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1.
Environ Res ; 214(Pt 2): 113947, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35931191

RESUMO

Pullulan and melanin have become important secondary metabolites that are now widely studied. In this study, a strain of Aureobasidium pullulans HIT-LCY3T 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 × 106 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 × 106 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.


Assuntos
Ascomicetos , Solanum tuberosum , Ascomicetos/metabolismo , Aureobasidium , Fermentação , Resíduos Industriais , Melaninas , Solanum tuberosum/química , Solanum tuberosum/metabolismo , Amido/química , Amido/metabolismo
2.
Curr Microbiol ; 79(10): 296, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35994212

RESUMO

Polygalacturonase (PGase) production by Aureobasidium pullulans P56 under submerged fermentation was investigated using agro-industrial wastes and commercial carbon and nitrogen sources. The maximum PGase concentration was equivalent to 8.6 U/mL that was obtained in presence of citrus pectin at 150 rpm, 30 °C, pH = 5.5, and 60 h of fermentation conditions. However, a significant amount of enzyme production was also recorded upon the utilization of corncob (5.3 U/mL) and wheat bran (4.4 U/mL) as carbon sources. Amongst the different nitrogen sources, the highest enzyme production (8.2 U/mL) was obtained in presence of ammonium sulphate and yeast extract simultaneously at a ratio of 1:1. The enzyme was partially purified by gel filtration using Sephadex G50 equilibrated and washed with 50 mM-sodium acetate buffer. The obtained yield and specific activity were determined equivalent to 17% and 9.53 U/mg, respectively. The molecular weight of the partially purified enzyme was estimated as 54 kDa on SDS-PAGE. The conditions affecting the enzyme activity were determined and the highest enzyme activity was recorded at 40 °C and 4.5 pH. Amongst the tested metal ions, 2 and 5 mM of CaCl2 concentrations increased the enzymatic activity by 30%. Overall, the use of corncob (2.5%) to produce PGase by A. pullulans represents an attractive agro-industrial substrate.


Assuntos
Resíduos Industriais , Poligalacturonase , Aureobasidium , Carbono , Fermentação , Concentração de Íons de Hidrogênio , Nitrogênio , Poligalacturonase/química , Poligalacturonase/metabolismo
3.
J Antibiot (Tokyo) ; 75(10): 589-592, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35986093

RESUMO

Biosurfactants have been widely used in various industrial fields including medicine, food, cosmetics, detergent, pulp and paper, and oil and fat degradation. The culture broth of Aureobasidium pullulans A11211-4-57 using glucose as carbon source exhibited potent surfactant activity. The culture broth was separated by column chromatographies using ODS, silica gel, and Sephadex LH-20 resins, consecutively, to provide two biosurfactants. Based on mass and NMR measurements, their structures were determined as myo-inositol lipids and named pullusurfactans F and G. These compounds showed a high degree of activity, with 27.25 mN/m and 24.07 mN/m, respectively, at 1.0 mg l-1, which is useful for washing and cleaning agents.


Assuntos
Ascomicetos , Erigeron , Ascomicetos/metabolismo , Aureobasidium , Tensoativos/química
4.
Bioprocess Biosyst Eng ; 45(10): 1673-1682, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35964262

RESUMO

Polymalic acid (PMA) is a water-soluble polyester produced by Aureobasidium pullulans. In this study, the physiological response of A. pullulans after the addition of vegetable oils was investigated. Soybean oil (SBO) is pivotal for shortening fermentation time and achieving high PMA titer. With the addition of 1% (w/v) SBO, the titer and productivity of PMA was, respectively, increased by 34.2% and 80%. SBO acted as a chemical stimulatory agent rather than a carbon source, the enhancement on PMA production was attributed to the component of fatty acid. SBO induced the dimorphism (yeast-like cells and mycelia) of A. pullulans, in vitro enzyme activities indicated that the TCA oxidative branch for malic acid synthesis might be strengthened, which could generate more ATP for PMA synthesis, and the assay of intracellular energy supply validated this deduction. This study provided a new sight for recognizing the regulatory behavior of SBO in A. pullulans.


