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In present work, a polysaccharide (GCP-WS) was successfully produced by Chaetomium globosum CGMCC 6882 from wheat straw. Monosaccharide composition of GCP-WS was rhamnose, glucosamine, galactose, glucose, xylose, fructose and glucuronic acid in a molar ratio of 21.46:1.58:1.11:55.15:36.37:7.04:7.34. Meanwhile, molecular weight of GCP-WS was 3.538 × 104 Da with a polydispersity of 1.043. Antioxidant assays revealed GCP-WS had strong scavenging effects on DPPH radical, ABTS radical, superoxide anions and hydroxyl radical in a dose-dependent manner. Results displayed that at the concentration of 5 mg/mL, the corresponding scavenging abilities of GCP-WS reached 83.08 ± 2.58%, 85.69 ± 1.62%, 79.38 ± 2.03% and 81.39 ± 1.47%, respectively. GCP-WS shows the potential for development as an effective antioxidant agent. [ABSTRACT FROM AUTHOR]

Chromosome segregation begins when the cysteine protease, separase, cleaves the Scc1 subunit of cohesin at the metaphase-to-anaphase transition. Separase is inhibited prior to metaphase by the tightly bound securin protein, which contains a pseudosubstrate motif that blocks the separase active site. To investigate separase substrate specificity and regulation, here we develop a system for producing recombinant, securin-free human separase. Using this enzyme, we identify an LPE motif on the Scc1 substrate that is distinct from the cleavage site and is required for rapid and specific substrate cleavage. Securin also contains a conserved LPE motif, and we provide evidence that this sequence blocks separase engagement of the Scc1 LPE motif. Our results suggest that rapid cohesin cleavage by separase requires a substrate docking interaction outside the active site. This interaction is blocked by securin, providing a second mechanism by which securin inhibits cohesin cleavage. Prior to anaphase, securin binds separase and thereby prevents cohesin cleavage. Here, the authors develop a method to produce active securin-free separase, identify a docking motif in cohesin that promotes cleavage, and show that securin interferes with this interaction. [ABSTRACT FROM AUTHOR]

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• A high dextranase-producing strain was obtained by ARTP-EMS from Chaetomium globosum. • A high yield of dextranase by optimizing fermentation conditions was obtained. • Dextranase activity was optimal at 60 °C and pH 5.5 and stable at 50 °C and pH 4.5–7.0. • The amino acid residue at position 578 changed from His to Leu after mutagenesis. • Dextranase inhibited biofilm formation and the clearance of Streptococcus mutans. Dextranase has extensive applications in the food, pharmaceutical, and chemical industries. However, enzyme production by the wild-type strain is generally low and few studies have conducted structural analysis of dextranase. This study describes an efficient and stable mutagenesis method for producing dextranase and the relationship between the enzyme structure and enzymatic properties before and after mutagenesis. Wild-type Chaetomium globosum was mutated by combined atmospheric and room temperature plasma treatment and ethyl methyl sulfone application. Mutant strains were screened for optimal dextranase production ability and genetic stability. The maximum yield of dextranase reached 824.73 U/mL. Dextranase produced by the mutant strain displayed the same optimum pH and temperature values of 5.5 and 60℃, respectively, as dextranase produced by the wild-type strain. However, dextranase from the mutant strain showed greater heat stability at 70℃. Furthermore, the three-dimensional structure of the enzyme changed slightly after mutagenesis, with the amino acid residue at position 578 changing from His to Leu. This change in the three-dimensional structure affected the properties of dextranase. Finally, dextranase significantly inhibited the growth of Streptococcus mutans. The results indicated dextranase from Chaetomium globosum would give potential implications in the medical, prevent dental caries and food industries. [ABSTRACT FROM AUTHOR]

The progress of research on silver nanoparticles (AgNPs) has led to their inclusion in many consumer products (chemicals, cosmetics, clothing, water filters, and medical devices) as a biocide. Despite the widespread use of AgNPs, their biocidal activity is not yet fully understood and is usually associated with various factors (size, composition, surface, red-ox potential, and concentration) and, obviously, specific features of microorganisms. There are merely a few studies concerning the interaction of molds with AgNPs. Therefore, the determination of the minimal AgNPs concentration required for effective growth suppression of five fungal species (Paecilomyces variotii, Penicillium pinophilum, Chaetomium globosum, Trichoderma virens, and Aspergillus brasiliensis), involved in the deterioration of construction materials, was particularly important. Inhibition of bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli) and yeasts (Candida albicans and Yarrowia lipolytica) was also assessed as the control of AgNPs effectiveness. AgNPs at the concentrations of 9-10.7 ppm displayed high inhibitory activity against moulds, yeast, and bacteria. The TEM images revealed that 20 nm AgNPs migrated into bacterial, yeast, and fungal cells but aggregated in larger particles (50-100 nm) exclusively inside eukaryotic cells. The aggregation of 20 nm AgNPs and particularly their accumulation in the cell wall, observed for A. brasiliensis cells, are described here for the first time. [ABSTRACT FROM AUTHOR]

