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Molecules (Basel, Switzerland) Oct 2022Fungus continues to attract great attention as a promising pool of biometabolites. Wilh (Aspergillaceae) has established its capacity to biosynthesize a myriad of... (Review)
Review
Fungus continues to attract great attention as a promising pool of biometabolites. Wilh (Aspergillaceae) has established its capacity to biosynthesize a myriad of metabolites belonging to different chemical classes, such as isocoumarins, pyrazines, sterols, indole alkaloids, diketopiperazines, polyketides, peptides, quinones, polyketides, and sesquiterpenoids, revealing various bioactivities that are antimicrobial, cytotoxic, antiviral, anti-inflammatory, insecticidal, and neuroprotective. Additionally, produces a variety of enzymes that could have variable industrial and biotechnological applications. From 1965 until June 2022, 165 metabolites were reported from isolated from different sources. In this review, the formerly separated metabolites from , including their bioactivities and biosynthesis, in addition, the industrial and biotechnological potential of are highlighted.
Topics: Anti-Infective Agents; Anti-Inflammatory Agents; Antiviral Agents; Aspergillus ochraceus; Diketopiperazines; Indole Alkaloids; Isocoumarins; Peptides; Polyketides; Pyrazines; Quinones; Sterols
PubMed: 36235292
DOI: 10.3390/molecules27196759 -
Frontiers in Chemistry 2022, generally known as a food spoilage fungus, is the representative species in section . strains are widely distributed in nature, and usually isolated from cereal,... (Review)
Review
, generally known as a food spoilage fungus, is the representative species in section . strains are widely distributed in nature, and usually isolated from cereal, coffee, fruit, and beverage. Increasing cases suggest acts as human and animal pathogens due to producing the mycotoxins. However, in terms of benefits to mankind, is the potential source of industrial enzymes, and has excellent capability to produce diverse structural products, including polyketides, nonribosomal peptides, diketopiperazine alkaloids, benzodiazepine alkaloids, pyrazines, bis-indolyl benzenoids, nitrobenzoyl sesquiterpenoids, and steroids. This review outlines recent discovery, chemical structure, biosynthetic pathway, and bio-activity of the natural compounds from .
PubMed: 36092677
DOI: 10.3389/fchem.2022.938626 -
Toxins Mar 2021Ochratoxin A (OTA) usually contaminates agricultural products such as grapes, oatmeal, coffee and spices. Light was reported as an effective strategy to control spoilage... (Comparative Study)
Comparative Study
Ochratoxin A (OTA) usually contaminates agricultural products such as grapes, oatmeal, coffee and spices. Light was reported as an effective strategy to control spoilage fungi and mycotoxins. This research investigated the effects of light with different wavelengths on the growth and the production of OTA in and . The results showed that the growth of both fungi were extremely inhibited by UV-B. Short-wavelength (blue, violet) significantly inhibited the production of OTA in both fungi, while the inhibitory effect of white was only demonstrated on . These results were supported by the expression profiles of OTA biosynthetic genes of and . To clarify, the decrease in OTA production is induced by inhibition or degradation; therefore, the degradation of OTA under different wavelengths of light was tested. Under UV-B, the degradation rate of 10 μg/mL OTA standard pure-solution samples could reach 96.50% in 15 days, and the degradation effect of blue light was relatively weak. Furthermore, infection experiments of pears showed that the pathogenicity of both fungi was significantly decreased under UV-B radiation. Thus, these results suggested that light could be used as a potential target for strategies in the prevention and control of ochratoxigenic fungi.
Topics: Aspergillus; Aspergillus ochraceus; Food Microbiology; Fruit; Gene Expression Regulation, Fungal; Ochratoxins; Pyrus; Time Factors; Ultraviolet Rays
PubMed: 33807312
DOI: 10.3390/toxins13040251 -
Molecules (Basel, Switzerland) Dec 2023Biotransformation of ursonic acid () by two fungal strains CGMCC 3.5324 and CGMCC 3.407 yielded thirteen new compounds (, , -, and -), along with five recognized ones....
