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International Journal of Molecular... Nov 2023(), a commonly found yeast-like fungus, exhibits adaptability to a wide range of pH environments. However, the specific mechanisms and regulatory pathways through which...
(), a commonly found yeast-like fungus, exhibits adaptability to a wide range of pH environments. However, the specific mechanisms and regulatory pathways through which respond to external pH remain to be fully understood. In this study, we first sequenced the whole genome of using Nanopore technology and generated a circle map. Subsequently, we explored the biomass, pullulan production, melanin production, and polymalic acid production of when cultivated at different pH levels. We selected pH 4.0, pH 7.0, and pH 10.0 to represent acidic, neutral, and alkaline environments, respectively, and examined the morphological characteristics of using SEM and TEM. Our observations revealed that predominantly exhibited hyphal growth with thicker cell walls under acidic conditions. In neutral environments, it primarily displayed thick-walled spores and yeast-like cells, while in alkaline conditions, it mainly assumed an elongated yeast-like cell morphology. Additionally, transcriptome analysis unveiled that orchestrates its response to shifts in environmental pH by modulating its cellular morphology and the expression of genes involved in pullulan, melanin, and polymalic acid synthesis. This research enhances the understanding of how regulates itself in diverse pH settings and offers valuable guidance for developing and applying engineered strains.
Topics: Ascomycota; Saccharomyces cerevisiae; Melanins; Gene Expression Profiling; Hydrogen-Ion Concentration; Fermentation
PubMed: 38003294
DOI: 10.3390/ijms242216103 -
Plants (Basel, Switzerland) Oct 2023The Korean fir tree , an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to...
The Korean fir tree , an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to enhance drought tolerance using a black yeast-like fungus identified as (AK10). The 16S/ITS metabarcoding analysis assessed the impact of drought and AK10 treatment on the seedlings' rhizosphere microbiome. Results revealed a profound drought influence on the microbiome, particularly affecting fungal mycobiota. Drought-stressed seedlings exhibited elevated Agaricaceae levels, opportunistic fungi generally associated with decomposition. AK10 treatment significantly mitigated this proliferation and increased the relative abundance of beneficial fungi like and , known biocontrol agents and phosphate solubilizers. A notable reduction in the phytopathogenic levels was observed with AK10, alongside an increase in beneficial bacteria, including and . Furthermore, the conducted correlation analysis shed light on microbial interrelationships within the rhizosphere, elucidating potential co-associations and antagonisms. Taken together, the isolated AK10 identified in this study serves as a potential biostimulant, enhancing the drought tolerance in through beneficial alterations in the rhizosphere microbiome. This approach presents a promising strategy for the conservation of this endangered species.
PubMed: 37896116
DOI: 10.3390/plants12203653 -
Foods (Basel, Switzerland) Oct 2023and are important pathogenic fungi that pose a serious threat because of their ability to produce mycotoxins, including ochratoxin A (OTA) and aflatoxins (AFs). The...
and are important pathogenic fungi that pose a serious threat because of their ability to produce mycotoxins, including ochratoxin A (OTA) and aflatoxins (AFs). The main method of reducing these pathogens is the use of chemical fungicides, though recently there has been a focus on finding biological control agents. The obtained results from this study indicate the great potential of two wild yeast strains, PP3 and D10, in the biological control of and and reductions in the amount of OTA and AFs they produce. In vitro, the growth of the mycelium of pathogens was reduced by 41.21% to 53.64%, and spore germination was inhibited by 58.39% to 71.22%. Both yeast strains produced the enzymes chitinase, β-1,3-glucanase, and amylase, and PP3 additionally produced protease and cellulase. This yeast strain also had the ability to grow over a wide range of temperature (4-30 °C), salinity (0-12%) and pH (4-11) conditions. No growth of the yeast was observed at 37 °C, nor any biogenic amines or hydrogen sulfide production. Adding the tested yeast inoculum to the dough reduced OTA (within 14.55-21.80%) and AFs (within 18.10-25.02%) in the model bread.
PubMed: 37893764
DOI: 10.3390/foods12203871 -
Plants (Basel, Switzerland) Sep 2023The growth of four commercial biocontrol agents (BCAs: (BAD), (APD), (MFN), and (TAS)) was evaluated using turbidimetric assays on artificial substrates mimicking...
