Niche specificity and functional diversity of the bacterial communities associated with Ginkgo biloba and Panax quinquefolius.

Plant-associated bacteria can establish mutualistic relationships with plants to support plant health. Plant tissues represent heterogeneous niches with distinct characteristics and may thus host distinct microbial populations. The objectives of this study are to investigate the bacterial communities associated with two medicinally and commercially important plant species; Ginkgo biloba and Panax quinquefolius using high Throughput Sequencing (HTS) of 16S rRNA gene, and to evaluate the extent of heterogeneity in bacterial communities associated with different plant niches. Alpha diversity showed that number of operational taxonomic units (OTUs) varied significantly by tissue type. Beta diversity revealed that the composition of bacterial communities varied between tissue types. In Ginkgo biloba and Panax quinquefolius, 13% and 49% of OTUs, respectively, were ubiquitous in leaf, stem and root. Proteobacteria, Bacteroidetes, Actinobacteria and Acidobacteria were the most abundant phyla in Ginkgo biloba while Proteobacteria, Bacteroidetes, Actinobacteria, Plantomycetes and Acidobacteria were the most abundant phyla in Panax quinquefolius. Functional prediction of these bacterial communities using MicrobiomeAnalyst revealed 5843 and 6251 KEGG orthologs in Ginkgo biloba and Panax quinquefolius, respectively. A number of these KEGG pathways were predicted at significantly different levels between tissues. These findings demonstrate the heterogeneity, niche specificity and functional diversity of plant-associated bacteria.

Submerged fermentation of Ginkgo biloba seed powder using Eurotium cristatum for the development of ginkgo seeds fermented products.

BACKGROUND: Ginkgo biloba seeds are well known for the significant curative effects on relieving cough and asthma. However, the development of products from ginkgo seeds still falls behind at present, resulting in a great waste of ginkgo seeds' resource. In this work, submerged fermentation of ginkgo seed powder using Eurotium cristatum was studied to investigate its feasibility as a new processing method. RESULTS: To promote the growth of E. cristatum, the optimum fermentation medium was 80.0 g L-1 of ginkgo seed powder with addition of 5.0 g L-1 calcium chloride (CaCl2 ), 4.0 g L-1 magnesium sulfate (MgSO4 ), 1.25 g L-1 zinc sulfate (ZnSO4 ) and 0.65 g L-1 iron(II) sulfate (FeSO4 ). The optimum fermentation conditions were pH 5.8 ± 0.1, inoculum size 5.1 × 106 CFU mL-1 , liquid medium volume 100 mL in 250-mL Erlenmeyer flask and fermentation 4 days. Through fermentation, the production of lovastatin in fermentation broth could reach up to 32.97 ± 0.17 µg mL-1 and the total antioxidant capacity was improved by more than two-fold. In addition, 40.15% of the ginkgotoxin in ginkgo seed powder was degraded while the entire degradation of ginkgolic acids was obtained. Moreover, fermented ginkgo seed powder suspension presented pleasant fragrances, and the activities of amylase and protease were enhanced to 11.30 ± 0.10 U mL-1 and 23.01 ± 0.20 U mL-1 , respectively. CONCLUSIONS: Submerged fermentation using E. cristatum could significantly enhance the functional value and safety of ginkgo seed powder, and had great potential to become a novel processing method for the development of ginkgo seeds fermented products. © 2020 Society of Chemical Industry.

Hymenobacter ginkgonis sp. nov., isolated from bark of Ginkgo biloba.