The genus Chaetomium is a frequently occurring fungal taxon world-wide. Chaetomium and Chaetomium-like species occur in indoor environments, where they can degrade cellulose-based building materials, thereby causing structural damage. Furthermore, several species of this genus may also cause adverse effects on human health. The aims of this research were to identify Chaetomium and Chaetomium-like strains isolated from indoor environments in Hungary and Finland, two geographically distant regions of Europe with drier and wetter continental climates, respectively, and to study their morphological and physiological properties, as well as their extracellular enzyme activities, thereby comparing the Chaetomium and Chaetomium-like species isolated from these two different regions of Europe and their properties. Chaetomium and Chaetomium-like strains were isolated from flats and offices in Hungary, as well as from schools, flats, and offices in Finland. Fragments of the translation elongation factor 1α (tef1α), the second largest subunit of RNA polymerase II (rpb2) and β-tubulin (tub2) genes, as well as the internal transcribed spacer (ITS) region of the ribosomal RNA gene cluster were sequenced, and phylogenetic analysis of the sequences performed. Morphological examinations were performed by stereomicroscopy and scanning electron microscopy. Thirty-one Chaetomium sp. strains (15 from Hungary and 16 from Finland) were examined during the study. The most abundant species was Ch. globosum in both countries. In Hungary, 13 strains were identified as Ch. globosum, 1 as Ch. cochliodes, and 1 as Ch. interruptum. In Finland, 10 strains were Ch. globosum, 2 strains were Ch. cochliodes, 2 were Ch. rectangulare, and 2 isolates (SZMC 26527, SZMC 26529) proved to be representatives of a yet undescribed phylogenetic species from the closely related genus Dichotomopilus, which we formally describe here as the new species Dichotomopilus finlandicus. Growth of the isolates was examined at different temperatures (4, 15, 20, 25, 30, 37, 35, 40, and 45 °C), while their extracellular enzyme production was determined spectrophotometrically.

In selective macroautophagy/autophagy, autophagy receptors are key molecules that determine cargo specificity. Most known autophagy receptors only exist in some but not all eukaryotic lineages. The exception is Nbr1 proteins, which are conserved across eukaryotes. The four-tryptophan (FW) domain is the hallmark of Nbr1 proteins, but its function has been unknown. Our recent study found that the FW domain in the Nbr1 protein of the filamentous fungus Chaetomium thermophilum binds the α-mannosidase Ams1, a known selective autophagy cargo in budding yeast and fission yeast. Furthermore, we showed that when C. thermophilum Nbr1 and Ams1 are expressed heterologously in fission yeast, FW domain-mediated binding can promote autophagic delivery of Ams1 into vacuoles. We solved the structure of the FW-Ams1 complex and revealed the structural mechanism underlying Ams1 recognition by the FW domain. The N-terminal di-glycine peptide of Ams1 fits into a conserved pocket of the FW domain. We propose that this cargo-binding mechanism may also be employed by Nbr1 proteins in other eukaryotes. [ABSTRACT FROM AUTHOR]

Apple Valsa canker (AVC) weakens apple trees and significantly reduces apple production in China and other East Asian countries. Thus far, very few AVC-targeting biocontrol resources have been described. Here, we present a thorough description of a fungal isolate ( Chaetomium globosum , 61239) that has strong antagonistic action toward the AVC causal agent Cytospora mali . Potato dextrose broth culture filtrate of strain 61239 completely suppressed the mycelial growth of C. mali on potato dextrose agar, and strongly constrained the development of AVC lesions in in vitro infection assays. ultra-performance liquid chromatography (UPLC) and HPLC-MS/MS investigations supported the conclusion that strain 61239 produces chaetoglobosin A, an antimicrobial metabolite that inhibits C. mali . Using genome sequencing, we discovered a gene cluster in strain 61239 that may be responsible for chaetoglobosin A production. Two of the cluster's genes- cheA , a PKS-NRPS hybrid enzyme, and cheB , an enoyl reductase-were individually silenced, which significantly decreased chaetoglobosin A accumulation as well as the strain's antagonistic activity against C. mali . Together, the findings of our investigation illustrate the potential use of Chaetomium globosum for the management of AVC disease and emphasize the significant contribution of chaetoglobosin A to the antagonistic action of strain 61239., Competing Interests: The author(s) declare no conflict of interest.

Crude glycerol is becoming a financial and environmental liability due to its surplus production from biodiesel industry, and its utilization as a fermentation feedstock for value-added chemicals production has been widely studied. In present work, the capacity of an endophytic fungus, Chaetomium globosum CGMCC 6882, using glycerol and crude glycerol for polysaccharide production was investigated. Results showed that the polysaccharide titers from glucose and glycerol were 1.85 and 3.8 g/L, respectively. Moreover, spore morphology of C. globosum CGMCC 6882 was favorable for polysaccharide production. Meanwhile, impurities in crude glycerol have no effect on polysaccharide production by C. globosum CGMCC 6882. Finally, characteristic results of polysaccharides produced from glucose, glycerol, and crude glycerol have suggested that metabolic flux might be a determinant factor on polysaccharide structure. Taken together, this research provided an innovative approach of utilizing crude glycerol produced from the biodiesel production process. [ABSTRACT FROM AUTHOR]

The sterilization process, due to its immense energy consumption, high facilities investment, and loss of raw materials by caramelization, during industrial production has drawn much attention. In this study, a methanol-resistant mutant strain, Chaetomium globosum ALE20, was obtained following 20 cycles of adaptive laboratory evolution process. The titer of anticancer polysaccharide (GCP-M) from C. globosum ALE20 reached 9.2 g/L with glycerol as sole carbon source using non-sterilized and fed-batch fermentation strategy. This titer represents a 200% increase compared with the 3.3 g/L attained with batch fermentation. The GCP-M monosaccharide was comprised of galactose, glucose, mannose and glucuronic acid, in a molar ratio of 3.83:66.37:3.26:1.95, respectively, and its weight-average molecular weight and polydispersity were 3.796 × 104 Da and 1.060, respectively. This work presents an ideal alternative and safer fermentation process without sterilization, and a useful approach for enhancing industrial production. • A methanol-resistant C. globosum ALE20 was obtained through ALE. • C. globosum ALE20 could tolerate 10% (v/v) methanol concentration. • GCP-M titer reached 9.2 g/L in non-sterilized fed-batch fermentation. [ABSTRACT FROM AUTHOR]

