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Xiao Fang Yu - One of the best experts on this subject based on the ideXlab platform.
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optimization and characterization of candidate strain for coxsackievirus a16 inactivated vaccine
Viruses, 2015Co-Authors: Jingliang Li, Junliang Chang, Jiaxin Yang, Wenyan Zhang, Xiao Fang YuAbstract:Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine.
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coxsackievirus a16 infection induces neural cell and non neural cell apoptosis in vitro
PLOS ONE, 2014Co-Authors: Zhaolong Li, Elana S Ehrlich, Jingliang Li, Xiao Fang Yu, Jinghua Yu, Hong Wang, Wenyan ZhangAbstract:Coxsackievirus A16 (CA16) is one of the main causative pathogens of hand, foot and mouth disease (HFMD). Viral replication typically results in host cell apoptosis. Although CA16 infection has been reported to induce apoptosis in the human rhabdomyosarcoma (RD) cell line, it remains unclear whether CA16 induces apoptosis in diverse cell types, especially neural cells which have important clinical significance. In the current study, CA16 infection was found to induce similar apoptotic responses in both neural cells and non-neural cells in vitro, including nuclear fragmentation, DNA fragmentation and phosphatidylserine translocation. CA16 generally is not known to lead to serious neurological symptoms in vivo. In order to further clarify the correlation between clinical symptoms and cell apoptosis, two CA16 strains from patients with different clinical features were investigated. The results showed that both CA16 strains with or without neurological symptoms in infected patients led to neural and muscle cell apoptosis. Furthermore, mechanistic studies showed that CA16 infection induced apoptosis through the same mechanism in both neural and non-neural cells, namely via activation of both the mitochondrial (intrinsic) pathway-related caspase 9 protein and the Fas death receptor (extrinsic) pathway-related caspase 8 protein. Understanding the mechanisms by which CA16 infection induces apoptosis in both neural and non-neural cells will facilitate a better understanding of CA16 pathogenesis.
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protection from lethal challenge in a neonatal mouse model by circulating recombinant form coxsackievirus a16 vaccine candidates
Journal of General Virology, 2014Co-Authors: Jingliang Li, Junliang Chang, Xiao Fang Yu, Jiaxin Yang, Wenyan ZhangAbstract:Circulating coxsackievirus A16 (CA16) is a major cause of hand, foot and mouth disease (HFMD) in South-east Asia. At present, there is no vaccine against CA16. Pathogenic animal models that are sensitive to diverse circulating CA16 viruses would be desirable for vaccine development and evaluation. In this study, we isolated and characterized several circulating CA16 viruses from recent HFMD patients. These CA16 viruses currently circulating in humans were highly pathogenic in a newly developed neonatal mouse model; we also observed and analysed the pathogenesis of representative circulating recombinant form CA16 viruses. An inactivated CA16 vaccine candidate, formulated with alum adjuvant and containing submicrogram quantities of viral proteins, protected neonatal mice born to immunized female mice from lethal-dose challenge with a series of CA16 viruses. Further analysis of humoral immunity showed that antibody elicited from both the immunized dams and their pups could neutralize various lethal viruses by a cytopathic effect in vitro. Moreover, viral titres and loads in the tissues of challenged pups in the vaccine group were far lower than those in the control group, and some were undetectable. This lethal-challenge model using pathogenic CA16 viruses and the vaccine candidates that mediated protection in this model could be useful tools for the future development and evaluation of CA16 vaccines.
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circulating coxsackievirus a16 identified as recombinant type a human enterovirus china
Emerging Infectious Diseases, 2011Co-Authors: Ke Zhao, Guanjun Wang, Wei Hu, Wenyan Zhang, Xiao Fang YuAbstract:To determine the relationship of coxsackievirus A16 (CA16) to prototype CA16-G10, we conducted a phylogenetic analysis of circulating CA16 strains in China. Complex recombinant forms of CA16-related viruses involving multiple human enteroviruses, subgroup A (CA4, CA16, and enterovirus 71), are prevalent among patients with hand, foot, and mouth disease.