The growth of four commercial biocontrol agents (BCAs: (BAD), (APD), (MFN), and (TAS)) was evaluated using turbidimetric assays on artificial substrates mimicking the chemical berry composition at four stages: pea-sized berries, veraison, softening, and ripe berries. The response of BCA growth differed among BCAs. Subsequently, the BCAs' population size was assessed after 1 to 13 days of incubation on the substrate mimicking ripe berries at 15 to 35 °C. The population size of BAD increased with temperatures, while that of MFN decreased; the population sizes of APD and TAS showed bell-shaped patterns with lower growth at 15 or 35 °C. Finally, the BCAs were applied to ripe berries and then incubated at 15 to 30 °C. After 1 to 13 days, the berries were inoculated with and incubated for 7 days, after which the BCA control efficacy was assessed. The highest control was observed at 25 °C for BAD and APD, at 15 to 20 °C for MFN, and at 25 to 30 °C for TAS. The results confirm that the plant substrates and temperature affect the population size of the BCA following application; temperature also affects the preventative efficacy of BCA against .
PubMed: 37836169
DOI: 10.3390/plants12193430 -
International Journal of Molecular... Sep 2023Ulcerative colitis (UC), a subtype of inflammatory bowel disease, is a chronic gastrointestinal inflammatory disease with unclear etiology and pathophysiology. Herein,...
Ulcerative colitis (UC), a subtype of inflammatory bowel disease, is a chronic gastrointestinal inflammatory disease with unclear etiology and pathophysiology. Herein, we determined the effects of extracellular polysaccharides purified from SM-2001 (Polycan) on tight junction protein expression, inflammation, and apoptosis in a dextran sodium sulfate (DSS)-induced acute colitis model. Fifty mice were divided into normal, DSS, DSS + Polycan 250 mg/kg (Polycan 250), DSS + Polycan 500 mg/kg (Polycan 500), and DSS + 5-aminosalicylic acid 100 mg/kg (5-ASA) groups. Their body weights, colon lengths, histological changes in colon tissue, and tight junction function were observed. Results showed that Polycan 250, Polycan 500, and 5-ASA significantly inhibited body weight loss compared with DSS. Similar to 5-ASA, Polycan 500 exhibited preventive effects on colon length shortening and histological changes in colon tissues. Polycan inhibited the DSS-induced decrease in fluorescein isothiocyanate-dextran permeability and myeloperoxidase activity. Moreover, Polycan significantly recovered serum cytokine (e.g., tumor necrosis factor-α, interleukin (IL)-6, and IL-1β) or mRNA expression in colon tissue compared with DSS. Polycan also inhibited apoptosis by reducing caspase-3 activity and the Bcl-2 associated X/B-cell lymphoma 2 (Bcl-2) ratio. Additionally, DSS treatment significantly reduced microbial abundance and diversity, but the administration of Polycan reversed this effect. Collectively, Polycan protected intestinal barrier function and inhibited inflammation and apoptosis in DSS-induced colitis.
Topics: Animals; Mice; Colitis, Ulcerative; Dextrans; Glucans; beta-Glucans; Colitis; Colon; Inflammation; Interleukin-6; Mesalamine; Proto-Oncogene Proteins c-bcl-2; Dextran Sulfate; Disease Models, Animal; Mice, Inbred C57BL
PubMed: 37834221
DOI: 10.3390/ijms241914773 -
BMC Plant Biology Oct 2023Microbial communities have occasionally been observed in part of the ephemeric reproductive structure of floral stigmas, but their prevalence, phylogenetic diversity and...
BACKGROUND
Microbial communities have occasionally been observed in part of the ephemeric reproductive structure of floral stigmas, but their prevalence, phylogenetic diversity and ecological roles are understudied. This report describes the first study of bacterial and fungal communities in immature and mature stigma tissue of the endangered holoparasitic plant Phelipanche arenaria. Culture-dependent methods coupled with next-generation sequencing indicated that a small surface of the flower stigma was an unexpectedly rich and diverse microhabitat for colonization of microbial. We also compared the enzymatic activity of the bacterial communities between immature and mature stigmas samples.