Background: Endophytic fungi are one of the most promising resources of natural bioactive products. In the present study, secondary metabolites were isolated from the endophytic fungus Chaetomium cupreum and evaluated in vitro for pharmaceutical potentials. Objective: To characterize the secondary metabolites obtained from the endophytic fungus Chaetomium cupreum from the plant Mussaenda luteola and to determine its antioxidant, cytotoxicity and anti-mycobacterial activities. Methods: Three secondary metabolites were isolated by column chromatography and solvent-solvent fractionation method from the ethyl acetate and methanol extract of C. cupreum. The structures were elucidated by spectroscopic studies includes FT-IR, NMR, MS analysis. Anti-mycobacterial activity of metabolites was determined by Microtitre Plate Alamar Blue Assay (MABA) against Mycobacterium tuberculosis H37Rv (ATCC27294) and also evaluated the antioxidant potentials using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. The cytotoxicity test was performed against breast cancer cell line MCF-7 using MTT assay. Results: Three secondary metabolites were characterized as 6- (heptacosa- 18' Z enyl)- 2- (- 18' hydroxyl- 1' enyl- 19' oxy)- 3 hydroxy benzoquinone (1), (3β -5α- dihydroxy -6β- phenyl acetyloxy - ergosta -7, 22 - diene) (2) and 2-dodecanol (3). The results of bio-assays revealed that the compound (1) and (2) exhibit significant inhibition of mycobacterium with MIC of 6.25μg/ml and 25μg/ml respectively, which is similar to the standard streptomycin drug. It also exhibit good DPPH scavenging potential of 72.07±1.95 and 71.63±1.40 % respectively. The cytotoxicity was tested against breast cancer cell line MCF-7 and found compound 1 and 2 had cytotoxicity of 52% and 49% respectively at 100μg/mL. Conclusion: The present study indicated that the isolated secondary metabolites from the endophytic fungus C. cupreum could be a potential lead molecule of antimicrobial agents. [ABSTRACT FROM AUTHOR]

Abstract Viable and metabolically active fungi in toxic mixed liquors, treating landfill leachates and municipal wastewaters, were identified by culture depending methods. A selective culture medium consisting of wastewater and agar (WA) restrained fungi that could be randomly present (94% of the 51 taxa retrieved on WA were sample-specific), overcoming the problem of fast growing fungi or mycoparasite fungi. Moreover, WA allowed the isolation of fungi with a possible role in the degradation of pollutants typically present in the two wastewaters. Phoma medicaginis var. medicaginis , Chaetomium globosum, and Geotrichum candidum were mainly found in municipal wastewater, whereas Pseudallescheria boydii , Scedosporium apiospermum, Aspergillus pseudodeflectus , and Scopulariopsis brevicaulis were typical of landfill leachate. Graphical abstract fx1 Highlights • Wastewater treatment may benefit from autochthonous fungal bioaugmentation. • Sludge from municipal wastewater treatment is more toxic than landfill leachate. • Wastewater-Agar is preferable for isolation of useful sample-specific fungi. • Phoma , Chaetomium , and Geotrichum could degrade molecules in municipal wastewaters. • Scedosporium , Aspergillus , Scopulariopsis could degrade molecules in leachates. [ABSTRACT FROM AUTHOR]

Aim: Pseudomonas orientalis and Chaetomium cupreum isolated from metal(oid)s-contaminated soil were characterized to evaluate their role in plant growth promotion and enhance the tolerance of Eucalyptus globulus to copper stress.Methods: We evaluated minimum inhibitory concentration and explored plant-promoting traits under copper stress. Moreover, changes in morphology and the accumulation of metals on the cell surface were determined by scanning electron microscopy images coupled with energy dispersive x-ray spectroscopy (SEM-EDX). The effect of inoculation with P. orientalis and C. cupreum on E. globulus plants established in soils contaminated with copper was determined through root and shoot biomass and antioxidant response.Results: Both strains showed high tolerance to metal(oid)s, whereas phosphate solubilization was only detected in P. orientalis. Under copper stress, C. cupreum presented a higher production rate of siderophores and indole acetic acid (4.5 mm day−1, 15.042 μg mL−1). SEM images and EDX analysis reflected cellular changes in fungus and proved biosorption of copper. Inoculation of P. orientalis and C. cupreum on Eucalyptus globulus plants significantly increased plant growth and mitigated the toxic effects of copper.Conclusions: According to these results, both microorganisms contribute positively to stimulated plant growth and to decreasing stress caused by high concentrations of copper in soil, especially C. cupreum. [ABSTRACT FROM AUTHOR]

Miscanthus sinensis Andersson is a pioneer plant species that grows naturally at mining sites. Miscanthus sinensis can detoxify aluminium (Al) by producing phytosiderophores, such as chlorogenic acid, citric acid, and malic acid, and localizing Al in cell walls. Root-endophytic Chaetomium cupreum, which produces microbial siderophores, enhances Al tolerance in M. sinensis. However, we could not determine whether the siderophores produced by C. cupreum actually enhance Al tolerance in M. sinensis, because the microbial siderophores have not yet been identified in previous research. The purpose of this study was to clarify how C. cupreum chemically increases Al tolerance in M. sinensis under acidic mining site conditions, especially considering siderophores. Using instrumental analyses, the siderophore produced by C. cupreum was identified as oosporein. Comparison of the stability constant between Al and phytosiderophores and oosporein indicated that oosporein could detoxify Al similarly to chlorogenic acid, which shows higher stability constant than citric acid and malic acid. Inoculation test of C. cupreum onto M. sinensis in acidic mine soil showed that C. cupreum promoted seedling growth, and enhanced Al tolerance via inducing chlorogenic-acid production and producing oosporein. These results suggested that C. cupreum could chemically enhance Al tolerance and might promote growth via reducing excessive Al in cell walls, the main site of Al accumulation. In addition, the chemical enhancement of Al tolerance by C. cupreum might be important for M. sinensis to adapt to acidic mining sites. [ABSTRACT FROM AUTHOR]