Assuntos
Ascomicetos , Óleo de Soja , Trifosfato de Adenosina , Aureobasidium , Carbono/farmacologia , Ácidos Graxos , Fermentação , Malatos/farmacologia , Poliésteres , Polímeros , Óleo de Soja/farmacologia , Água
5.
Microbiol Spectr ; 10(4): e0145522, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35880866

RESUMO

Apples are affected by numerous fungi known as storage rots, which cause significant losses before and after harvest. Concerns about increasing antimicrobial resistance, bans on various fungicides, and changing consumer preferences are motivating the search for safer means to prevent fruit rot. The use of antagonistic microbes has been shown to be an efficient and environmentally friendly alternative to conventional phytopharmaceuticals. Here, we investigate the potential of Aureobasidium subglaciale for postharvest rot control. We tested the antagonistic activity of 9 strains of A. subglaciale and 7 closely related strains against relevant phytopathogenic fungi under conditions simulating low-temperature storage: Botrytis cinerea, Penicillium expansum, and Colletotrichum acutatum. We also investigated a selection of phenotypic traits of all strains and sequenced their whole genomes. The tested strains significantly reduced postharvest rot of apples at low temperatures caused by B. cinerea, C. acutatum (over 60%), and P. expansum (about 40%). Several phenotypic traits were observed that may contribute to this biocontrol capacity: growth at low temperatures, tolerance to high temperatures and elevated solute concentrations, and strong production of several extracellular enzymes and siderophores. Population genomics revealed that 7 of the 15 strains originally identified as A. subglaciale most likely belong to other, possibly undescribed species of the same genus. In addition, the population structure and linkage disequilibrium of the species suggest that A. subglaciale is strictly clonal and therefore particularly well suited for use in biocontrol. Overall, these data suggest substantial biological control potential for A. subglaciale, which represents another promising biological agent for disease control in fresh fruit. IMPORTANCE After harvest, fruits are often stored at low temperatures to prolong their life. However, despite the low temperatures, much of the fruit is lost to rot caused by a variety of fungi, resulting in major economic losses and food safety risks. An increasingly important environmentally friendly alternative to conventional methods of mitigating the effects of plant diseases is the use of microorganisms that act similarly to probiotics-occupying the available space, producing antimicrobial compounds, and consuming the nutrients needed by the rot-causing species. To find a new microorganism for biological control that is particularly suitable for cold storage of fruit, we tested different isolates of the cold-loving yeast Aureobasidium subglaciale and studied their phenotypic characteristics and genomes. We demonstrated that A. subglaciale can significantly reduce rotting of apples caused by three rot-causing molds at low temperatures and thus has great potential for preventing fruit rot during cold storage.


Assuntos
Ascomicetos , Malus , Ascomicetos/genética , Aureobasidium , Frutas/microbiologia , Camada de Gelo , Malus/microbiologia , Metagenômica , Controle Biológico de Vetores/métodos
6.
Mar Drugs ; 20(5)2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35621983

RESUMO

Marine fungi represent an important and sustainable resource, from which the search for novel biological substances for application in the pharmacy or food industry offers great potential. In our research, novel polysaccharide (AUM-1) was obtained from marine Aureobasidium melanogenum SCAU-266 were obtained and the molecular weight of AUM-1 was determined to be 8000 Da with 97.30% of glucose, 1.9% of mannose, and 0.08% galactose, owing to a potential backbone of α-D-Glcp-(1→2)-α-D-Manp-(1→4)-α-D-Glcp-(1→6)-(SO3-)-4-α-D-Glcp-(1→6)-1-ß-D-Glcp-1→2)-α-D-Glcp-(1→6)-ß-D-Glcp-1→6)-α-D-Glcp-1→4)-α-D-Glcp-6→1)-[α-D-Glcp-4]26→1)-α-D-Glcp and two side chains that consisted of α-D-Glcp-1 and α-D-Glcp-(1→6)-α-D-Glcp residues. The immunomodulatory effect of AUM-1 was identified. Then, the potential molecular mechanism by which AUM-1 may be connected to ferroptosis was indicated by metabonomics, and the expression of COX2, SLC7A11, GPX4, ACSL4, FTH1, and ROS were further verified. Thus, we first speculated that AUM-1 has a potential effect on the ferroptosis-related immunomodulatory property in RAW 264.7 cells by adjusting the expression of GPX4, regulated glutathione (oxidative), directly causing lipid peroxidation owing to the higher ROS level through the glutamate metabolism and TCA cycle. Thus, the ferroptosis related immunomodulatory effect of AUM-1 was obtained.