Strain HMF4947T, isolated from the bark of a ginkgo tree, was a pale-pink coloured, Gram-stain-negative, non-motile, strictly aerobic and rod-shaped bacterium. The isolate grew optimally on Reasoner's 2A agar at 30 °C, pH 7.0 and with 0 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HMF4947T belonged to the genus Hymenobacter and was most closely related to Hymenobacter metalli A2-91T (96.9 % sequence similarity) and Hymenobacter pomorum 9-2-1-1T (96.5 %). The average nucleotide identity and estimated DNA-DNA hybridization values between strain HMF4947T and Hymenobacter arizonensis DSM 17870T were 74.3 and 20.5 %, respectively. The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), iso-C15 : 0 and C16 : 1 ω5c. The predominant isoprenoid quinone was menaquinone-7. The polar lipids comprised phosphatidylethanolamine, one unidentified aminoglycolipid, three unidentified aminophospholipids, one unidentified phospholipid, three unidentified aminolipids, two unidentified glycolipids and three unidentified polar lipids. The genomic DNA G+C content was 59.3 mol%. Thus, based on phylogenetic, phenotypic and chemotaxonomic data, strain HMF4947T represents a novel species of the genus Hymenobacter, for which the name Hymenobacter ginkgonis sp. nov. is proposed. The type strain of the species is strain HMF4947T (=KCTC 72780T=NBRC 114271T).

Community structure and diversity of the microbiomes of two microhabitats at the root-soil interface: implications of meta-analysis of the root-zone soil and root endosphere microbial communities in Xiong'an New Area.

The diversity of the microbial compositions of the root-zone soil (the rhizosphere-surrounding soil) and root endosphere (all inner root tissues) of Pinus tabulaeformis Carr. and Ginkgo biloba L. were evaluated in Xiong'an New Area using high-throughput sequencing; the influence of the soil edaphic parameters on microbial community compositions was also evaluated. Our results showed that both the taxonomic and phylogenetic diversities of the root endosphere were lower than those of the root-zone soil, but the variation in the endosphere microbial community structure was remarkably higher than that of the root-zone soil. Spearman correlation analysis showed that the soil organic matter, total nitrogen, total phosphate, total potassium, ratio of carbon to nitrogen, and pH significantly explained the α-diversity of the bacterial community and that total nitrogen differentially contributed to the α-diversity of the fungal community. Variation partitioning analysis showed that plant species had a greater influence on microbial composition variations than did any other soil property, although soil chemical parameters explained more variation when integrated. Together, our results suggest that both plant species and soil chemical parameters played a critical role in shaping the microbial community composition.

Anti-cervical cancer activity of secondary metabolites of endophytic fungi from Ginkgo biloba.

OBJECTIVES: The purpose of this study was to isolate the secondary metabolites of endophytic fungi from Ginkgo biloba (SMEFGB) and investigate their anti-cervical cancer activity. METHODS: SMEFGB were cultured. The secondary metabolites of endophytic fungi was extracted, purified and identified. The effects of secondary metabolites on proliferation, apoptosis and migration of human cervical cancer HeLa cells were determined. In addition, the effects of SMEFGB on growth of Hela implanted tumor in mice were investigated. RESULTS: In 9 stains of endophytic fungi successfully isolated from the leaves of Ginkgo biloba, the stain J-1, J-2 and J-3 could produce podophyllotoxin. These 3 stains were identified by molecular biology. The secondary metabolites of stain J-1, J-2 and J-3 markedly inhibited the proliferation of HeLa cells, promoted their apoptosis and blocked their migration. In addition, the secondary metabolites of stain J-1, J-2 and J-3 significantly attenuated the growth of HeLa implanted tumor in mice. CONCLUSIONS: Our results indicated that SMEFGB had obvious anti-cervical cancer activity in vitro and in vivo.

Chemical and activity investigation on metabolites produced by an endophytic fungi Psathyrella candolleana from the seed of Ginkgo biloba.

An endophytic fungus that can produce flavonoids was isolated from the seed of Ginkgo biloba cultured in Czapek-Dox medium and chromatographic separation of the ethyl acetate extract of the broth and mycelium led to the isolation of ergosterol (1), 2'-hydroxychalcone (2), myristic acid (3), cis-9-octadecenoamide (4), quercetin (5), carboxybenzene (6), uracil (7) and nicotinamide (8). This study is the first to report of the isolation of the endophytic fungus Psathyrella candolleana from the seed of Ginkgo biloba with complete assignments of 1-8. Compound (5) exhibited strong antioxidant activity of diphenyl picryl hydrazinyl (CL50 14.538 µg/mg) and compounds (5), (6) and (8) have antibacterial activity against Staphylococcus aureus (MIC 0.3906, 0.7812 and 6.25 mg/mL).

