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Pathogenic fungi can cause significant annual losses in the quality and quantity of fruits belonging to Rosaceae family during pre‐ and postharvest. Synthetic fungicides are considered the main method for controlling diseases in food crops; however, they pose a great risk to human health and to the environment. As a result, biological control methods, which are based on living microorganisms to reduce the population or to inhibit the growth of pathogens, have arisen as a safe alternative. In this review, we highlight the principal mechanisms (e.g., nutrition and space competition, mycoparasitism, induced resistance and growth enhancement, production of volatile organic compounds, and antibiosis) utilized by the most frequently reported non‐Saccharomyces biocontrol agents (BCAs) yeasts: Meyerozyma guilliermondii, Pichia membranifaciens, Wickerhamomyces anomalus, Metschnikowia pulcherrima, Hanseniaspora uvarum, and Aureobasidium pullulans, against the common pathogenic fungi found within Rosaceae family: Penicillium expansum, Botrytis cinerea, and Monilinia spp. Understanding BCAs' importance and mode of action is a necessary step in order to reduce the detrimental effect of spoilage fungi in the agriculture and food industry, by achieving a more sustainable and safer control of them. [ABSTRACT FROM AUTHOR]

The culturable yeast communities in temperate forest soils under the ornithogenic influence were studied in a seasonal dynamic. To investigate the intense ornithogenic influence, conventional and "live" feeders were used, which were attached to trees in the forest and constantly replenished throughout the year. It was found that the yeast abundance in the soil under strong ornithogenic influence reached the highest values in winter compared to the other seasons and amounted to 4.8 lg (cfu/g). This was almost an order of magnitude higher than the minimum value of yeast abundance in ornithogenic soils determined for summer. A total of 44 yeast species, 21 ascomycetes and 23 basidiomycetes, were detected in ornithogenic soil samples during the year. These included soil-related species (Barnettozyma californica, Cyberlindnera misumaiensis, Cutaneotrichosporon moniliiforme, Goffeauzyma gastrica, Holtermanniella festucosa, Leucosporidium creatinivorum, L. yakuticum, Naganishia adeliensis, N. albidosimilis, N. globosa, Tausonia pullulans, and Vanrija albida), eurybionts (yeast-like fungus Aureobasidium pullulans, Debaryomyces hansenii, and Rhodotorula mucilaginosa), inhabitants of plant substrates and litter (Cystofilobasidium capitatum, Cys. infirmominiatum, Cys. macerans, Filobasidium magnum, Hanseniaspora uvarum, Metschnikowia pulcherrima, and Rh. babjevae) as well as a group of pathogenic and opportunistic yeast species (Arxiozyma bovina, Candida albicans, C. parapsilosis, C. tropicalis, Clavispora lusitaniae, and Nakaseomyces glabratus). Under an ornithogenic influence, the diversity of soil yeasts was higher compared to the control, confirming the uneven distribution of yeasts in temperate forest soils and their dependence on natural hosts and vectors. Interestingly, the absolute dominant species in ornithogenic soils in winter (when the topsoil temperature was below zero) was the basidiomycetous psychrotolerant yeast T. pullulans. It is regularly observed in various soils in different geographical regions. Screening of the hydrolytic activity of 50 strains of this species at different temperatures (2, 4, 10, 15 and 20 °C) showed that the activity of esterases, lipases and proteases was significantly higher at the cultivation temperature. Ornithogenic soils could be a source for the relatively easy isolation of a large number of strains of the psychrotolerant yeast T. pullulans to test, study and optimize their potential for the production of cold-adapted enzymes for industry. [ABSTRACT FROM AUTHOR]

Endophytic fungi are widely known as fungi that infect internal tissues of host plants for all or part of their life cycles, without causing visible symptoms of disease. The present study was carried out to identify and investigate the pathogenicity of endophytic fungi residing in husks, silks, and kernels of corn. Endophytic fungi were isolated from surface-sterilised silks, kernels, and husks of healthy corn plants and identified using sequencing of multiple markers comprising TEF-1α, β-tubulin, calmodulin, ITS, LSU, and ACT. A total of 56 isolates of endophytic fungi belonging to 17 species, namely Fusarium pseudocircinatum (n = 8), F. verticillioides (n = 2), F. andiyazi (n = 4), F. sacchari (n = 1), F. mangiferae (n = 1), F. fujikuroi (n = 1), F. proliferatum (n = 3), F. incarnatum (n = 2), Penicillium oxalicum (n = 2), P. polonicum (n = 2), P. citrinum (n = 11), Aspergillus flavus (n = 10), A. tubingensis (n = 1), Cladosporium tenuissimum (n = 3), Aureobasidium pullulans (n = 3), Curvularia lunata (n = 1), and Epicoccum sorghinum (n = 1) were identified. Pathogenicity test showed that all endophytic fungi induced varying severities of disease symptoms on corn plants such as leaf chlorosis and necrosis, stem malformation, wilt, and stunted growth with F. verticillioides being the most virulent. The study revealed that corn tissues harbour diverse genera of endophytic fungi that can infect corn plants and may cause harmful effects to the host plants. [ABSTRACT FROM AUTHOR]

Abstract Objectives The ascomycotic yeast-like fungus Aureobasidium exhibits the natural ability to synthesize several secondary metabolites, like polymalic acid, pullulan, or polyol lipids, with potential biotechnological applications. Combined with its polyextremotolerance, these properties make Aureobasidium a promising production host candidate. Hence, plenty of genomes of Aureobasidia have been sequenced recently. Here, we provide the annotated draft genome sequence of the polyol lipid-producing strain A. pullulans NRRL 62042. Data description The genome of A. pullulans NRRL 62042 was sequenced using Illumina NovaSeq 6000. Genome assembly revealed a genome size of 24.2 Mb divided into 39 scaffolds with a GC content of 50.1%. Genome annotation using Genemark v4.68 and GenDBE yielded 9,596 genes.