Assuntos
Ferroptose , Aureobasidium , Configuração de Carboidratos , Sequência de Carboidratos , Fungos , Polissacarídeos/farmacologia , Espécies Reativas de Oxigênio
7.
World J Microbiol Biotechnol ; 38(6): 107, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35507122

RESUMO

Liamocins and Massoia lactone have many applications. In this study, the glucose-derepressed mutant Δcrea5 in which the CREA gene was removed could produce 36.5 g/L of liamocins. Furthermore, overexpression of the MSN2 gene in the mutant Δcrea5 made the transformant M60 produce 41.4 g/L of liamocins and further overexpression of the GAL1 gene in the transformant M60 rendered the transformant G40 to produce 49.5 ± 0.4 g/L of liamocins during the 10-L fermentation while their wild type strain 9-1 made only 26.3 g/L of liamocins. The expressed transcription activators Msn2 and Gal1 were localized in the nuclei, promoting expression of the genes responsible for liamocins biosynthesis and sugar transport. Massoia lactone prepared from the produced liamocins could actively kill the spores of the pathogenic fungi from the diseased human skin by inhibiting spore germination and causing cellular necrosis of the fungal spores.


Assuntos
Aureobasidium , Lactonas , Fermentação , Humanos , Esporos Fúngicos/genética
8.
Carbohydr Polym ; 288: 119366, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35450628

RESUMO

Exopolysaccharide (EPS-1) was isolated from Aureobasidium pullulans CGMCC 23063 and purified with DEAE 650M and Sephadex G-100 column chromatography. The structural characteristics and immunomodulatory activity of EPS-1 were investigated. The results showed EPS-1 (294.9 KDa) was ß-glucan consisting of the backbone (1→3)-linked ß-Glcp and ß-(1,6)-branches by Ion chromatography, gas chromatography-mass spectrometry, and 1D/2D NMR spectroscopy. The SEM and AFM showed that EPS-1 composed spheres joined by triple-helix conformation into chains and circles. In vitro cell experiments, EPS-1 displayed immunological activity on the RAW264.7 cells. After being treated with EPS-1 (400 µg/mL), the concentration of NO, TNF-α, and IL-6 could reach 17.05 µM, 448.46 pg/mL, and 15.18 pg/mL, respectively. In addition, the cytokines mRNA levels also demonstrated the above results at the molecular level. The western-blot results demonstrated that the expression of phosphorylated p65 and p-erk associated with cytokine release, was increased with the dose of EPS-1.


Assuntos
Aureobasidium , beta-Glucanas , Animais , Citocinas , Camundongos , Polissacarídeos Bacterianos/química , Células RAW 264.7 , beta-Glucanas/química
9.
J Biotechnol ; 350: 11-16, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35398275

RESUMO

Species of the genus Aureobasidium are ubiquitous, polyextremotolerant, "yeast-like" ascomycetes used for the industrial production of pullulan and other products and as biocontrol agents in agriculture. Their application potential and wide-spread occurrence make Aureobasidium spp. interesting study objects. The availability of a fast and efficient genome editing method is an obvious advantage for future basic and applied research on Aureobasidium. In this study, we describe the development of a CRISPR/Cas9-based genome editing method using ribonucleoproteins (RNPs) in A. pullulans and A. melanogenum. We demonstrate that this method can be used for single and multiplex genome editing using only RNPs by targeting URA3 (encoding for orotidine-5'-phosphate decarboxylase), ADE2 (encoding for phosphoribosylaminoimidazole carboxylase) and ARG4 (encoding for argininosuccinate lyase). We demonstrate the applicability of Trichoderma reesei pyr4 and Aspergillus fumigatus pyrG to complement the URA3 deficiency. Further, we show that using RNPs improves the homologous recombination rate and 20 bp long homologous flanks are sufficient. Therefore, the repair cassettes can be constructed by a single PCR, abolishing the need for laborious and time-consuming cloning, which is necessary for previously described methods for CRISPR-mediated genome editing in these fungi. The here presented method allows fast and efficient genome editing for gene deletions, modifications, and insertions in Auresobasidium with a minimized risk of off-target effects.