Biotransformation of ursonic acid () by two fungal strains CGMCC 3.5324 and CGMCC 3.407 yielded thirteen new compounds (, , -, and -), along with five recognized ones. The structural details of new compounds were determined through spectroscopic examination (NMR, IR, and HR-MS) and X-ray crystallography. Various modifications, including hydroxylation, epoxidation, lactonization, oxygen introduction, and transmethylation, were identified on the ursane core. Additionally, the anti-neuroinflammatory efficacy of these derivatives was assessed on BV-2 cells affected by lipopolysaccharides. It was observed that certain methoxylated and epoxylated derivatives (, , and ) showcased enhanced suppressive capabilities, boasting IC values of 8.2, 6.9, and 5.3 μM. Such ursonic acid derivatives might emerge as potential primary molecules in addressing neurodegenerative diseases.
Topics: Aspergillus ochraceus; Aspergillus oryzae; Crystallography, X-Ray; Biotransformation
PubMed: 38138433
DOI: 10.3390/molecules28247943 -
Life (Basel, Switzerland) Aug 2021In this study, we investigated the properties of proteolytic enzymes of two species of , 1 (with a high degree of pathogenicity) and L-1 (a conditional pathogen), and...
In this study, we investigated the properties of proteolytic enzymes of two species of , 1 (with a high degree of pathogenicity) and L-1 (a conditional pathogen), and their effects on various components of the hemostasis system (in vitro) in the case of their penetration into the bloodstream. We showed that micromycete proteases were highly active in cleaving both globular (albuminolysis) and fibrillar (fibrin) proteins, and, to varying degrees, they could coagulate the plasma of humans and animals (due to proteolysis of factors of the blood coagulation cascade) but were not able to coagulate fibrinogen. The proteases of both fully hydrolyzed thrombi in 120-180 min. Micromycetes did not show hemolytic activity but were able to break down hemoglobin.
PubMed: 34440526
DOI: 10.3390/life11080782 -
Cellular and Molecular Life Sciences :... May 2024Aspergillus ochraceus is the traditional ochratoxin A (OTA)-producing fungus with density-dependent behaviors, which is known as quorum sensing (QS) that is mediated by...
Aspergillus ochraceus is the traditional ochratoxin A (OTA)-producing fungus with density-dependent behaviors, which is known as quorum sensing (QS) that is mediated by signaling molecules. Individual cells trend to adapt environmental changes in a "whole" flora through communications, allowing fungus to occupy an important ecological niche. Signals perception, transmission, and feedback are all rely on a signal network that constituted by membrane receptors and intracellular effectors. However, the interference of density information in signal transduction, which regulates most life activities of Aspergillus, have yet to be elucidated. Here we show that the G protein-coupled receptor (GPCR) to cAMP pathway is responsible for transmitting density information, and regulates the key point in life cycle of A. ochraceus. Firstly, the quorum sensing phenomenon of A. ochraceus is confirmed, and identified the density threshold is 10 spores/mL, which represents the low density that produces the most OTA in a series quorum density. Moreover, the GprC that classified as sugar sensor, and intracellular adenylate cyclase (AcyA)-cAMP-PKA pathway that in response to ligands glucose and HODEs are verified. Furthermore, GprC and AcyA regulate the primary metabolism as well as secondary metabolism, and further affects the growth of A. ochraceus during the entire life cycle. These studies highlight a crucial G protein signaling pathway for cell communication that is mediated by carbohydrate and oxylipins, and clarified a comprehensive effect of fungal development, which include the direct gene regulation and indirect substrate or energy supply. Our work revealed more signal molecules that mediated density information and connected effects on important adaptive behaviors of Aspergillus ochraceus, hoping to achieve comprehensive prevention and control of mycotoxin pollution from interrupting cell communication.
Topics: Quorum Sensing; Aspergillus ochraceus; Signal Transduction; Glucose; Cyclic AMP; Adenylyl Cyclases; Receptors, G-Protein-Coupled; Fungal Proteins; Ochratoxins
PubMed: 38806811
DOI: 10.1007/s00018-024-05160-z -
Foods (Basel, Switzerland) Oct 2023and are important pathogenic fungi that pose a serious threat because of their ability to produce mycotoxins, including ochratoxin A (OTA) and aflatoxins (AFs). The...
and 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, PP3 and D10, in the biological control of and 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 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.