Abstract Background Aureobasidium pullulans is a generalist polyextremotolerant black yeast fungus. It tolerates temperatures below 0 °C or salt concentrations up to 18%, among other stresses. A. pullulans genome sequencing revealed a high potential for producing bioactive metabolites. Only few molecular tools exist to edit the genome of A. pullulans, hence it is important to make full use of its potential. Two CRISPR/Cas9 methods have been proposed for the protoplast-based transformation of A. pullulans. These methods require the integration of a marker gene into the locus of the gene to be deleted, when the deletion of this gene does not yield a selectable phenotype. We present the adaptation of a plasmid-based CRISPR/Cas9 system developed in Aspergillus niger for A. pullulans to create deletion strains. Results The A. niger CRISPR/Cas9 plasmid led to efficient genomic deletions in A. pullulans. In this study, strains with deletions ranging from 30 to 862 bp were obtained by using an AMA1 plasmid-based genome editing strategy. Conclusion The CRISPR/Cas9 transformation system presented in this study provides new opportunities for strain engineering of A. pullulans. This system allows expression of Cas9 and antibiotic resistance while being easy to adapt. This strategy could open the path to intensive genomic engineering in A. pullulans.

Due to its unique physicochemical properties, Pullulan is an exopolysaccharide with many applications in the food, biomedical, and pharmaceutical industries. Aiming to reduce its production cost, an interesting alternative is to consider other possibilities of raw materials, including the production of this biopolymer in a lignocellulosic biorefinery concept. Xylose is the main sugar of hemicellulosic hydrolysates obtained from different biomasses, and it is a sugar still not extensively exploited regarding its potential for pullulan production. This study aimed to evaluate the production of pullulan from sugarcane bagasse hemicellulosic hydrolysate by cultivating Aureobasidium pullulans ATCC 42023 in a bubble column reactor. The hemicellulosic hydrolysate was obtained through dilute acid treatment carried out in a stirred tank reactor before being detoxified to remove microbial growth inhibitors. The maximum concentration of 28.62 ± 1.43 g/L of pullulan was obtained after 120 h of fermentation in a bubble column reactor in batch mode. Analysis of spectroscopic properties through FTIR of the obtained pullulan revealed α-(1→6)-linked maltosyl units, similar to those of commercial samples of the biopolymer. XRD analysis showed that the prepared pullulan is amorphous, and a homogeneous morphology with a smooth surface of the pullulan was observed in SEM analysis. This study showed the potential of the production of pullulan from sugarcane bagasse hemicellulosic hydrolysate in a bubble column bioreactor, an alternative strategy for the industrial production of this biopolymer. [ABSTRACT FROM AUTHOR]

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A high-yielding microbial polysaccharide-producing strain, named RM1603, was isolated from rhizosphere soil and identified by morphological and phylogenetic analysis. The extracellular polysaccharides (EPS) were identified by thin-layer chromatography and infrared spectroscopy. The fermentation conditions were optimized by single factor experiments in shake flasks and a 5-L fermentor. The results of morphological and phylogenetic tree analysis showed that RM1603 was a strain of Aureobasidium pullulans. Its microbial polysaccharide was identified as pullulan, and the EPS production capacity reached 33.07 ± 1.03 g L−1 in shake flasks. The fermentation conditions were optimized in a 5-L fermentor, and were found to encompass an initial pH of 6.5, aeration rate of 2 vvm, rotor speed of 600 rpm, and inoculum size of 2 %. Under these conditions, the pullulan yield of RM1603 reached 62.52 ± 0.24 g L−1. Thus, this study contributes RM1603 as a new isolation with high-yielding pullulan and potential application value in biotechnology. [ABSTRACT FROM AUTHOR]

Biofinish is an innovative wood protection system inspired by biological processes. It enhances the hydrophobicity of wood through oil treatment, resulting in improved dimensional stability. Living cells of the fungus Aureobasidium pullulans effectively protect wood from deterioration caused by other decaying fungi. The melanin pigment produced by the fungus provides an appealing dark surface and additionally protects the wood substrate against UV radiation. The significant advantage of Biofinish is its remarkable self-healing ability, which distinguishes it from conventional wood protection methods. This research aimed to explore fungal species colonising surfaces exposed to natural weathering and assess the survival of A. pullulans on wood surfaces coated with Biofinish during its in-service period. This study was performed on a facade composed of European larch wood (Larix decidua) treated with linseed oil and coated with Biofinish at the InnoRenew CoE building in Izola, Slovenia, following a 9-month exposure period. The majority of the detected species belonged to the genera Aureobasidium. The results indicated the survival and effective antagonistic action of A. pullulans, the living and active ingredient of the coating, against other wood-decaying fungi. [ABSTRACT FROM AUTHOR]

Verticillium wilt of olive (VWO) caused by Verticillium dahliae is considered a major olive (Olea europaea) disease in Mediterranean-type climate regions. The lack of effective chemical products against VWO makes it necessary to search for alternatives such as biological control. The main goal of this study was to evaluate the effect of six Streptomyces spp. strains as biological control agents (BCAs) against VWO. All of them were molecularly characterized by sequencing 16S or 23S rRNA genes and via phylogenetic analysis. Their effect was evaluated in vitro on the mycelial growth of V. dahliae (isolates V004 and V323) and on microsclerotia (MS) viability using naturally infested soils. Bioassays in olive plants inoculated with V. dahliae were also conducted to evaluate their effect against disease progress. In all the experiments, the reference BCAs Fusarium oxysporum FO12 and Aureobasidium pullulans AP08 were included for comparative purposes. The six strains were identified as Streptomyces spp., and they were considered as potential new species. All the BCAs, including Streptomyces strains, showed a significant effect on mycelial growth inhibition for both V. dahliae isolates compared to the positive control, with FO12 being the most effective, followed by AP08, while the Streptomyces spp. strains showed an intermediate effect. All the BCAs tested also showed a significant effect on the inhibition of germination of V. dahliae MS compared to the untreated control, with FO12 being the most effective treatment. Irrigation treatments with Streptomyces strain CBQ-EBa-21 or FO12 were significantly more effective in reducing disease severity and disease progress in olive plants inoculated with V. dahliae compared to the remaining treatments. This study represents the first approach to elucidating the potential effect of Streptomyces strains against VWO. [ABSTRACT FROM AUTHOR]

