity and mortality. It often results in catheter loss and modifying therapy from PD to hemodialysis. The causative organisms are often Candida species. In this report, a PD-associated peritonitis caused by Wickerhamomyces anomalus (Candida pelliculosa), a rare fungal infection agent with increasing clinical importance by causing different clinical pictures was presented. An outpatient peritoneal fluid culture was sent from a 48-yearold male patient, who had been undergoing continuous peritoneal dialysis (CAPD) for 9 years, due to abdominal pain and blur in peritoneal fluid during dialysis. The patient admitted to the emergency department four days later due to the persistence of his complaints. A sample of peritoneal fluid was taken in the emergency department and sent to the laboratory for microbiological analysis. In the direct microscopical examination of the peritoneal fluid; cell number was determined as 210/mm3, and no microorganisms were seen in the Gram and methylene blue staining. The patient was admitted to the nephrology service with a pre-diagnosis of PD-associated peritonitis. Enterobacter aerogenes was grown in the peritoneal fluid culture which was sent from the dialysis outpatient clinic four days ago. The peritoneal fluid sample sent from the emergency department was inoculated on 5% sheep blood , EMB and chocolate agars and no growth was detected. As the patient's complaints and peritoneal fluid leukocyte count continued to increase, peritoneal fluid cultures were repeated and recurrent growth of yeast was detected in cultures. The yeast was identified as Candida pelliculosa by matrix assisted laser desorption ionization time-of-flight mass spectrofotometry (MALDI-TOF) VITEK®MS (bioMerieux, France). The species identification was confirmed by sequencing the target ITS gene regions on the rRNA and the isolate was identified as 100% Wickerhamomyces anomalus (sexual reproduction form of Candida pelliculosa, teleomorph). The reference microdilution method was performed according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI) in order to test the antifungal susceptibility. After 24 hour incubation, the minimal inhibitory concentrations (MIC) were determined as 0.03 μg/ml for amphotericin B, 0.125 μg/ml for caspofungin 0.125 μg/ml for voriconazole, 0.03 μg/ ml for itraconazole and 4 μg/ml for fluconazole. Fluconazole and anidulafungin were started for the treatment of fungal peritonitis. The patient's peritoneal dialysis catheter was removed and hemodialysis was applied to the patient. Clinical and laboratory symptoms regressed with antifungal therapy and the patient's anidulafungin treatment was discontinued for 14 days after the catheter removal. In conclusion, in patients undergoing CAPD, as in our case, fungal pathogens should also be considered although it is rare, when there is no laboratory and clinical improvement, and the response to treatment is not complete in PD-associated peritonitis to prevent delays in diagnosis and treatment.
Topics: Animals; Antifungal Agents; Candida; Humans; Male; Peritoneal Dialysis; Peritonitis; Saccharomycetales; Sheep
PubMed: 34666666
DOI: 10.5578/mb.20219718 -
Frontiers in Microbiology 2021Cacao plantations from South America have been afflicted with the severe fungal disease known as (WBD), caused by the basidiomycete . Yeasts are increasingly recognized...
Cacao plantations from South America have been afflicted with the severe fungal disease known as (WBD), caused by the basidiomycete . Yeasts are increasingly recognized as good fungal biocides, although their application is still mostly restricted to the postharvest control of plant and fruit decay. Their possible utilization in the field, in a preharvest phase, is nevertheless promising, particularly if the strains are locally adapted and evolved and if they belong to species considered safe for man and the environment. In this work, a group of yeast strains originating from sugarcane-based fermentative processes in Brazil, the cacao-producing country where the disease is most severe, were tested for their ability to antagonize . LBCM1105 and strains LBCM1112 from spontaneous fermentations used to produce , and PE2 widely used in Brazil in the industrial production of bioethanol, efficiently antagonized six strains of , originating from several South American countries. The two fastest growing fungal strains, both originating from Brazil, were further used to assess the mechanisms underlying the yeasts' antagonism. Yeasts were able to inhibit fungal growth and kill the fungus at three different temperatures, under starvation, at different culture stages, or using an inoculum from old yeast cultures. Moreover, SEM analysis revealed that and PE2 cluster and adhere to the hyphae, push their surface, and fuse to them, ultimately draining the cells. This behavior concurs with that classified as necrotrophic parasitism/mycoparasitism. In particular, within the adhered clusters appear to be ligated to each other through roundish groups of fimbriae-like structures filled with bundles of microtubule-sized formations, which appear to close after cells detach, leaving a scar. SEM also revealed the formation of tube-like structures apparently connecting yeast to hypha. This evidence suggests cells form a network of yeast cells connecting with each other and with hyphae, supporting a possible cooperative collective killing and feeding strategy. The present results provide an initial step toward the formulation of a new eco-friendly and effective alternative for controlling cacao WBD using live yeast biocides.