Frataxins form an interesting family of iron‐binding proteins with an almost unique fold and are highly conserved from bacteria to primates. They have a pivotal role in iron–sulfur cluster biogenesis as regulators of the rates of cluster formation, as it is testified by the fact that frataxin absence is incompatible with life and reduced levels of the protein lead to the recessive neurodegenerative disease Friedreich's ataxia. Despite its importance, the structure of frataxin has been solved only from relatively few species. Here, we discuss the X‐ray structure of frataxin from the thermophilic fungus Chaetomium thermophilum, and the characterization of its interactions and dynamics in solution. We show that this eukaryotic frataxin has an unusual variation in the classical frataxin fold: the last helix is shorter than in other frataxins which results in a less symmetrical and compact structure. The stability of this protein is comparable to that of human frataxin, currently the most stable among the frataxin orthologues. We also characterized the iron‐binding mode of Ct frataxin and demonstrated that it binds it through a semiconserved negatively charged ridge on the first helix and beta‐strand. Moreover, this frataxin is also able to bind the bacterial ortholog of the desulfurase, which is central in iron–sulfur cluster synthesis, and act as its inhibitor. In this manuscript, we solved the structure of Chaetomium thermophilum frataxin and showed that it is less symmetric and compact compared to other orthologs, due to a variation in the canonical frataxin fold. Furthermore, we characterized the iron‐binding mode of this frataxin and its interaction with bacterial desulfurase. In this image, a structural superposition compares the structures of Ct (green) and human (magenta) frataxins. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Structure of MIF4G-like domain from the CCR4-NOT deadenylase complex. • This domain cannot interact with DEAD-box RNA helicases. • No interactions observed with subunits of CCR4-NOT in binding assays. • Structural conservation hints at important role but function is unknown. Abstract The CCR4-NOT complex plays a central role in the regulation of gene expression and degradation of messenger RNAs. The multisubunit complex assembles on the NOT1 protein, which acts as a 'scaffold' and is highly conserved in eukaryotes. NOT1 consists of a series of helical domains that serve as docking sites for other CCR4-NOT subunits. We describe a crystal structure of a connector domain of NOT1 from the thermophilic fungus Chaetomium thermophilum (Ct). Comparative structural analysis indicates that this domain adopts a MIF4G-like fold and we have termed it the MIF4G-C domain. Solution scattering studies indicate that the human MIF4G-C domain likely adopts a very similar fold to the Ct MIF4G-C. MIF4G domains have been described to mediate interactions with DEAD-box helicases such as DDX6. However, comparison of the interfaces of the MIF4G-C with the MIF4G domain of NOT1 that interacts with DDX6 reveals key structural differences that explain why the MIF4G-C does not bind DDX6. We further show that the human MIF4G-C does not interact stably with other subunits of the CCR4-NOT complex. The structural conservation of the MIF4G-C domain suggests that it may have an important but presently undefined role in the CCR4-NOT complex. [ABSTRACT FROM AUTHOR]

Abstract By feeding L -tyrosine into the culture medium, nine undescribed compounds, termed as armochaetoglasins A–I, together with three known analogues, namely armochaetoglobin E, chaetoglobosin V, and chaetoglobosin J, were isolated and identified from the medicinal terrestrial arthropod-derived fungus Chaetomium globosum TW1-1. Their structures were elucidated by means of NMR spectroscopy, single-crystal X-ray crystallography, and comparison of their electronic circular dichroism (ECD) spectra. Structurally, armochaetoglasin A represented the first tyrosine-derived cytochalasan alkaloid characterized by a 13-membered carbocyclic ring system; armochaetoglasins B and C possessed a rare 19,20- seco -chaetoglobosin skeleton. Armochaetoglasin B, chaetoglobosin V, and chaetoglobosin J showed weak cytotoxic activity with IC 50 values ranging from 19.5 to 34.72 μ M. Graphical abstract Nine undescribed cytochalasan alkaloids and three known analogues were isolated from the medicinal terrestrial arthropod-derived fungus Chaetomium globosum TW1-1. Armochaetoglasin B, chaetoglobosin V, and chaetoglobosin J showed weak cytotoxic activity. Image 1 Highlights • Armochaetoglasins A–I were isolated from the fungus Chaetomium globosum TW1-1. • Chemical structures were ascertained by spectroscopic and mass spectrometric analyses. • Absolute configurations were assigned by crystallography and experimental ECD analyses. • Armochaetoglasin B, chaetoglobosin V, and chaetoglobosin J showed cytotoxic activity. [ABSTRACT FROM AUTHOR]

