Fungus Chaetomium Globosum Research Articles

A new class of dimeric product isolated from the fungus Chaetomium globosum: evaluation of chemical structure and biological activity.

Chaetomium globosum is a filamentous fungus from which we have previously isolated a series of interesting natural products. Here, we isolated a previously unknown natural product from the culture of C. globosum. Through spectroscopic and crystallographic characterization, we determined the compound to be a new dimerized azaphilone-type product which we termed cochliodone J (1). Furthermore, our investigation into the biological activity of the natural product determined that 1 was cytotoxic to human cervix carcinoma HeLa cells with an IC50 of 17.3 µM. Lastly, a plausible biosynthetic mechanism for 1 is suggested based on our previous study on the biosynthesis of a closely related compound, cochliodone A (2).

Bioactivities and Future Perspectives of Chaetoglobosins.

Chaetoglobosins belonging to cytochalasan alkaloids represent a large class of fungal secondary metabolites. To date, around 100 chaetoglobosins and their analogues have been isolated and identified over the years from a variety of fungi, mainly from the fungus Chaetomium globosum. Studies have found that chaetoglobosins possess a broad range of biological activities, including antitumor, antifungal, phytotoxic, fibrinolytic, antibacterial, nematicidal, anti-inflammatory, and anti-HIV activities. This review will comprehensively summarize the biological activities and mechanisms of action of nature-derived chaetoglobosins.

Two anti-inflammatory chlorinated azaphilones from Chaetomium globosum TW1-1 cultured with 1-methyl-l-tryptophan and structure revision of chaephilone C

By feeding 1-methyl-l-tryptophan (1-MT) into the inactivated rice cultures of an arthropod-derived fungus Chaetomium globosum TW1-1, two new chlorinated azaphilones (1 and 2) were isolated and identified. Their structures incorporating absolute configurations were determined by comprehensive spectroscopic analyses and single-crystal X-ray diffraction. Remarkably, chaephilone C, which was reported to possess an unprecedented 6-6-5-6-fused ring system with a chlorine substitution, was structurally revised to 1. Chaephilones C (1) and D (2) showed moderate anti-inflammatory activity against the NO production with IC50 values of 15.12 ± 1.48 and 20.65 ± 0.95 μM, respectively.

Characterization and Antioxidant Activity of a Low-Molecular-Weight Xanthan Gum.

In the present work, a low-molecular-weight xanthan gum (LW-XG) was successfully obtained via biodegradation of commercial xanthan by the endophytic fungus Chaetomium globosum CGMCC 6882. The monosaccharide composition of LW-XG was glucose, mannose, and glucuronic acid in a molar ratio of 1.63:1.5:1.0. The molecular weight of LW-XG was 4.07 × 104 Da and much smaller than that of commercial xanthan (2.95 × 106 Da). Antioxidant assays showed that LW-XG had a good scavenging ability on DPPH radicals, superoxide anions, and hydroxyl radicals and good ferric reducing power. Moreover, LW-XG exhibited excellent protective effect on H2O2-injured Caco-2 cells. Results of this work suggested that LW-XG could be used in foods or pharmaceuticals to alleviate and resist the oxidative damage induced by the overproduction of reactive oxygen species.

Aureonitols A and B, Two New C13 -Polyketides from Chaetomium globosum, an Endophytic Fungus in Salvia miltiorrhiza.

Two new C13 -polyketides, aureonitols A and B (1 and 2), along with five known compounds (3-7), were isolated from the solid fermentation culture of the plant endophytic fungus Chaetomium globosum from the aerial parts of Salvia miltiorrhiza. The structures and absolute configurations of 1 and 2 were determined by comprehensive spectroscopic data analysis and computed methods. Compound 5 was found to display the remarkable antimicrobial activities against four multidrug-resistant bacteria (Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, and Staphylococcus epidermidis) with MIC values of 3.13-6.25 μg/mL (ciprofloxacin: 0.78-1.56 μg/mL), and also against all tested fungal strains with MIC values of 3.13-25 μg/mL (ketoconazole: 0.78-12.50 μg/mL).