Different preventive strategies are needed to minimize the intake risks of mycotoxins, including zearalenone (ZEN). The aim of this study was to determine the ZEN adsorption ability of an autolyzed biomass preparation of polymorphic yeast Aureobasidium pullulans A.p.-3. The evaluation of the antitoxic properties of the preparation was also performed in relation to Saccharomyces cerevisiae yeast (ATCC 2366, ATCC 7090 and ATCC 9763) used as a model cell exposed to a toxic ZEN dose. The preparation at a dose of 5 mg/mL showed the adsorption of ZEN present in model systems at concentrations between 1 μg/mL to 100 μg/mL. The highest degree of adsorption was established for ZEN concentrations of 1 μg/mL and 5 μg/mL, becoming limited at higher doses of the toxin. Based on the Langmuir model of adsorption isotherms, the predicted maximum ZEN adsorption was approx. 190 µg/mL, regardless of pH. The growth of three strains of S. cerevisiae yeast cells in the medium with ZEN at concentrations within the range of 1.56 μg/mL–100 μg/mL was analyzed to determine the minimum inhibitory concentration. The growth of all tested strains was especially limited by high doses of ZEN, i.e., 50 and 100 μg/mL. The protective effect of the tested preparation was noted in relation to yeast cells exposed to toxic 100 μg/mL ZEN doses. The highest yeast cell growth (app. 36% percentage) was noted for a S. cerevisiae ATCC 9763 strain compared to the medium with ZEN but without preparation. More detailed tests determining the antitoxic mechanisms of the A. pullulans preparation are planned in the future, including cell culture bioassays and animal digestive tract models. [ABSTRACT FROM AUTHOR]

This study addresses the production enhancement of pullulan, an extracellular polysaccharide with various applications. Pullulan is primarily produced by Aureobasidium pullulans (A. pullulans), and genetic modification is commonly used to increase its yield. However, there is a need for a more efficient and safer method. To achieve this, we designed a high-throughput screening system utilizing a unique fluorescent protein specific to pullulan. Ultraviolet (UV) mutagenesis was applied to create a pool of mutant strains, and flow cytometry allowed for single-cell screening. Our approach yielded strain M1-B3, which exhibited a substantial increase in pullulan production from 26.5 g/L to 76.88 g/L. Additionally, the molecular weight of the produced pullulan significantly increased, expanding its potential commercial application. This study demonstrates an efficient and safe method to enhance pullulan production in A. pullulans. The UV mutagenesis and flow cytometry based on screening not only increased yield but also improved pullulan's molecular weight. The adaptability of this method to other polysaccharides and its potential for genomic analysis and broader applications make it a valuable tool in bioproduction. [ABSTRACT FROM AUTHOR]

Post-harvest decay of fresh table grapes causes considerable annual production losses. The main fungal agents of decay both in pre- and post-harvest are B. cinerea, Penicillium spp., Aspergillus spp., Alternaria spp., and Cladosporium spp. To date, the use of agrochemicals and SO2 are the main methods to control grape molds in pre- and postharvest, respectively. Significant improvements, however, have already been made in to apply innovative and more environmentally sustainable control strategies, such as Biological Control Agents (BCAs), which can reduce disease severity in both pre- and post-harvest. In this study, 31 new non-Saccharomyces yeast strains, isolated from berries of native Apulian table grape genotypes, were tested for their in vivo effectiveness against grey mold of table grapes, resulting in two St. bacillaris ('N22_I1' and 'S13_I3'), one S. diversa ('N22_I3'), one A. pullulans ('OLB_9.1_VL') and one H. uvarum ('OLB_9.1_BR') yeast strains that were marked as efficient and good BCAs. Their mechanisms of action were characterized through in vitro assays, and additional characteristics were evaluated to assess the economic feasibility and viability for future technological employment. Their effectiveness was tested by reducing the working concentration, their antagonistic effect on a wide range of fungal pathogens, their ability to survive in formulations with long shelf life, and their safety to human health. [ABSTRACT FROM AUTHOR]

Results of an experiment named "Test" on survival and variability of microorganisms in open space near the International Space Station are presented. It was found after two-years exposure, spore-forming bacteria of the species Bacillus subtilis, fungi of the species Aureobasidium pullulans and archaea of the species Methanosarcina mazei S-6T, deposited on cotton wool, are able to survive, and their numbers decreased equally, regardless of whether the microorganisms belong to different taxonomic groups. The main factors for the long-term survival could be the result of their dehydration and partial lyophilization in the vacuum of near-Earth space. For the first time, after being in outer space, cyst-like cells of the archaea strain M. mazeiS-6T and a 14-day delay in their growth were detected when cultured on a nutrient medium compared to the ground-based control strain. In 30% of fungi species strains A. pullulans, isolated after a two-year stay in outer space, the resistance to γ—radiation increased compared to the control strain. It was found that the reaction to the action of various concentrations of hydrogen peroxide and 1% chlorine in the surviving strains of the fungus A. pullulans on the ISS is less pronounced than in the control strain. [ABSTRACT FROM AUTHOR]

Textile industries are growing rapidly due to increased demand for textile products worldwide. The discharge of textile effluent containing synthetic dyes, chlorides, pigments, aromatic compounds, and heavy metals contributes substantially to water pollution due to its toxicity and chemical composition. This work is focused on the potential usage of treated Aureobasidium pullulans biomass (TAPB) to remove the toxic chemical pollutant, Methylene Blue (MB), from an aqueous solution. Experimental results found that maximum MB removal of 76.5% was observed using TAPB dosage of 3 g/L, initial pH 8.0, temperature 30 (C, and initial MB concentration of 50 mg/L. The maximum biosorption capacity of TAPB was found to be 113.75 mg/g using the Langmuir non-linear approach. Successive biosorption and desorption experiments showed better regeneration capacity of TAPB until the fourth trial. These results demonstrated that maximum MB removal (%) could be possible with a small quantity of biomass, consequently offering a minimum size of the contactor and less capital cost requirement for biosorption. It also showed a greater regeneration capacity biosorbent for removing MB. Hence, the feedstock consumption for MB removal could be considerably decreased in large-scale processes. [ABSTRACT FROM AUTHOR]

