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J.-Y. Roh H.-W. Park Y.-H. Je D.-W. Lee B.-R. Jin H.-W. Oh S. S. Gill & S.-K. Kang 《Letters in applied microbiology》1997,24(6):451-454
Bacillus thuringiensis NTB-1 isolated from soil samples in Korea produces ovoidal parasporal inclusions with proteins of approximately 24–40 kDa in size. Although serological study indicated that the isolate has a flagella (H) antigen identical with subsp. israelensis , it seemed to be non-insecticidal against Lepidoptera and Coleoptera as well as Diptera. To investigate the activity of non-insecticidal B. thuringiensis transformed with insecticidal crystal protein genes, cryIVD and cytA genes of B. thuringiensis subsp. morrisoni PG-14, highly toxic to mosquito larvae, were introduced into the isolate NTB-1. The expression of mosquitocidal crystal protein genes in NTB-1 was characterized by SDS–PAGE analysis and electron microscopy. The results showed that crystalline inclusions of host, CryIVD and CytA were stably expressed in the transformant. However, the mosquitocidal activity of transformant was similar to that of B. thuringiensis subsp. kurstaki Cry− B harbouring cryIVD and cytA genes, demonstrating that a synergistic effect by an interaction of both introduced insecticidal and resident non-insecticidal crystal proteins was not observed. 相似文献
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J Kwang S Bolin E T Littledike E J Dubovi R O Donis 《Biochemical and biophysical research communications》1991,178(3):1326-1334
A 917-base pair segment of the bovine viral diarrhea virus (BVDV) genome encoding part of the p80 region was cloned into plasmid Gex-2T expression vector for expression as a fusion protein with glutathione-S-transferase (GST). When the p80 and GST sequences were in the same reading frames, the resulting GST-p80 fusion protein had a molecular mass of 58 kilodaltons (kDa) in SDS-PAGE. Extracts of control E. coli carrying only the vector plasmid (Gex-2T) did not contain this new 58-kDa protein band. Mouse monoclonal antibody specific to BVDV-p80 recognized this recombinant protein. Seventy cattle sera that had an SN titer (to TGAC isolate of cytopathic BVDV) greater than 1:8 reacted with this recombinant protein in Western blots. Of 28 cattle sera that had SN titers less than or equal to 1:8, only one serum tested positive on Western blots. 相似文献
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88 rice and 75 soybean samples were collected from 8 provinces of Korea from March through September in 1988. The Fusarium mycotoxins, zearalenone was analyzed by direct competitive enzyme linked immunosorbent assay. 10.2% of rice and 9.3 % of soybean samples contained detectable zearalenone. The average levels of zearalenone of rice and soybean samples were 11.78μg/kg and 7.70μ/kg, respectively. 相似文献
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The removal of hydrogen sulfide (H2S) from aqueous media was investigated using Thiobacillus novellas cells immobilized on a SiO2 carrier (biosand). The optimal growth conditions for the bacterial strain were 30 degrees C and initial pH of 7.0. The main product of hydrogen sulfide oxidation by T. novellus was identified as the sulfate ion. A removal efficiency of 98% was maintained in the three-phase fluidized-bed reactor, whereas the efficiency was reduced to 90% for the two-phase fluidized-bed reactor and 68% for the two-phase reactor without cells. The maximum gas removal capacity for the system was 254 g H2S/m3/h when the inlet H2S loading was 300 g/m3/h (1,500 ppm). Stable operation of the immobilized reactor was possible for 20 days with the inlet H2S concentration held to 1,100 ppm. The fluidized bed bioreactor appeared to be an effective means for controlling hydrogen sulfide emissions. 相似文献
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The genome length of the Ascaris lumbricoides, human parasitic roundworm, is 14,281 bp with a nucleotide composition of 22.1% A, 49.8% T, 7.8% C, and 20.3% G. The genome consists of 12 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 control region. 相似文献
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Poliovirus entry into human brain microvascular cells requires receptor-induced activation of SHP-2 总被引:1,自引:0,他引:1
Viruses use specific receptor molecules to bind selectively to target cells. Receptors have often been considered as mere docking sites, but they may also possess intrinsic signaling capacities that serve to prime the cell for entry and infection. Poliovirus (PV) initiates infection by binding to the PV receptor (PVR) and causes paralytic poliomyelitis by replicating within motor neurons of the brain and spinal cord. We have examined the process by which PV enters cultured human brain microvascular endothelial cells (HBMEC), an in vitro model of the blood-brain barrier. We found that PV enters HBMEC by dynamin-dependent caveolar endocytosis, and that entry depends on intracellular signals triggered by virus attachment to PVR. Tyrosine kinase and RhoA GTPase activation initiated by PVR ligation were both essential. Virus attachment also induced tyrosine phosphorylation of PVR; this permitted the association of PVR with SHP-2, a protein tyrosine phosphatase whose activation was required for entry and infection. The results indicate that receptor-induced signals promote virus entry and suggest a role for tyrosine phosphatases in viral pathogenesis. 相似文献