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Bioresources and Bioprocessing Aug 2023Aureobasidium pullulans (A. pullulans) has a wide range of applications. Ultraviolet (UV) rays from the sun can cause skin photoaging. In order to explore the protective...
BACKGROUND
Aureobasidium pullulans (A. pullulans) has a wide range of applications. Ultraviolet (UV) rays from the sun can cause skin photoaging. In order to explore the protective effect and application potential of A. pullulans lysate on UV-damaged human skin fibroblasts (HSF) and HaCaT Cells, this study investigates the anti-aging and anti-inflammatory effects of A. pullulans lysate as well as the mechanism of anti-oxidative stress at the cellular and molecular levels through cytotoxicity experiments, enzyme-linked immunosorbent assays (ELISA), and real-time quantitative PCR (RT-qPCR).
RESULTS
The experimental results have shown that the A. pullulans lysate can effectively reduce the loss of extracellular matrix components (EMC), such as collagen and hyaluronic acid (HA). It is also capable of scavenging excess reactive oxygen species (ROS) from the body, thereby increasing the activity of catalase, decreasing the overexpression of intracellular matrix metalloproteinases (MMPs), enhancing the gene expression of metalloproteinase inhibitors (TIMPs), and decreasing the level of inflammatory factors, reducing UV-induced apoptosis of HaCaT cells. Meanwhile, oxidative stress homeostasis is also regulated through the Nrf2/Keap1 and MAPK signaling pathways.
CONCLUSIONS
This study shows that the A. pullulans lysate has the potential to resist photoaging.
PubMed: 38647892
DOI: 10.1186/s40643-023-00678-9 -
Fungal Biology and Biotechnology Nov 2022Extracellular vesicles (EVs) are increasingly recognized as an important mechanism for cell-cell interactions. Their role in fungi is still poorly understood and they...
Extracellular vesicles (EVs) are increasingly recognized as an important mechanism for cell-cell interactions. Their role in fungi is still poorly understood and they have been isolated from only a handful of species. Here, we isolated and characterized EVs from Aureobasidium pullulans, a biotechnologically important black yeast-like fungus that is increasingly used for biocontrol of phytopathogenic fungi and bacteria. After optimization of the isolation protocol, characterization of EVs from A. pullulans by transmission electron microscopy (TEM) revealed a typical cup-shaped morphology and different subpopulations of EVs. These results were confirmed by nanoparticle tracking analysis (NTA), which revealed that A. pullulans produced 6.1 × 10 nanoparticles per milliliter of culture medium. Proteomic analysis of EVs detected 642 proteins. A small fraction of them had signal peptides for secretion and transmembrane domains. Proteins characteristic of different synthesis pathways were found, suggesting that EVs are synthesized by multiple pathways in A. pullulans. Enrichment analysis using Gene Ontology showed that most of the proteins found in the EVs were associated with primary metabolism. When sequencing the small RNA fraction of A. pullulans EVs, we found two hypothetical novel mil-RNAs. Finally, we tested the biocontrol potential of EVs from A. pullulans. The EVs did not inhibit the germination of spores of three important phytopathogenic fungi-Botrytis cinerea, Colletotrichum acutatum, and Penicillium expansum. However, exposure of grown cultures of C. acutatum and P. expansum to A. pullulans EVs resulted in visible changes in morphology of colonies. These preliminary results suggest that EVs may be part of the antagonistic activity of A. pullulans, which is so far only partially understood. Thus, the first isolation and characterization of EVs from A. pullulans provides a starting point for further studies of EVs in the biotechnologically important traits of the biocontrol black fungus A. pullulans in particular and in the biological role of fungal EVs in general.
PubMed: 36320088
DOI: 10.1186/s40694-022-00146-7 -
Environmental Research Nov 2022Pullulan and melanin have become important secondary metabolites that are now widely studied. In this study, a strain of Aureobasidium pullulans HIT-LCY3 was used to...
Pullulan and melanin have become important secondary metabolites that are now widely studied. In this study, a strain of Aureobasidium pullulans HIT-LCY3 was used to ferment potato starch industrial waste to produce pullulan and melanin. After optimization, the culture conditions for the fermentation medium were obtained: inoculum age of 48 h, initial pH of 6.0, inoculation quantity of 1.5%, temperature of 26 °C, fermentation time of 5 d and speed of 160 rpm. Under these conditions, the yield of pullulan was 23.47 g/L with a molecular weight (MW) of 1.21 × 10 Da and the yield of melanin was 18.98 g/L. In addition, the adaptive evolution could significantly increase the yield of pullulan and melanin and the air-floating fermenters was more conductive to product accumulation. Through the 5 L small-scale test and 1000 L pilot test, the yield of pullulan reached 16.52 g/L with molecular weight of 0.92 × 10 Da and the yield of melanin was 12.08 g/L at the trial production of 30,000 L. This work could provide strong support for industrial production and new guidance for waste utilization and environmental protection.
