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Plants (Basel, Switzerland) Jan 2023is an important pathogenic fungus affecting many crops and is one of the main sources of their aflatoxin contamination. The primary method of limiting this pathogen is...
is an important pathogenic fungus affecting many crops and is one of the main sources of their aflatoxin contamination. The primary method of limiting this pathogen is using chemical fungicides, but researchers focus on searching for other effective agents for its control due to many disadvantages and limitations of these agrochemicals. The results obtained in the present study indicate the high potential of two yeast strains, PP4 and ZD1, in the biological control of Under in vitro conditions, mycelial growth was reduced by 53.61% and 63.05%, and spore germination was inhibited by 68.97% and 79.66% by ZD1 and PP4 strains, respectively. Both strains produced the lytic enzymes chitinase and β-1,3-glucanase after 5 days of cultivation with cell wall preparations (CWP) of in the medium as a carbon source. In addition, the tested yeasts showed the ability to grow over a wide range of temperatures (4-30 °C), pH (4-11), and salinity (0-12%) and showed tolerance to fungicides at concentrations corresponding to field conditions. Both isolates tested were highly tolerant to cupric oxychloride, showing biomass gains of 85.84% (ZD1) and 87.25% (PP4). Biomass growth in the presence of fungicides azoxystrobin was 78.71% (ZD1) and 82.65% (PP4), while in the presence of difenoconazole, it was 70.09% (ZD1) and 75.25% (PP4). The yeast strains were also tested for antagonistic effects against directly on tomato fruit. Both isolates acted effectively by reducing lesion diameter from 29.13 mm (control) to 8.04 mm (PP4) and 8.83 mm (ZD1).
PubMed: 36678949
DOI: 10.3390/plants12020236 -
Molecules (Basel, Switzerland) Feb 2021Intrinsic hydrophobicity is the reason for efficient bacterial settlement and biofilm growth on silicone materials. Those unwelcomed phenomena may play an important role...
Intrinsic hydrophobicity is the reason for efficient bacterial settlement and biofilm growth on silicone materials. Those unwelcomed phenomena may play an important role in pathogen transmission. We have proposed an approach towards the development of new anti-biofilm strategies that resulted in novel antimicrobial hydrophobic silicones. Those functionalized polysiloxanes grafted with side 2-(carboxymethylthioethyl)-, 2-(-propylamidomethylthioethyl)- and 2-(mercaptoethylamidomethylthioethyl)- groups showed a wide range of antimicrobial properties towards selected strains of bacteria (reference strains , and water-borne isolates , ), fungi () and algae (), which makes them valuable antibacterial and antibiofilm agents. Tested microorganisms showed various levels of biofilm formation, but particularly effective antibiofilm activity was demonstrated for bacterial isolate with high adhesion abilities. In the case of modified surfaces, the relative coefficient of adhesion for this strain was 18 times lower in comparison to the control glass sample.
Topics: Anti-Infective Agents; Cell Adhesion; Hydrophobic and Hydrophilic Interactions; Siloxanes
PubMed: 33557279
DOI: 10.3390/molecules26040814 -
Scientific Reports Mar 2020Volatile organic compounds (VOCs) produced by Aureobasidium pullulans were investigated for antagonistic actions against Alternaria alternata and Botrytis cinerea....
Volatile organic compounds (VOCs) produced by Aureobasidium pullulans were investigated for antagonistic actions against Alternaria alternata and Botrytis cinerea. Conidia germination and colony growth of these two phytopathogens were suppressed by A. pullulans VOCs. A novel experimental setup was devised to directly extract VOCs using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) from antagonist-pathogen culture headspace. The proposed system is a robust method to quantify microbial VOCs using an internal standard. Multivariate curve resolution-alternating least squares deconvolution of SPME-GC-MS spectra identified fourteen A. pullulans VOCs. 3-Methyl-1-hexanol, acetone, 2-heptanone, ethyl butyrate, 3-methylbutyl acetate and 2-methylpropyl acetate were newly identified in A. pullulans headspace. Partial least squares discriminant analysis models with variable importance in projection and selectivity ratio identified four VOCs (ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-phenylethanol), with high explanatory power for discrimination between A. pullulans and pathogen. The antifungal activity and synergistic interactions of the four VOCs were evaluated using a Box-Behnken design with response surface modelling. Ethanol and 2-phenylethanol are the key inhibitory A. pullulans VOCs against both B. cinerea and A. alternata. Our findings introduce a novel, robust, quantitative approach for microbial VOCs analyses and give insights into the potential use of A. pullulans VOCs to control B. cinerea and A. alternata.
