Microlunatus nigridraconis sp. nov., an actinobacterium from rhizosphere soil

An actinobacterium, designated strain CPCC 203993T, was isolated from a rhizosphere soil sample collected from Heilongjiang Province, northeast China, and was characterized using a polyphasic taxonomy approach. Cells of the strain were Gram-stain-positive, non-motile and non-endospore-forming cocci. The 16S rRNA gene sequence comparison of strain CPCC 203993T with members of the genus Microlunatus yielded 93.9 % to 97.8 % similarities. In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 203993T was affiliated to the clade of the genus Microlunatus next to Microlunatus parietis DSM 22083T, while the DNA-DNA hybridization value of 31.5 % (±1.8 %) between strain CPCC 203993T and Microlunatus. parietis DSM 22083T was far below 70 %. This result indicated that strain CPCC 203993T represented a different genomic species from M. parietis. Chemotaxonomically, the strain contained ll-2,6-diaminopimelic acid as the diagnostic diamino acid, MK-9(H4) as the only menaquinone, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, three unidentified glycolipids and one unidentified phospholipid in the polar lipids extracts, and anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0 as the major cellular fatty acids, without mycolic acids. The genomic DNA G+C content was 64.04 mol%. The above evidence from the polyphasic study merit the recognition of strain CPCC 203993T as a representative of a novel species of the genus Microlunatus, for which Microlunatus nigridraconis sp. nov. is proposed. The type strain is CPCC 203993T (=DSM 29529T=NBRC 110715T=KCTC 29689T).

Diversity and Composition of Airborne Fungal Community Associated with Particulate Matters in Beijing during Haze and Non-haze Days

To assess the diversity and composition of airborne fungi associated with particulate matters (PMs) in Beijing, China, a total of 81 PM samples were collected, which were derived from PM2.5, PM10 fractions, and total suspended particles during haze and non-haze days. The airborne fungal community in these samples was analyzed using the Illumina Miseq platform with fungi-specific primers targeting the internal transcribed spacer 1 region of the large subunit rRNA gene. A total of 797,040 reads belonging to 1633 operational taxonomic units were observed. Of these, 1102 belonged to Ascomycota, 502 to Basidiomycota, 24 to Zygomycota, and 5 to Chytridiomycota. The dominant orders were Pleosporales (29.39%), Capnodiales (27.96%), Eurotiales (10.64%), and Hypocreales (9.01%). The dominant genera were Cladosporium, Alternaria, Fusarium, Penicillium, Sporisorium, and Aspergilus. Analysis of similarities revealed that both particulate matter sizes (R = 0.175, p = 0.001) and air quality levels (R = 0.076, p = 0.006) significantly affected the airborne fungal community composition. The relative abundance of many fungal genera was found to significantly differ among various PM types and air quality levels. Alternaria and Epicoccum were more abundant in total suspended particles samples, Aspergillus in heavy-haze days and PM2.5 samples, and Malassezia in PM2.5 samples and heavy-haze days. Canonical correspondence analysis and permutation tests showed that temperature (p < 0.01), NO₂ (p < 0.01), PM10 (p < 0.01), SO₂(p < 0.01), CO (p < 0.01), and relative humidity (p < 0.05) were significant factors that determine airborne fungal community composition. The results suggest that diverse airborne fungal communities are associated with particulate matters and may provide reliable data for studying the responses of human body to the increasing level of air pollution in Beijing.

Diversity and Distribution of Aquatic Fungal Communities in the Ny-Ålesund Region, Svalbard (High Arctic): Aquatic Fungi in the Arctic

We assessed the diversity and distribution of fungi in 13 water samples collected from four aquatic environments (stream, pond, melting ice water, and estuary) in the Ny-Ålesund Region, Svalbard (High Arctic) using 454 pyrosequencing with fungi-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Aquatic fungal communities in this region showed high diversity, with a total of 43,061 reads belonging to 641 operational taxonomic units (OTUs) being found. Of these OTUs, 200 belonged to Ascomycota, 196 to Chytridiomycota, 120 to Basidiomycota, 13 to Glomeromycota, and 10 to early diverging fungal lineages (traditional Zygomycota), whereas 102 belonged to unknown fungi. The major orders were Helotiales, Eurotiales, and Pleosporales in Ascomycota; Chytridiales and Rhizophydiales in Chytridiomycota; and Leucosporidiales and Sporidiobolales in Basidiomycota. The common fungal genera Penicillium, Rhodotorula, Epicoccum, Glaciozyma, Holtermanniella, Betamyces, and Phoma were identified. Interestingly, the four aquatic environments in this region harbored different aquatic fungal communities. Salinity, conductivity, and temperature were important factors in determining the aquatic fungal diversity and community composition. The results suggest the presence of diverse fungal communities and a considerable number of potentially novel fungal species in Arctic aquatic environments, which can provide reliable data for studying the ecological and evolutionary responses of fungi to climate change in the Arctic ecosystem.