Topics: Ascomycota; Aureobasidium; Fermentation; Industrial Waste; Melanins; Solanum tuberosum; Starch
PubMed: 35931191
DOI: 10.1016/j.envres.2022.113947 -
Fungal Biology Jan 2018Intracellular glycerol accumulation is one of the main fungal adaptations to osmotic and also cold stress. We investigated the management of glycerol metabolism in...
Intracellular glycerol accumulation is one of the main fungal adaptations to osmotic and also cold stress. We investigated the management of glycerol metabolism in polyextremotolerant black yeasts Aureobasidium pullulans and Aureobasidium subglaciale. We show that increased salinity (5 % and 10 %; w/v), but not cold (10 °C) trigger intracellular glycerol accumulation. The transcriptional response of the genes involved in glycerol synthesis, degradation and import, to increased salinity, low temperature or a combination of both was analysed with real-time PCR. Each of the two species contains an NAD-dependent glycerol-3-phosphate dehydrogenase, a glycerol-3-phosphate phosphatase, a mitochondrial glycerol-3-phosphate dehydrogenase, two copies of a glycerol kinase, and more than ten copies of major facilitator superfamily transporters similar to glycerol proton symporters. Similarly to glycerol accumulation itself, transcriptional response to hypersaline stress was larger compared to low temperature stress and was more consistent in A. pullulans compared to A. subglaciale, reflecting the different stress tolerance and ecological strategy of each species.
Topics: Ascomycota; Extremophiles; Gene Expression Regulation, Fungal; Genes, Duplicate; Genes, Fungal; Glycerol; Glycerol Kinase; Glycerolphosphate Dehydrogenase; Phosphoric Monoester Hydrolases; Phylogeny; Real-Time Polymerase Chain Reaction; Salinity; Stress, Physiological; Symporters; Transcriptome
PubMed: 29248115
DOI: 10.1016/j.funbio.2017.10.005 -
Phytopathology Aug 2023Biological control is a promising approach to reduce plant diseases caused by fungal pathogens and ensure high productivity in horticultural production. In the present...
Biological control is a promising approach to reduce plant diseases caused by fungal pathogens and ensure high productivity in horticultural production. In the present study, we evaluated the biocontrol potential and underlying mechanisms of the beneficial fungus against and , casual agents of gray mold and anthracnose diseases in strawberry. Notably, this is the first time that has been tested against in strawberry. strains (AP-30044, AP-30273, AP-53383, and AP-SLU6) showed significant variation in terms of growth and conidia production. An inverse relationship was found between the growth and conidiation rate, suggesting a trade-off between resource allocation for growth and conidial production. Dual plate co-culturing assays showed that mycelial growth of and was reduced by up to 35 and 18%, respectively, when challenged with compared with control treatments. Likewise, culture filtrates of showed varying levels of antifungal activity against and , reducing the mycelial biomass by up to 90 and 72%, respectively. Furthermore, milk powder plate assays showed that produced substantial amounts of extracellular proteases, which are known to degrade fungal cuticle. Ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) analyses revealed that produced exophilins, liamocins, and free fatty acids known to have antifungal properties. shows high potential for successful biological control of strawberry diseases and discuss opportunities for further optimization of this beneficial fungus.
PubMed: 36945727
DOI: 10.1094/PHYTO-02-23-0067-R -
Frontiers in Bioengineering and... 2023Pullulan has many potential applications in the food, pharmaceutical, cosmetic and environmental industries. However, the yield and molecular properties of pullulan...
Pullulan has many potential applications in the food, pharmaceutical, cosmetic and environmental industries. However, the yield and molecular properties of pullulan produced by various strains still need to be promoted to fit the application needs. A novel yeast-like strain BL06 producing high molecular weight (Mw) pullulan (3.3 × 10 Da) was isolated and identified in this study. The remarkable Mw of pullulan produced by BL06 was the highest level ever reported thus far. To further regulate the biosynthesis of pullulan in BL06, three gene knockout strains BL06 ΔPMAs, BL06 Δmel, and BL06 ΔPMAsΔmel, were constructed. The results showed that BL06 ΔPMAs could produce 140.2 g/L of moderate Mw (1.3 × 10 Da) pullulan after 120 h of fermentation. The highest yield level of pullulan to date could vastly reduce its production cost and expand its application scope and potential. The application experiments in food preservation showed that the moderate-Mw pullulan obtained in this work could reduce the weight loss of celery cabbages and mangos by 12.5% and 22%, respectively. Thus, the novel strains BL06 and BL06 ΔPMAs possessed unlimited development prospects in pullulan production at various Mw ranges and pullulan applications in multiple fields.
