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Fungal Genetics and Biology : FG & B Apr 2022Acetolactate synthase (AHAS) catalyses the first common step in the biosynthesis pathways of three branched-chain amino acids (BCAAs) of valine, isoleucine and leucine....
Acetolactate synthases regulatory subunit and catalytic subunit genes VdILVs are involved in BCAA biosynthesis, microscletotial and conidial formation and virulence in Verticillium dahliae.
Acetolactate synthase (AHAS) catalyses the first common step in the biosynthesis pathways of three branched-chain amino acids (BCAAs) of valine, isoleucine and leucine. Here, we characterized one regulatory subunit (VdILV6) and three catalytic subunits (VdILV2A, VdILV2B and VdILV2C) of AHAS from the important cotton Verticillium wilt fungus Verticillium dahliae. Phenotypic analysis showed that VdILV6 knockout mutants were auxotrophic for valine and isoleucine and were defective in conidial morphogenesis, hypha penetration and virulence to cotton, and lost ability of microscletotial formation. The growth of single catalytic subunit gene knockout mutants were significantly inhibited by leucine at higher concentration and single catalytic subunit gene knockout mutants showed significantly reduced virulence to cotton. VdILV2B knockout also led to obviously reduced microscletotial formation and conidial production, VdILV2C knockout led to reduced conidial production. Further studies suggested that both feedback inhibition by leucine and the inhibition by AHAS inhibiting herbicides of tribenuron and bispyribac resulted in significantly down-regulated expression of the four subunit VdILVs genes (VdILV2A, VdILV2B, VdILV2C and VdILV6). Any single catalytic subunit gene knockout led to reduced expression of the other three subunit genes, whereas VdILV6 knckout induced increased expression of the three catalytic subunit genes. VdILV2B, VdILV2C and VdILV6 knockout resulted in increased expression of VdCPC1 regulator gene of the cross-pathway control of amino acid biosynthesis. Taken together, these results indicate multiple roles of four VdILVs genes in the biosynthesis of BCAAs, virulence, fungal growth and development in the filamentous fungi V. dahliae.
Topics: Acetolactate Synthase; Acremonium; Amino Acids, Branched-Chain; Catalytic Domain; Fungal Proteins; Isoleucine; Lactates; Leucine; Plant Diseases; Spores, Fungal; Valine; Verticillium; Virulence
PubMed: 35041986
DOI: 10.1016/j.fgb.2022.103667 -
Marine Drugs Dec 2023Four new compounds, including two ascochlorin-type meroterpenoids acremocholrins A () and B (), one pyridone alkaloid acremopyridone A (), and one cyclopentenone...
Four new compounds, including two ascochlorin-type meroterpenoids acremocholrins A () and B (), one pyridone alkaloid acremopyridone A (), and one cyclopentenone derivative acremoketene A (), together with eight known compounds (- and -), were isolated and identified from the hadal trench-derived fungus YP-213. Their structures were determined with a detailed spectroscopic analysis of NMR and MS data, NOE analysis, octant rule and quantum chemical calculations of ECD, and NMR (with DP4+ probability analysis). Among the compounds, represent a novel scaffold derived from a pyridone alkaloid by cleavage of the C-16-C-17 bond following oxidation to give a ketone. Compounds , , and showed potent in vivo anti-inflammatory activity in transgenic zebrafish, while compound exhibited significant proangiogenic activity in transgenic zebrafish.
Topics: Animals; Zebrafish; Anti-Inflammatory Agents; Fungi; Pyridones; Alkaloids; Acremonium
PubMed: 38248650
DOI: 10.3390/md22010025 -
The Journal of General and Applied... Jun 2022Ascofuranone and its precursor, ilicicolin A, are secondary metabolites with various pharmacological activities that are produced by Acremonium egyptiacum. In...
Ascofuranone and its precursor, ilicicolin A, are secondary metabolites with various pharmacological activities that are produced by Acremonium egyptiacum. In particular, ascofuranone strongly inhibits trypanosome alternative oxidase and represents a potential drug candidate against African trypanosomiasis. However, difficulties associated with industrial production of ascofuranone by A. egyptiacum, specifically the co-production of ascochlorin, which inhibits mammalian respiratory chain complex III at low concentrations, has precluded its widespread application. Therefore, in this study, ascofuranone biosynthetic genes (ascA-E and H-J) were heterologously expressed in Aspergillus sojae, which produced very low-levels of endogenous secondary metabolites under conventional culture conditions. As a result, although we obtained transformants producing both ilicicolin A and ascofuranone, they were produced only when an adequate concentration of chloride ions was added to the medium. In addition, we succeeded in increasing the production of ilicicolin A, by enhancing the expression of the rate-determining enzyme AscD, using a multi-copy integration system. The heterologous expression approach described here afforded the production of both ascofuranone and ilicicolin A, allowing for their development as therapeutics.
Topics: Animals; Aspergillus; Mammals; Sesquiterpenes
PubMed: 35418536
DOI: 10.2323/jgam.2021.08.001 -
Frontiers in Microbiology 2022Meat and bone meal (MBM), as slaughterhouse waste, is a potential biostimulating agent, but its efficiency and reliability in composting are largely unknown. To access...