PubMed: 37893764
DOI: 10.3390/foods12203871 -
Heliyon Nov 2023Essential oils (EOs) are natural products called volatile oils or aromatic and ethereal oils derived from various parts of plants. They possess antioxidant and... (Review)
Review
Essential oils (EOs) are natural products called volatile oils or aromatic and ethereal oils derived from various parts of plants. They possess antioxidant and antimicrobial properties, which offer natural protection against a variety of pathogens and spoilage microorganisms. Studies conducted in the last decade have demonstrated the unique applications of these compounds in the fields of the food industry, agriculture, and skin health. This systematic article provides a summary of recent data pertaining to the effectiveness of EOs and their constituents in combating fungal pathogens through diverse mechanisms. Antifungal investigations involving EOs were conducted on multiple academic platforms, including Google Scholar, Science Direct, Elsevier, Springer, Scopus, and PubMed, spanning from April 2000 to October 2023. Various combinations of keywords, such as "essential oil," "volatile oils," "antifungal," and " species," were used in the search. Numerous essential oils have demonstrated both and antifungal activity against different species of , including , , A. , A. , and A. ochraceus. They have also exhibited efficacy against other fungal species, such as species, , and Alternaria. The findings of this study offer novel insights into inhibitory pathways and suggest the potential of essential oils as promising agents with antifungal and anti-mycotoxigenic properties. These properties could make them viable alternatives to conventional preservatives, thereby enhancing the shelf life of various food products.
PubMed: 37954273
DOI: 10.1016/j.heliyon.2023.e21386 -
Toxins Jan 2021Dry-cured meat products are worldwide food with high-salt content, and filamentous fungi are beneficial to the maturation process. However, some salt-tolerant strains of...
Dry-cured meat products are worldwide food with high-salt content, and filamentous fungi are beneficial to the maturation process. However, some salt-tolerant strains of and produce ochratoxin A (OTA) on these products and thus threaten food safety. In our study, proteomic analysis was performed to reveal the mechanism of adaptability to high-salt environment by . Twenty g/L and 70 g/L NaCl substrates were used to provide medium- and high-NaCl content environments, respectively. The NaCl addition could induce fungal growth, but only 20 g/L NaCl addition could induce spore production while 70 g/L repressed it. Proteomics analysis identified 2646 proteins in fc-1, of which 237 and 251 were differentially expressed with 20 g/L and 70 g/L NaCl addition, respectively. Potential factors affecting fungal growth and development were identified by GO and KEGG analyses of biological process, cellular component, and molecular function terms. The results revealed that ergosterol synthesis pathway was significantly upregulated with 20 g/L and 70 g/L NaCl addition. However, fungal growth and development including OTA production were complex processes associated with many factors including nutrient uptake, cell membrane integrity, cell cycle, energy metabolism, intracellular redox homeostasis, protein synthesis and processing, autophagy, and secondary metabolism. Reactive oxygen species may be an important window to understand the mechanism that medium-salt content was conducive to intracellular signal transduction while high-salt content caused oxidative stress. The findings would help to improve the processes and storage conditions of dry-cured meat products.
Topics: Animals; Aspergillus ochraceus; Culture Media; Food Contamination; Food Microbiology; Mycotoxins; Ochratoxins; Proteome; Sodium Chloride
PubMed: 33450861
DOI: 10.3390/toxins13010051 -
Frontiers in Fungal Biology 2022fungi produce mycotoxins that are detrimental to human and animal health. Two sections of aspergilli are of particular importance to cereal food crops such as corn and...
fungi produce mycotoxins that are detrimental to human and animal health. Two sections of aspergilli are of particular importance to cereal food crops such as corn and barley. section species like and produce aflatoxins, while section species like and produce ochratoxin A. Mitigating these toxins in food and feed is a critical and ongoing worldwide effort. We have previously investigated biosynthetic gene clusters in that are linked to fungal virulence in corn. We found that one such cluster, , is responsible for the production of aspergillic acid, an iron-binding, hydroxamic acid-containing pyrazinone metabolite. Furthermore, we found that the gene cluster is present in many other aflatoxin- and ochratoxin-producing aspergilli. The core gene in the cluster encodes the small nonribosomal peptide synthetase-like (NRPS-like) protein AsaC. We have swapped the ortholog from into , replacing its native copy, and have also cloned both orthologs into . We show that AsaC orthologs in section and section , while only containing adenylation-thiolation-reductase (ATR) domains, can selectively biosynthesize distinct pyrazinone natural products: deoxyaspergillic acid and flavacol, respectively. Because pyrazinone natural products and the gene clusters responsible for their production are implicated in a variety of important microbe-host interactions, uncovering the function and selectivity of the enzymes involved could lead to strategies that ultimately benefit human health.
PubMed: 37746228
DOI: 10.3389/ffunb.2022.1029195