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IUBMB Life Apr 2024Experimental evolution was carried out to investigate the adaptive responses of extremotolerant fungi to a stressful environment. For 12 cultivation cycles, the...
Experimental evolution was carried out to investigate the adaptive responses of extremotolerant fungi to a stressful environment. For 12 cultivation cycles, the halotolerant black yeasts Aureobasidium pullulans and Aureobasidium subglaciale were grown at high NaCl or glycerol concentrations, and the halophilic basidiomycete Wallemia ichthyophaga was grown close to its lower NaCl growth limit. All evolved Aureobasidium spp. accelerated their growth at low water activity. Whole genomes of the evolved strains were sequenced. No aneuploidies were detected in any of the genomes, contrary to previous studies on experimental evolution at high salinity with other species. However, several hundred single-nucleotide polymorphisms were identified compared with the genomes of the progenitor strains. Two functional groups of genes were overrepresented among the genes presumably affected by single-nucleotide polymorphisms: voltage-gated potassium channels in A. pullulans at high NaCl concentration, and hydrophobins in W. ichthyophaga at low NaCl concentration. Both groups of genes were previously associated with adaptation to high salinity. Finally, most evolved Aureobasidium spp. strains were found to have increased intracellular and decreased extracellular glycerol concentrations at high salinity, suggesting that the strains have optimised their management of glycerol, their most important compatible solute. Experimental evolution therefore not only confirmed the role of potassium transport, glycerol management, and cell wall in survival at low water activity, but also demonstrated that fungi from extreme environments can further improve their growth rates under constant extreme conditions in a relatively short time and without large scale genomic rearrangements.
PubMed: 38647201
DOI: 10.1002/iub.2825 -
Respiratory Physiology & Neurobiology Sep 2023Occupational exposure to microbially contaminated metal working fluids (MWF) can cause hypersensitivity pneumonitis (HP). An important step in the diagnosis of HP is to...
Occupational exposure to microbially contaminated metal working fluids (MWF) can cause hypersensitivity pneumonitis (HP). An important step in the diagnosis of HP is to identify the triggering antigen by detection of corresponding specific IgG antibodies (sIgG). As commercial sIgG tests are currently not available, protein antigens were prepared from MWF-workplace samples and from MWF-typical bacterial isolates. In 57 % of suspected HP-cases (n = 30) elevated sIgG concentrations were measured to at least one MWF-relevant antigen, of which Mycobacterium immunogenum was most prominent (88 %), followed by Pseudomonas oleovorans and Pseudomonas spec (82 % each), MWF-antigen mix and Pseudomonas alcaliphila (65 % each). Elevated sIgG concentrations to other microorganisms were measured to Micropolyspora faeni (82 %) and Aureobasidium pullulans (77 %). Correlation of sIgG values of all tested microbial antigens showed a significant relationship of MWF-antigen mixture to Pseudomonas antigens, but a low correlation to moulds. These newly prepared MWF-antigens are useful tools for the diagnosis of patients with suspected MWF-HP and are available for further investigations.
Topics: Humans; Occupational Diseases; Alveolitis, Extrinsic Allergic; Occupational Exposure; Immunoglobulin G
PubMed: 37451418
DOI: 10.1016/j.resp.2023.104107 -
Food Chemistry Dec 2023This study hypothesized the existence of cultivar-associated correlations between grape berry metabolites and its microbial residents, in Douro wine region. Integrated...
This study hypothesized the existence of cultivar-associated correlations between grape berry metabolites and its microbial residents, in Douro wine region. Integrated metabolomics with metabarcoding showed that the microbial biodiversity is not associated to berry sugar concentration, but closely connected to the profile of amino acids, flavonoids and wax compounds, which drove cultivar differentiation together with the prevalence of pathogenic fungi, yeasts and bacteria, mainly Dothideomycetes and Gammaproteobacteria. Over 7000 metabolite-microbiota correlations with ρ >|0.99| exposed a core of 15 metabolites linked to 11 microbial taxa. Serine, oxalate, cyanidin-3-O-glucoside, petunidin-3-O-glucoside, gallic acid, germanicol, sitosterol and erythrodiol correlated negatively to the abundance of most taxa, including Alternaria, Aureobasidium, Pseudopithomyces, Pseudomonas and Sphingomonas. In contrast, phenylalanine, asparagine, alanine, (epi)gallocatechin and procyanidin gallate mediated positive metabolite-OTU correlations. E. necator and A. carbonarius correlated negatively with stigmasterol and amyrin. Complex fungi-bacteria relationships ruled by Dothideomycetes and Alphaproteobacteria further suggest tight host-microbe interactions at the carposphere.