Assuntos
Ascomicetos , Edição de Genes , Ascomicetos/genética , Aureobasidium , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Ribonucleoproteínas/genética , Saccharomyces cerevisiae/genética
10.
BMC Infect Dis ; 22(1): 335, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35382751

RESUMO

BACKGROUND: Aureobasidium melanigenum is a ubiquitous dematiaceous fungus that rarely causes invasive human infections. Here, we present a case of Aureobasidium melanigenum bloodstream infection in a 20-year-old man with long-term catheter use. CASE PRESENTATION: A 20-year-old man receiving home care with severe disabilities due to cerebral palsy and short bowel syndrome, resulting in long-term central venous catheter use, was referred to our hospital with a fever. After the detection of yeast-like cells in blood cultures on day 3, antifungal therapy was initiated. Two identification tests performed at a clinical microbiological laboratory showed different identification results: Aureobasidium pullulans from matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and Cryptococcus albidus from a VITEK2 system. Therefore, we changed the antifungal drug to liposomal amphotericin B. The fungus was identified as A. melanigenum by DNA sequence-based analysis. The patient recovered with antifungal therapy and long-term catheter removal. CONCLUSION: It is difficult to correctly identify A. melanigenum by routine microbiological testing. Clinicians must pay attention to the process of identification of yeast-like cells and retain A. melanigenum in cases of refractory fungal infection.


Assuntos
Cateteres Venosos Centrais , Micoses , Sepse , Adulto , Antifúngicos/uso terapêutico , Aureobasidium , Humanos , Masculino , Micoses/tratamento farmacológico , Sepse/tratamento farmacológico , Adulto Jovem
11.
Microbiol Res ; 260: 127041, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35483312

RESUMO

Aureobasidium melanogenum HN6.2 is a high siderophore-producing yeast-like fungal strain. After blocking siderophore biosynthesis and attenuating the expression of the ornithine carbamoyltransferase gene (the OTC gene), the obtained D-LCFAO-cre strain produced 2.1 ± 0.02 mg of intracellular L-ornithine per mg of the protein. The overexpression of the L-ornithine decarboxylase gene (the SPE1-S gene) from Saccharomyces cerevisiae in the mutant D-LCFAO-cre could make the transformant E-SPE1-S synthesize 3.6 ± 0.1 of intracellular ornithine per mg of protein and produce 10.5 g/L of putrescine. The further overexpression of the ArgB/C gene encoding bifunctional acetylglutamate kinase/N-acetyl-gamma-glutamyl-phosphate reductase in the transformant E-SPE1-S caused the transformant E-SPE1-S-ArgB/C to accumulate L-ornithine (4.2 mg/mg protein) and to produce 21.3 g/L of putrescine. During fed-batch fermentation, the transformant E-SPE1-S-ArgB/C could produce 33.4 g/L of putrescine, the yield was 0.96 g/g of glucose, and the productivity was 0.28 g/L/h. The putrescine titer was much higher than that produced by most engineered strains obtained thus far.


Assuntos
Engenharia Metabólica , Putrescina , Aureobasidium , Ornitina/genética , Saccharomyces cerevisiae/genética , Sideróforos
12.
Appl Microbiol Biotechnol ; 106(8): 2855-2868, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35445856

RESUMO

Poly(ß-L-malic acid) (PMLA) is a water-soluble, biodegradable, and biocompatible polymer with broad prospective applications and can be hydrolyzed to produce widely used acidulant L-malic acid. In order to meet an increasing demand of PMLA, we employed two effective cell-recycling strategies to produce PMLA from raw cassava hydrolysate by Aureobasidium pullulans ZD-3d. In fed-batch fermentation with raw cassava hydrolysate, 101.9 g/L PMLA was obtained with the productivity and yield of 0.77 g/L/h and 0.40 g/g, respectively. Further, three times of membrane filtration-based cell recycling fermentation was carried out, with a high productivity and yield of 1.04-1.64 g/L/h and 0.5-0.84 g/g achieved, respectively. While harnessing centrifugation-based cell recycling fermentation for five times, the productivity and yield approached 0.98-1.76 g/L/h and 0.78-0.86 g/g, respectively. To our knowledge, the processes showed the highest average PMLA productivity compared with others using low-cost biomass, which offered efficient and economical alternatives for PMLA production. KEY POINTS: • PMLA production from raw cassava hydrolysate by Aureobasidium pullulans was studied • High PMLA productivity and yield were obtained via two cell recycling strategies • The highest average PMLA productivity from low-cost biomass to date was achieved.