PubMed: 34630345
DOI: 10.3389/fmicb.2021.706675 -
Biotechnology For Biofuels Oct 2021Ethyl acetate (CHO) and hydrogen (H) are industrially relevant compounds that preferably are produced via sustainable, non-petrochemical production processes. Both...
BACKGROUND
Ethyl acetate (CHO) and hydrogen (H) are industrially relevant compounds that preferably are produced via sustainable, non-petrochemical production processes. Both compounds are volatile and can be produced by Escherichia coli before. However, relatively low yields for hydrogen are obtained and a mix of by-products renders the sole production of hydrogen by micro-organisms unfeasible. High yields for ethyl acetate have been achieved, but accumulation of formate remained an undesired but inevitable obstacle. Coupling ethyl acetate production to the conversion of formate into H may offer an interesting solution to both drawbacks. Ethyl acetate production requires equimolar amounts of ethanol and acetyl-CoA, which enables a redox neutral fermentation, without the need for production of by-products, other than hydrogen and CO.
RESULTS
We engineered Escherichia coli towards improved conversion of formate into H and CO by inactivating the formate hydrogen lyase repressor (hycA), both uptake hydrogenases (hyaAB, hybBC) and/or overexpressing the hydrogen formate lyase activator (fhlA), in an acetate kinase (ackA) and lactate dehydrogenase (ldhA)-deficient background strain. Initially 10 strains, with increasing number of modifications were evaluated in anaerobic serum bottles with respect to growth. Four reference strains ΔldhAΔackA, ΔldhAΔackA p3-fhlA, ΔldhAΔackAΔhycAΔhyaABΔhybBC and ΔldhAΔackAΔhycAΔhyaABΔhybBC p3-fhlA were further equipped with a plasmid carrying the heterologous ethanol acyltransferase (Eat1) from Wickerhamomyces anomalus and analyzed with respect to their ethyl acetate and hydrogen co-production capacity. Anaerobic co-production of hydrogen and ethyl acetate via Eat1 was achieved in 1.5-L pH-controlled bioreactors. The cultivation was performed at 30 °C in modified M9 medium with glucose as the sole carbon source. Anaerobic conditions and gas stripping were established by supplying N gas.
CONCLUSIONS
We showed that the engineered strains co-produced ethyl acetate and hydrogen to yields exceeding 70% of the pathway maximum for ethyl acetate and hydrogen, and propose in situ product removal via gas stripping as efficient technique to isolate the products of interest.
PubMed: 34598726
DOI: 10.1186/s13068-021-02036-3 -
Scientific Reports Sep 2021Symbiotic fungi of wood-inhabiting insects are often considered to aid wood digestion of host insects when the associated fungi can assimilate wood-associated...
Symbiotic fungi of wood-inhabiting insects are often considered to aid wood digestion of host insects when the associated fungi can assimilate wood-associated indigestible materials. In most cases, however, the components of wood that are utilized by fungal symbionts remain poorly understood. The lizard beetle Doubledaya bucculenta (Coleoptera, Erotylidae, Languriinae) farms the symbiotic yeast Wickerhamomyces anomalus inside the cavity of host bamboo internodes, which serves as food for larvae. To determine the carbon sources of the internodes serving as nutritional substrates for W. anomalus, we used ion exchange chromatography measurements to analyze free and structural sugar compositions in fresh pith (FP), yeast-cultured pith (YP), and larva-reared pith (LP) of internodes. Glucose and fructose were the major free sugars in FP and markedly decreased in YP and LP. For structural sugars, no sugar significantly decreased in YP or LP compared with FP. Carbon assimilation tests showed that W. anomalus assimilated glucose, mannose, fructose, and sucrose strongly, xylose and cellobiose moderately, and xylan weakly. Elemental analysis revealed that the compositions of carbon, hydrogen, and nitrogen were not significantly different among tissue types. These results suggest that W. anomalus does not consume bamboo-associated indigestible sugars but most free sugars, mainly glucose and fructose, in the pith. Our findings suggest that a symbiont's abilities may not always benefit its host in nature.
Topics: Animals; Carbon; Coleoptera; Female; Larva; Oviposition; Saccharomycetales; Sasa; Symbiosis
PubMed: 34584161
DOI: 10.1038/s41598-021-98733-y