The zoonotic pathogens Salmonella spp. infection disrupted intestinal epithelial barrier function and induced local gastroenteritis and systemic inflammation in humans and animals. Sophy β-glucan, a water-soluble β-1,3/1,6-glucan synthesized from the black yeast Aureobasidium pullulans, was reported with immune-regulatory, anti-inflammatory, and anti-infective properties. Here, we investigated the protective role of sophy β-glucan on Salmonella enterica serotype Enteritidis (SE)-challenged Caco-2 cells monolayer and explored underlying action mechanisms. The results showed that pretreatment with sophy β-glucan blocked the adhesion and invasion of SE onto Caco-2 cells along with alleviating SE-induced epithelial barrier injury, as evidenced by increased trans-epithelial electrical resistance, decreased fluorescently-labeled dextran 4 flux permeability, and an enhanced Claudin-4 protein level in the SE-stimulated Caco-2 cell monolayer. Moreover, treatment with β-glucan down-regulated pro-inflammatory factors (IL-1β, IL-8, and TNF-α) while up-regulating anti-inflammatory factors IL-10 at mRNA and protein levels in SE-infected Caco-2 cells. Furthermore, sophy β-glucan strengthened the anti-oxidative capacity of Caco-2 monolayers cells by elevating T-AOC and SOD activity and inhibiting MDA production defending SE. Together, our data showed that sophy β-glucan could prevent intestinal epithelial injury induced by SE, possibly by exerting anti-oxidant and anti-inflammatory properties, and it might be helpful for controlling SE infection. [ABSTRACT FROM AUTHOR]

Environmental concerns are gradually reducing the global yield capacity of agricultural systems, with climate change representing the most significant challenge. Globally, Potatoes are the most essential non-cereal crop. Therefore, understanding the potential impacts of climate change on potato production is crucial for maintaining future global food security. This study aims to explore the roles played by PGPMs in two distinct regions, which are characterized by different climatic conditions, to assess their influence on two potato varieties, namely Siena and Bellini. Inoculation with these strains, particularly the Aureobasidium pullulans strains Ach1-1 and Ach1-2, resulted in significant improvements in growth and yield. In 2018, impressive yields of 194.1 kg/0.05 ha and 186.6 kg/0.05 ha were recorded for the two strains, with the Ain Taoujdate site achieving yields of 157.1 kg/0.05 ha and 151.1 kg/0.05 ha for each of the two strains. Additionally, further observations revealed that the Siena variety is more susceptible to rot than the Bellini variety. However, Ach1-1 and Ach1-2 strains had a significant effect on this rot, showcasing their potential to mitigate this negative issue in the Bellini variety. These promising results underscore the potential of PGPMs to enhance potato production in the Fez–Meknes region of Morocco, contributing to global food security amid climate change.

Environmental concerns are gradually reducing the global yield capacity of agricultural systems, with climate change representing the most significant challenge. Globally, Potatoes are the most essential non-cereal crop. Therefore, understanding the potential impacts of climate change on potato production is crucial for maintaining future global food security. This study aims to explore the roles played by PGPMs in two distinct regions, which are characterized by different climatic conditions, to assess their influence on two potato varieties, namely Siena and Bellini. Inoculation with these strains, particularly the Aureobasidium pullulans strains Ach1-1 and Ach1-2, resulted in significant improvements in growth and yield. In 2018, impressive yields of 194.1 kg/0.05 ha and 186.6 kg/0.05 ha were recorded for the two strains, with the Ain Taoujdate site achieving yields of 157.1 kg/0.05 ha and 151.1 kg/0.05 ha for each of the two strains. Additionally, further observations revealed that the Siena variety is more susceptible to rot than the Bellini variety. However, Ach1-1 and Ach1-2 strains had a significant effect on this rot, showcasing their potential to mitigate this negative issue in the Bellini variety. These promising results underscore the potential of PGPMs to enhance potato production in the Fez–Meknes region of Morocco, contributing to global food security amid climate change. [ABSTRACT FROM AUTHOR]

The effect of three independent variables (i.e., tyrosine, sucrose, and incubation time) on melanin production by Aureobasidium pullulans AKW was unraveled by two distinctive approaches: response surface methodology (i.e. Box Behnken design (BBD)) and artificial neural network (ANN) in this study for the first time ever using a simple medium. Regarding BBD, sucrose and incubation intervals did impose a significant influence on the output (melanin levels), however, tyrosine did not. The validation process exhibited a high consistency of BBD and ANN paradigms with the experimental melanin production. Concerning ANN, the predicted values of melanin were highly comparable to the experimental values, with minor errors competing with BBD. Highly comparable experimental values of melanin were achieved upon using BBD (9.295 ± 0.556 g/L) and ANN (10.192 ± 0.782 g/L). ANN accurately predicted melanin production and showed more improvement in melanin production by about 9.7% higher than BBD. The purified melanin structure was verified by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction pattern (XRD), and thermogravimetric analysis (TGA). The results verified the hierarchical architecture of the particles as small compasses by SEM analysis, inter-layer spacing in the XRD analysis, maximal atomic % for carbon, and oxygen atoms in the EDX analysis, and the great thermal stability in the TGA analysis of the purified melanin. Interestingly, the current novel endophytic strain was tyrosine-independent, and the uniquely applied ANN paradigm was more efficient in modeling the melanin production with appreciate amount on a simple medium in a relatively short time (168 h), suggesting additional optimization studies for further maximization of melanin production. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aureobasidium pullulans (A. pullulans), 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. pullulans respond to external pH remain to be fully understood. In this study, we first sequenced the whole genome of A. pullulans using Nanopore technology and generated a circle map. Subsequently, we explored the biomass, pullulan production, melanin production, and polymalic acid production of A. pullulans 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 A. pullulans using SEM and TEM. Our observations revealed that A. pullulans 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 A. pullulans 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 A. pullulans regulates itself in diverse pH settings and offers valuable guidance for developing and applying engineered strains. [ABSTRACT FROM AUTHOR]