Topics: Vitis; Wine; Fruit; Flavonoids; Microbiota; Fungi
PubMed: 37463536
DOI: 10.1016/j.foodchem.2023.136859 -
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 -
Molecular Biology of the Cell Apr 2024is a ubiquitous fungus with a wide variety of morphologies and growth modes including "typical" single-budding yeast, and interestingly, larger multinucleate yeast than...
is a ubiquitous fungus with a wide variety of morphologies and growth modes including "typical" single-budding yeast, and interestingly, larger multinucleate yeast than can make multiple buds in a single cell cycle. The study of promises to uncover novel cell biology, but currently tools are lacking to achieve this goal. Here, we describe initial components of a cell biology toolkit for , which is used to express and image fluorescent probes for nuclei as well as components of the cytoskeleton. These tools allowed live-cell imaging of the multinucleate and multibudding cycles, revealing highly synchronous mitoses in multinucleate yeast that occur in a semiopen manner with an intact but permeable nuclear envelope. These findings open the door to using this ubiquitous polyextremotolerant fungus as a model for evolutionary cell biology.
Topics: Saccharomyces cerevisiae; Ascomycota; Aureobasidium; Cytoskeleton
PubMed: 38446617
DOI: 10.1091/mbc.E23-10-0388 -
The Journal of Antibiotics Dec 2023Biosurfactants have found widespread use across multiple industrial fields, including medicine, food, cosmetics, detergents, pulp, and paper, as well as the degradation...
Biosurfactants have found widespread use across multiple industrial fields, including medicine, food, cosmetics, detergents, pulp, and paper, as well as the degradation of oil and fat. The culture broth of Aureobasidium pullulans A11231-1-58 isolated from flowers of Chrysanthemum boreale Makino exhibited potent surfactant activity. Surfactant activity-guided fractionation led to the isolation of three new biosurfactants, pullusurfactins A‒C (1‒3). Their chemical structures were established through the use of spectroscopic techniques, predominantly 1D and 2D NMR, in conjunction with mass measurements. We evaluated the surface tension activities of isolated compounds. At 1.0 mg l, these compounds showed high degrees of surfactant activity (31.15 dyne/cm, 33.75 dyne/cm, and 33.83 dyne/cm, respectively).
Topics: Chrysanthemum; Surface-Active Agents
PubMed: 37749218
DOI: 10.1038/s41429-023-00660-9 -
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 -
World Journal of Microbiology &... Jun 2024Liamocins, a group of high-density glycolipids, are only produced by certain strains of the yeast-like fungi in the genus Aureobasidium. Until now, few studies have...
Liamocins, a group of high-density glycolipids, are only produced by certain strains of the yeast-like fungi in the genus Aureobasidium. Until now, few studies have focused on the surfactant properties of liamocins produced from the highly diverse tropical strains of Aureobasidium. Therefore, the aims of this research were to screen the liamocin production from tropical strains of Aureobasidium spp. and to characterize their surfactant properties. A total of 41 strains of Thai Aureobasidium spp. were screened for their ability to produce liamocins, and the products were detected using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and thin-layer chromatography. Of those strains, 30 strains of Aureobasidium spp. tested were found to produce liamocins with yields ranging from 0.53 to 10.60 g/l. The nature of all crude liamocins was heterogeneous, with different compositions and ratios depending on the yeast strain. These liamocins exhibited relatively high emulsifying activity against vegetable oils tested, with an emulsification index of around 40-50%; the emulsion stability of some liamocins was up to 30 days. The obtained critical micelle concentration values were varied, with those of liamocins produced from A. pullulans, A. melanogenum and A. thailandense falling in ranges from 7.70 to 119.78, 10.73 to > 1,000, and 68.56 to > 1,000 mg/l, respectively. The emulsification activity of liamocins was higher than that of the analytical grade rhamnolipids. These compounds showed strong surface tension reduction in a sodium chloride concentration range of 2-12% (w/v), pH values between 3 and 7, and temperatures between 4 and 121 °C. This is the first report of liamocins produced by A. thailandense.