Generation of Indoles with Agrochemical Significance through Biotransformation by Chaetomium globosum.

Six new (1-6) and two known (7 and 8) indole alkaloids were produced by the marine fish-derived fungus Chaetomium globosum 1C51 through biotransformation. The structures of these alkaloids were elucidated by a combination of MS, NMR, and X-ray crystallography analyses. Chaetoindolone A (1) was shown to inhibit the growth of the rice-pathogenic bacteria Xanthomonas oryzae pv. oryzae (xoo) both in vitro and in vivo. Chaetogline A (7) was found to be fungicidal against Sclerotinia sclerotiorum, a pathogen causing rape sclerotinia rot. Collectively, this work provides access to new indole alkaloids with potential agrochemical significance.

Efficient production of polysaccharide by Chaetomium globosum CGMCC 6882 through co-culture with host plant Gynostemma pentaphyllum.

Endophytic fungus, as a new kind of microbial resources and separated from plants, has attracted increasing attention due to its ability to synthesize the same or similar bioactive secondary metabolites as the host plants. Nevertheless, the effects of the symbiotic relationship between microorganisms and elicitors existed in host plant on metabolite production are not adequately understood. In the present work, the impacts of elicitors (ginseng saponin and puerarin) and symbiotic microorganisms on endophytic fungus Chaetomium globosum CGMCC 6882 synthesizing polysaccharide were evaluated. Results show that the polysaccharide titers increased from 2.36 to 3.88g/L and 3.67g/L with the addition of 16μg/L ginseng saponin and puerarin, respectively. Moreover, the maximum polysaccharide titer reached 4.55g/L when C. globosum CGMCC 6882 was co-cultured with UV-irradiated G. pentaphyllum. This work brings a significant contribution to the research and interpretation of the relationship between endophytic fungus and its host plant.

Utilization of glycerol and crude glycerol for polysaccharide production by an endophytic fungus Chaetomium globosum CGMCC 6882

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.

Trophic and non-trophic interactions in binary links affect carbon flow in the soil micro-food web

Soil organisms constitute multitrophic food webs, which are important determinants for nutrient and carbon flow through terrestrial systems. However, these complex interactions are not well understood, particular in the most cryptic compartment – the link between microorganisms and microfauna. The present study investigates binary trophic links between microbial prey and nematodes in a controlled semi-natural soil environment. A microcosm system with circulating airflow was filled with γ-irradiated arable soil (Luvisol), inoculated with 13C labelled microbial diet and nematode grazers, and incubated for 72 h. Signatures of 13C and CO2 evolved from microcosms, soil phospholipid fatty acids and nematode densities were determined. Except for the model nematode Caenorhabditis elegans, all organisms joint in the 12 different investigated binary links represent dominant taxa at the arable field site. Studied were the fungal grazers Aphelenchoides saprophilus and Aphelenchus sp. in combination with the fungi Chaetomium globosum, Aspergillus terreus or Cryptococcus terreus as well as the bacterial grazers C. elegans and Acrobeloides buetschlii in combination with the bacteria Pseudomonas putida, Kitasatospora sp. or Sphingomonas trueperi.The results assigned trophic and non-trophic interactions and considerable variation between binary links. The biomass decline of S. trueperi in presence of C. elegans as well as the increased release of 13C in links of C. globosum and A. terreus with Aphelenchus sp. and S. trueperi with A. buetschlii assign nematode grazing and thus a classical predator-prey system. Such direct trophic interactions can induce distinct C fluxes within a binary link as assigned by the increased density (i.e. biomass) of C. elegans when feeding on S. trueperi. In contrast, the numbers of Aphelenchus sp. declined when feeding on A. terreus, and thus reduced C flow to the next trophic level. Grazing can also foster C allocation in microbial biomass via compensatory growth, as indicated e.g. for the link of Aphelenchus sp. with the fungi C. globosum and A. terreus. While these diverse responses to grazing were to be expected, the use of CO2 and 13C measurements further revealed that non-trophic interactions shape C flux in a binary link, particularly in the bacterial channel. Besides the fungal link of C. terreus with Aphelenchus sp., non-trophic interactions were obvious for the bacterial links Kitasatospora sp. with C. elegans or A. buetschlii, and P. putida with A. buetschlii. The presence of nematodes caused a reduction in respiration (evolved CO2), thus a decline in microbial activity. The formation of chemical and/or morphological defense is likely a reason for that reduced prey activity. For further studies the inclusion of such non-trophic interactions is necessary to achieve realistic models for C flow through soil food webs.