RESULTS
Using high-throughput sequencing methods, we identified and classified 39 to over 51 OTUs per sample for bacterial OTUs represented by Pantoea agglomerans and P. ananatis, comprising 50.6%, followed by Pseudomonas, Luteibacter spp., Sphingomonas spp. with 17% of total frequency. The bacterial profile of immature stigmas of P. arenaria contained unique microorganisms (21 of the most numerous OTUs) that were not confirmed in mature stigmas. However, the enzymatic activity of bacteria in mature stigmas of P. arenaria showed more activity than observed in immature stigmas. In the fungal profile, we recorded even 80 OTUs in mature stigmas, consisting of Capnodiales 45.03% of the total abundance with 28.27% of frequency was created by Alternaria eichhorniae (10.55%), Mycosphaerella tassiana (9.69%), and Aureobasidium pullulans (8.03%). Additionally, numerous putative plant growth-promoting bacteria, fungal pathogens and pathogen-antagonistic yeasts were also detected.
CONCLUSIONS
Our study uncovered that P. arenaria stigmas host diverse bacterial and fungal communities. These microorganisms are well known and have been described as beneficial for biotechnological and environmental applications (e.g., production of different enzymes and antimicrobial compounds). This research provided valuable insight into the parasitic plant-microbe interactions.
Topics: Phylogeny; Orobanchaceae; Microbiota; Bacteria; Flowers
PubMed: 37821804
DOI: 10.1186/s12870-023-04488-1 -
Scientific Reports Oct 2023Recent advances in the management of Duchenne muscular dystrophy (DMD), such as exon skipping and gene therapy, though have reached a clinical stage, the outcome at its...
Recent advances in the management of Duchenne muscular dystrophy (DMD), such as exon skipping and gene therapy, though have reached a clinical stage, the outcome at its best is still considered suboptimal. In this study, we evaluated a novel N-163 strain of Aureobasidium pullulans produced β-glucan (Neu-REFIX) for its potential as an adjuvant to slow down the progression of the disease by anti-inflammatory and anti-fibrotic effects. In this study, 45 mice in the three groups, 15 each in a group; Gr. 1 normal mice, Gr.2 mdx mice as vehicle, and Gr.3 mdx mice administered the N-163 β-glucan for 45 days. The N-163 β-glucan group showed a significant decrease in the plasma ALT, AST, and LDH levels (126 ± 69 U/l, 634 ± 371 U/l, 3335 ± 1258 U/l) compared with the vehicle group (177 ± 27 U/l, 912 ± 126 U/l, 4186 ± 398 U/l). Plasma TGF-β levels increased, and plasma IL-13 levels decreased in the N-163 group. The inflammation score of HE-stained muscle sections in the N-163 group (1.5 ± 0.8) was lower than that in the vehicle group (2.0 ± 0.8). The N-163 strain β-glucan group (24.22 ± 4.80) showed a significant decrease in the fibrosis area (Masson's Trichrome-positive area) compared with the vehicle group (36.78 ± 5.74). The percentage of centrally nucleated fibres evaluated by Masson's trichrome staining was 0 in the normal group, while it increased to 80% in the vehicle group but remained at 76.8% in the N-163 group. The N-163 β-glucan group showed a significant decrease in the fibrosis area. Considering their safety and easy oral consumption, Neu-REFIX β-glucan could be worth large multicentre clinical studies as adjuvant in slowing down the progress of DMD.
Topics: Animals; Mice; Mice, Inbred mdx; beta-Glucans; Muscular Dystrophy, Duchenne; Fibrosis; Muscle, Skeletal
PubMed: 37813938
DOI: 10.1038/s41598-023-44330-0 -
Polymers Sep 2023Melanin as a natural polymer is found in all living organisms, and plays an important role in protecting the body from harmful UV rays from the sun. The efficiency of...
A Comparative Study of Cr(VI) Sorption by AKW Biomass and Its Extracellular Melanin: Complementary Modeling with Equilibrium Isotherms, Kinetic Studies, and Decision Tree Modeling.