Steroidal Saponins from the Rhizomes of Aspidistra typica

Eleven new furostanol saponins, typaspidosides B-L (1–11), one new spirostanol saponin, typaspidoside M (12), and five known spirostanol saponins, 25S-atropuroside (13), neoaspidistrin (14), (25S)-pratioside D₁ (15), 25S-aspidistrin (16) and 25S-neosibiricoside (17) were isolated from the rhizomes of Aspidistra typica Baill. The structures of the new compounds were established using 1D and 2D NMR (¹H-¹H COSY, HMQC, HMBC and ROESY) spectroscopy, high resolution mass spectrometry, and chemical methods. The aglycones of 1–3 (unusual furostanol saponins with opened E ring type), 9 and 10 (the methoxyl substituent at C-23 position) were found, identified from natural products for the first time. Moreover, the anti-HIV activities of the isolated steroidal glycosides were assessed, and compounds 13, 14, 16 and 17 exhibited high active against HIV-1.

Structures of an all-α protein running along the DNA major groove

Despite over 3300 protein–DNA complex structures have been reported in the past decades, there remain some unknown recognition patterns between protein and target DNA. The silkgland-specific transcription factor FMBP-1 from the silkworm Bombyx mori contains a unique DNA-binding domain of four tandem STPRs, namely the score and three amino acid peptide repeats. Here we report three structures of this STPR domain (termed BmSTPR) in complex with DNA of various lengths. In the presence of target DNA, BmSTPR adopts a zig-zag structure of three or four tandem α-helices that run along the major groove of DNA. Structural analyses combined with binding assays indicate BmSTPR prefers the AT-rich sequences, with each α-helix covering a DNA sequence of 4 bp. The successive AT-rich DNAs adopt a wider major groove, which is in complementary in shape and size to the tandem α-helices of BmSTPR. Substitutions of DNA sequences and affinity comparison further prove that BmSTPR recognizes the major groove mainly via shape readout. Multiple-sequence alignment suggests this unique DNA-binding pattern should be highly conserved for the STPR domain containing proteins which are widespread in animals. Together, our findings provide structural insights into the specific interactions between a novel DNA-binding protein and a unique deformed B-DNA.

Soil pH is a Key Determinant of Soil Fungal Community Composition in the Ny-Ålesund Region, Svalbard (High Arctic)

This study assessed the fungal community composition and its relationships with properties of surface soils in the Ny-Ålesund Region (Svalbard, High Arctic). A total of thirteen soil samples were collected and soil fungal community was analyzed by 454 pyrosequencing with fungi-specific primers targeting the rDNA internal transcribed spacer (ITS) region. The following eight soil properties were analyzed: pH, organic carbon (C), organic nitrogen (N), ammonium nitrogen (NH4 (+)-N), silicate silicon (SiO4 (2-)-Si), nitrite nitrogen (NO2 (-)-N), phosphate phosphorus (PO4 (3-)-P), and nitrate nitrogen (NO3 (-)-N). A total of 57,952 reads belonging to 541 operational taxonomic units (OTUs) were found. of these OTUs, 343 belonged to Ascomycota, 100 to Basidiomycota, 31 to Chytridiomycota, 22 to Glomeromycota, 11 to Zygomycota, 10 to Rozellomycota, whereas 24 belonged to unknown fungi. The dominant orders were Helotiales, Verrucariales, Agaricales, Lecanorales, Chaetothyriales, Lecideales, and Capnodiales. The common genera (>eight soil samples) were Tetracladium, Mortierella, Fusarium, Cortinarius, and Atla. Distance-based redundancy analysis (db-rda) and analysis of similarities (ANOSIM) revealed that soil pH (p = 0.001) was the most significant factor in determining the soil fungal community composition. Members of Verrucariales were found to predominate in soils of pH 8-9, whereas Sordariales predominated in soils of pH 7-8 and Coniochaetales predominated in soils of pH 6-7. The results suggest the presence and distribution of diverse soil fungal communities in the High Arctic, which can provide reliable data for studying the ecological responses of soil fungal communities to climate changes in the Arctic.