Control of Foodborne Pathogenic Bacteria by Endophytic Bacteria Isolated from Ginkgo biloba L.

Endophytic bacteria (EB) are a prospective source of natural and novel bioactive compounds with pharmaceutical relevance. In the present study, a total of 50 EB were isolated from the fruits and leaves of ginkgo tree (Ginkgo biloba L.), the only living species in the division Ginkgophyta and popularly known as a living fossil. All the isolated EB were screened for their antibacterial activity against five deleterious foodborne pathogenic bacteria namely Escherichia coli ATCC 43890, Salmonella Typhimurium ATCC 19586, Bacillus cereus ATCC 10876, Listeria monocytogenes ATCC19115, and Staphylococcus aureus ATCC 12600. Among the isolated EB, GbF-96, GbF-97, and GbF-98 exhibited antibacterial activity against all the pathogenic bacteria tested, with inhibition zone ranging from 33.47 to 9.55 mm. GbF-96, identified as Bacillus subtilis, exerted the highest antibacterial activity against all the tested bacteria. In contrast, the ethyl acetate extract of GbF-96 showed antibacterial activity against only B. cereus, E. coli, and Salmonella Typhimurium. Scanning electron microscopy results indicated cracked and irregular, swollen, shrunken, and lysed cell surfaces of the pathogenic bacteria treated with ethyl acetate extract of GbF-96 or B. subtilis, indicating that the metabolites of GbF-96 might penetrate the bacterial cell membranes and evoke pathways inducing cell lysis. Together, the data suggest that B. subtilis from G. biloba can be a potential candidate for controlling dreadful foodborne pathogenic bacteria, either by itself or by its metabolites.

Effect of Bacillus natto solid-state fermentation on the functional constituents and properties of Ginkgo seeds.

In the present investigation, fibrinolytic Ginkgo seeds were produced by solid-state fermentation (SSF) with Bacillus natto strains, and some parameters of the fermentation processes were investigated. Under optimal fermentation conditions, the fibrinolytic activity of Ginkgo seeds reached 3,682 ± 43 IU/g with the fermentation parameters of relative humidity 80%, initial water content 73%, fermentation temperature 38°C, inoculation volume 18%, and fermentation time 38 hr, respectively. The fermented Ginkgo seeds possessed a superior potential for the production of Nattokinase. What's more, the fermented Ginkgo seeds possessed higher total flavonoid and lower ginkgolic acids contents, which could enhance bioactivity and guarantee food safety. Sensory evaluations indicated that Ginkgo seeds produced by SSF could also be consumed as a kind of popular food. PRACTICAL APPLICATIONS: Fermented food is popular in countries. It can not only improve the sensory properties of the products, reduce undesirable constituents, and make nutrients easily absorbable, but also improve the nutritional properties. Ginkgo biloba L is one of the oldest species that has existed on earth for more than 200 million years. However, the application of Ginkgo seeds has been limited because of the ginkgolic acids. In a previous study, immobilized Bacillus natto acted upon Ginkgo seeds to enhance the bioactivity and safety of fermented Ginkgo seeds. However, separating the fermented Ginkgo seeds from the liquid needs a large amount of energy. The solid-state fermentation of Ginkgo seeds is a good choice to produce functional Ginkgo seed products.

Sphingomonas ginkgonis sp. nov., isolated from phyllosphere of Ginkgo biloba.

Strain HMF7854T, isolated from a ginkgo tree, was an orange-pigmented, Gram-stain-negative, motile by means of a single flagellum, strictly aerobic, rod-shaped bacterium. The isolate grew optimally on Reasoner's 2A agar at 30 °C, pH 7.0-8.0 and 0 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HMF7854T belonged to the genus Sphingomonas and was most closely related to Sphingomonasagri HKS-06T (96.8 % sequence similarity). The major fatty acids were C17 : 1 ω6c, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The predominant isoprenoid quinone was ubiquinone-10. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid, two unidentified lipids and two unidentified glycolipids. The genomic DNA G+C content was 68.4 mol%. Thus, based on its phylogenetic, phenotypic and chemotaxonomic data, strain HMF7854T represents a novel species of the genus Sphingomonas, for which the name Sphingomonasginkgonis sp. nov. is proposed. The type strain of the species is strain HMF7854T (=KCTC 62461T=NBRC 113337T).

