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991.
The entomopathogenic fungus Paecilomyces farinosus showed proteolytic activity in both solid and semi-liquid culture with gelatin as sole N and C source. Semi-liquid cultures
were used to characterise proteases. Zymography of crude culture filtrates showed several bands of gelatin degradation in
electrophoresis gels. Gel filtration chromatography of these filtrates revealed two peaks of proteolytic activity. Ion-exchange
absorption eliminated gelatin from culture filtrates while retaining activity and was used to semipurify P. farinosus proteases. Semipurified culture filtrates had basic pH (8.5 approx.) optimum for proteolytic activity. Treatment of these
filtrates with effectors revealed that P. farinosus proteases are serine proteases containing sulphydryl groups. Isoelectrofocusing combined with zymography revealed the presence
of several active basic isoforms. Larvae of the lepidopteran Galleria mellonella showed cuticle damage and protein release 1h after incubation with semipurified extracts of P. farinosus. These results indicate that proteolytic enzymes could be involved in insect host penetration by P. farinosus. 相似文献
992.
Dang Quan Nguyen Dinh Hoa Hoang Michael Nelson Lokesh Nigam Vo Thanh Thao Nguyen Lianjun Zhang Tram Kim Thi Pham Huu Duc Ho Dai Dong Thi Nguyen Trung Quoc Lam Trinh To Tat Yasmin Elhajmoussa Quoc Trung Ly Flavia Pichiorri Vinod Pullarkat Bin Zhang Ya-Huei Kuo Guido Marcucci Le Xuan Truong Nguyen 《Journal of cellular physiology》2020,235(10):7567-7579
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995.
High frequency shoot regeneration from Rhynchostylis gigantea (orchidaceae) using thin cell layers 总被引:2,自引:0,他引:2
Bui van Le N.T. Hang Phuong L.T. Anh Hong K. Tran Thanh Van 《Plant Growth Regulation》1999,28(3):179-185
Often regeneration in orchids is only achieved through protocorms, i.e., the juvenile stage. In order to produce directly shoots via bud regeneration both rapidly and with a high frequency, a transverse thin cell layer (tTCL) method is extended to Rhynchostylis gigantea. Transverse thin cell layer (tTCL) explants (0.3--0.5 mm) excised along the stem from the basis to the shoot tip of one-year-old plantlets were cultured on Murashige and Skoog (1962) medium supplemented with different combinations of benzyladenine (BAP), 1-naphthaleneacetic acid (NAA), thidiazuron (TDZ) and 3% sucrose. The optimal combination for maximal bud regeneration was 3 µM BAP and 3 µM TDZ, giving rise to 11.7 buds per tTCL. Roots were obtained with 10 µM forchlofenuron (CPPU) and 1% sucrose. The in vitro plants (> 3 cm long) obtained 4 to 6 weeks after the tTCLs culture were transferred to the greenhouse; their morphology was normal. Efficient micropropagation of direct production of shoots without passing through protocorm stage of orchid species can be achieved using the thin cell layer (TCL) method. 相似文献
996.
Application of powder diets may promote development of the predator Geocoris ochropterus (Fieber) when densities are low in greenhouses or fields. Development and nymphal survival ratio of G. ochropterus fed on different powder diets including silkworm pupae (A), crickets (B), silkworm pupae and sunflower seed (C) and crickets and sunflower seed (D) were examined. Total average development period was 30.14 days for instars fed on silkworm pupae, 34.43 days for instars fed on crickets, 26.28 days for instars fed on silkworm pupae and sunflower seed and 29.67 days for instars fed on crickets and sunflower seed, and they were significantly different. Head width, body length, forewing length, dry body weight of adults and sex ratio were not affected by the different diets. There were significantly different found in survival rates among the diets when the nymph reached 5th instar. Results indicate that the combination powder of silkworm pupae and sunflower seed will promise as an alternative diet in the greenhouses to maintain the population of G. ochropterus. 相似文献
997.