Diversity and distribution of lichen-associated fungi in the Ny-Ålesund Region (Svalbard, High Arctic) as revealed by 454 pyrosequencing

This study assessed the diversity and distribution of fungal communities associated with seven lichen species in the Ny-Ålesund Region (Svalbard, High Arctic) using Roche 454 pyrosequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Lichen-associated fungal communities showed high diversity, with a total of 42,259 reads belonging to 370 operational taxonomic units (OTUs) being found. Of these OTUs, 294 belonged to Ascomycota, 54 to Basidiomycota, 2 to Zygomycota, and 20 to unknown fungi. Leotiomycetes, Dothideomycetes, and Eurotiomycetes were the major classes, whereas the dominant orders were Helotiales, Capnodiales, and Chaetothyriales. Interestingly, most fungal OTUs were closely related to fungi from various habitats (e.g., soil, rock, plant tissues) in the Arctic, Antarctic and alpine regions, which suggests that living in association with lichen thalli may be a transient stage of life cycle for these fungi and that long-distance dispersal may be important to the fungi in the Arctic. In addition, host-related factors shaped the lichen-associated fungal communities in this region. Taken together, these results suggest that lichens thalli act as reservoirs of diverse fungi from various niches, which may improve our understanding of fungal evolution and ecology in the Arctic.

Tenggerimyces mesophilus gen. nov., sp. nov., a member of the family Nocardioidaceae

A novel aerobic actinomycete, designated strain I12A-02601T, was isolated from a desert soil crusts sample collected from the Shapotou region of Tengger Desert, north-west China. The substrate mycelia of this isolate were well-developed and branched, but not fragmented. The maturity aerial mycelia formed short chains of small, rod-shaped spores. The strain contained ll-diaminopimelic acid, dd-diaminopimelic acid, galactose, glucose, ribose and xylose in its whole-cell hydrolysates. The polar lipids consisted of diphosphatidylglycerol, N-acetylglucosamine-containing phospholipids, phosphatidylinositolmannoside and glycolipids. The predominant menaquinones were MK-10(H6) and MK-10(H8). The major fatty acids were iso-C15 : 0, anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. The G+C content of the genomic DNA was 72.2 mol%. The 16S rRNA gene sequences comparison showed that strain I12A-02601T was most closely related to members of the family Nocardioidaceae, such as Actinopolymorpha alba YIM 48868T (93.3 % sequence similarity), Actinopolymorpha pittospori PIP 143T (93.2 %), and Flindersiella endophytica EUM 378T (93.2 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain I12A-02601T formed a clade with the members of the genera Flindersiella, Thermasporomyces, and Actinopolymorpha in the family Nocardioidaceae. Combined data from this taxonomic study using a polyphasic approach, led to the conclusion that strain I12A-02601T represents a novel species of a new genus in the family Nocardioidaceae, for which the name Tenggerimyces mesophilus gen. nov., sp. nov. is proposed. The type strain of the type species is I12A-02601T ( = CPCC 203544T = DSM 45829T = NBRC 109454T).

Ubiquity, diversity and physiological characteristics of Geodermatophilaceae in Shapotou National Desert Ecological Reserve

The goal of this study was to gain insight into the diversity of culturable actinobacteria in desert soil crusts and to determine the physiological characteristics of the predominant actinobacterial group in these crusts. Culture-dependent method was employed to obtain actinobacterial strains from desert soil samples collected from Shapotou National Desert Ecological Reserve (NDER) located in Tengger Desert, China. A total of 376 actinobacterial strains were isolated and 16S rRNA gene sequences analysis indicated that these isolates belonged to 29 genera within 18 families, among which the members of the family Geodermatophilaceae were predominant. The combination of 16S rRNA gene information and the phenotypic data allowed these newly-isolated Geodermatophilaceae members to be classified into 33 “species clusters,” 11 of which represented hitherto unrecognized species. Fermentation broths from 19.7% of the isolated strains showed activity in at least one of the six screens for antibiotic activity. These isolates exhibited bio-diversity in enzymatic characteristics and carbon utilization profiles. The physiological characteristics of the isolates from different types of crusts or bare sand samples were specific to their respective micro-ecological environments. Our study revealed that members of the family Geodermatophilaceae were ubiquitous, abundant, and diverse in Shapotou NDER, and these strains may represent a new major group of potential functional actinobacteria in desert soil.