Changes of volatile organic compounds and bioactivity of Alternaria brassicae GL07 in different ages.

Plant endophytes are rich in secondary metabolites and are widely used in medicine, chemical, food, agriculture, and other fields. Here, an endophytic fungus is isolated from Ginkgo biloba L. leaves and identified as Alternaria brassicae GL07 through genotypic characterizations. It can produce fruity scented volatiles. The analysis of volatile organic compounds (VOCs) was done by gas chromatography-mass spectrometry. A total of 32 components were identified; and at different culture times, the composition of VOCs was different. It had more components in the first two weeks, but a fewer components on the 21st day. More olefins, ketone, aldehyde, and alcohol were found in the growth period and more amines and esters were found in the decline period. Also, 2,5-dihydroxyacetophenone, ß-ionone, and nonanal were found. They were the same ingredients in Ginkgo essential oils and some of them were isolated for the first time in the volatile constituents of endophytes. The antioxidant activity and whitening activities of all extracts were also evaluated. When cultured for 10 days, it had the strongest 2,2-diphenyl-2-picrylhydrazyl radical (IC50 , 0.56 g/L), hydroxyl radical scavenging ability (IC50 , 0.47 g/L), reducing ability, and tyrosinase inhibition ability (IC50 , 5.18 g/L), which may be due to a large amount of ketones and alcohols produced during the log phase. This demonstrates the potential of A. brassicae GL07 to produce bioactive compounds and to be used for perfume and cosmetic industries.

An endophytic Fungi of Ginkgo biloba L. produces antimicrobial metabolites as potential inhibitors of FtsZ of Staphylococcus aureus.

A total of 58 fungal isolates, belonging to 24 genera, were obtained from the leaves, stems and roots of Ginkgo biloba L.. Among them, one endophytic fungal strain, Penicillium cataractum SYPF 7131, displayed the strongest antibacterial activity. Four new compounds (1-4) were isolated from the strain fermentation broth together with four known compounds (5-8). These structures were determined on the basis of 1D and 2D NMR and [Rh2(OCOCF3)4]-induced electronic circular dichroism (ECD) spectroscopic analyses. All the isolated compounds were screened for their in vitro antimicrobial activities. Compound 3 and 4 showed moderate inhibitory activity against Staphylococcus aureus. Compound 7 exhibited significant inhibitory activity against S. aureus with MIC value of 10 µg/mL. Further, the in silico molecular docking studies of the active compounds was used to explore the binding interactions with the active site of filamentous temperature-sensitive protein Z (FtsZ) from Staphylococcus aureus. The docking results revealed that compounds 3, 4 and 7 showed high binding energies, strong H-bond interactions and hydrophobic interactions with FtsZ from S. aureus validating the observed antimicrobial activity. Based on antimicrobial activities and docking studies, compounds 3, 4 and 7 were identified as promising antimicrobial lead molecules.

Streptomyces ginkgonis sp. nov., an endophyte from Ginkgo biloba.