K Nagarajan - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic functions of ba10 po4 6cl2 sr10 po4 6cl2 and CA10 po4 6cl2
Thermochimica Acta, 2011Co-Authors: R Babu, Hrudananda Jena, K Govindan V Kutty, K NagarajanAbstract:Abstract Alkaline earth chloroapatites, M10(PO4)6Cl2 (M = Ba, Sr, Ca) were prepared by solid state reaction route and characterized by XRD. The lattice constants of Ba10(PO4)6Cl2, Sr10(PO4)6Cl2, CA10(PO4)6Cl2 were determined to be a = 10.27(1) A, c = 7.66(1) A; a = 9.87(2) A, c = 7.18(1) A and a = 9.52(1) A, c = 6.85(1) A respectively. The enthalpy increments were measured by inverse drop calorimetric method in the temperature range 523–1423 K using a high temperature calorimeter. Thermodynamic functions such as heat capacity, entropy and Gibbs energy functions in the temperature range 298–1500 K, were computed from the measured enthalpy increments.
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heat capacity of sr10 po4 6cl2 and CA10 po4 6cl2 by dsc
Thermochimica Acta, 2008Co-Authors: Venkata R Krishnan, Hrudananda Jena, K Govindan V Kutty, K NagarajanAbstract:Abstract Strontium and calcium chloroapatites were synthesized by wet chemical method, characterized by X-ray diffraction and are found to be phase pure materials. The measured room temperature lattice parameter of CA10(PO4)6Cl2 is a = 9.523 A, c = 6.855 A and for Sr10(PO4)6Cl2 is a = 9.876 A, c = 7.188 A. Heat capacity measurements were carried out on CA10(PO4)6Cl2 and Sr10(PO4)6Cl2 by DSC in the temperature range 298–800 K. The heat capacity values of Sr10(PO4)6Cl2 is higher at all temperatures than CA10(PO4)6Cl2. Enthalpy and entropy increments were computed. Heat capacity values of CA10(PO4)6Cl2 and Sr10(PO4)6Cl2 at 298 K are 758 and 868 J K−1 mol−1, respectively.
Zhong Huang - One of the best experts on this subject based on the ideXlab platform.
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coxsackievirus a16 like particles produced in pichia pastoris elicit high titer neutralizing antibodies and confer protection against lethal viral challenge in mice
Antiviral Research, 2016Co-Authors: Chao Zhang, Zhiqiang Ku, Yang Hu, Xiaohua Ye, Yingyi Zhang, Zhong HuangAbstract:Abstract Coxsackievirus A16 (CA16) is a major causative agent of hand, foot and mouse disease (HFMD) which has been affecting millions of young children annually in the Asia–Pacific region over the last seven years. However, no commercial CA16 vaccines are currently available. In the present study, we investigated the expression of virus-like particles (VLPs) of CA16 in Pichia pastoris yeast and their immunogenicity and protective efficacy in mice. We found that CA16-VLPs could be produced at relatively high levels in P. pastoris yeast transformed with a construct co-expressing the P1 and 3CD proteins of CA16. Mice immunized with the yeast-derived CA16-VLPs produced high-titer serum antibodies with potent neutralization effect specifically on CA16. More importantly, passive immunization with the yeast-derived VLPs fully protected neonatal mice against CA16 lethal challenge in both antisera transfer and maternal immunization experiments. Collectively, our results demonstrate that P. pastoris-derived CA16-VLPs represent a promising CA16 vaccine candidate with proven preclinical efficacy and desirable traits for manufacturing at industrial scale.