Assuntos
Manihot , Aureobasidium , Fermentação , Malatos/metabolismo , Manihot/metabolismo
13.
World J Microbiol Biotechnol ; 38(3): 52, 2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35132493

RESUMO

Xylanolytic enzymes are involved in xylan hydrolysis, the main ones being endo-ß-1,4-xylanases (xylanases). This can be applied in the bioconversion of lignocellulosic materials into value-added products such as xylooligosaccharides (XOS). This study aimed to establish a protocol for the purification of xylanases, as well as to characterize and apply the purified enzyme extract in the production of XOS. The enzyme purification techniques studied were ammonium sulfate ((NH4)2SO4) and ethanol precipitation. Purification of xylanase by fractional precipitation (20-60%) with (NH4)2SO4 was more efficient than with ethanol because the salt precipitation reached a purification factor of 10.27-fold and an enzymatic recovery of 48.6% The purified xylanase exhibited optimum temperature and pH of 50 °C and 4.5, respectively. The Michaelis-Menten constant using beechwood xylan for the enzyme was 74.9 mg/mL. The addition of salts such as CaCl2, ZnCl2, and FeCl3 in the reaction medium increased the xylanase activity. Xylanase showed greater thermal stability (half-life = 169 h) at 45 °C and pH 4.5. Under these conditions and in the presence of Ca2+ (10 mmol/L) the enzyme was even more stable (half-life = 231 h). Total XOS contents (6.7 mg/mL) and the conversion of xylan to XOS (22.3%) between 2 and 24 h were statistically equal. The hydrolysates showed the majority composition of xylobiose, xylotriose, and xylose. The addition of Ca2+ ions did not contribute to an increase in the total XOS content or to a greater conversion of xylan into XOS, but the hydrolysate was richer in xylobiose and had a lower xylose content.


Assuntos
Endo-1,4-beta-Xilanases , Glucuronatos , Aureobasidium , Hidrólise , Oligossacarídeos , Xilanos
14.
Curr Microbiol ; 79(3): 93, 2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35138484

RESUMO

Agro-industrial wastes are rich sources of some nutrients. Thus, utilization of wastes seems to be ecologically sound and economically advantageous. The aim of this work was to investigate the potential usage of various agro-industrial wastes as fermentation medium for pullulan production by a domestic strain; Aureobasidium pullulans AZ-6. In this study, different agro-industrial wastes; various citrus peels, grape pomace, the hydrolysates of hazelnut and chestnut shells, sugarcane molasses residue, dried and fresh hazelnut husks and pumpkin peel, were used as fermentation media without adding any extra nutritional component for pullulan production by A. pullulans AZ-6. As a result, among the tested media, the maximum pullulan concentration was obtained as 33.59 gL-1 using the sugarcane molasses residue, and followed by the corresponding value of 30.02 gL-1 obtained in the dried hazelnut husk hydrolysate medium. Therefore, the usage of agro-industrial wastes as fermentation media is considered to make pullulan production cost effective. In addition, waste treatment from this aspect solves a relevant environmental problem. In this study, sugarcane molasses residue and dried hazelnut husk hydrolysate were used directly as fermentation media for pullulan production for the first time. Pullulan production from sugarcane molasses residue and dried hazelnut husk hydrolysate media might be a promising substrate for economical point of view.


Assuntos
Ascomicetos , Resíduos Industriais , Aureobasidium , Fermentação , Glucanos , Resíduos Industriais/análise
15.
Bioprocess Biosyst Eng ; 45(3): 573-587, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35184225

RESUMO

Bacterial cellulose (BC) exhibits a unique combination of porosity, tensile strength, reticulated crystal structure and biocompatibility useful for many applications in the food, biomedical and other industries. Polysaccharide addition has been shown to improve the production and the mechanical properties of BC nanocomposites. This study examined the effect of pullulan on BC fermentation as well as the co-culturing of the BC producer with Aureobasidium pullulans, a fungal strain that produces pullulan as an exopolysaccharide. Results showed that a 1% pullulan addition improved Young's modulus of BC pellicles for sixfold. Addition of pullulan at 1.5% and 2% levels could increase the BC production from 0.447 to 0.814 and 1.997 g/L, respectively. The co-culture fermentation demonstrated a mixed effect on the aggregation and bundling of BC while resulting in a significant improvement in mechanical properties. The study provided a polysaccharide additive and a novel fermentation method to produce BC with improved properties.