A novel endophytic actinomycete strain, designated KM-1-2T, was isolated from seeds of Ginkgo biloba at Yangling, China. A polyphasic approach was used to study the taxonomy of strain KM-1-2T and it was found to show a range of phylogenetic and chemotaxonomic properties consistent with those of members of the genus Streptomyces. The diamino acid of the cell wall peptidoglycan was identified as LL-diaminopimelic acid. No diagnostic sugars were detected in whole cell hydrolysates. The predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The diagnostic phospholipids were found to be phosphatidylethanolamine and phosphatidylcholine. The DNA G + C content of the novel strain was determined to be 72.9 mol%. The predominant cellular fatty acids (> 10.0 %) were identified as iso-C14 : 0, iso-C16 : 0, C16 : 0 and C17 : 0 cyclo. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain is closely related to Streptomyces carpaticus JCM 6915T (99.3%), Streptomyces harbinensis DSM 42076T (98.9%) and Streptomyces cheonanensis JCM 14549T (98.5%). DNA-DNA hybridizations with these three close relatives gave similarity values of 39.1 ± 1.9, 35.8 ± 2.3, and 47.4 ± 2.7%, respectively, which indicated that strain KM-1-2T represents a novel species of the genus Streptomyces. This is consistent with the morphological, physiological and chemotaxonomic data. Cumulatively, these data suggest that strain KM-1-2T represents a novel Streptomyces species, for which the name Streptomyces ginkgonis sp. nov. is proposed, with the type strain KM-1-2T (= CCTCC AA2016004T = KCTC 39801T).

[Genome-wide prediction and analysis of the secretory proteins and ORFs signal peptide of ginkgo endophyte KM-1-2]

Objective: Endophytes are widespread in plants and build long-term mutually beneficial symbiotic relationship with the host. However, the mechanism of their interactions with the host needs further study. To explore the mechanism of endophytic bacterium ginkgo endophyte KM-1-2, we managed to forecast its secretory proteins based on its genome and explicit characteristics. Methods: Signal peptide analysis software SignalP, transmembrane helical structure analysis software TMHMM and Phobius, cells position software PSORT, subcellar localization software TargetP and GPI anchor site analysis software big-PI Predictor were used to predict the scope of all secreted proteins, which were defined as secretome. Results: Altogether 128 typical signal peptide secretory proteins were screened out of 5299 protein sequences in KM-1-2 genome, accounting for 2.4% of the whole genome. The shortest ORF encoding these proteins is 61 bp, the longest one is 2105 bp and the average is 373 bp. The length of the signal peptide guiding secretory protein was distributed between 15 to 37 aa, with the average length of 24 aa. Amino acid with the highest present frequency of signal peptide in proper order is alanine, leucine and valine. The type of signal peptide cleavage belongs to A-X-A which named SPI cleavage type. Among the total secretory proteins 66 pieces have functional description and 26 pieces were enzymes. These enzymes mainly include glycoside hydrolase, esterase transferase, REDOX enzyme and carbon oxygen lyase. Conclusion: The predicted secretory proteins of Streptomyces lavendulae KM-1-2 were achieved through bioinformatics analysis. These secretory proteins involved some enzymes and other unknown functions. This result laid the foundation for further study between endophyte and host.

Chaetomium globosum CDW7, a potential biological control strain and its antifungal metabolites.

Screening for endophytic fungi with antifungal activity is an effective strategy for the discovery of novel biopesticides. Our previous work indicated that Chaetomium globosum CDW7, an endophyte from Ginkgo biloba, exhibited strong inhibitory activity against plant pathogenic fungi in vitro. In this study, we evaluated the CDW7 strain for its antifungal activities against nine phytopathogenic fungi and its biocontrol potential against rape sclerotinia rot caused by Sclerotinia sclerotiorum. The fermentation broth of CDW7 could successfully inhibit disease development in S. sclerotiorum-infected rape in vivo with 57.8% protective efficiency, which is comparable to that of carbendazim (59.8%) at 250 µg mL-1. The fermentation broth also expressed significant activity stability when exposed to 60°C and UV illumination, or when stored at 4°C. Furthermore, we found that 10% fermentation broth can promote the germination and growth of rape seedlings. Followed by the bioassay-guided approach, seven known metabolites were isolated and identified by spectroscopic analyses. Among them, chaetoglobosin A and D exhibited inhibitory activity against S. sclerotiorum with IC50 values of 0.35 and 0.62 µg mL-1, respectively, compared with carbendazim (0.17 µg mL-1). Therefore, our study demonstrated that CDW7 is a promising biocontrol fungus against S. sclerotiorum in agriculture.

Arthrobacter ginkgonis sp. nov., an actinomycete isolated from rhizosphere of Ginkgo biloba L.