Meat and bone meal (MBM), as slaughterhouse waste, is a potential biostimulating agent, but its efficiency and reliability in composting are largely unknown. To access the MBM application to the composting process of asparagus straw rice, we followed the composting process for 60 days in 220-L composters and another 180 days in 20-L buckets in treatments applied with MBM or urea. The microbial succession was investigated by high-throughput sequencing. Compared with urea treatments, MBM addition stabilized pH and extended the thermophilic phase for 7 days. The germination index of MBM treatments was 24.76% higher than that of urea treatments. MBM also promoted higher microbial diversity and shifted community compositions. Organic matter and pH were the most significant factors that influence the bacterial and fungal community structure. At the genus level, MBM enriched relative abundances of organic matter-degrading bacteria () and lignocellulose-degrading fungi (), as well as lignocellulolytic enzyme activities. Notably, MBM addition decreased sum abundances of plant pathogenic fungi of , and from 17.27 to 0.11%. This study demonstrated the potential of MBM as an effective additive in asparagus straw composting, thus providing insights into the development of new industrial aerobic fermentation.
PubMed: 36204619
DOI: 10.3389/fmicb.2022.953783 -
Current Microbiology Jul 2022In a recent work we showed that, besides lovastatin, ROS also accumulate during the production phase in Pencillium chrysogenum and in Acremonium chrysogenum, and that...
In a recent work we showed that, besides lovastatin, ROS also accumulate during the production phase in Pencillium chrysogenum and in Acremonium chrysogenum, and that these ROS regulate the biosynthesis of penicillin and cephalosporin C. In the present study, we investigated the level at which this positive regulation is exerted. Internal ROS levels were manipulated, i.e., increased or decreased, in the production phase of the respective fermentations. Penicillin production decreased by 51.2% when internal ROS concentration was diminished by 50%, while a 62% production increase was observed when ROS were increased (62%). Similarly, Cephalosporin production decreased (35%) with antioxidants and increased (54.1%) with exogenous ROS. Expression analysis of the respective pcbAB genes, encoding the non-ribosomal peptide synthetase enzymes, was performed. Results showed down regulation of these genes in fermentations with lower ROS content, and upregulation in the cultures with higher ROS content, in both species. This showed that ROS regulation of penicillin in P. chrysogenum and of cephalosporin C in A. chrysogenum, is exerted at transcriptional level. In silico analysis of the pcbAB gene promoters in both species, suggested that this regulation could be mediated by stress-response transcription factors like Yap1, SrrA and/or MsnA, and/or by the Hap complex.
Topics: Cephalosporins; Gene Expression Regulation, Fungal; Penicillins; Reactive Oxygen Species; Transcription Factors
PubMed: 35796838
DOI: 10.1007/s00284-022-02935-0 -
Plant Disease Aug 2019Apple fruit spot disease has caused serious economic losses for years in China since the widespread application of fruit bagging in production. Although the three genera...
Apple fruit spot disease has caused serious economic losses for years in China since the widespread application of fruit bagging in production. Although the three genera , , and have been reported to be the causal agents, studies on the disease etiology and pathogen biology are still sparse. Here, we report characterization of eight fungal isolates from lesions on 126 symptomatic fruit samples collected in Shaanxi Province, China. Pathogenicity of the isolates was assessed. DNA sequences were obtained at four loci, including D1/D2 domains of the large-subunit nrRNA gene, internal transcribed spacer regions 1 and 2, 5.8S nrDAN gene, a fragment of the actin gene, and a fragment of the β-tubulin. Based on phylogenetic analysis and morphological features, three new species were found: , , and . In addition, we made the first report of as a plant pathogen. Temperature and moisture significantly affected in vitro conidial germination of five -like species, and their impact on infection of apple fruit was tested using . Conidia of five species germinated from 15 to 35°C in free water; four of the species had optimum temperature around 25°C, whereas conidia of had an optimum temperature of 30°C. Conidial germination rate increased as relative humidity (RH) increased. The five isolates had relatively high conidial germination rates at RH > 97%, with a significant decline at 95% RH. Incidence of infection also increased in proportion to RH. In free water, conidial germination was relatively unaffected by temperature.
Topics: Acremonium; Ascomycota; China; Fruit; Malus; Phylogeny; Temperature
PubMed: 31161920
DOI: 10.1094/PDIS-10-18-1794-RE -
International Journal of Food... Oct 2022Microbial antagonists are effective and environmentally friendly in controlling postharvest diseases of fruit. The present study investigated the influence of D....
Microbial antagonists are effective and environmentally friendly in controlling postharvest diseases of fruit. The present study investigated the influence of D. nepalensis on epiphytic microbiome and postharvest decay of jujube. Results showed that D. nepalensis notably reduced fungal decay, maintained the fruit firmness and delayed discoloration. The epiphytic microbiome revealed that D. nepalensis changed the fungal communities, but few influence on bacterial communities were observed. D. nepalensis, as the dominant population in the treatment group, decreased the abundance of pathogenic fungi of Alternaria, Penicillium, Fusarium and Botrytis, while increased the beneficial bacteria of Pantoea. The canonical correspondence analysis revealed that Debaryomyces was negatively correlated with the decay rate, whereas Penicillium, Acremonium, Rhodosporidiobolus and Hansfordia were positively correlated. In conclusion, D. nepalensis altered the successional process of fungal and bacterial communities to reduce the decay rate of jujube during storage.