Abstract To evaluate the antioxidant properties of different extracts (chloroform, ethyl acetate, n-butanol and methanol extracts) of fungus C. cupreum SS02. The antioxidant properties were evaluated by using five antioxidant methods, metal chelating assay, 2,2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid (ABTS), hydroxyl radical (HO) scavenging assay, superoxide anion (O 2 ) radical scavenging assay, and nitric oxide (NO) scavenging assay. Methanol extract of C. cupreum showed highest metal chelating activity (63.61 ± 0.07 mg EDTAE/g DW), followed by chloroform extract (57.25 ± 0.12 mg E DTAE/g DW) and n-butanol extract (27.33 ± 0.07 mg E DTAE/g DW) whereas ethyl acetate extract showed least metal chelating activity (18.35 ± 0.07 mg E DTAE/g DW) at 50 µg/ml. In ABTS assay, n-butanol extract showed highest ABTS inhibition activity (19.91 ± 0.14 μmol RE/g DW), followed by ethyl acetate extract (13.07 ± 0.59 μmol RE/g DW) and chloroform extract (13.07 ± 0.82 μmol RE/g DW) whereas methanol extract showed the lowest activity (11.65 ± 0.16 μmol RE/g DW at 50 µg/ml). In hydroxyl radical scavenging assay, n-butanol extract showed highest scavenging activity (31.95 ± 0.21 mg RE/g DW), followed by ethyl acetate extract (28.19 ± 0.21 mg RE/g DW), methanol extract (22.93 ± 0.37 mg RE/g DW) and chloroform extract (18.04 ± 0.21 mg RE/g DW) at 50 µg/ml. In superoxide anion scavenging assay, chloroform extract showed highest scavenging activity (56.44 ± 0.03 mg RE/g DW) followed by ethyl acetate extract (49.88 ± 0.09 mg RE/g DW), n-butanol extract (19.49 ± 0.09 mg RE/g DW) and methanol extract (7.75 ± 0.06 mg RE/g DW) at 50 µg/ml. The highest inhibition of nitric oxide radical was observed in chloroform extract of C. cupreum (11.23 ± 0.11%) followed by ethyl acetate extract (7.62 ± 0.06%), n-butanol extract (4.72 ± 0.90%) and methanol extract (3.20 ± 0.06%) at 50 µg/ml. The results showed that different extracts of C. cupreum have significant antioxidant activity due to the presence of different phytochemicals. Thus, it is suggested that C. cupreum extracts should be further studied for their antioxidant properties for food and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

A new endoglucanase encoding gene ( ctendo7 ) was cloned from the thermophilic fungus Chaetomium thermophilum and heterologously expressed in Pichia pastoris . The recombinant CTendo7 enzyme was purified by Ni 2+ affinity chromatography and subsequently characterized. CTendo7 belongs to glycoside hydrolase family 7, and exhibited considerable activity against sodium carboxymethyl cellulose (CMC-Na) and xylan of 1.91 IU/mg and 3.05 IU/mg at the optimum reaction condition of 55 °C, pH 5.0, respectively. The purified enzyme displayed relatively good thermostability. The residual endoglucanase and xylanase activities were 74.3% and 66.2% after a 60 min pre-incubation at 70 °C. Additionally, Ag + , Fe 3+ and Cu 2+ negatively affected the enzyme's activity, while the presence of 1 mM and 5 mM Mn 2+ significantly enhanced both endoglucanase and xylanase activities. Generation of soluble oligosaccharides from lignocellulose is a critical step in bioethanol production, and it is noteworthy that CTendo7 produced cello-oligosaccharides and xylo-oligosaccharides from the continuous enzymatic saccharification of CMC-Na and xylan, respectively. This is the first detailed report on a novel bifunctional endoglucanase/xylanase enzyme from C. thermophilum . Furthermore, the excellent properties of CTendo7 distinguish it as a promising candidate for industrial lignocellulosic biomass conversion. [ABSTRACT FROM AUTHOR]

Objective: We aimed to identify new high-yield dextranase strains and study the catalytic potential of dextranase from the strain in industrial applications.Results: Dextranase-producing strains were screened from soil samples, and a potential strain was identified as Chaetomium globosum according to its phenotype, biochemical characteristics, and rDNA analysis. Crude dextranase was purified to reach 10.97-fold specific activity and 18.7% recovery. The molecular weight of the enzyme was 53 kDa with an optimum temperature and pH of 60 °C and 5.5, respectively. Enzyme activity was stable at pH 4.0-7.0 and displayed sufficient thermal stability at temperatures < 50 °C. Mn2+ (10 mM) enhanced dextranase activity by 134.44%. The enzyme was identified as an endodextranase. It displayed very high hydrolytic affinity toward high-molecular weight dextran T2000, reaching 97.9% hydrolysis within 15 min at 2 U/mL.Conclusion: Collectively, these results suggest that Chaetomium globosum shows higher production and specificity of dextranase than that from other reported strains. These findings may offer new insights into the potential of dextranase in the sugar, medical, and food industries.Graphical abstract: [ABSTRACT FROM AUTHOR]

Fraction B was chromatographed on silica gel column with a gradient of ethyl acetate in petroleum ether (1:0, 50:1, 25:1) to give three subfractions (subfrs. The ethyl acetate extract was subjected to silica gel column chromatography eluting successively with dichloromethane-methanol gradient (50:1-0:1) to yield five fractions (A-E). Subfraction C2 was chromatographed over a silica gel column eluting with petroleum ether-ethyl acetate and then PTLC to afford compounds B 4 b (4.4 mg) and B 5 b (6.7 mg). [Extracted from the article]