Topics: Alternaria; Antifungal Agents; Ascomycota; Botrytis; Gas Chromatography-Mass Spectrometry; Metabolomics; Microbial Sensitivity Tests; Solid Phase Microextraction; Volatile Organic Compounds
PubMed: 32161291
DOI: 10.1038/s41598-020-61471-8 -
Molecules (Basel, Switzerland) Mar 2023Pullulan is a linear exopolysaccharide, produced in the fermentation media of , with a variety of applications in the food and pharmaceutical industries. Pullulan...
Pullulan is a linear exopolysaccharide, produced in the fermentation media of , with a variety of applications in the food and pharmaceutical industries. Pullulan derivatives have growing potential for biomedical applications, but the high cost of pullulan biofabrication currently restricts its commercial use. Better control over pullulan yield, molecular weight and melanin production by altering fermentation conditions could improve the economics. In this study, the effects of sugar and mineral salt stresses on the pullulan production of ATCC 42023 were examined in batch processes. The chemical structure of the recovered pullulan was characterized by FTIR and NMR spectroscopy, and the molecular weight distribution was obtained via SEC. Pullulan yield and melanin production varied when the conditions were adjusted, and pullulans with different molar masses were obtained. Higher-yield pullulan production and a lower polydispersity index were observed when CuSO was added to the fermentation in comparison with the control and with the addition of sugars and other salts. Biofabrication of pullulan under stress conditions is a promising strategy to enhance biopolymer yield and to obtain pullulan with a targeted molecular weight.
Topics: Salts; Sugars; Melanins; Ascomycota; Fermentation; Minerals
PubMed: 36985449
DOI: 10.3390/molecules28062478 -
Research in Microbiology 2021Aureobasidium pullulans is a yeast-like fungus that produces volatile organic compounds (VOCs) with antifungal properties. VOCs have the potential to trigger the...
Aureobasidium pullulans is a yeast-like fungus that produces volatile organic compounds (VOCs) with antifungal properties. VOCs have the potential to trigger the production of intracellular reactive oxygen species (ROS), lipid peroxidation and electrolyte loss in microorganisms. The relationship among A. pullulans VOCs, induced ROS accumulation and electrolyte leakage was investigated in Botrytis cinerea and Alternaria alternata in vitro. Exposure to a mixture of A. pullulans VOCs: ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-phenylethanol, resulted in electrolyte leakage in both B. cinerea and A. alternata. Fluorescence microscopy using 2',7'-dichlorofluorescein diacetate indicated triggered ROS accumulation in exposed fungal mycelia and the presence of the superoxide radical was evident by intense red fluorescence with dihydroethidium. Partial inhibition of enzymes of the mitochondrial respiratory chain complex I of B. cinerea and A. alternata by pre-treatment with rotenone reduced ROS accumulation in hypha exposed to A. pullulans VOCs and reversed the VOCs inhibition of fungal growth. Scanning electron micrographs revealed that B. cinerea and A. alternata hypha exposed to A. pullulans VOCs had altered cell wall structures. Our findings give insights into the potential mechanisms involved in the antifungal properties of A. pullulans in the suppression of B. cinerea and A. alternata growth in vitro.
Topics: Alternaria; Antifungal Agents; Aureobasidium; Biological Control Agents; Botrytis; Cell Wall; Electrolytes; Electron Transport; Lipid Peroxidation; Mitochondria; Oxidative Stress; Reactive Oxygen Species; Volatile Organic Compounds
PubMed: 33049328
DOI: 10.1016/j.resmic.2020.10.003 -
Polymers Sep 2023Melanin as a natural polymer is found in all living organisms, and plays an important role in protecting the body from harmful UV rays from the sun. The efficiency of...
A Comparative Study of Cr(VI) Sorption by AKW Biomass and Its Extracellular Melanin: Complementary Modeling with Equilibrium Isotherms, Kinetic Studies, and Decision Tree Modeling.