This study analyzed the impact of LED light on bioemulsifier production by Aureobasidium pullulans LB83 in solid-state fermentation (SSF) using pre-treated sugarcane bagasse (PSB). The biomass was subjected to alkaline pre-treatment and conducted fermentations in Erlenmeyer flasks containing 2 g of PSB that were immersed in a humectant solution with a cell concentration of 108 cells/mL. The screening involved varying LED light wavelengths (green, red, orange, and blue) over a 7-day period at 28 °C. Notably, under the influence of blue light, the process achieved maximum production, yielding an EI24% of 63.9% and 45.1% for soybean oil and kerosene, respectively. Prolonged exposure to blue light for 11 days at 28 °C resulted in maximum bioemulsifier production (75%) and cellulolytic enzyme activity (3.67 IU g−1 for endoglucanase and 0.41 IU g−1 for exoglucanase) with soybean oil and kerosene. Experiments in a bioreactor, with varying light conditions (dark, white light, and blue LED light), demonstrated that the blue LED bioreactor outperformed others, achieving EI24% values of 55.0% and 45.7% for soybean oil and kerosene, respectively. The scanning electron microscopy (SEM) confirmed yeast growth under these conditions after 9 days. Our findings highlight the significant potential of LED light to enhance bioemulsifier production by A. pullulans LB83 from PSB. [ABSTRACT FROM AUTHOR]

Aspergillus parasiticus and Aspergillus ochraceus 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, Aureobasidium pullulans PP3 and Saitozyma podzolicus D10, in the biological control of A. parasiticus and A. ochraceus 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 A. pullulans 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. [ABSTRACT FROM AUTHOR]

The Korean fir tree Abies koreana, an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to enhance A. koreana drought tolerance using a black yeast-like fungus identified as Aureobasidium pullulans (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 Cystofilobasidium and Mortierella, known biocontrol agents and phosphate solubilizers. A notable reduction in the phytopathogenic Fusarium levels was observed with AK10, alongside an increase in beneficial bacteria, including Azospirillum and Nitrospirillum. Furthermore, the conducted correlation analysis shed light on microbial interrelationships within the rhizosphere, elucidating potential co-associations and antagonisms. Taken together, the isolated A. pullulans AK10 identified in this study serves as a potential biostimulant, enhancing the drought tolerance in A. koreana through beneficial alterations in the rhizosphere microbiome. This approach presents a promising strategy for the conservation of this endangered species. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 Aureobasidium pullulans 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. [ABSTRACT FROM AUTHOR]

Objective: The aim of this research was the isolation, structure elucidation and evaluation of the bioactivity of natural products produced by an Aureobasidium pullulans fungal endophyte of the medicinal plant Thuja occidentalis. Methods: The natural products were isolated from an extract of A. pullulans culture broth by reversed-phase chromatography and their structures were elucidated based on analysis of HRESIMS and 1D/2D NMR data. The absolute configurations of the compounds were assigned by comparison of their electronic circular dichroism (ECD) and optical rotatory dispersion (ORD) data with values obtained for Boltzmann-weighted conformer ensembles calculated by density functional theory. Results/Conclusion: Two new C11-polyketides, aureobasidol A (1) and B (2), were isolated from the A. pullulans extract. Both polyketides showed selective but weak inhibitory activity against Mycobacterium tuberculosis in vitro. [ABSTRACT FROM AUTHOR]

The growth of four commercial biocontrol agents (BCAs: Bacillus amyloliquefaciens (BAD), Aureobasidium pullulans (APD), Metschnikowia fructicola (MFN), and Trichoderma atroviride (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 B. cinerea 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 B. cinerea. [ABSTRACT FROM AUTHOR]

Biological control agents (BCAs) are a promising option for managing postharvest diseases. Their environmentally friendly nature makes them valuable for sustainable and eco-friendly postharvest disease management. This study evaluated the antagonistic potential of epiphytic yeasts isolated from a local apple genotype known as "Niğde Elması" and a range of wild fruits: rosehip, hawthorn, and wild pear. There were 375 yeast isolates obtained and screened in vitro and in vivo. Initially selected were 32 isolates able to inhibit the growth of Alternaria alternata mycelia in the in vitro experiments and identified using molecular methods as candidate BCAs. These isolates were identified as Aureobasidium pullulans using sequence analysis of the internal transcribed spacer (ITS) and the translation elongation factor EF-1α gene (EF1α). Based on two rounds of in vivo screening, four isolates were subsequently selected for their capability to control the infection of apple fruits under high inoculum pressure. Finally, their volatile and non-volatile antimicrobial activity was tested against Alternaria spp. These findings showed how wild fruits and a local apple genotype could represent a promising source for new BCA isolation. However, further studies are needed to reveal the mechanisms of action of these putative BCAs for application during the postharvest processing and storage of apples. [ABSTRACT FROM AUTHOR]

Polyol lipids (a.k.a. liamocins) produced by the polyextremotolerant, yeast-like fungus Aureobasidium pullulans are amphiphilic molecules with high potential to serve as biosurfactants. So far, cultivations of A. pullulans have been performed in media with complex components, which complicates further process optimization due to their undefined composition. In this study, we developed and optimized a minimal medium, focusing on biosurfactant production. Firstly, we replaced yeast extract and peptone in the best-performing polyol lipid production medium to date with a vitamin solution, a trace-element solution, and a nitrogen source. We employed a design of experiments approach with a factor screening using a two-level-factorial design, followed by a central composite design. The polyol lipid titer was increased by 56% to 48 g L−1, and the space-time yield from 0.13 to 0.20 g L−1 h−1 in microtiter plate cultivations. This was followed by a successful transfer to a 1 L bioreactor, reaching a polyol lipid concentration of 41 g L−1. The final minimal medium allows the investigation of alternative carbon sources and the metabolic pathways involved, to pinpoint targets for genetic modifications. The results are discussed in the context of the industrial applicability of this robust and versatile fungus.

Due to its unique physicochemical properties, Pullulan is an exopolysaccharide with many applications in the food, biomedical, and pharmaceutical industries. Aiming to reduce its production cost, an interesting alternative is to consider other possibilities of raw materials, including the production of this biopolymer in a lignocellulosic biorefinery concept. Xylose is the main sugar of hemicellulosic hydrolysates obtained from different biomasses, and it is a sugar still not extensively exploited regarding its potential for pullulan production. This study aimed to evaluate the production of pullulan from sugarcane bagasse hemicellulosic hydrolysate by cultivating Aureobasidium pullulans ATCC 42023 in a bubble column reactor. The hemicellulosic hydrolysate was obtained through dilute acid treatment carried out in a stirred tank reactor before being detoxified to remove microbial growth inhibitors. The maximum concentration of 28.62 ± 1.43 g/L of pullulan was obtained after 120 h of fermentation in a bubble column reactor in batch mode. Analysis of spectroscopic properties through FTIR of the obtained pullulan revealed α-(1→6)-linked maltosyl units, similar to those of commercial samples of the biopolymer. XRD analysis showed that the prepared pullulan is amorphous, and a homogeneous morphology with a smooth surface of the pullulan was observed in SEM analysis. This study showed the potential of the production of pullulan from sugarcane bagasse hemicellulosic hydrolysate in a bubble column bioreactor, an alternative strategy for the industrial production of this biopolymer.