Karsten Eichholz Thierry Bru Thi Thu Phuong Tran Paulo Fernandes Hugh Welles Franck J. D. Mennechet Nicolas Manel Paula Alves Matthieu Perreau Eric J. Kremer 《PLoS pathogens》2016,12(9)
Human adenoviruses (HAdVs) are nonenveloped proteinaceous particles containing a linear double-stranded DNA genome. HAdVs cause a spectrum of pathologies in all populations regardless of health standards. Following repeat exposure to multiple HAdV types, we develop robust and long-lived humoral and cellular immune responses that provide life-long protection from de novo infections and persistent HAdV. How HAdVs, anti-HAdV antibodies and antigen presenting cells (APCs) interact to influence infection is still incompletely understood. In our study, we used physical, pharmacological, biochemical, fluorescence and electron microscopy, molecular and cell biology approaches to dissect the impact of immune-complexed HAdV (IC-HAdV) on human monocyte-derived dendritic cells (MoDCs). We show that IC-HAdV generate stabilized complexes of ~200 nm that are efficiently internalized by, and aggregate in, MoDCs. By comparing IC-HAdV, IC-empty capsid, IC-Ad2ts1 (a HAdV-C2 impaired in endosomal escape due to a mutation that impacts protease encapsidation) and IC-AdL40Q (a HAdV-C5 impaired in endosomal escape due to a mutation in protein VI), we demonstrate that protein VI-dependent endosomal escape is required for the HAdV genome to engage the DNA pattern recognition receptor AIM2 (absent in melanoma 2). AIM2 engagement induces pyroptotic MoDC death via ASC (apoptosis-associated speck protein containing a caspase activation/recruitment domain) aggregation, inflammasome formation, caspase 1 activation, and IL-1β and gasdermin D (GSDMD) cleavage. Our study provides mechanistic insight into how humoral immunity initiates an innate immune response to HAdV-C5 in human professional APCs. 相似文献
998.
The effect of dicumarol on growth of selected soil bacteria: Azotobacter chroococcum, Arthrobacter globiformis, A. citreus and Bacillus megaterium was studied. The following minimum concentrations were inhibitory in vitro: Arthrobacter citreus--20 mug/ml., Bacillus megaterium--40 mug/ml., Azotobacter chroococcum--40 mug/ml. Arthrobacter globiformis--70 mug/ml. Cells of all microorganisms studied grown in the presence of dicumarol developed aberrant morphological forms. 相似文献
999.
Trinh Thi Diep Luong Van Dung Phung Van Trung Nguyen Thi Hoai Do Thi Thao Nguyen Thi To Uyen Tran Thi Hoai Linh Trang Hanh Nhat Ha Huynh Thanh Truc 《化学与生物多样性》2023,20(8):e202300649
This study was aimed to investigate the chemical composition and biological activities of leaf and stem essential oils of Zanthoxylum acanthopodium DC. from Vietnam. Their chemical composition was analyzed by GC/MS. Antimicrobial activities were evaluated by microdilution broth assay. Anti-inflammatory activity was evaluated by the ability to inhibit nitric oxide production in macrophage cells. Cytotoxic activity was evaluated using the sulforhodamine B assay on three human cancer cell lines. Forty-four compounds were identified in the leaf oil, among which dehydroaromadendrane (23.4 %), (E)-carpacin (17.6 %), 2-tridecanone (12.2 %), and 9-methyl-2-decanone (11.8 %) were the most abundant. The stem oil contained fifty-five identified constituents, mainly γ-gurjunene (51.1 %) and butyl acetate (11.8 %). Both oils exhibited inhibitory effects on three bacterial strains, namely S. aureus, E. coli, P. aeruginosa and a fungal strain C. albican, while showed insignificant effects on B. subtilis, L. fermentum, and S. enterica. Both oils showed weak NO production inhibition in LPS-induced RAW264.7 cells, but exhibited potent cytotoxic activity against all three tested cell lines SK-LU-1, MCF-7, and HepG2 with the IC50 values ranging from 16.03±0.77 to 35.60±1.62 μg/mL. This is the first report on the antimicrobial, anti-inflammatory and cytotoxic activities of essential oils from the leaves and stems of Z. acanthopodium. 相似文献
1000.
Dong Tu Nguyen Tuan Cuong Ngo Huy Hoang Tran Thi Phuong Lan Nguyen Binh Minh Nguyen Kouichi Morita & Masahiko Ehara 《FEMS microbiology letters》2009,298(1):37-43
Autoagglutinable strains of Vibrio cholerae O1 (seven nonfimbriate strains and one fimbriate strain) were transformed to obtain resistance to ampicillin. Two distinct mechanisms were found in these strains. One was operating in nonfimbriate strains by reducing OmpU protein production and the other was operating in a fimbriate strain (Bgd17) by newly overproducing cpxP protein. The twitching motility in the fimbriate Bgd17 strain disappeared depending on the production of cpxP protein, suggesting that fimbriation of V. cholerae O1 is controlled by a two-component signal transduction system. 相似文献