Properties and fungal biodegradation of the different cellulose derivatives structure included into castor oil-based polyurethane composites

The requirement to protect the environment involves the synthesis of new polymers, blends, and composites with a high content of biodegradable components. This work studies the synthesis and biodegradation of castor oil-based polyurethanes filled with different cellulose derivatives (hydroxyethyl cellulose and hydroxypropyl cellulose). The polyurethane composites present a slight decrease in tensile strength and thermal stability with the increase in cellulose derivatives content. Scanning electron microscopy results showed a good dispersion of the cellulose derivatives within the polyurethane matrix. The degradation of polyurethane–cellulose derivatives by the soft rot fungus Chaetomium globosum was investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, and behavior of mechanical properties. The results showed that the inclusion of cellulose derivatives results in an increase in the rate of degradation. The obtained polyurethane–cellulose derivative composites have preserved their processability and mechanical resistance and exhibited enhanced biodegradability becoming useful eco-friendly polymeric materials.

Consolidated bioprocess of corn stover to polysaccharide using Chaetomium globosum CGMCC 6882

Abstract Polysaccharide produced from medicinal endophytic fungus not only has applications in foods, but also exhibits multiple biological activities. In this work, an endophytic fungus Chaetomium globosum CGMCC 6882 could use corn stover to produce a polysaccharide (GCP-SC) by consolidated bioprocess and the titer of GCP-SC reached 3.2 g/L. The transcriptional levels of genes related to cellulose degradation (cbh, cdh, glu and egl) in C. globosum CGMCC 6882 were 4.38, 3.85, 3.13, and 2.17 folds compared to the control group when corn stover was used as the sole carbon source. Moreover, GCP-SC showed a time- and dose-dependent manner of inhibitory effect on A549 cells and the inhibitory rate reached 93.3%. This work provides meaningful data on agricultural residues utilization and facilitation of future relative resource conversion studies.

Biological resistance of nanoclay-treated plastic composites with different bamboo contents to three types of fungi

The present study investigated the effects of exposure of bamboo–plastic composites to three aggressive fungi species on mass loss values. Polyvinyl chloride was used as the synthetic matrix of the composite. Three mixing combinations were used for bamboo–polymer composites, namely 40/60, 50/50, and 60/40. The injection-molded process was employed to produce the composites. Specimens were prepared according to modified European standard specifications (EN-113) to be exposed to white-, brown-, and soft-rot fungi each month for 4 months. The results indicated that the soft-rot fungus ( Chaetomium globosum) generally caused higher mass losses in all bamboo/plastic combination ratios. Brown- and soft-rot fungi demonstrated different mass losses on different combination ratios. However, the white-rot fungus ( Trametes versicolor) caused nearly the same mass losses on all three combination ratios. Moreover, T. versicolor was highly significant with respect to mass loss and moisture content. It can therefore be concluded that the T. versicolor has a different decay metabolism when compared to the brown- and soft-rot fungus used in this study.

Anticancer Activity of Polysaccharides Produced from Glycerol and Crude Glycerol by an Endophytic Fungus Chaetomium globosum CGMCC 6882 on Human Lung Cancer A549 Cells.

