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1.
This study investigated the endophytic fungi diversity of Taxus chinensis and screened the taxol-producing fungi in the host. A total of 115 endophytic fungi isolates obtained from bark segments of T. chinensis were grouped into 23 genera based on the morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in T. chinensis are diverse and abundant. Diaporthe, Phomopsis (anamorph of Diaporthe), Acremonium, and Pezicula were the dominant genera, whereas the remaining genera were infrequent groups. The 13 representative species of the distinct genera were capable of producing taxol verified by reverse-phase high performance liquid chromatography (HPLC). Among the taxol-producing fungi, the yield of taxol produced by the Metarhizium anisopliae, H-27 was 846.1 μg l−1 in reformative potato dextrose liquid medium, and the fungal taxol was further validated by mass spectrometry (MS). The taxol-producing fungi (92.3%) were infrequent communities, suggesting that infrequent fungi associated with T. chinensis might be a fascinating reservoir of taxol-generating fungi.  相似文献   

2.
Many endophytic fungi are known to protect plants from plant pathogens, but the antagonistic mechanism has rarely been revealed. In this study, we wished to learn whether an endophytic Aspergillus sp., isolated from Taxus mairei, would indeed produce bioactive components, and if so whether (a) they would antagonize plant pathogenic fungi; and (b) whether this Aspergillus sp. would produce the compound also under conditions of confrontation with these fungi. The endophytic fungal strain from T. mairei was identified as Aspergillus clavatonanicus by analysis of morphological characteristics and the sequence of the internal transcribed spacers (ITS rDNA) of rDNA. When grown in surface culture, the fungus produced clavatol (2′,4′-dihydroxy-3′,5′-dimethylacetophenone) and patulin (2-hydroxy-3,7-dioxabicyclo [4.3.0]nona-5,9-dien-8-one), as shown by shown by NMR, MS, X-ray, and EI-MS analysis. Both exhibited inhibitory activity in vitro against several plant pathogenic fungi, i.e., Botrytis cinerea, Didymella bryoniae, Fusarium oxysporum f. sp. cucumerinum, Rhizoctonia solani, and Pythium ultimum. During confrontation with P. ultimum, A. clavatonanicus antagonized its growth of P. ultimum, and both clavatol as well as patulin were formed as the only bioactive components, albeit with different kinetics. We conclude that A. clavatonanicus produces clavatol and patulin, and that these two polyketides may be involved in the protection of T. mairei against attack by plant pathogens by this Aspergillus sp.  相似文献   

3.
Asparagus spears collected from a total of six commercial plantings in Austria during the main harvest periods in May and June of 2003 and 2004 were examined for endophytic colonization byFusarium spp., particularlyF. proliferatum. Potentially toxigenic fungi such asF. proliferatum were isolated and identified by morphological characteristics using light microscopy. Fumonisin B1 inF. proliferatum-infected asparagus spears was detected with IAS-HPLC-FLD or HPLC-MS/MS. The identity of endophytic fungi colonizing of a total of 816 individual spears was determined. The incidence of infection byF. proliferatum and otherFusarium spp. was highly dependent on location and sampling date. The dominantFusarium species among the endophytic microflora wasF. oxysporum. Other frequently isolated species includedF. proliferatum, F. sambucinum, F. culmorum, F. avenaceum andF. equiseti. The incidence ofF. proliferatum-infected asparagus spears was less than 10% at four of the six sampling locations. At the two remaining locations, 20–47% of the spears examined were infected withF. proliferatum. Further exploration of FB1 generation in asparagus is required because the low levels of FB1 (10–50 (μg/kg) detected in harvested spears in 2003 and 2004 cannot be explained by the results of this study.
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4.
The co-culture of the suspension cells of Taxus chinensis var. mairei and its endophytic fungi, Fusarium mairei, in a 20-L co-bioreactor was successfully established for paclitaxel production. The co-bioreactor consists of two-unit tanks (10 L each) with a repairable separate membrane in the center, culturing Taxus suspension cells in one tank and growing fungi in another. By optimizing the co-culture conditions, there was a desirable yield of paclitaxel in Taxus cell cultures. The Taxus cell cultures by co-culture produced 25.63 mg/L of paclitaxel within 15 days; it was equivalent to a productivity of 1.71 mg/L per day and 38-fold higher than that by uncoupled culture (0.68 mg/L within 15 days). The optimum conditions for co-culture in the co-bioreactor were: B5 medium, inoculating fungi when Taxus cells had grown for 5 days in the co-bioreactor, hydrophilic separate membrane in the center of the co-bioreactor, and air flow rate of 1:0.85 v/v/m in fungus cultures.  相似文献   