Assuntos
Ascomicetos , Celulose , Acetobacteraceae , Ascomicetos/química , Aureobasidium , Celulose/química , Técnicas de Cocultura , Fermentação , Glucanos
16.
Int J Biol Macromol ; 202: 608-619, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35081435

RESUMO

Polymalate (PMA) produced by the whole genome duplicated strain Aureobasidium melanogenum OUC had a high molecular weight (Mw) of 3.9 × 105 Da while the Mw of PMA produced by A. melanogenum ATCC62921 was 3.8 × 104 Da. Therefore, the purified PMA produced by A. melanogenum OUC could form hydrogel and film and the precipitated Ca2+-PMA looked like noodle whereas the purified PMA produced by A. melanogenum ATCC62921 could not form such a hydrogel and a film and the precipitated PMA was powder-like. The high Mw PMA biosynthesis in A. melanogenum OUC was also controlled by the PMA synthetase. However, it was still unclear why the PMA synthetase in A. melanogenum OUC could catalyze the high Mw PMA biosynthesis. Both removal of two copies of the PKS genes and overexpression of the PYC1 gene, the VGB gene and the CRZ2 gene rendered the new transformant Crz46 to produce 34.6 ± 0.3 g/L of extracellular Ca2+-PMA with Mw of 4.9 × 105 Da while its native A. melanogenum OUC only produced 17.2 ± 0.3 g/L of Ca2+-PMA. During the 10-Liter fermentation, 35.6 ± 1.2 g/L of Ca2+-PMA and 13.9 g/Lof cell mass were produced within 168 h, leading to the yield of 0.36 g/g of glucose and the productivity of 0.21 g/L/h. This was the first time to report that the whole genome duplicated strain A. melanogenum OUC and its engineered mutants could produce the high Mw PMA.


Assuntos
Aureobasidium , Glucose , Fermentação , Peso Molecular
17.
Biotechnol Adv ; 55: 107898, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34974157

RESUMO

Aureobasidium spp. can use a wide range of substrates and are widely distributed in different environments, suggesting that they can sense and response to various extracellular signals and be adapted to different environments. It is true that their pullulan, lipid and liamocin biosynthesis and cell growth are regulated by the cAMP-PKA signaling pathway; Polymalate (PMA) and pullulan biosynthesis is controlled by the Ca2+ and TORC1 signaling pathways; the HOG1 signaling pathway determines high osmotic tolerance and high pullulan and liamocin biosynthesis; the Snf1/Mig1 pathway controls glucose repression on pullulan and liamocin biosynthesis; DHN-melanin biosynthesis and stress resistance are regulated by the CWI signaling pathway and TORC1 signaling pathway. In addition, the HSF1 pathway may control cell growth of some novel strains of A. melanogenum at 37 °C. However, the detailed molecular mechanisms of high temperature growth and thermotolerance of some novel strains of A. melanogenum and glucose derepression in A. melanogenum TN3-1 are still unclear.


Assuntos
Aureobasidium , Saccharomyces cerevisiae , Glucose/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Saccharomyces cerevisiae/metabolismo , Transdução de Sinais
18.
Biomed Pharmacother ; 145: 112243, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34840031

RESUMO

OBJECTIVE: In this pilot clinical study, we report the beneficial effects of beta glucans derived from two strains AFO-202 and N-163 of a black yeast Aureobasidium pullulans on the biomarkers for cytokine storm and coagulopathy in COVID-19 patients. METHODS: A total of 24 RT-PCR positive COVID-19 patients were recruited and randomly divided into three groups (Gr): Gr. 1 control (n = 8) - Standard treatment; Gr. 2: Standard treatment + AFO-202 beta glucan (n = 8); and Gr. 3, Standard treatment + combination of AFO-202 and N-163 beta glucans (n = 8) for 30 days. RESULTS: There was no mortality or requirement of ventilation of the subjects in any of the groups. There was a decrease in D-Dimer values (751 ng/ml to 143.89 ng/ml) and IL-6 values (7.395-3.16 pg/ml) in Gr. 1 in 15 days but the levels increased to abnormal levels on day 30 (D-Dimer: 202.5 ng/ml; IL-6 55.37 pg/ml); which steadily decreased up to day 30 in groups 2 (D-dimer: 560.99 ng/dl to 79.615; IL-6: 26.18-3.41 pg/ml) and 3 (D-dimer: 1614 ng/dl to 164.25 ng/dl; IL-6: 6.25-0.5 pg/ml). The same trend was observed with ESR. LCR and LeCR increased while NLR decreased significantly in Gr. 3. CD4 + and CD8 + T cell count showed relatively higher increase in Gr.3. There was no difference in CRP within the groups. CONCLUSION: As these beta glucans are well known food supplements with a track record for safety, larger multi-centric clinical studies are recommended to validate their use as an adjunct in the management of COVID-19 and the ensuing long COVID-19 syndrome.