A Gram-stain-positive, aerobic actinobacterial strain (designated SYP-A7299T), which displayed a rod-coccus growth lifecycle, was isolated from the rhizosphere of Ginkgo biloba L. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SYP-A7299T belongs to the genus Arthrobacter and is most closely related to Arthrobacter halodurans JSM 078085T (97.4 % 16S rRNA gene sequence similarity). The DNA-DNA relatedness value between strain SYP-A7299T and A. halodurans JSM 078085T was 37 % ±2.9. The cell-wall peptidoglycan was A4α, and glucose and galactose were whole-cell sugars. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two glycolipids and an unknown polar lipid. The major menaquinone were MK-8(H2) (72 %) and MK-9(H2) (28 %), and the predominant cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. The DNA G+C content was 68.9 mol%. Based on the morphological, physiological, biochemical and chemotaxonomic characters presented in this study, strain SYP-A7299T represents a novel species of the genus Arthrobacter, for which the name Arthrobacter ginkgonis sp. nov. is proposed. The type strain is SYP-A7299T (=DSM 100491T=KCTC 39 592T).

Potential allelopathic azaphilones produced by the endophytic Chaetomium globosum TY1 inhabited in Ginkgo biloba using the one strain-many compounds method.

On the basis of the one strain-many compounds strategy, seven azaphilones, including Chaetomugilin A (1), D (2), S (3), I (4), J (5), Q (6) and O (7), were isolated from the endophytic Chaetomium globosum TY1. Their structures were identified by NMR and HRESIMS spectrometry data. All azaphilones were evaluated for plant growth regulation using eight species of herbaceous plant seeds seedling growth bioassay, which showed the plant growth influence of the seedling. Among these compounds tested, Chaetomugilin O (7) with tetrahydrofuran exhibited higher response index and lower IC50 values than positive control glyphosate, a broad-spectrum systemic herbicide. 1-3 also showed better or similar inhibit activity to glyphosate. The structure-allelopathic activity relationship analysis of these isolated azaphilones indicates that both tetrahydrofuran and tetrahydrofuran combine with lactones ring groups give potent inhibition of seedling growth. Chaetomugilin O and Chaetomugilin A, D, S could be used to develop natural eco-friendly herbicides.

Pseudochaetosphaeronema ginkgonis sp. nov., an endophyte isolated from Ginkgo biloba.

An endophytic strain (designated as SYPF 7195T) was isolated from a branch of a ginkgo tree in Liaoning province of China. Strain SYPF 7195T was characterized by its grey to greyish-green aerial mycelium, velvety to floccose surface and swelling near the septa. Phylogenetic analyses, which were inferred from the internal transcribed spacer (ITS) and partial sequences of the LSU and SSU of the rDNA and translation elongation factor 1-alpha (TEF1), showed that strain SYPF 7195T belonged to the genus Pseudochaetosphaeronema, and was distinct from all other species with high bootstrap-supported values (92 %). Strain SYPF 7195T constitutes a separate evolutionary clade with Pseudochaetosphaeronema larense and Pseudochaetosphaeronema martinelli, with P. martinelli as its closest phylogenetic neighbour. The nucleotide differences between strain SYPF 7195T and P. martinelli were 71 substitutions in the ITS region. Strain SYPF 7195Tcould also be distinguished from P. martinelli by a number of physiological characteristics. Combined with morphology and molecular analyses, strain SYPF 7195T merits recognition as a representative of a novel species of the genus Pseudochaetosphaeronema, for which the name Pseudochaetosphaeronemaginkgonis sp. nov. is proposed. The type strain is CBS 140953T (=CGMCC 3.17865T=SYPF 7195T). The Mycobank number is MB 816567.

A Bilobalide-Producing Endophytic Fungus, Pestalotiopsis uvicola from Medicinal Plant Ginkgo biloba.