5.
Although the terrestrial and temperate orchids–fungal biology have been largely explored, knowledge of tropical epiphytic orchids–fungus relationships, especially on the ecological roles imparted by non-mycorrhizal fungal endophytes, is less known. Exploitation of the endophytic fungal mycobiota residing in epiphytic orchid plants may be of great importance to further elucidate the fungal ecology in this special habitat as well as developing new approaches for orchid conversations. The composition of fungal endophytes associated with leaves, stems and roots of an epiphytic orchid (Dendrobium nobile), a famous Chinese traditional medicinal plant, was investigated. Microscopic imaging, culture-dependant method and molecular phylogeny were used to estimate their entity and diversity. Totally, there were 172 isolates, at least 14 fungal genera and 33 different morphospecies recovered from 288 samples. Ascomycetes, coelomycetes and hyphomycetes were three major fungal groups. There were higher overall colonization and isolation rates of endophytic fungi from leaves than from other tissues. Guignardia mangiferae was the dominant fungal species within leaves; while the endophytic Xylariaceae were frequently observed in all plant tissues; Colletotrichum, Phomopsis and Fusarium were also frequently observed. Phylogenetic analysis based on ITS gene revealed the high diversity of Xylariacea fungi and relatively diverse of non-Xylariacea fungi. Some potentially promising beneficial fungi such as Clonostachys rosea and Trichoderma chlorosporum were found in roots. This is the first report concerning above-ground and below-ground endophytic fungi community of an epiphytic medicinal orchid, suggesting the ubiquitous distribution of non-mycorrhizal fungal endophytes in orchid plants together with heterogeneity and tissue specificity of the endophyte assemblage. Possible physiological functions played by these fungal endophytes and their potential applications are also discussed briefly. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

6.
Diverse endophytic fungi exist within plant aerial tissues, with a global estimate of up to a million undescribed species. These endophytes constitute a rich bio-resource for exploration to discover new natural products. Here we investigate fungal endophytes associated with a medicinal plant, Nerium oleander L. (Apocynaceae). A total of 42 endophytic fungal strains were isolated from the host plant. Total antioxidant capacity, xanthine oxidase inhibitory activity, antimicrobial activity, and total phenolic content (TPC) were evaluated for 16 representative fungal cultures grown in improved Czapek’s broth and for the host plant. The total antioxidant capacities and phenolic contents of the fungal cultures ranged from 9.59 to 150.79 μmol trolox/100 mL culture, and from 0.52 to 13.95 mg gallic acid/100 mL culture, respectively. The fungal culture of an endophytic strain Chaetomium sp. showed the strongest antioxidant capacity, contained the highest level of phenolics, and to some extent inhibited xanthine oxidase activity with an IC50 value of 109.8 μg/mL. A significant positive correlation was found between antioxidant capacity and TPC in the tested samples. Most of the endophytic fungal cultures tested have a wide range of antimicrobial activities, which were not very strong, but much better than those of the host plant. The major bioactive constituents of the fungal cultures were investigated using LC-ESI-MS and GC-MS, and preliminary identification detected phenolics (e.g. phenolic acids and their derivatives, flavonoids) and volatile and aliphatic compounds. This study shows that the endophytic fungi isolated from N. oleander can be a potential antioxidant resource.  相似文献   