Melanin as a natural polymer is found in all living organisms, and plays an important role in protecting the body from harmful UV rays from the sun. The efficiency of fungal biomass () and its extracellular melanin as Cr(VI) biosorbents was comparatively considered. The efficiency of Cr(VI) biosorption by the two sorbents used was augmented up to 240 min. The maximum sorption capacities were 485.747 (fungus biomass) and 595.974 (melanin) mg/g. The practical data were merely fitted to both Langmuir and Freundlich isotherms. The kinetics of the biosorption process obeyed the pseudo-first-order. Melanin was superior in Cr(VI) sorption than fungal biomass. Furthermore, four independent variables (contact time, initial concentration of Cr(VI), biosorbent dosage, and pH,) were modeled by the two decision trees (DTs). Conversely, to equilibrium isotherms and kinetic studies, DT of fungal biomass had lower errors compared to DT of melanin. Lately, the DTs improved the efficacy of the Cr(VI) removal process, thus introducing complementary and alternative solutions to equilibrium isotherms and kinetic studies. The Cr(VI) biosorption onto the biosorbents was confirmed and elucidated through FTIR, SEM, and EDX investigations. Conclusively, this is the first report study attaining the biosorption of Cr(VI) by biomass of . and its extracellular melanin among equilibrium isotherms, kinetic study, and algorithmic decision tree modeling.
PubMed: 37765609
DOI: 10.3390/polym15183754 -
Journal of Infection in Developing... Dec 2019Aureobasidium pullulans (A. pullulans) is a dematiaceous, yeast-like fungus that is ubiquitous in nature, which can colonize the human hair and skin. A. pullulans has...
Aureobasidium pullulans (A. pullulans) is a dematiaceous, yeast-like fungus that is ubiquitous in nature, which can colonize the human hair and skin. A. pullulans has been clinically implicated to cause skin and soft tissue infections, meningitis, splenic abscesses, and peritonitis. Herein, molecular diagnostic of internal transcribed spacer (ITS) sequencing was used to investigate a suspected case of A. pullulans infection, and the infection source had been traced. A 27-year-old female case was suspected of kala-azar due to the recurrent fever. Bone marrow specimens were analyzed. The samples were negative for Leishmania, Penicillium marneffei and Histoplasma capsulatum. DNA was extracted from the bone marrow specimens, and the 583-bp sequence was amplified with the fungal ITS universal primers. The sequence was compared by Blast query to be identified as A. pullulans. A strain of A. pullulans was also isolated from the kitchen of the patient's living room. Culture characteristics were the same as the human pathogens of A. pullulans, and the ITS sequence was identical to the bone marrow ITS amplification. In conclusion, a deep infection caused by A. pullulans is rare, often occurring in the indwelling catheter, which may cause peritonitis and other symptoms. ITS sequencing of fungi can be used as a diagnostic reference. As A. pullulans is a common fungus in environment, amplification of ITS sequence of A. pullulans in the aseptic body fluid would be necessary to make a comprehensive diagnosis based on the clinical symptoms and signs.
Topics: Adult; Amphotericin B; Antifungal Agents; Ascomycota; Base Sequence; Bone Marrow; China; DNA, Fungal; Environmental Microbiology; Female; Fever of Unknown Origin; Housing; Humans; Invasive Fungal Infections; Sequence Homology, Nucleic Acid; Species Specificity
PubMed: 32088707
DOI: 10.3855/jidc.11830 -
Journal of Zhejiang University....An extracellular lipase from Aureobasidium pullulans was obtained and purified with a specific activity of 17.7 U/mg of protein using ultrafiltration and a...
An extracellular lipase from Aureobasidium pullulans was obtained and purified with a specific activity of 17.7 U/mg of protein using ultrafiltration and a DEAE-Sepharose Fast Flow column. Characterization of the lipase indicated that it is a novel finding from the species A. pullulans. The molecular weight of the lipase was 39.5 kDa, determined by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited its optimum activity at 40 °C and pH of 7. It also showed a remarkable stability in some organic solutions (30%, v/v) including n-propanol, isopropanol, dimethyl sulfoxide (DMSO), and hexane. The catalytic activity of the lipase was enhanced by Ca and was slightly inhibited by Mn and Zn at a concentration of 10 mmol/L. The lipase was activated by the anionic surfactant SDS and the non-ionic surfactants Tween 20, Tween 80, and Triton X-100, but it was drastically inhibited by the cationic surfactant cetyl trimethyl ammonium bromide (CTAB). Furthermore, the lipase was able to hydrolyze a wide variety of edible oils, such as peanut oil, corn oil, sunflower seed oil, sesame oil, and olive oil. Our study indicated that the lipase we obtained is a potential biocatalyst for industrial use.