PubMed: 36777253
DOI: 10.3389/fbioe.2023.1131875 -
Carbohydrate Polymers Sep 2017Pullulan is an imperative natural polymer produced commercially by yeast like fungus Aureobasidium pullulans. It is non-toxic, non-immunogenic, non-carcinogenic and... (Review)
Review
Pullulan is an imperative natural polymer produced commercially by yeast like fungus Aureobasidium pullulans. It is non-toxic, non-immunogenic, non-carcinogenic and non-mutagenic in nature. The structure of pullulan consist unique linkage pattern with two α-(1→4) and one α-(1→6) glycosidic bonds in maltotriose repeating units (G). Pullulan endows distinctive physical traits due to the presence of nine hydroxyl groups on glucopyranose rings of G units. It can be derivatized in various forms by substituting these hydroxyl groups to enhance its utility in biomedical applications. Pullulan and its derivatives are completely explored for their applications in food and pharmaceutical industries. Owing to these special properties, native pullulan and its derivatives possess potential application in multiple diagnostics. This review presents elaborated discussion on role of pullulan and its derivatives in various biomedical applications e.g. drug delivery, gene targeting, tissue engineering, vaccination, plasma substitution, chaperone-like activity, medical imaging, insulinotropic activity, pharmaceutical dosages formation, coating, etc.
Topics: Ascomycota; Biomedical Technology; Glucans
PubMed: 28578944
DOI: 10.1016/j.carbpol.2017.04.089 -
Carbohydrate Polymers Dec 2023Aureobasidium pullulans β-(1 → 3, 1 → 6)-glucan (APG) has a high degree of β-(1 → 6)-glucosyl branching and a regular triple helical structure similar to...
Aureobasidium pullulans β-(1 → 3, 1 → 6)-glucan (APG) has a high degree of β-(1 → 6)-glucosyl branching and a regular triple helical structure similar to that of schizophyllan. In this study, APG was carboxymethylated to different degrees of substitution (DS = 0.51, 1.0, and 2.0, denoted CMAPG 1-3, respectively) using a heterogeneous reaction. With increasing DS, the triple-helix structure drastically decreased and converted to a random coil structure in CMAPG 3. Further, aqueous solutions of CMAPG changed from pseudoplastic fluids to perfect Newtonian liquids with increasing DS, indicating that the intra- and intermolecular hydrogen bonds had been cleaved by the substituents to form a random coil structure. In addition, APG and CMAPG solutions exhibited scavenging ability against hydroxyl, organic, and sulfate radicals. It was also found that the carboxymethylation of APG drastically enhanced the organic radical scavenging ability. On the basis of the relationship between the DS and radical scavenging ability of the CMAPG samples, we believe hydroxyl and organic radicals were preferably scavenged by the donation of hydrogen atoms from the glucose rings and the methylene moieties of the carboxymethyl groups, respectively. Considering the obtained results, CMAPG and APG are expected to have applications in pharmaceuticals, functional foods, and cosmetics as antioxidant polysaccharides.
Topics: Glucans; Antioxidants; Polysaccharides; Sizofiran; beta-Glucans
PubMed: 37839833
DOI: 10.1016/j.carbpol.2023.121357 -
International Journal of Biological... May 2022Pullulan is a microbial polymer, commercially produced from Aureobasidium pullulans. Downstream processing of pullulan involves a multi-stage process which should be... (Review)
Review
Pullulan is a microbial polymer, commercially produced from Aureobasidium pullulans. Downstream processing of pullulan involves a multi-stage process which should be efficient, safe and reproducible. In liquid-liquid separations, firstly cell free extract is separated. Cell biomass can be separated after fermentation either by centrifugation or filtration. Due to practically insolubility of pullulan in organic solvents, ethanol and isopropanol are the most commonly used organic solvents for its recovery. Pullulan can also be purified by chromatographic techniques, but these are not cost effective for the purification of pullulan. Efficient aqueous two-phase system can be used for the purification of pullulan. The current review describes the methods and perspectives used for solid-liquid separation, liquid-liquid separations and finishing steps for the recovery of pullulan. Techniques used to determine the structural attributes of pullulan have also been highlighted.
Topics: Ascomycota; Fermentation; Glucans; Solvents
PubMed: 35354070
DOI: 10.1016/j.ijbiomac.2022.03.163 -
Biochemical Genetics Jun 2024Endophytic fungi associated with plants may contain undiscovered bioactive compounds. Under standard laboratory conditions, most undiscovered compounds are inactive,...
Endophytic fungi associated with plants may contain undiscovered bioactive compounds. Under standard laboratory conditions, most undiscovered compounds are inactive, whereas their production could be stimulated under different cultivation conditions. In this study, six endophytic fungi were isolated from the bark of Koelreuteria paniculata in Quancheng Park, Jinan City, Shandong Province, one of which was identified as a new subspecies of Aureobasidium pullulans, named A. pullulans KB3. Additionally, metabolomic tools were used to screen suitable media for A. pullulans KB3 fermentation, and the results showed that peptone dextrose medium (PDM) was more beneficial to culture A. pullulans KB3 for isolation of novel compounds. Sphaerolone, a polyketone compound, was initially isolated from A. pullulans KB3 via scaled up fermentation utilizing PDM. Additionally, the whole-genome DNA of A. pullulans KB3 was sequenced to facilitate compound isolation and identify the biosynthesis gene clusters (BGCs). This study reports the multi-omics (metabolome and genome) analysis of A. pullulans KB3, laying the foundation for discovering novel compounds of silent BGCs and identifying their biosynthesis pathway.
PubMed: 38877158
DOI: 10.1007/s10528-024-10866-7