Plants exhibit beneficial associations between fungal endophytes and roots for better growth, disease suppression, and stress tolerance. Considerable information is now available about the beneficial role of fungal endophytes. In this study, endophytic fungi Chaetomium sp. , Curvularia chonburiensis, C. specifera, C. hawaiiensis, Rhizoctonia solani, Fusarium solani, Talaromyces assiutensis and T. trachyspermus isolated and evaluated for nematocidal activity against a root-knot nematode Meloidogyne javanica. The culture filtrates of endophytic fungi were prepared and used to check their efficacy against root knot nematodes. The culture filtrates of endophytic fungi were applied to pot and field experiments using soybean as host plants. In vitro study of these endophytic fungal culture filtrates showed strong nematocidal activity by killing juveniles of M. javanica to a certain degree, while Chaetomium sp. , and Talaromyces assiutensis showed 100% mortality rate after 48 h. The application of Cephalosporium sp., Chaetomium sp., Talaromyces trachyspermus and T. assiutensis suppressed root rotting fungi of soybean in both screen house and field plots experiments. Significance of fungal isolates was further confirmed by repeated experiments. Endophytic fungi also showed positive impacts on the host plants by increasing the rate of their growth and improving their tolerance level to biotic stress which was evident by the production of increased amounts of resistance markers like salicylic acid and polyphenol contents with subsequent improvement of the antioxidant status. The n- hexane fraction of the culture filtrate of Chaetomium sp. , were subjected to GC-MS analysis for the identification of compounds and some new compounds have been reported for the first time from this fungus. The results will facilitate a better understanding of host plant and fungal interaction and are likely to assist in the screening and utilization of beneficial microbes. • Species of Cephalosporium, Chaetomium and Talaromyces are known to possess antimicrobial activity against phytopathogens but their actual use in agriculture is negligible. • The antifungal properties against phytopathogenic fungi by these isolates indicate the presence of certain types of compounds that may suppress the growth of phyto-pathogen. • It is suggested that fungal endophytes are the main source of producing wide range of secondary metabolites. Each year, billions dollar losses occur just because of phytopathogens like, species of Fusarium, Verticillium, Rhizoctonia, Sclerotinia and Macrophomina. • The use of biological control for the management of plant disease is an alternative to chemical used in the field, but the main application of biological control for the management of disease is very rare, due to the limited efficacy and their inconsistent performance. • The detailed study of plant and fungal symbiosis reveals possible pathways often involved in their association as well as in the synthesis of bioactive metabolites which play a major role in stress tolerance in plants. [ABSTRACT FROM AUTHOR]

Serious crop diseases caused by soil microecological disturbances have been considered important causes of continuous cropping obstacles. Continuous long-term farming of cotton, an important cash crop, can lead to cotton yield and quality decline and the aggravation of soil-borne pathogens, such as Verticillium dahliae. A pot experiment was carried out in the continuous cropping cotton field soil of Xinjiang to investigate the impact of the biocontrol fungus Chaetomium globosum CEF-082 on removing the barrier to continuous cropping in cotton fields and its impact on soil microecology in cotton fields. The addition of CEF-082 increased the diversity and abundance of bacterial species, decreasing the abundance of pathogenic fungi, such as Fusarium and Verticillium , and decreasing the abundance ratio of fungi to bacteria (F/B) in soil according to high-throughput sequencing of cotton rhizosphere soil. Furthermore, the application of CEF-082 enhanced soil enzyme activity and soil pH value, controlled soil nutrient levels, and reduced the soil C/N ratio through the cotton root surrounding the soil nutrient level and enzyme activity change test. These modifications imply that the use of the biocontrol fungus CEF-082 may improve soil health, reduce the prevalence of soil-borne pathogens, restore damaged soil microecology, and have a favorable impact on easing the obstacles of continuous cotton cropping. [Display omitted] • The addition of CEF-082 increased the diversity and abundance of bacterial species, decreasing the abundance of pathogenic fungi, such as Fusarium and Verticillium, and decreasing the abundance ratio of fungi to bacteria (F/B) in soil. • Application of CEF-082 could increase the activities of soil sucrase, soil catalase and soil urease and soil pH value in continuous cropping soil. • Application of CEF-082 can increase the content of available phosphorus and available potassium in continuous cropping soil and regulate the soil nutrient balance. [ABSTRACT FROM AUTHOR]

A study on molecular docking-based virtual screening has been conducted to select virtual hit of compounds, reported its existence in fungal endophytes of Chaetomium sp. as cytotoxic agent of breast cancer. The ligands were docked into Human Estrogen Receptor alpha (HERa) as the protein which regulates the breast cancer growth via estradiol-estrogen receptor binding intervention. The results showed that two compounds bearing xanthone and two compounds bearing benzonaphtyridinedione scaffolds were selected as virtual hit ligands for HERa leading to the conclusion that these compounds were good to be developed as anti breast cancer.

The purpose of this study was to assess the impact of metallurgical industry wastes on the semiarid soil microbiota using physico-chemical and microbiological parameters, highlighting the filamentous fungi assembly. Soil samples were collected in an area of industrial waste deposit contaminated with lead and mixed with natural soil (control soil) in seven different concentrations (0, 7.5, 15, 30, 45, 60 and 100%). The results showed alterations on the physico-chemical properties of the soil treated with industrial wastes, with a gradate increase of the soil's pH (5.6-10.4) and electrical conductivity (0.3-14.7 dS m-1) and also reduction of organic matter (7.0-1.8%). The use of microbiological parameters (fungal richness and diversity, CO2emission, and the carbon on the microbial biomass) enabled the identification of alterations on the microbial community due to stress caused by the exposure to industrial wastes, despite the presence of Thielavia, Chaetomium and Aspergillus tolerant to high concentrations of the scoria. Therefore, these filamentous fungi could be used in biomonitoring and bioremediation studies in the soils contaminated by industrial wastes.