Topics: Alternaria; Bacteria; Food Preservation; Fruit; Microbiota; Penicillium; Saccharomycetales; Ziziphus
PubMed: 35944358
DOI: 10.1016/j.ijfoodmicro.2022.109866 -
Frontiers in Microbiology 2022Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful microorganism identification tool. Research on...
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful microorganism identification tool. Research on MALDI-TOF MS identification of rare filamentous fungi is still lacking. This study aimed to evaluate the performance of MALDI-TOF MS in the identification of , -like, , and species. Sabouraud broth cultivation and formic acid/acetonitrile protein extraction were used for MALDI-TOF MS identification by a Bruker Biotyper system. An in-house database containing 29 isolates of , -like, , and spp. was constructed. A total of 52 clinical isolates were identified using the Bruker Filamentous Fungi Library v1.0 (FFL v1.0) alone, and Filamentous Fungi Library v1.0 plus the in-house library, respectively. The mass spectrum profile (MSP) dendrograms of the 28 isolates, 26 -like isolates, and 27 and isolates were constructed by MALDI Biotyper OC 4.0 software, respectively. The correct species identification rate significantly improved when using the combined databases compared with that when using FFL v1.0 alone ( spp., 75% versus 0%; -like spp., 100% versus 0%; and spp., 100% versus 62.5%). The MSP dendrograms differentiated -like species, and species clearly, but cannot distinguish species in the complex. In conclusion, with an expanded database, MALDI-TOF MS is an effective tool for the identification of , -like, , and species.
PubMed: 35308359
DOI: 10.3389/fmicb.2022.841286 -
Marine Drugs Sep 2021Cyclopeptides usually play a pivotal role, either in the viability or virulence of fungi. Two types of cyclopeptides, six new hydroxamate siderophore cyclohexapeptides...
Cyclopeptides usually play a pivotal role, either in the viability or virulence of fungi. Two types of cyclopeptides, six new hydroxamate siderophore cyclohexapeptides (-), including acremonpeptides E and F, and their complexes with aluminum and ferric ions; one new cyclic pentapeptolide, aselacin D (); together with a known compound, aselacin C (), were isolated and characterized from the sponge-derived fungus F10. In addition, two new siderophore analogues chelating gallium ions (Ga), Ga (III)-acremonpeptide E () and Ga (III)-acremonpeptide F (), using isolated acremonpeptides E and F, were prepared. The planar structures of - were elucidated by HRESIMS and (1D and 2D) NMR. The absolute configurations of amino acids were determined by means of the advanced Marfey's method and X-ray single-crystal diffraction analysis. X-ray fluorescence (XRF) spectrometer was performed to disclose the elements of compound , indicating the existence of aluminum (Al). Al (III)-acremonpeptides E (), Ga (III)-acremonpeptides E (), Al (III)-acremonpeptide F (), and Ga (III)-acremonpeptide F () displayed high in vitro anti-fungal activities, which are comparable to amphotericin B, against and
Topics: Acremonium; Animals; Antifungal Agents; Aquatic Organisms; Aspergillus; Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Microbial Sensitivity Tests; Nuclear Magnetic Resonance, Biomolecular; Peptides, Cyclic; Porifera; Structure-Activity Relationship
PubMed: 34677436
DOI: 10.3390/md19100537 -
Fungi associated with ornamental plants in some Nurseries in Al-Qurayyat, Jouf region, Saudi Arabia.Iranian Journal of Microbiology Feb 2023Fungi communities are important soil components as decomposers and plant symbionts, and they play an important part in natural ecological and biogeochemical processes....
BACKGROUND AND OBJECTIVES
Fungi communities are important soil components as decomposers and plant symbionts, and they play an important part in natural ecological and biogeochemical processes. In this study, isolation and identification of terrestrial and zoosporic fungi were detected.
MATERIALS AND METHODS
Sixty-seven fungal species from thirty-four genera were isolated from 45 soil samples obtained randomly from nurseries in Al-Qurayyat, Jouf reagon, Saudi Arabia using the soil dilution technique on glucose-Czapek's agar medium, cellulose-Czapek's agar, and Potato dextrose agar medium.Authentic fungus manuals were then used to identify and characterise the mycoflora.
RESULTS
A total of 46 fungal species belonging to 22 terrestrial fungal genera were recovered on glucose-Czapek's agar, 38 species belonging to 20 terrestrial fungal genera were recovered on cellulos-Czapek's agar and 27 fungal species belonging to 15 terrestrial fungal genera were recovered on PDA medium while 12 species belonging to 7 genera zoosporic fungal genera were discovered.
CONCLUSION
The most common terrestrial fungal genera were and while in zoosporic fungus. was the most prevalent, followed by and .
PubMed: 37069907
DOI: 10.18502/ijm.v15i1.11934