For screening bilobalide (BB)-producing endophytic fungi from medicinal plant Ginkgo biloba, a total of 57 fungal isolates were isolated from the internal stem, root, leaf, and bark of the plant G. biloba. Fermentation processes using BB-producing fungi other than G. biloba may become a novel way to produce BB, which is a terpene trilactones exhibiting neuroprotective effects. In this study, a BB-producing endophytic fungal strain GZUYX13 was isolated from the leaves of G. biloba grown in the campus of Guizhou University, Guiyang city, Guizhou province, China. The strain produced BB when grown in potato dextrose liquid medium. The amount of BB produced by this endophytic fungus was quantified to be 106 µg/L via high-performance liquid chromatography (HPLC), substantially lower than that produced by the host tissue. The fungal BB which was analyzed by thin layer chromatography (TLC) and HPLC was proven to be identical to authentic BB. The strain GZUYX13 was identified as Pestalotiopsis uvicola via morphology and ITS rDNA phylogeny. To the best of our knowledge, this is the first report concerning the isolation and identification of endophytic BB-producing Pestalotiopsis spp. from the host plant, which further proved that endophytic fungi have the potential to produce bioactive compounds.

Anti-phytopathogenic activity of sporothriolide, a metabolite from endophyte Nodulisporium sp. A21 in Ginkgo biloba.

Phytopathogenic fungi such as Rhizoctonia solani and Sclerotinia sclerotiorum caused multiple plant diseases resulting in severe loss of crop production. Increasing documents endorsed that endophytes are a striking resource pool for numerous metabolites with various bioactivities such as anti-fungal. Here we reported the characterization and anti-phytopathogenic activity of sporothriolide, a metabolite produced by Nodulisporium sp. A21-an endophytic fungus in the leaves of Ginkgo biloba. Among the total twenty-five endophytic fungi isolated from the healthy leaves of G. biloba, the fermentation broth (FB) of the strain A21 was found potently inhibitory activity against R. solani and S. sclerotiorum using mycelia growth inhibition method. A21 was then identified as Nodulisporium sp., the asexual stage of Hypoxylon sp., by microscopic examination and ITS rDNA sequence data comparison. Under the bioassay-guided fractionation, sporothriolide was isolated from the petroleum ether extract of the FB of A21, whose structure was established by integrated interpretation of HR-ESI-MS and (1)H- and (13)C-NMR. Furthermore, the crystal structure of sporothriolide was first reported. In addition, sporothriolide was validated to be potently antifungal against R. solani, S. sclerotiorum and inhibit conidium germination of Magnaporthe oryzae in vitro and in vivo, indicating that it could be used as a lead compound for new fungicide development.

Nocardioides ginkgobilobae sp. nov., an endophytic actinobacterium isolated from the root of the living fossil Ginkgo biloba L.

A Gram-stain-positive, aerobic and yellow actinobacterial strain, designated SYP-A7303T, was isolated from the root of Ginkgo biloba L. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SYP-A7303T belongs to the genus Nocardioides. The 16S rRNA gene sequence of strain SYP-A7303T showed highest similarity to Nocardioides marinus CL-DD14T ( = JCM 15615T) (98.3 %) and Nocardioides aquiterrae GW-9T ( = JCM 11813T) (97.1 %), and less than 96.9 % to the type strains of other species of the genus Nocardioides. Strain SYP-A7303T grew optimally at 28 °C, pH 7.0 and in the absence of NaCl. It contained ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, with mannose, ribose, rhamnose, glucose and galactose as whole-cell sugars. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unknown lipid. The menaquinone was MK-8(H4) and the predominant cellular fatty acids were iso-C16 : 0, C18 : 1ω9c and C17 : 1ω8c. The DNA G+C content was 72 mol%. Mean DNA-DNA relatedness values between strain SYP-A7303T and the closely related strains N. marinus JCM 15615T and N. aquiterrae JCM 11813T were 62.5 ± 2.4 and 56.5 ± 3.5 %, respectively. Based on the morphological, physiological, biochemical and chemotaxonomic characteristics presented in this study, strain SYP-A7303T represents a novel species of the genus Nocardioides, for which the name Nocardioides ginkgobilobae sp. nov. is proposed. The type strain is SYP-A7303T ( = DSM 100492T = KCTC 39594T).