7.
The metabolites of endophytic fungus Penicillium sp. from the leaf of Hopea hainanensis were reported for the first time. By bioassay-guided fractionation, the EtOAc extract of a solid-matrix steady culture of this fungus afforded six compounds, which were identified through a combination of spectral and chemical methods (IR, MS, 1H- and 13C-NMR) to be monomethylsulochrin (1), rhizoctonic acid (2), asperfumoid (3), physcion (4), 7,8-dimethyl-iso-alloxazine (5) and 3,5-dichloro-p-anisic acid (6). Compounds 2, 3 and 6 were obtained from Penicillium sp. for the first time. All of the six isolates were subjected to in vitro bioactive assays including antifungal action against three human pathogenic fungi Candida albicans, Trichophyton rubrum and Aspergillus niger and cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line and human liver cancer HepG2 cell line. As a result, compounds 24 and 6 inhibited the growth of C. albicans with MICs of 40.0, 20.0, 50.0 and 15.0 μg/ml, respectively and the compound 6 showed growth inhibition against A. niger with MICs of 40.0 μg/ml. In addition, compounds 13 and 6 exhibited cytotoxic activity against KB cell line with IC50 value of 30.0, 20.0, 20.0, 5.0 μg/ml, respectively and against HepG2 cell line with IC50 value of 30.0, 25.0, 15.0, 10.0 μg/ml, respectively.  相似文献   

8.
A total of 38 endophytic fungus strains were isolated from Taxus chinensis var. mairei by the aseptic technique. Genomic DNA was extracted from isolated endophytic fungi and subjected to polymerase chain reaction (PCR) analysis for the presence of the Taxus taxadiene synthase (TS) gene, a rate-limiting enzyme gene in the taxol biosynthetic pathway. Twelve out of 38 isolated endophytic fungus strains showed PCR positive for the ts gene. Subsequently, taxol and its related compounds were extracted from culture filtrates and mycelia of the PCR positive strains, separated by column chromatography, and analyzed by High Performance Liquid Chromatography and Mass Spectrum. The analysis result showed that 3 strains could produce taxol and its related compounds at the detectible level. This study indicates that molecular detection of the ts gene is an efficient method for primary screening of taxol or its related compound-producing endophytic fungi, which can improve prominently screening efficiency. Published in Russian in Prikladnaya Biokhimiya i Mikrobiologiya, 2007, Vol. 43, No. 4, pp. 490–494. The text was submitted by the authors in English.  相似文献   

9.
Trametes versicolor and Agaricus augustus, with a maximum tolerable concentration (MTC) of 80 μg ml−1 tribromophenol (TBP), were selected to evaluate TBP biodegradation capacity. These fungi were capable of decreased TBP concentrations and A. augustus was also capable of biotransforming TBP to tribromoanisole (TBA). Peroxidase and laccase activities were observed in the T. versicolor supernatant but not in that of A. augustus. These tolerance levels could be due to either lignolytic enzymes that degrade TBP or the ability of the fungi to biotransform TBP to tribromoanisole, respectively. The sustained ability of T. versicolor to degrade TBP (total of 40 μg ml−1) in the presence of an additional carbon source suggests that it may have potential applications in the degradation of forestry industry waste.  相似文献   

10.
Concentrations of the DNA topoisomerase I inhibitor camptothecin were determined in different tissues of Camptotheca acuminata (Nyssaceae). The data were dependent on tissue type and developmental stage. Despite the presence of the toxic compound camptothecin, nine endophytic fungi were isolated from healthy C. acuminata plants and were tested for their camptothecin sensitivity. Two isolates showed almost no inhibition at a camptothecin concentration of 10 μg/ml. Even at a concentration of 100 μg/ml the inhibition was moderate.  相似文献   