Regio-selective deglycosylation of icariin by cell suspension cultures of Glycyrrhiza uralensis and Morus alba

Biotransformations of icariin (1) by cell suspension cultures of Glycyrrhiza uralensis and Morus alba yielded two new metabolites, icaruralins A and B (2 and 3), and one known metabolite, baohuoside I (4). Their structures were determined on the basis of extensive spectroscopic analysis. This is the first report that the cell suspension cultures of G. uralensis and M. alba possess deglycosylation functionality.

New 2-arylbenzofuran metabolite from cell cultures of Morus alba

A new 2-arylbenzofuran compound, 5-dehydroxy-moracin U (1), along with 10 known compounds (2-11), were isolated from cell cultures of Morus alba. Their structures were elucidated on the basis of extensive spectroscopic analyses. The anti-inflammatory activity assay of 1-8 showed that 2 and 8 exhibited significant inhibitory effect on LPS-induced NO production with the values of 76.4% and 98.7% at 10(- 5) M, respectively.

A new trichostatin analog from Streptomyces sp. CPCC 203909

A new trichostatin analog (1) and two known analogs (2, 3) have been isolated from the rice fermentation of the Streptomyces sp. CPCC 203909. Their structures were determined by spectroscopic and chemical methods. The absolute configurations of 1 were assigned by Marfey's method, combined with comparing the NMR and circular dichroism spectroscopic data of 2 and 3. Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC50 value of 39.2 μM.

New polyoxypregnane glycosides from the roots of Marsdenia tenacissima

For the first time, a systematic phytochemical study was performed on the roots of Marsdenia tenacissima. Finally, sixteen new polyoxypregnane glycosides, marstenacissides A1-A7 (1-7) and marstenacissides B1-B9 (8-16), were isolated from M. tenacissima roots. The structures of these new compounds were established by various spectroscopic techniques, including 1D and 2D NMR spectroscopy and mass spectrometry.

Steroidal saponins obtained by biotransformation of total furostanol glycosides from Dioscorea zingiberensis with Absidia coerulea

Five new steroidal saponins (1-5) were isolated from the fermentation broth of total furostanol glycosides from tubers of Dioscorea zingiberensis C.H. Wright incubated with a fungal, Absidia coerulea AS 3.3389, along with known saponins, zingiberensis new saponin (6), deltonin (7), prosapogenin A of dioscin (8), and protobioside (9), and their structures were established by NMR spectroscopy and mass spectrometry as well as by comparison with previously reported spectral data in the literatures. The induced effects in vitro on rat platelet aggregation of all compounds were evaluated.

Actinophytocola gilvus sp. nov., isolated from desert soil crusts, and emended description of the genus Actinophytocola Indananda et al. 2010

An actinomycete strain, designated I12A-02593(T), was isolated from a desert soil crust sample collected in the Shapotou region of Tengger Desert, north-west China. The isolate grew well on International Streptomyces Project (ISP) media 2, 3, 5 and 7, YS and Bennett's agar; it produced spherical bodies and formed clumps on the aerial mycelia on ISP 5 agar plates. Chemotaxonomically, the strain contained meso-diaminopimelic acid as the diagnostic diamino acid, arabinose and galactose as the diagnostic sugars in whole-cell hydrolysates, MK-9(H4) as the sole isoprenoid quinone, and iso-C16 : 0, iso-C16 : 0 2-OH and iso-C16 : 1 H as the major cellular fatty acids, without mycolic acids. The profile of the phospholipids mainly comprised diphosphatidylglycerol, phosphatidylethanolamine and hydroxyphosphatidylethanolamine. The genomic DNA G+C content was 70.1 mol%. The 16S rRNA gene sequence of strain I12A-02593(T) exhibited 96.4-97.4 % similarities with members of the genus Actinophytocola. In the phylogenetic tree based on 16S rRNA gene sequences, the isolate formed a robust cluster with Actinophytocola oryzae NBRC 105245(T), Aactinophytocola timorensis NBRC 105524(T), Actinophytocola corallina NBRC 105525(T), Actinophytocola burenkhanensis NBRC 105883(T)and Actinophytocola xinjiangensis NBRC 106673(T). DNA-DNA hybridization values between strain I12A-02593(T) and the five species of the genus Actinophytocola were all less than 70 %. On the basis of the polyphasic taxonomy evidence, a novel species of the genus Actinophytocola is proposed, with the name Actinophytocola gilvus sp. nov. The type strain is I12A-02593(T) ( = CPCC 203543(T) = DSM 45828(T) = NBRC 109453(T) = KCTC 29165(T)). An emended description of the genus Actinophytocola is also provided.