Two polysaccharides were produced by Chaetomium globosum CGMCC 6882 from glycerol (GCP-1) and crude glycerol (GCP-2). Chemical characteristics results showed GCP-1 and GCP-2 were similar polysaccharides, but the molecular weights of GCP-1 and GCP-2 were 5.340 × 104 Da and 3.105 × 104 Da, respectively. Viabilities of A549 cells after treatment with GCP-1 and GCP-2 were 49% and 39% compared to the control group. Meanwhile, flow cytometry results indicated that GCP-1 and GCP-2 could induce 17.79% and 24.28% of A549 cells to apoptosis with 200 μg/mL concentration treated for 24 h. RT-PCR results suggested that GCP-1 and GCP-2 could be used as potential and effective apoptosis inducers on A549 cells by increasing BAX, CASPASE-3, CASPASE-9, TIMP-1, TIMP-2 expression and decreasing BCL-2 expression. This research provided an innovative approach to using a byproduct of biodiesel production (crude glycerol) to produce polysaccharides of potential medicinal benefit.

Bioactive xanthoquinodins and epipolythiodioxopiperazines from Chaetomium globosum 7s-1, an endophytic fungus isolated from Rhapis cochinchinensis (Lour.) Mart

A new xanthoquinodin B9 (1), together with two known xanthoquinodins, xanthoquinodin A1 (2) and xanthoquinodin A3 (3), three epipolythiodioxopiperazines, chetomin (4), chaetocochin C (5) and dethio-tetra(methylthio)chetomin (6), and four other compounds, chrysophanol (7), emodin (8), alatinone (9), and ergosterol (10) were isolated from the endophytic fungus Chaetomium globosum 7s-1, isolated from Rhapis cochinchinensis (Lour.) Mart. All isolated structures were established based on their spectroscopic data analyses. Compounds 1–6 showed antibacterial activity against Gram positive bacteria with MICs ranging from 0.02 pM to 10.81 µM. Compounds 1–6 also exhibited cytotoxicity against KB, MCF-7 and NCI-H187 cancer cell lines (IC50 0.04–18.40 µM). However, they were cytotoxic towards a normal cell line (Vero cell) with IC50 values ranging from 0.04 to 3.86 µM.

New Metabolites from Endophytic Fungus Chaetomium globosum CDW7.

Five metabolites including two new ones, prochaetoviridin A (1) and chaetoindolin A (2), were isolated from the endophytic fungus Chaetomium globosum CDW7. Compounds 1 and 2 were characterized as an isocoumarin and an indole alkaloid derivative, respectively, with their structures elucidated by comprehensive spectroscopic analyses including high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), NMR, and circular dichroism (CD) comparison. Compounds 3–5 were identified as chaetoviridin A, chaetoglobosin R, and chaetoglobosin T, respectively. Chaetoviridin A (3) exhibited antifungal activity against Sclerotinia sclerotiorum with an EC50 value of 1.97 μg/mL. In vivo test showed that 3 displayed a protective efficacy of 64.3% against rape Sclerotinia rot at the dosage of 200 μg/mL, comparable to that of carbendazim (69.2%).

Antibacterial activity against drug-resistant microbial pathogens of cytochalasan alkaloids from the arthropod-associated fungus Chaetomium globosum TW1-1