Assuntos
Aureobasidium , COVID-19 , Síndrome da Liberação de Citocina , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Interleucina-6/análise , beta-Glucanas/administração & dosagem , Biomarcadores/sangue , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/tratamento farmacológico , Terapias Complementares/métodos , Síndrome da Liberação de Citocina/sangue , Síndrome da Liberação de Citocina/etiologia , Síndrome da Liberação de Citocina/prevenção & controle , Suplementos Nutricionais , Feminino , Humanos , Fatores Imunológicos/administração & dosagem , Masculino , Pessoa de Meia-Idade , Projetos Piloto , SARS-CoV-2 , Resultado do Tratamento
19.
Crit Rev Biotechnol ; 42(1): 93-105, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34154468

RESUMO

Liamocins synthesized by Aureobasidium spp. are glycolipids composed of a single mannitol or arabitol headgroup linked to either three, four or even six 3,5-dihydroxydecanoic ester tail-groups. The highest titer of liamocin achieved was over 40.0 g/L. The substrates for liamocins synthesis include glucose, sucrose, xylose, mannitol, and others. The Pks1 is responsible for the biosynthesis of the tail-group 3,5-dihydroxydecanoic acid, both mannitol dehydrogenase (MDH) and mannitol 1-phosphate 5-dehydrogenase (MPDH) catalyze the mannitol biosynthesis and the arabitol biosynthesis is controlled by arabitol dehydrogenase (ArDH). The ester bond formation between 3,5-dihydroxydecanoic acid and mannitol or arabitol is catalyzed by the esterase (Est1). Liamocin biosynthesis is regulated by the specific transcriptional activator (Gal1), global transcriptional activator (Msn2), various signaling pathways, acetyl-CoA flux while Pks1 activity is controlled by PPTase activity. The synthesized liamocins have high bioactivity against the pathogenic bacteria Streptococcus spp. and some kinds of cancer cells while Massoia lactone released liamocins which exhibited obvious antifungal and anticancer activities. Therefore, liamocins and Massoia lactone have many applications in various sectors of biotechnology.


Assuntos
Ascomicetos , Aureobasidium , Bactérias , Manitol , Xilose
20.
Phytopathology ; 112(2): 232-237, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34181440

RESUMO

Gray mold caused by Botrytis cinerea is a common postharvest disease in strawberries, reducing shelf life considerably. We investigated the potential of the yeast-like biocontrol fungus Aureobasidium pullulans (AP-SLU6) vectored by bumblebees (Bombus terrestris) in the Flying Doctors® system to inhibit the pathogen and increase the shelf life of harvested strawberries (cultivar Sonata). Using bumblebees as vectors of various biocontrol agents is becoming increasingly popular, but any potentially negative effects on bee performance have been understudied. Our results show that, over the 4-week period of the trial, the performance and activity of the bees were not negatively affected by A. pullulans. The bees successfully picked up the powder formulation; then, they carried and deposited it on the flowers. The vectoring of the biocontrol agent significantly reduced gray mold development on the harvested fruits by 45% and increased shelf life by 100% in comparison with control treatments. This suggests that the biocontrol fungus applied during flowering successfully reduced Botrytis infection and thus, effectively protected the fruits from gray mold. In addition, the bee-vectored application of the biocontrol agent was found to be significantly more effective than spray application because the latter may temporarily increase humidity around the flower, thereby creating a suitable environment for the pathogen to thrive. In summary, our study demonstrates that A. pullulans vectored by bumblebees can decrease gray mold infection and improve the shelf life of strawberries without adversely affecting the bees, thus providing a basis for the sustainable and efficient control of gray mold on strawberry.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.


Assuntos
Fragaria , Animais , Aureobasidium , Abelhas , Botrytis , Fragaria/microbiologia , Frutas/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
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