Cryptococcus fildesensis sp. nov., a psychrophilic basidiomycetous yeast isolated from Antarctic moss

Two yeast strains isolated from the moss Chorisodontium aciphyllum from the Fildes Region, King George Island, maritime Antarctica, were classified as members of the genus Cryptococcus based on sequence analyses of the D1/D2 domains of the large subunit rRNA gene and the internal transcribed spacer (ITS) regions. The rRNA gene sequence analyses indicated that the two strains represented a novel species of the genus Cryptococcus, for which the name Cryptococcus fildesensis sp. nov. is proposed (type strain: CPCC 300017(T) = DSM 26442(T) = CBS 12705(T)). The MycoBank number of the novel species is MB 805542.

Kurtzmanomyces shapotouensis sp. nov., an anamorphic, basidiomycetous yeast isolated from desert soil crusts

Two yeast strains isolated from soil crusts in the Shapotou region of Tengger Desert (north-western China) were grouped in the genus Kurtzmanomyces based on morphological characteristics. rRNA gene sequence analyses (including the D1/D2 domain of the large subunit rRNA gene and internal transcribed spacer region) indicated that these two strains represented a novel species of the genus Kurtzmanomyces, for which the name Kurtzmanomyces shapotouensis sp. nov. is proposed (type strain: CPCC 300020T = DSM 26579T = CBS 12707T). The MycoBank number of the novel species is MB 804959.

Williamsia sterculiae sp. nov., isolated from a Chinese medicinal plant

Two actinobacterial strains, CPCC 203464(T) and CPCC 203448, isolated from surface-sterilized stems of medicinal plants were subjected to a polyphasic taxonomic study. These two aerobic organisms formed pale yellow colonies on tryptic soy agar (TSA). Cells were Gram-stain-positive, non-acid-fast, non-motile, rod- or coccoid-like elements. Comparative 16S rRNA gene sequence analysis indicated that strains CPCC 203464(T) and CPCC 203448 were most closely related to the type strains of the species of the genus Williamsia. Chemotaxonomic properties such as containing meso-diaminopimelic acid in the cell wall, arabinose, galactose and ribose being the whole-cell hydrolysate sugars, phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and phosphatidylinositol (PI) as the phospholipids, and C16 : 0, 10-methyl C18 : 0, C18 : 1ω9c, C16 : 1ω7c and/or iso-C15 : 0 2-OH as major fatty acids supported the affiliation of strains CPCC 203464(T) and CPCC 203448 to the genus Williamsia. The DNA-DNA hybridization values in combination with differentiating chemotaxonomic and physiological characteristics strongly suggested that these two isolates should be classified as representatives of a novel species of the genus Williamsia. The name Williamsia sterculiae sp. nov. is proposed, with strain CPCC 203464(T) ( = DSM 45741(T) = KCTC 29118(T)) as the type strain.

[Effects of class I( phosphatidylinositol-3-kinases inhibitor on gastric cancer cell xenografts in nude mice]

OBJECTIVE

To investigate the effect of recombinant adenovirus (phosphatidylinositol-3-kinases(PI3K)(I()-RNAi-AD which blocks the class I( PI3K signaling pathway on gastric carcinoma cells xenografts in nude mice.

METHODS

Subcutaneous tumor models of nude mice were established with SGC7901 cells and randomly divided into PI3K(I()-RNAi-AD group, NC-RNAi-GFP-AD group and control group. The tumor size and the inhibitory rate of tumor growth on days 3, 6, and 9 after cell transplantation were measured. The expression of TNF-α, COX2, P53, PCNA, E-cadherin and nm23/DNPK in tumor tissues were detected by immunohistochemistry.

RESULTS

Tumor growth was significantly inhibited in the PI3K(I()-RNAi-AD group(14.2%, 21.0%, and 28.1%) on days 3, 6, 9 compared with NC-RNAi-GFP-AD group(1.3%, 1.9%, and 2.0%, all P<0.05). The expressions of TNF-α, P53, E-cadherin and nm23/DNPK were up-regulated, and the expressions of COX2 and PCNA were down-regulated in the PI3K(I()-RNAi-AD group by immunohistochemical staining(all P<0.05).

CONCLUSIONS

PI3K(I()-RNAi-AD can inhibit the growth of SGC7901 cell transplantation tumor in vivo in nude mice by inhibiting cell growth, reducing the capacity of tumor invasion and inhibiting tumor angiogenesis.