In order to investigate the effect of different starch raw materials on pullulan biosynthesis by Aureobasidium pullulans, the starch derived from such crops as cassava, corn, potato, sweet potato and wheat was separately used as carbon source for fermentative production of pullulan polysaccharide. The results showed that cassava starch was beneficial to the biosynthesis of pullulan polysaccharide, and the maximum pullulan yield of 23.96 g/L was obtained. Sweet potato starch was not conducive to the biosynthesis of pullulan polysaccharide, and significantly (P

In an attempt to enhance the value of sugarcane leaf, xylan was extracted and used for xylooligosaccharide (XO) production via enzymatic hydrolysis using xylanase from the black yeast Aureobasidium pullulans. The xylan was extracted from sugarcane leaf using alkali extraction according to the response surface methodology. The highest xylan yield (99.42 ± 4.05 % recovery) was obtained using 14.32 % (w/v) NaOH, 13.25:1 liquid: solid ratio, at 121 °C and 15 lb.in2 for 32 min. Sugar composition and FTIR spectrum analyses confirmed its structure as arabinoxylan. The extracted arabinoxylan had a relatively high molecular weight compared to previous studies. Crude endoxylanase from A. pullulans NRRL 58523 was selected for enzymatic hydrolysis of the xylan. The enzyme hydrolyzed well at 50 °C, pH 4.0 and was relatively stable under this condition (87.38 ± 1.26 % of the activity remained after 60 h). XOs, especially xylobiose and xylotriose, were obtained at the maximum yield of 237.51 ± 17.69 mg/g xylan via endoxylanase hydrolysis under the optimum conditions (50 °C, pH 4.0, 65.31 U/g xylan, 53 h). XOs exhibited species-specific prebiotic activity toward three strains of Lactobacillus spp. but not toward Bifidobacterium spp.

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 (Aureobasidium pullulans) 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 A. pullulans and its extracellular melanin among equilibrium isotherms, kinetic study, and algorithmic decision tree modeling. [ABSTRACT FROM AUTHOR]

The organoleptic profile and quality of wine are affected by the presence of different non-Saccharomyces species and strains. Therefore, the identification and characterization of non-Saccharomyces 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-Saccharomyces 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-Saccharomyces yeast species belonging to 10 genera were identified, including Aureobasidium pullulans, Cryptococcus albidus, Cryptococcus sp., C. flavescens, C. terrestris, C. magnus, Cystofilobasidium ferigula, Candida zemplinina, Filobasidium magnum, Filobasidium sp., F. elegans, Hanseniaspora uvarum, Metschnikowia pimensis, M. pulcherrima, Naganishia albida, Pichia kluyveri, P. kudriavzevii, Rhodotorula glutinis and R. graminis. Hanseniaspora uvarum, C. zemplinina, and M. pulcherrima were the three most dominated species, while other non-Saccharomyces 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-Saccharomyces species in Ningxia, China, and made an important contribution of genetic resources for further strain development. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 Aureobasidium pullulans against Botrytis cinerea and Colletotrichum acutatum, casual agents of gray mold and anthracnose diseases in strawberry. Notably, this is the first time that A. pullulans has been tested against C. acutatum in strawberry. A. pullulans 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 B. cinerea and C. acutatum was reduced by up to 35 and 18%, respectively, when challenged with A. pullulans compared with control treatments. Likewise, culture filtrates of A. pullulans showed varying levels of antifungal activity against B. cinerea and C. acutatum, reducing the mycelial biomass by up to 90 and 72%, respectively. Furthermore, milk powder plate assays showed that A. pullulans 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 A. pullulans produced exophilins, liamocins, and free fatty acids known to have antifungal properties. A. pullulans shows high potential for successful biological control of strawberry diseases and discuss opportunities for further optimization of this beneficial fungus. [ABSTRACT FROM AUTHOR]

In this study, we aimed to isolate and phenotypically characterize non-Saccharomyces yeast strains (NSYSs) from the skin of aromatic (Italy) and non-aromatic (Negra Criolla) grapes from vineyards in Moquegua, Peru, typically used for the production of pisco. Our second objective was to characterize the volatile compounds and sensory attributes of pisco made from these grapes. Pichia terricola (56%), Metschnikowia pulcherrima (31%), and Naganishia vaughanmartiniae (13%) were the main NSYSs isolated from the skin of aromatic Italy grapes and identified; meanwhile, Vishniacozyma carnescens (50%), Vishniacozyma heimaeyensis (30%), and Aureobasidium pullulans (20%) were identified on the skin of the non-aromatic Negra Criolla grapes. These NSYSs showed different capacities in terms of carbohydrate fermentation, polygalacturonase activity, ethanol tolerance, sulphite production, and nitrogen consumption. Moreover, the pisco resulting from these varieties of grape had different volatile profiles. Terpene alcohols such as citronellol, geraniol, linalool, and nerol were found in pisco made from Italy grapes, while higher contents of 2-phenylacetate and ethyl esters were found in Negra Criolla Pisco. Intermediate levels of both 1-hexanol and bencyl alcohol were also found in all the pisco. Sensory analysis performed by a trained pisco tasting panel showed that citric, floral, alcohol, and syrup descriptors were more marked in Italy Pisco, while nuts, syrup, alcohol, and floral were the most intense attributes of Negra Criolla Pisco. These results will contribute to determining the potential of indigenous grape yeasts from the Moquegua region as fermentation starters to improve the typical sensory qualities of the pisco produced in this region, which deserves further study. [ABSTRACT FROM AUTHOR]