Topics: Glycolipids; Aureobasidium; Surface-Active Agents; Thailand; Chromatography, Thin Layer; Plant Oils; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Emulsifying Agents; Emulsions
PubMed: 38914906
DOI: 10.1007/s11274-024-04058-z -
Applied Microbiology and Biotechnology Nov 2023Pullulan is a polymer produced by Aureobasidium spp. The yield of pullulan production can be impacted by the cellular differentiation of Aureobasidium spp., which...
Pullulan is a polymer produced by Aureobasidium spp. The yield of pullulan production can be impacted by the cellular differentiation of Aureobasidium spp., which changes with alterations in the growth environment. To improve pullulan yield, identifying key factors that regulate cellular differentiation is crucial. In this study, the main form of pullulan synthesis in Aureobasidium pullulans NG was through swollen cells (SC). The results showed that citric acid (CA) can regulate the cellular differentiation of Aureobasidium pullulans NG by accumulating higher levels of CA in the cells to maintain growth in SC form and increase pullulan production. The addition of 1.0% CA to Aureobasidium pullulans NG for 96 h resulted in a significant increase in pullulan production, producing 18.32 g/l compared to the control group which produced 10.23 g/l. Our findings suggest that controlling cellular differentiation using CA is a promising approach for enhancing pullulan production in Aureobasidium pullulans. KEY POINTS: • The regulation of cell differentiation in Aureobasidium pullulans NG is demonstrated to be influenced by citric acid. • Intracellular citric acid levels in Aureobasidium pullulans NG have been shown to support the growth of swollen cells. • Citric acid has been found to increase pullulan production in Aureobasidium pullulans NG.
PubMed: 37698607
DOI: 10.1007/s00253-023-12758-z -
Plants (Basel, Switzerland) Aug 2023Many grape endophytic microorganisms exhibit high potential for suppressing the development of grape diseases and stimulating grapevine growth and fitness, as well as...
Many grape endophytic microorganisms exhibit high potential for suppressing the development of grape diseases and stimulating grapevine growth and fitness, as well as beneficial properties of the crop. The microbiome of wild grapevines is a promising source of biocontrol agents, which can be beneficial for domesticated grapevines. Using next-generation sequencing (NGS) and classical microbiology techniques, we performed an analysis of bacterial and fungal endophytic communities of wild grapevines Rupr. and Pulliat growing in the Russian Far East. According to the NGS analysis, 24 and 18 bacterial taxa from the class level were present in and grapevines, respectively. Gammaproteobacteria (35%) was the predominant class of endophytic bacteria in and Alphaproteobacteria (46%) in Three taxa, namely , and were the most common bacterial genera for and . Metagenomic analysis showed the presence of 23 and 22 fungi and fungus-like taxa of class level in and , respectively. The predominant fungal classes were Dothideomycetes (61-65%) and Tremellomycetes (10-11%), while and were the most common fungal genera in and respectively. A comparative analysis of the endophytic communities of and with the previously reported endophytic communities of revealed that the bacterial biodiversity of and was similar in alpha diversity to 's bacterial biodiversity. The fungal alpha diversity of and was statistically different from that of . The beta diversity analysis of bacterial and fungal endophytes showed that samples of formed separate clusters, while samples formed a separate cluster including samples. The data revealed that the endophytic community of bacteria and fungi from wild was richer than that from grapes and cultivated grapes. Therefore, the data obtained in this work could be of high value in the search for potentially useful microorganisms for viticulture.
PubMed: 37631163
DOI: 10.3390/plants12162952