Effects of small interfering RNA inhibit Class I phosphoinositide 3-kinase on human gastric cancer cells

AIM: To investigate the effects of small interfering RNA (siRNA)-mediated inhibition of Class I phosphoinositide 3-kinase (Class I PI3K) signal transduction on the proliferation, apoptosis, and autophagy of gastric cancer SGC7901 and MGC803 cells.

METHODS: We constructed the recombinant replication adenovirus PI3K(I)-RNA interference (RNAi)-green fluorescent protein (GFP) and control adenovirus NC-RNAi-GFP, and infected it into human gastric cancer cells. MTT assay was used to determine the growth rate of the gastric cancer cells. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after adenovirus PI3K(I)-RNAi-GFP and control adenovirus NC-RNAi-GFP treatment. Immunofluorescence staining was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. The expression of autophagy was monitored with MDC, LC3 staining, and transmission electron microscopy. Western blotting was used to detect p53, Beclin-1, Bcl-2, and LC3 protein expression in the culture supernatant.

RESULTS: The viability of gastric cancer cells was inhibited after siRNA targeting to the Class I PI3K blocked Class I PI3K signal pathway. MTT assays revealed that, after SGC7901 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 27.48% ± 2.71% at 24 h, 41.92% ± 2.02% at 48 h, and 50.85% ± 0.91% at 72 h. After MGC803 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 24.39% ± 0.93% at 24 h, 47.00% ± 0.87% at 48 h, and 70.30% ± 0.86% at 72 h (P < 0.05 compared to control group). It was determined that when 50 MOI, the transfection efficiency was 95% ± 2.4%. Adenovirus PI3K(I)-RNAi-GFP (50 MOI) induced mitochondrial dysfunction and activated cell apoptosis in SGC7901 cells, and the results described here prove that RNAi of Class I PI3K induced apoptosis in SGC7901 cells. The results showed that adenovirus PI3K(I)-RNAi-GFP transfection induced punctate distribution of LC3 immunoreactivity, indicating increased formation of autophagosomes. The results showed that the basal level of Beclin-1 and LC3 protein in SGC7901 cells was low. After incubating with adenovirus PI3K(I)-RNAi-GFP (50 MOI), Beclin-1, LC3, and p53 protein expression was significantly increased from 24 to 72 h. We also found that Bcl-2 protein expression down-regulated with the treatment of adenovirus PI3K(I)-RNAi-GFP (50 MOI). A number of isolated membranes, possibly derived from ribosome-free endoplasmic reticulum, were seen. These isolated membranes were elongated and curved to engulf a cytoplasmic fraction and organelles. We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after adenovirus PI3K(I)-RNAi-GFP (50 MOI) treatment. Control cells showed a round shape and contained normal-looking organelles, nucleus, and chromatin, while adenovirus PI3K(I)-RNAi-GFP (50 MOI)-treated cells exhibited the typical signs of autophagy.

CONCLUSION: After the Class I PI3K signaling pathway has been blocked by siRNA, the proliferation of cells was inhibited and the apoptosis of gastric cancer cells was enhanced.

Allonocardiopsis opalescens gen. nov., sp. nov., a new member of the suborder Streptosporangineae , from the surface-sterilized fruit of a medicinal plant

An endophytic actinomycete, designated strain I10A-01259T, was isolated from a surface-sterilized fruit of Lonicera maackii (Rupr.) Maxim., a medicinal plant, which was collected from a suburb of Beijing, China. Whole-cell hydrolysates of the isolate contained galactose and meso-diaminopimelic acid. The predominant phospholipids were phosphatidylglycerol and diphosphatidylglycerol; the menaquinones consisted mainly of MK-9, MK-11 and MK-12, with a minor amount of MK-10. The major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C15 : 0. Comparative analysis of 16S rRNA gene sequences indicated that strain I10A-01259T was most closely related to Nocardiopsis arabia S186T (93.2 % sequence similarity), Thermobifida halotolerans YIM 90462T (93.0 %) and other strains of genera within the families Nocardiopsaceae and Thermomonosporaceae . On the phylogenetic tree based on 16S rRNA gene sequences, strain I10A-01259T fell within the radius of the suborder Streptosporangineae , in which the strain formed a distinct lineage next to the genera of the families Nocardiopsaceae and Thermomonosporaceae . Based on the data from our polyphasic taxonomic study, a novel genus and species, Allonocardiopsis opalescens gen. nov., sp. nov., are proposed within the suborder Streptosporangineae . The type strain of Allonocardiopsis opalescens is strain I10A-01259T ( = CPCC 203428T  = DSM 45601T  = KCTC 19844T).