11.
The influence of dried cell powder and culture filtrates of endophytic fungi on production of inophyllum in cell suspension cultures of leaf- and stem-derived callus of Calophyllum inophyllum was investigated. Two fungi, Nigrospora sphaerica and Phoma spp., endophytic to C. inophyllum, were isolated from leaf tissues, and were identified by both 18S rRNA gene amplification and sequencing. Elicitation of suspension cultures of both callus types of C. inophyllum with dried cell powder and culture filtrates of both fungi consistently elicited production of inophyllum A, B, C, and P. In comparison to stem-derived callus, suspension cultures of leaf-derived callus enhanced production of most inophyllum. Of the four inophyllum studied, the highest production of inophyllum A, C, and P was achieved in elicited suspension cultures of leaf-derived callus. Suspension cultures of stem-derived callus enhanced production only of inophyllum B. When suspension cultures of leaf-derived callus were elicited with 40 mg dried cell powder of Phoma spp., a level of 751-fold (6.84 mg/100 g elicited biomass) of inophyllum A was produced, compared to control. Whereas, a level of 414-fold (6.22 mg/100 g elicited biomass) of inophyllum B was produced when suspension cultures of stem-derived callus were elicited with 20 mg dried cell powder of N. sphaerica. When compared to control, a 10% culture filtrate of N. sphaerica in suspension cultures of leaf-derived callus elicited inophyllum C and P production by 928-fold (7.43 mg/100 g elicited biomass) and 750-fold (1.5 mg/100 g elicited biomass), respectively.  相似文献   

12.
The effect of fungal infection on the reproductive potential of two-spotted spider mite, Tetranychus urticae, was evaluated as part of the full biocontrol potential of three entomopathogenic fungi by modeling of fecundity probability. Female mites (≤2-day-old) on leaves were exposed to the sprays of Beauveria bassiana, Paecilomyces fumosoroseus and Metarhizium anisopliae at the concentrations of 1.13 × 103, 1.55 × 103 and 0.95 × 103 deposited conidia mm−2 and then individually reared at 25°C and 12:12 L:D for oviposition. Mite mortalities 10 days after spraying were 73.1, 75.4 and 67.9% in the fungal treatments versus 15.5% in control. On average, females infected by the three fungal species survived 5.8, 6.2 and 6.3 days, and laid 3.1, 4.0 and 4.0 eggs per capita, respectively. These were 3–4 fold lower than the control fecundity at 12.3. The cumulative probabilities [P(m ≤ N)] for the counts of infected and non-infected (control) females laying m eggs per capita (m ≤ N) during 10 days fit very well the equation P(m ≤ N) = 1/[1 + exp(a + bm)] (r 2 ≥ 0.98), yielding a solution to the probability for the female mites to achieve a specific fecundity {P(m ≤ N)−P[m ≤ (N − 1)]}. Consequently, the infected mites had 71–78% chance to lay ≤5 eggs per capita but only 5–8% to deposit >10 eggs despite some variation among the tested fungi. In contrast, the chances for the non-infected mites to achieve the low and high fecundities were 23 and 55%. The fitted probabilities provide a full coverage of the fecundity potential of infected versus non-infected mites and are more informative than the mean fecundities.  相似文献   

13.
Some strains of white rot fungi, non-lignolytic fungi and litter-decomposing basidiomycetes have been recognized as PAH degraders. The purpose of our research was to enlarge the scope of PAH-degrading fungi and explore the huge endophytic microorganism resource for bioremediation of PAHs. In this study, phenanthrene was used as a model PAHs compound. Nine strains of endophytic fungi isolated from four kinds of plant from Eupharbiaceae were screened for degradation of phenanthrene. The endophytic fungus Ceratobasidum stevensii (strain B6) isolated from Bischofia polycarpam showed high degradation efficiency and was selected for further studies. Into the fungal culture, 100 mg l−1 phenanthrene was added, and after 10 days of incubation, about 89.51% of the phenanthrene was removed by strain B6. Extracellular ligninolytic enzyme activities of strain B6 were tested. The results showed that manganese peroxidase [MnP] was the predominant ligninolytic enzyme and that its production was greatly induced by the presence of phenanthrene. To confirm the involvement of MnP in phenanthrene degradation, promotion and inhibition studies on MnP in different concentration level of Mn2+ and NaN3 were performed. Additionally, fungal mycelium-free and resuspended experiments were carried out. The results showed no apparent correlation between MnP activity and phenanthrene degradation. The mycelium and fresh medium were the crucial factors affecting the degradation of phenanthrene. To date, this is the first report on PAH degradation by Ceratobasidum stevensii. This study suggests that endophytic fungi might be a novel and important resource for microorganisms that have PAH-degrading capabilities.  相似文献   