Pullulan is a commercially available exopolymer biosynthesized by Aureobasidium pullulans supplemented with nitrogen, carbon and other vital components through submerged and solid-state fermentation. These nutrients are very expensive and it raises the cost for the production of pullulan. Hence, the need of alternative cost-effective raw materials for its production is a prerequisite. Owing to its unique physicochemical features, pullulan has various applications in the food, pharmacological, and biomedical domains. Food industrial wastes generate a considerable number of by-products which accumulates and has a negative influence on the environment. These by-products are made up of proteins, carbohydrates, and other components, can be employed as substrates for the production of pullulan. The present review briefs on the pullulan production using food processing waste and by-products and the elements that impact it. It provides an insight into versatile applications of pullulan in food industries. Various challenges and future prospects in the field of research on pullulan production have been uncovered. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is associated with an immune response caused by the excessive production of IgE antibodies. This is accompanied by excessive itching as a clinical symptom, leading to a great burden and anxiety in daily life. At present, there is no established treatment that can completely cure AD, and symptomatic treatment alleviates symptoms to the extent that they do not interfere with daily life. Recent research has suggested that the ingestion of either various lactic acid bacteria or β-glucan suppressed the production of IgE antibodies and alleviated the symptoms of AD. Therefore, in this study, we used a drug-induced AD mouse model to evaluate the amelioration effect of EC-12 and β-glucan derived from black yeast to investigate the mechanism involved. The oral administration of lactic acid bacteria inhibited the expression of inflammatory cytokine genes at the lesion site, and the administration of β-glucan downregulated serum IgE levels and inhibited the expression of inflammatory cytokine genes at the lesion site. The concomitant administration of EC-12 and β-glucan strongly suppressed AD symptoms, downregulated serum IgE levels, and inhibited the expression of inflammatory cytokines at the lesion site. In summary, the oral administration of EC-12 and β-glucan prevented AD in mice. [ABSTRACT FROM AUTHOR]

Fire blight, caused by Erwinia amylovora, is a devastating disease of apple. Blossom Protect, a product that contains Aureobasidium pullulans as the active ingredient, is one of the most effective biological controls of fire blight. It has been postulated that the mode of action of A. pullulans is to compete against and antagonize epiphytic growth of E. amylovora on flowers, but recent studies have found that flowers treated with Blossom Protect harbored similar to or only slightly reduced E. amylovora populations compared with nontreated flowers. In this study, we tested the hypothesis that A. pn/Zu/ans-mediated biocontrol of fire blight is the result of induced host resistance. We found that PR genes in the systemic acquired resistance pathway, but not genes in the induced systemic resistance pathway, were induced in hypanthial tissue of apple flowers after the Blossom Protect treatment. Additionally, the induction of PR gene expression was coupled with an increase of plant-derived salicylic acid in this tissue. After inoculation with E. amylovora, PR gene expression was suppressed in nontreated flowers, but in flowers pretreated with Blossom Protect, the heightened PR expression offset the immune repression caused by E. amylovora, and prevented infection. Temporal and spatial analysis of PR gene induction showed that induction of PR genes occurred 2 days after the Blossom Protect treatment, and required direct flower-yeast contact. Finally, we observed deterioration of the epidermal layer of the hypanthium in some of the Blossom Protect-treated flowers, suggesting that PR gene induction in flowers may be a result of pathogenesis by A. pullulans. [ABSTRACT FROM AUTHOR]

Die Weinrebe stellt ein natürliches Reservoir ansässiger mikrobieller Ressourcen dar, die in ein komplexes Mikroökosystem eingebettet ist. Ziel dieser Studie war herauszufinden, welche Keime sich im Blutungssaft befinden. Die Gewinnung des Blutungssaftes erfolgte mittels einer sauberen, mit Alkohol desinfizierten PET-Flasche. Nach erfolgter Anreicherung wurde die DNA-Extraktion mit anschließender NGS-Analyse mit der Zielregion V1V3 untersucht und die erhaltenen Sequenzen mit der NCBI-Datenbank abgeglichen. Die dominantesten Gattungen in den Rebstöcken waren Pseudomonas und Massilia, gefolgt von den Gattungen Zoogloea, Bacillus, Idonella, Sphingomonas und Paenibacillus. Zusätzlich konnte der hefeähnliche Mikroorganismus Aureobasidium pullulans bei zwei Rebstöcken bestimmt werden sowie wenige andere Bakteriengattungen, die vereinzelt auftreten. Die literarisch beschriebene hemmende Interaktion zwischen Pseudomonas und Aureobasidium konnte auch in unserer Studie bestätigt werden. Alle im Blutungssaft bestimmten Mikroorganismen haben generell einen pflanzenstärkenden Einfluss und stellen eine Basis für eine Besiedlung in gewebespezifische Pflanzenteile dar.

Different preventive strategies are needed to minimize the intake risks of mycotoxins, including zearalenone (ZEN). The aim of this study was to determine the ZEN adsorption ability of an autolyzed biomass preparation of polymorphic yeast Aureobasidium pullulans A.p.-3. The evaluation of the antitoxic properties of the preparation was also performed in relation to Saccharomyces cerevisiae yeast (ATCC 2366, ATCC 7090 and ATCC 9763) used as a model cell exposed to a toxic ZEN dose. The preparation at a dose of 5 mg/mL showed the adsorption of ZEN present in model systems at concentrations between 1 μg/mL to 100 μg/mL. The highest degree of adsorption was established for ZEN concentrations of 1 μg/mL and 5 μg/mL, becoming limited at higher doses of the toxin. Based on the Langmuir model of adsorption isotherms, the predicted maximum ZEN adsorption was approx. 190 µg/mL, regardless of pH. The growth of three strains of S. cerevisiae yeast cells in the medium with ZEN at concentrations within the range of 1.56 μg/mL–100 μg/mL was analyzed to determine the minimum inhibitory concentration. The growth of all tested strains was especially limited by high doses of ZEN, i.e., 50 and 100 μg/mL. The protective effect of the tested preparation was noted in relation to yeast cells exposed to toxic 100 μg/mL ZEN doses. The highest yeast cell growth (app. 36% percentage) was noted for a S. cerevisiae ATCC 9763 strain compared to the medium with ZEN but without preparation. More detailed tests determining the antitoxic mechanisms of the A. pullulans preparation are planned in the future, including cell culture bioassays and animal digestive tract models.