Melanin as a natural polymer is found in all living organisms, and plays an important role in protecting the body from harmful UV rays from the sun. The efficiency of fungal biomass () and its extracellular melanin as Cr(VI) biosorbents was comparatively considered. The efficiency of Cr(VI) biosorption by the two sorbents used was augmented up to 240 min. The maximum sorption capacities were 485.747 (fungus biomass) and 595.974 (melanin) mg/g. The practical data were merely fitted to both Langmuir and Freundlich isotherms. The kinetics of the biosorption process obeyed the pseudo-first-order. Melanin was superior in Cr(VI) sorption than fungal biomass. Furthermore, four independent variables (contact time, initial concentration of Cr(VI), biosorbent dosage, and pH,) were modeled by the two decision trees (DTs). Conversely, to equilibrium isotherms and kinetic studies, DT of fungal biomass had lower errors compared to DT of melanin. Lately, the DTs improved the efficacy of the Cr(VI) removal process, thus introducing complementary and alternative solutions to equilibrium isotherms and kinetic studies. The Cr(VI) biosorption onto the biosorbents was confirmed and elucidated through FTIR, SEM, and EDX investigations. Conclusively, this is the first report study attaining the biosorption of Cr(VI) by biomass of . and its extracellular melanin among equilibrium isotherms, kinetic study, and algorithmic decision tree modeling.
PubMed: 37765609
DOI: 10.3390/polym15183754 -
Access Microbiology 2023Fungal keratitis is a time-sensitive ocular infection that often requires a high index of suspicion followed by intensive medical/surgical interventions to achieve a...
Fungal keratitis is a time-sensitive ocular infection that often requires a high index of suspicion followed by intensive medical/surgical interventions to achieve a successful clinical outcome. COVID-19 pandemic-related restrictions, necessitated the modification of conventional protocols and guidelines associated with the treatment of keratomycosis. We report four cases of atypical fungal keratitis with poorly differentiated clinical characteristics. The challenges faced during their management were (1) the dilemma of clinically differentiating fungal () and bacterial keratitis; (2) treatment of and keratitis with natamycin monotherapy; (3) mixed infection of and and continuing medications before rescraping the corneal ulcer against the recommended treatment guidelines; (4) phenotypic identification and differentiation among morphologically resembling fungi; and (5) decision making arising out of disparities between KOH and fungal culture results. Three patients responded well to conservative treatments. The fourth patient underwent therapeutic keratoplasty but was lost to follow-up due to travelrelated pandemic restrictions. This case series seeks to broaden the clinician's knowledge of rare and emerging moulds as presumptive aetiologies of keratomycosis. It also intends to emphasize the significance of early microbiological investigations, (direct microscopy and culture), in resource-limited settings, for initiating empirical treatment for a better visual prognosis.
PubMed: 37691845
DOI: 10.1099/acmi.0.000570.v3 -
Frontiers in Microbiology 2023The organoleptic profile and quality of wine are affected by the presence of different non-s species and strains. Therefore, the identification and characterization of...
The organoleptic profile and quality of wine are affected by the presence of different non-s species and strains. Therefore, the identification and characterization of non-s yeasts are the first step to understand their function, and to develop a better strain selection program for winemaking. This study investigated the biodiversity of non- yeasts associated with spontaneous fermentation of Cabernet Sauvignon wines from five sub-regions (Shi Zuishan, Yinchuan, Yu Quanying, Qing Tongxia and Hong Sibu) in Ningxia, China. Yeast species were identified by sequencing the 26S rRNA D1/D2 region, and strains at the subspecies level were discriminated using tandem repeat-tRNA (TRtRNA) PCR analysis. A total of 524 yeast colonies were isolated, and 19 non- yeast species belonging to 10 genera were identified, including , , sp., , , , , , sp., , , , , , , and . , , and were the three most dominated species, while other non- species were only present in the early stage of spontaneous fermentations at different levels. Further, for the yeast discrimination at strain level, 34 profiles were obtained by amplification with primer pairs TtRNASC/5CAG, while 40 profiles were obtained with primer pairs TtRNASC/ISSR-MB. This study explored the diversity of non- species in Ningxia, China, and made an important contribution of genetic resources for further strain development.
PubMed: 37664125
DOI: 10.3389/fmicb.2023.1253969