Maturation of iron-sulfur (Fe-S) proteins in eukaryotes requires complex machineries in mitochondria and cytosol. Initially, Fe-S clusters are assembled on dedicated scaffold proteins and then are trafficked to target apoproteins. Within the cytosolic Fe-S protein assembly (CIA) machinery, the conserved P-loop nucleoside triphosphatase Nbp35 performs a scaffold function. In yeast, Nbp35 cooperates with the related Cfd1, which is evolutionary less conserved and is absent in plants. Here, we investigated the potential scaffold function of human CFD1 (NUBP2) in CFD1-depleted HeLa cells by measuring Fe-S enzyme activities or 55Fe incorporation into Fe-S target proteins. We show that CFD1, in complex with NBP35 (NUBP1), performs a crucial role in the maturation of all tested cytosolic and nuclear Fe-S proteins, including essential ones involved in protein translation and DNA maintenance. CFD1 also matures iron regulatory protein 1 and thus is critical for cellular iron homeostasis. To better understand the scaffold function of CFD1-NBP35, we resolved the crystal structure of Chaetomium thermophilum holo-Cfd1 (ctCfd1) at 2.6-Å resolution as a model Cfd1 protein. Importantly, two ctCfd1 monomers coordinate a bridging [4Fe-4S] cluster via two conserved cysteine residues. The surface-exposed topology of the cluster is ideally suited for both de novo assembly and facile transfer to Fe-S apoproteins mediated by other CIA factors. ctCfd1 specifically interacted with ATP, which presumably associates with a pocket near the Cfd1 dimer interface formed by the conserved Walker motif. In contrast, ctNbp35 preferentially bound GTP, implying differential regulation of the two fungal scaffold components during Fe-S cluster assembly and/or release. [ABSTRACT FROM AUTHOR]

Enzymatic saccharification of lignocellulosic biomass is increasingly applied in agricultural and industrial applications. Nevertheless, low performance in the extreme environment severely prevents the utilization of commercial enzyme preparations. To obtain cellobiohydrolases with improved catalytic activity and thermostability, structure-based rational design was performed based on a thermostable cellobiohydrolase CtCel6 from Chaetomium thermophilum . In the present study, four conserved and noncatalytic residue substitutions were generated via site-directed mutagenesis. Mutations were heterologously expressed in yeast Pichia pastoris , purified, and ultimately assayed for enzymatic characteristics. The mutant Y119F increased the catalytic activity 1.82-, 1.65- and 1.43-fold against β- d -glucan, phosphoric acid swollen cellulose (PASC) and carboxymethylcellulose sodium (CMC-Na), respectively. In addition, S131 W effectively enhanced the enzyme's heat resistance to elevated temperatures. The half-life (t 1/2 ) of this mutant enzyme was increased 1.42- and 2.40-fold at 80 °C and 90 °C, respectively, compared to the wild-type. This study offers initial insight into the biological function of the conserved and noncatalytic residues of thermostable cellobiohydrolases and provides a valid approach to the improvement of enzyme redesign proposal. [ABSTRACT FROM AUTHOR]

Catalase-peroxidases represent one important subfamily of ancestral antioxidant enzymes originally evolved in bacteria for the protection against various forms of oxidative stress. KatG genes coding for these bifunctional catalase-peroxidases were during their peculiar evolution transferred from Bacteroidetes to the fungal phylum Ascomycota via a horizontal gene transfer event. Here we analyse a newly discovered fungal katG gene without introns coding for a thermostable catalase-peroxidase from Chaetomium thermophilum var. dissitum and compare it with closely related thermophilic and mesophilic katG s and their translation products. We show that CthediskatG gene resembling its bacterial counterparts has a typical eukaryotic transcription start site and also contains a conserved eukaryotic polyadenylation signal behind its 3′ terminus. Moreover, we have detected polyA tails in corresponding transcripts of katG from two different mRNA libraries of C. thermophilum var. disstum . Although otherwise highly conserved, only in katG genes of two C. thermophilum variants a unique 60 bp long deletion leading in the translated product with high probability to a modified loop and thus access to the prosthetic heme group was observed. We also present an updated molecular phylogeny revealing the evolutionary position of fungal thermostable catalase-peroxidases within a robust phylogenetic tree of the whole KatG subfamily. [ABSTRACT FROM AUTHOR]

Two putative type III polyketide synthase genes (PKS) were identified from Sordariomycetes fungi. These two type III PKS genes from Sordaria macrospora (SmPKS) and Chaetomium thermophilum (CtPKS), shared 59.8% sequence identity. Both, full-length and truncated versions of type III PKSs were successfully cloned and overexpressed in a bacterial host, Escherichia Coli BL21 (DE3) using a N-terminus hexa-histidine tag. The full-length and the truncated construct of PKSs showed similar activity profiles, suggesting that additional amino acid residues at the C-terminal of both SmPKS and CtPKS may not be involved in catalytic functions. We demonstrate that these two recombinant polyketide synthases could efficiently synthesize tri- and tetraketide pyrones, resorcinols and resorcylic acids using various acyl-CoAs (C 4 –C 20 ) as starter units. The truncated S. macrospora polyketide synthases (TrSmPKS) showed a maximum of 7.0 × 10 4  s −1  M −1 catalytic efficiency towards stearoyl-CoA.Whereas, truncated C. thermophilum polyketide synthases (TrCtPKS) preferred the long-chain acyl-CoA starter arachidoyl-CoA, to produce pentaketide and hexaketide resorcinols with a high catalytic efficiency of 6.2 × 10 4  s −1  M −1 . Homology model and substrate docking analyses suggest a shorter distance between sulfur of catalytic Cys152 and thioester carbonyl group of arachidoyl-CoA as well as stronger imidazolium–thiolate ion pair distance in TrCtPKS between catalytic Cys152-His309 compared to TrSmPKS- arachidoyl CoA complex. Enhanced binding interactions of CtPKS residues forming intermolecular contacts at the active site could be attributed to its high specificity towards arachidoyl-CoA. This study reports the functional characterization of two fungal type III polyketide synthases, SmPKS and CtPKS with high catalytic efficiency from S. macrospora and C. thermophilum respectively. Furthermore, the results suggested that the both SmPKS and CtPKS could be attractive targets for protein engineering to discern the unique substrate specificity and catalytic efficiency. [ABSTRACT FROM AUTHOR]