14.
Rohitukine is a chromane alkaloid possessing anti-inflammatory, anti-cancer and immuno-modulatory properties. The compound was first reported from Amoora rohituka (Meliaceae) and later from Dysoxylum binectariferum (Meliaceae) and Schumanniophyton problematicum (Rubiaceae). Flavopiridol, a semi-synthetic derivative of rohitukine is a potent CDK inhibitor and is currently in Phase III clinical trials. In this study, the isolation of an endophytic fungus, Fusarium proliferatum (MTCC 9690) from the inner bark tissue of Dysoxylum binectariferum Hook.f (Meliaceae) is reported. The endophytic fungus produces rohitukine when cultured in shake flasks containing potato dextrose broth. The yield of rohitukine was 186 μg/100 g dry mycelial weight, substantially lower than that produced by the host tissue. The compound from the fungus was authenticated by comparing the LC–HRMS and LC–HRMS/MS spectra with those of the reference standard and that produced by the host plant. Methanolic extract of the fungus was cytotoxic against HCT-116 and MCF-7 human cancer cell lines (IC50 = 10 μg/ml for both cancer cell lines).  相似文献   

15.
Enterobacter sp. was isolated from the diseased and dead caterpillars of the tea leaf roller (Caloptilia theivora) from the Darjeeling foothill region. When the vegetative form of the bacterium was applied via food, mortality of Ctheivora showed an LC50 value at 363.1 μg/ml (bacterial wt./vol. of water) with fiducial limits 363.25 and 362.94 μg/ml respectively. The LT50 values for Ctheivora were 6 days for 100 μg/ml, 5.96 days for 300 μg/ml, 5.81 days for 500 μg/ml, 4.96 days for 750 μg/ml and 4.61 days for 1,000 μg/ml concentrations. The finding would enable one to contemplate development of a microbial pesticide using this novel Enterobacter sp. DD01 for control of the leaf rolling pest.  相似文献   

16.
This paper reports the isolation from soil of Penicillium strain PY-1 with strong antagonistic activity against plant pathogenic fungi. On the basis of its morphological characteristics and the sequence of the ITS region, strain PY-1 was identified as P. oxalicum. Strain PY-1 produces antifungal substances that suppress the mycelial growth of Sclerotinia sclerotiorum and many other plant pathogenic fungi tested; the highest antagonistic activity was detected at 72 h when cultured in a 250-ml flask containing 80 ml potato dextrose broth. Compared with carbendazim, the relative activity of the antifungal substances produced by strain PY-1 was approximately 4 μg active ingredient (a.i.) per milliliter. The antifungal substances were extracted with ethyl acetate and further separated by high-performance liquid chromatography (HPLC); at least two active components were discovered. The ability to control plant disease with strain PY-1 was confirmed with S. sclerotiorum, a widespread pathogenic fungus that attacks rapeseed (Brassica napus) and other plants. Spores (106 or 107 ml−1) and filtrate (tenfold diluted or undiluted) of strain PY-1 could significantly suppress infection and/or the extent of infection by S. sclerotiorum of plants at seven-true-leaves stage. The potential of strain PY-1 for identifying new antibiotics to control fungal disease and for biological control of plant disease, for example oilseed rape stem rot, is discussed.  相似文献   