By feeding 1-methyl-l-tryptophan (1-MT) into cultures of the arthropod-associated fungus Chaetomium globosum TW1-1, three novel cytochalasan alkaloids, termed as armochaetoglosins A–C (1–3), together with five known analogues, namely prochaetoglobosin I (4), chaetoglobosin T (5), chaetoglobosin C (6), armochaetoglobin Y (7), and chaetoglobosin Vb (8), were isolated and characterized. Their structures including absolute configurations were elucidated by means of NMR spectroscopy, single-crystal X-ray crystallography, and comparison of the experimental electronic circular dichroism (ECD) spectra. Structurally, compounds 1–3 represented the first examples of 1′-N-methyl-chaetoglobosins, which were possibly biosynthesized from the additive 1-MT rather than tryptophan. Additionally, compound 3 showed the highest antibacterial activity against K. pneumoniae and ESBL-E. coli with MIC values of 4.0 μg/mL and 16.0 μg/mL, respectively, wherein the inhibitory effect of 3 against K. pneumoniae was stronger than that of the clinically used antibiotic meropenem, with an MIC value of 8 μg/mL. Our findings may provide new chemical templates for the development of new antibacterial agents against drug-resistant microbial pathogens.

Armochaetoglasins A–I: Cytochalasan alkaloids from fermentation broth of Chaetomium globosum TW1-1 by feeding L-tyrosine

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 IC50 values ranging from 19.5 to 34.72 μM.

Aureochaeglobosins A-C, Three [4 + 2] Adducts of Chaetoglobosin and Aureonitol Derivatives from Chaetomium globosum.

Aureochaeglobosins A-C (1-3), three novel [4 + 2] cycloaddition heterodimers of chaetoglobosin and aureonitol derivatives, were obtained from the culture of endophytic fungus Chaetomium globosum, representing the first adduct examples of chaetoglobosins. Their structures were elucidated by extensive spectroscopic analyses, single-crystal X-ray diffraction, and a modified Mosher's method. Compounds 2 and 3 showed significant cytotoxicities against human MDA-MB-231 cancer cells with IC50 values of 7.6 and 10.8 μM, respectively.

Effect of thermal modification on the durability and decay patterns of hardwoods and softwoods exposed to soft rot fungi

The durability and decay patterns of thermo-vacuum (Termovuoto process for 3–4 h at 160–220 °C) treated hardwoods (ash, beech) and softwoods (spruce, fir) TMWs exposed to three soft rot fungi (Chaetomium globosum, Phialophora malorum, P. mutabilis) were investigated using the soil-block test, light- and electron microscopy. Monitoring of mass loss over 1 year indicated that soft rot fungi do not attack softwood TMWs as rapidly or as extensively as hardwood TMWs. Decay resistance progressively increased in hardwood TMWs with increase in temperature but was unclear/or varied in softwood TMWs depending on fungal/wood species, particularly at lower temperatures (160–180 °C). Soft- and hardwood TMWs showed a major increase in decay resistance at 200–220 °C and 210–220 °C, respectively. Light microscopy of decayed hardwood TMWs showed formation of typical soft rot Type-I cavities in fibres at lower temperatures (190–200 °C). However, cavities were significantly inhibited or delayed at higher temperatures (210–220 °C). Cavity formation in vessels and parenchyma cells were only observed in beech TMW treated at 190 °C or references, indicating higher resistance than fibres. Transmission electron microscopy of decayed ash TMW treated at 200 °C showed a radial-like distribution of electron dense materials in cavities and lack of fibrillar-like materials within degraded fibre walls, which differed from reference.

The antifungal efficiency of carbide lime slurry compared with the commercial lime efficiency

The article deals with studying the antifungal efficiency of carbide lime slurry compared to industrially manufactured commercial lime. Antifungal efficiency expressed as mould proofness properties was tested on the fungi using the procedure given in standard CSN 72 4310. A mixture of fungi Aspergillus niger, Chaetomium globosum, Penicillium funiculosum, Paecilomyces variotii and Gliocladium virens was utilized for testing. The scale for evaluating mould proofness properties according to CSN 72 4310 is from 0 to 5 in degree of fungi growth, where 0 means that no fungi growth occurs and the building products and materials possess fungistatic properties. The study confirms the fungistatic propeties of carbide lime slurry as well as industrially manufactured commercial lime. However, carbide lime slurry and industrially manufactured commercial lime possess no fungicidal effect.