Topics: Ascomycota; Calcium; Catalysis; Corn Oil; Detergents; Enzyme Stability; Fungal Proteins; Glucans; Hexanes; Hydrogen-Ion Concentration; Hydrolysis; Industrial Microbiology; Lipase; Manganese; Olive Oil; Peanut Oil; Sesame Oil; Substrate Specificity; Sunflower Oil; Surface-Active Agents; Temperature; Zinc
PubMed: 30932378
DOI: 10.1631/jzus.B1800213 -
3 Biotech Sep 2022The maximum yield of the crude mannanase from NRRL 58524 was 8.42 ± 0.18 U mL when cultured for 72 h in the optimized medium containing 3% (w v) defatted spent...
Production and characterization of thermostable acidophilic β-mannanase from NRRL 58524 and its potential in mannooligosaccharide production from spent coffee ground galactomannan.
UNLABELLED
The maximum yield of the crude mannanase from NRRL 58524 was 8.42 ± 0.18 U mL when cultured for 72 h in the optimized medium containing 3% (w v) defatted spent coffee grounds (SCG) and 0.67% (w v) ammonium sulphate. Two forms of mannanase were observed in the crude enzyme and the principal mannanase was enriched to apparent homogeneity via sequential filtration and anion exchange chromatography. The molecular mass of the enzyme was approximately 63 kDa as determined by SDS-PAGE. The enriched mannanase was active at high temperatures (45-75 °C) and a pH range from 3 to 6 with the maximum activity at 55 °C and pH 4.0. The enzyme was relatively thermostable with more than 75% of its initial activity remained after a 12 h incubation at 55 °C. The half-lives of the enriched mannanase were over 8 and 6 h at 60 and 65 °C, respectively. The enzyme was not adversely affected by chelator and most ions tested. This enzyme could hydrolyze both glucomannan and galactomannan and exhibited limited catalytic activity on beta-glucan. When the crude mannanase was used to hydrolyze galactomannan extracted from SCG, the maximum yield of reducing sugars mainly comprising of mannobiose (16.27 ± 0.84 mg 100 mg), and mannotriose (2.85 ± 0.20 mg 100 mg) was obtained at 58.22 ± 2.04 mg 100 mg dry weight, under optimized condition (84.87 U g mannanase, 41 h 34 min incubation at 55 °C and pH 4.0). These results suggested the prospect of the enzyme in mannan hydrolysis and mannooligosaccharide production at a larger scale.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-022-03301-4.
PubMed: 36003897
DOI: 10.1007/s13205-022-03301-4 -
International Journal of Molecular... Dec 2021Global reports on multidrug resistance (MDR) and life-threatening pathogens such as SARS-CoV-2 and have stimulated researchers to explore new antimicrobials that are... (Review)
Review
Global reports on multidrug resistance (MDR) and life-threatening pathogens such as SARS-CoV-2 and have stimulated researchers to explore new antimicrobials that are eco-friendly and economically viable. In this context, biodegradable polymers such as nisin, chitin, and pullulan play an important role in solving the problem. Pullulan is an important edible, biocompatible, water-soluble polymer secreted by that occurs ubiquitously. It consists of maltotriose units linked with α-1,6 glycosidic bonds and is classed as Generally Regarded as Safe (GRAS) by the Food and Drug Administration (FDA) in the USA. Pullulan is known for its antibacterial, antifungal, antiviral, and antitumor activities when incorporated with other additives such as antibiotics, drugs, nanoparticles, and so on. Considering the importance of its antimicrobial activities, this polymer can be used as a potential antimicrobial agent against various pathogenic microorganisms including the multidrug-resistant (MDR) pathogens. Moreover, pullulan has ability to synthesize biogenic silver nanoparticles (AgNPs), which are remarkably efficacious against pathogenic microbes. The pullulan-based nanocomposites can be applied for wound healing, food packaging, and also enhancing the shelf-life of fruits and vegetables. In this review, we have discussed biosynthesis of pullulan and its role as antibacterial, antiviral, and antifungal agent. Pullulan-based films impregnated with different antimicrobials such as AgNPs, chitosan, essential oils, and so on, forming nanocomposites have also been discussed as natural alternatives to combat the problems posed by pathogens.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Antifungal Agents; COVID-19; Chitin; Chitosan; Drug Resistance, Multiple; Food Packaging; Glucans; Humans; Metal Nanoparticles; Nanocomposites; Nisin; Polymers; SARS-CoV-2
PubMed: 34948392
DOI: 10.3390/ijms222413596