17.
A strain LF70 endophytic fungus was isolated from the leaves of Huperzia serrata. The fungus was identified as Cladosporium cladosporioides LF70 according to its morphological characteristics and nuclear ribosomal DNA ITS sequence analysis. The strain could produce Huperzine A (HupA) identified through thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) with authentic HupA. The amount of HupA produced by this endophytic fungus was quantified to be 56.84 μg/L by HPLC, which was higher than that of other reported endophytic fungi, Acremonium sp., Blastomyces sp., and Botrytis sp. Acetylcholinesterase inhibition activity of HupA produced by strain LF70 was also similar to authentic HupA in vitro. Isolation of such a fungus may provide a promising alternative approach to producing HupA, which is used in treating Alzheimer’s disease and preventing further memory degeneration.  相似文献   

18.
Tang  Pei-jia  Zhang  Zhi-hui  Niu  Li-li  Gu  Cheng-bo  Zheng  Wen-yi  Cui  Hai-chao  Yuan  Xiao-han 《Biotechnology letters》2021,43(7):1371-1383

The study aimed to characterize a novel vitexin-producing endophytic fungus Fusarium solani G6 from Cajanus cajan, improve its capability for producing vitexin and evaluate its osteoblastic proliferation activity. A total of 153 endophytic fungi, classified into 6 genera, were isolated from C. cajan. Among them, only one strain, endophyte G6 identified as Fusarium solani, was found to produce vitexin. After the optimization of fermentation conditions, the highest vitexin yield (18.72 mg/L) for the strain was observed in PDB liquid medium containing 20.54 g/L of glucose and 8.90 g/L of ammonium sulfate, at an initial medium pH of 5.1 and at 28 °C for 6 days of cultivation. Moreover, the fungal vitexin exhibited notable osteoblastic proliferation stimulating activity. A novel vitexin-producing endophytic fungus F. solani G6 was characterized from C. cajan for the first time. The findings highlighted its potential use for large-scale production of vitexin and might have a promising use as therapeutic agent for osteoporosis.

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19.
The aim of this work was to select endophytic fungi from mangrove plants that produced antimicrobial substances. Minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) or minimal fungicidal concentrations (MFC) of crude extracts from 150 isolates were determined against potential human pathogens by a colorimetric microdilution method. Ninety-two isolates (61.3%) produced inhibitory compounds. Most of the extracts (28–32%) inhibited Staphylococcus aureus (MIC/MBC 4–200/64–200 μg ml−1). Only two extracts inhibited Pseudomonas aeruginosa (MIC/MBC 200/>200 μg ml−1). 25.5 and 11.7% inhibited Microsporum gypseum and Cryptococcus neoformans (MIC/MFC 4–200/8–200 μg ml−1 and 8–200/8–200 μg ml−1, respectively), while 7.5% were active against Candida albicans (MIC/MFC 32–200/32–200 μg ml−1). None of the extracts inhibited Escherichia coli. The most active fungal extracts were from six genera, Acremonium, Diaporthe, Hypoxylon, Pestalotiopsis, Phomopsis, and Xylaria as identified using morphological and molecular methods. Phomopsis sp. MA194 (GU592007, GU592018) isolated from Rhizophora apiculata showed the broadest antimicrobial spectrum with low MIC values of 8–32 μg ml−1against Gram-positive bacteria, yeasts and M. gypseum. It was concluded that endophytic fungi from mangrove plants are diverse, many produce compounds with antimicrobial activity and could be suitable sources of new antimicrobial natural products.  相似文献   

20.
An endophytic fungus, Tax-3, was isolated from barks of Taxus chinensis grown in the Qinba mountains, China. The strain was classified into Fusarium solani based on the morphological characteristics and the molecular phylogenetics inferred from the nuclear ribosomal DNA ITS sequences with the sequence similarity values of 100%. High performance liquid chromatography (HPLC) assay showed the F. solani, Tax-3, produced taxol with a higher yield of 163.35 μg/L in the reformative potato dextrose liquid medium (d), revealing its potential applications for taxol production. Bai Wan Deng and Kai Hui Liu contributed equally to this work.  相似文献   

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