Four different laccase-producing strains were isolated from arid soils and used for bisphenol A (BPA) degradation. These strains were identified as Chaetomium strumarium G5I, Thielavia arenaria CH9, Thielavia arenaria HJ22 and Thielavia arenaria SM1(III) by internal transcribed spacer 5.8 S rDNA analysis. Residual BPA was evaluated by HPLC analysis during 48 h of incubation. A complete removal of BPA was observed by the whole cell fungal cultures within different times, depending on each strain. C. strumarium G5I was the most efficient degrader, showing 100% of removal within 8 h of incubation. The degradation of BPA was accompanied by the production of laccase and dye decolorizing peroxidase (DyP) under degradation conditions. The presence of aminobenzotriazole (ABT) as an inhibitor of cytochrome P450s monooxygenases (CYP) demonstrated a slight decrease in BPA removal rate, suggesting the effective contribution of CYP in the conversion. The great involvement of laccase in BPA transformation together with cell-associated enzymes, such as CYP, was supported by the identification of hydroxylated metabolites by ultra-high performance liquid chromatography-mass spectroscopy (UHPLC-MS). The metabolic pathway of BPA transformation was proposed based on the detected metabolites. The acute toxicity of BPA and its products was investigated and showed a significant reduction, except for T. arenaria SM1(III) that did not caused reduction of toxicity (IC 50 < 8%), possibly due to the presence of toxic metabolites. The results of the present study point out the potential application of the isolated ascomycetes in pollutant removal processes, especially C. strumarium G5I as an efficient degrader of BPA. [ABSTRACT FROM AUTHOR]

The highly photosensitive characteristic of poly-sulfide chetomins was first unveiled, and four new unstable analogues, chetomins A–D (1–4), with significant cytotoxicity were successfully purified in darkness. The visible-light-induced desulfurization and intermolecular disproportionation were revealed to initiate the interconversion of chetomin analogues, which explained the long-recognized puzzle of rarity and instability of chetomin analogues. [ABSTRACT FROM AUTHOR]

Abstract: Miscanthus sinensis Andersson grows naturally at the Hitachi mine. The root‐zone soil was acidic and contained high concentrations of Cu, Pb, Zn and exchangeable Al. Adventitious roots accumulated high concentrations of Al and Fe, but not other heavy metals. The purpose of this study was to elucidate the mechanism of tolerance of Al in M. sinensis, focusing on its chemical interaction with root endophytes. We isolated Chaetomium cupreum, which produced siderophores, from adventitious roots of M. sinensis via CAS assay. In inoculation tests, C. cupreum promoted M. sinensis seedling growth and increased Al and Fe uptake in the roots, although C. cupreum did not stimulate M. sinensis to produce Al detoxicants, such as citric and malic acids. Observation of the pattern of Al localization in the roots clarified that C. cupreum reduced Al toxicity in M. sinensis via compartmentalizing Al into fungal mycelia surrounding the roots and creating a less toxic Al‐localization pattern, allocating Al to the epidermis, endodermis and stele of roots. In conclusion, our results indicated that C. cupreum increases Al tolerance in M. sinensis growing at the acidic mine site. [ABSTRACT FROM AUTHOR]

Four novel compounds, chaephilone C (1), chaetoviridides A-C (2-4), were obtained from the culture of a deep sea derived fungus Chaetomium sp. NA-S01-R1, together with four known compounds-chaetoviridin A (5), chaetoviridine E (6), chaetomugilin D (7) and cochliodone A (8). Their structures, including absolute configurations, were assigned based on NMR, MS and time-dependent density functional theory (TD-DFT) ECD calculations. A plausible biogenetic pathway for compounds 1-3 was proposed. Compounds 2 and 3 exhibited antibacterial activities against Vibrio rotiferianus and Vibrio vulnificus. Compounds 1, 3 and 4 displayed similar anti-methicillin resistant Staphylococcus aureus (anti-MRSA) activities in comparison to chloramphenicol. Compound 2 showed the most potent cytotoxic activities towards the Hep G2 cell and compounds 1 and 3 demonstrated relatively stronger cytotoxic activities than the other compounds against the HeLa cell. [ABSTRACT FROM AUTHOR]

Colletotrichum gloeosporioides is proved to be a pathogenic isolate causing anthracnose disease on coffee var. Arabica in Lao PDR. Chaetomium cupreum CC3003 inhibits sporulation of C. gloeosporiodes by 42.60 % in 30 days. The tested nano CCH, nano CCE and nano CCM derived from C. cupreum CC3003 significantly inhibits C. gloeosporioides that cause coffee anthracnose at low concentrations of about 3-15 ppm. The tested nano-particles applied to inoculated coffee seedlings significantly reduce coffee anthracnose. Research and development on nano-particles extracted from fungi are necessary to discover new strategies to control plant disease. [ABSTRACT FROM AUTHOR]

Nucleocytoplasmic transport occurs through nuclear pore complexes (NPCs), which are formed from multiple copies of ~30 different nucleoporins (Nups) and inserted into the double nuclear membrane. Many of these Nups are organized into subcomplexes, of which the Y-shaped Nup84 complex is the major constituent of the nuclear and cytoplasmic rings. The Nup82–Nup159–Nsp1 complex is another module that, however, is only assembled into the cytoplasmic ring. By means of crosslinking mass spectrometry, biochemical reconstitution, and molecular modeling, we identified a short linear motif in the unstructured N-terminal region of Chaetomium thermophilum Nup145C, a subunit of the Y-complex, that is sufficient to recruit the Nup82 complex, but only in its assembled state. This finding points to a more general mechanism that short linear motifs in structural Nups can act as sensors to cooperatively connect pre-assembled NPC modules, thereby facilitating the formation and regulation of the higher-order NPC assembly. [ABSTRACT FROM AUTHOR]