This study addresses the production enhancement of pullulan, an extracellular polysaccharide with various applications. Pullulan is primarily produced by Aureobasidium pullulans (A. pullulans), and genetic modification is commonly used to increase its yield. However, there is a need for a more efficient and safer method. To achieve this, we designed a high-throughput screening system utilizing a unique fluorescent protein specific to pullulan. Ultraviolet (UV) mutagenesis was applied to create a pool of mutant strains, and flow cytometry allowed for single-cell screening. Our approach yielded strain M1-B3, which exhibited a substantial increase in pullulan production from 26.5 g/L to 76.88 g/L. Additionally, the molecular weight of the produced pullulan significantly increased, expanding its potential commercial application. This study demonstrates an efficient and safe method to enhance pullulan production in A. pullulans. The UV mutagenesis and flow cytometry based on screening not only increased yield but also improved pullulan’s molecular weight. The adaptability of this method to other polysaccharides and its potential for genomic analysis and broader applications make it a valuable tool in bioproduction.

Introduction: Biopolymers, such as pullulan, a natural exopolysaccharide from Aureobasidium pullulans, and their nanocomposites are commonly used in the food, pharmaceutical, and medical industries due to their unique physical and chemical properties.Methods: Pullulan was synthesized by the A. pullulans ATCC 201253 strain. Nanocomposite films based on biosynthesized pullulan were prepared and loaded with different concentrations of silver nanoparticles (AgNPs) synthesized by the Fusarium culmorum strain JTW1. AgNPs were characterized by transmission electron microscopy, Zeta potential measurements, and Fourier-transform infrared spectroscopy. In turn, the produced films were subjected to physico-chemical analyses such as goniometry, UV shielding capacity, attenuated total reflection–Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy, and their mechanical and degradation properties were assessed. The antibacterial assays of the nanoparticles and the nanocomposite films against both food-borne and reference pathogens, including Listeria monocytogenes, Salmonella infantis, Salmonella enterica, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, were performed using standard methods.Results: AgNPs were small (mean 15.1 nm), spherical, and displayed good stability, being coated with protein biomolecules. When used in higher concentrations as an additive to pullulan films, they resulted in reduced hydrophilicity and light transmission for both UV-B and UV-A lights. Moreover, the produced films exhibited a smooth surface. Therefore, it can be concluded that the addition of biogenic AgNPs did not change the morphology and texture of the films compared to the control film. The nanoparticles and nanocomposite films demonstrated remarkable antibacterial activity against both food-borne and reference bacteria. The highest activity of the prepared films was observed against L. monocytogenes.Discussion: The obtained results suggest that the novel nanocomposite films prepared from biosynthesized pullulan and AgNPs can be considered for use in the development of medical products and food packaging. Moreover, this is the first report on pullulan-based nanocomposites with mycogenic AgNPs for such applications.

Saccharomyces cerevisiae, an essential player in alcoholic fermentation during winemaking, is rarely found in intact grapes. Although grape-skin environment is unsuitable for S. cerevisiae's stable residence, Saccharomycetaceae-family fermentative yeasts can increase population on grape berries after colonization during raisin production. Here, we addressed adaptation of S. cerevisiae to grape-skin ecosystem. The yeast-like fungus Aureobasidium pullulans, a major grape-skin resident, exhibited broad spectrum assimilation of plant-derived carbon sources, including ω-hydroxy fatty acid, arising from degradation of plant cuticles. In fact, A. pullulans encoded and secreted possible cutinase-like esterase for cuticle degradation. When intact grape berries were used as a sole carbon source, such grape-skin associated fungi increased the accessibility to fermentable sugars by degrading and assimilating the plant cell wall and cuticle compounds. Their ability seems also helpful for S. cerevisiae to obtain energy through alcoholic fermentation. Thus, degradation and utilization of grape-skin materials by resident microbiota may account for their residence on grape-skin and S. cerevisiae's possible commensal behaviors. Conclusively, this study focused on the symbiosis between grape-skin microbiota and S. cerevisiae from the perspective of winemaking origin. Such plant–microbe symbiotic interaction may be a prerequisite for triggering spontaneous food fermentation. [ABSTRACT FROM AUTHOR]

Although intestinal microbiota play crucial roles in fish digestion and health, little is known about intestinal fungi in fish. This study investigated the intestinal fungal diversity of three coral reef fish (Lates calcarifer, Trachinotus blochii, and Lutjanus argentimaculatus) from the South China Sea using a culturable method. A total of 387 isolates were recovered and identified by sequencing their internal transcribed spacer sequences, belonging to 29 known fungal species. The similarity of fungal communities in the intestines of the three fish verified that the fungal colonization might be influenced by their surrounding environments. Furthermore, the fungal communities in different intestines of some fish were significantly different, and the number of yeasts in the hindgut was less than that in fore- and mid-intestines, suggesting that the distribution of fungi in fishes' intestines may be related to the physiological functions of various intestinal segments. In addition, 51.4% of tested fungal isolates exhibited antimicrobial activity against at least one marine pathogenic microorganism. Notably, isolate Aureobasidium pullulans SCAU243 exhibited strong antifungal activity against Aspergillus versicolor, and isolate Schizophyllum commune SCAU255 displayed extensive antimicrobial activity against four marine pathogenic microorganisms. This study contributed to our understanding of intestinal fungi in coral reef fish and further increased the library of fungi available for natural bioactive product screening. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we used an obese and diabetic mouse model to compare two strains of Aureobasidium pullulans (AFO-202 and N-163) produced beta-glucans (β-glucans), which alleviate lipotoxicity. Methods: Four groups of KK-Ay mice were used, with six subjects in each group. Group 1: sacrificed on day 0 for baseline values; Group 2: control (drinking water); Group 3: AFO-202 beta glucan—200 mg/kg/day; Group 4: N-163 beta glucan—300 mg/kg/day for 28 consecutive days. Results: Group 4 (N-163) had the lowest non-esterified fatty acids (NEFA) levels and marginally decreased triglyceride levels compared to the other groups. There were no significant differences in blood glucose, hemoglobin A1c (HbA1c), triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol levels. N-163 β-glucans decreased NEFA levels after 28 days. Conclusion: These results, although modest, warrant further in-depth research into lipotoxicity and associated inflammatory cascades in both healthy and diseased subjects for the prevention and management of metabolic dysregulation and associated diseases such as non-alcoholic fatty liver disease (NAFLD). [ABSTRACT FROM AUTHOR]