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improved plasmid based recovery of coxsackievirus a16 infectious clone driven by human rna polymerase i promoter
Virologica Sinica, 2016Co-Authors: Xiaoli Wang, Chaoyun Shen, Tan Chen, Zhong Huang, Yunfang ZhangAbstract:Coxsackievirus A16 (CA16) is one of the major viral pathogens associated with hand, foot, and mouth disease. CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded positivesense RNA genome (Mao et al., 2014). Reverse genetics is an important tool for CA16 research. Previously, a reverse genetics T7 polymerase-based system was developed for poliovirus (Moss et al., 1989), foot-andmouth disease virus (FMDV) (Zibert et al., 1990), coxsackievirus B3 (Klump et al., 1990), enterovirus 71 (EV71) (Han et al., 2010; Shang et al., 2013), and even CA16 (Liu et al., 2011). However, in that system, cDNA must be transcribed to RNA by an exogenous T7 polymerase in vitro or in vivo. To develop a more rapid and simple method, a reverse genetics system based on human polymerase I (Pol I ) was developed for FMDV (Chang et al., 2009) and EV71 (Meng et al., 2012). In the current study, we developed a high-efficiency Pol I-driven plasmid-based reverse genetics system for CA16 (Gen- Bank: EU262658), and systemically characterized recovered CA16 particles.
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a virus like particle based bivalent vaccine confers dual protection against enterovirus 71 and coxsackievirus a16 infections in mice
Vaccine, 2014Co-Authors: Zhiqiang Ku, Xiaoli Wang, Dapeng Li, Xiaohua Ye, Wenqi An, Zhong HuangAbstract:Abstract Enterovirus 71(EV71) and coxsackievirus A16 (CA16) are responsible for hand, foot and mouth disease which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Co-circulation of and co-infection by both viruses underscores the importance and urgency of developing vaccines against both viruses simultaneously. Here we report the immunogenicity and protective efficacy of a bivalent combination vaccine comprised of EV71 and CA16 virus-like particles (VLPs). We show that monovalent EV71- or CA16-VLPs-elicited serum antibodies exhibited potent neutralization effect on the homotypic virus but little or no effect on the heterotypic one, whereas the antisera against the bivalent vaccine formulation were able to efficiently neutralize both EV71 and CA16, indicating there is no immunological interference between the two antigens with respect to their ability to induce virus-specific neutralizing antibodies. Passive immunization with monovalent VLP vaccines protected mice against a homotypic virus challenge but not heterotypic infection. Surprisingly, antibody-dependent enhancement (ADE) of disease was observed in mice passively transferred with mono-specific anti-CA16 VLP sera and subsequently challenged with EV71. In contrast, the bivalent VLP vaccine conferred full protection against lethal challenge by either EV71 or CA16, thus eliminating the potential of ADE. Taken together, our results demonstrate for the first time that the bivalent VLP approach represents a safe and efficacious vaccine strategy for both EV71 and CA16.
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a murine model of coxsackievirus a16 infection for anti viral evaluation
Antiviral Research, 2014Co-Authors: Xulin Huang, Zhong HuangAbstract:Abstract Coxsackievirus A16 (CA16) is one of the main causative agents of hand, foot and mouth disease (HFMD), which is a common infectious disease in children. CA16 infection may lead to severe nervous system damage and even death in humans. However, study of the pathogenesis of CA16 infection and development of vaccines and anti-viral agents are hindered partly by the lack of an appropriate small animal model. In the present study, we developed and characterized a murine model of CA16 infection. We show that neonatal mice are susceptible to CA16 infection via intraperitoneal inoculation. One-day-old mice infected with 2 × 10 6 TCID50 of CA16/SZ05 strain consistently exhibited clinical signs, including reduced mobility, and limb weakness and paralysis. About 57% of the mice died within 14 days after infection. Significant damage in the brainstem, limb muscles and intestines of the infected mice in the moribund state was observed by histological examination, and the presence of CA16 in neurons of the brainstem was demonstrated by immunohistochemical staining with a CA16-specific polyclonal antibody, strongly suggesting the involvement of the central nervous system in CA16 infection. Analysis of virus titers in various organs/tissues collected at 3, 6 and 9 days post-infection, showed that skeletal muscle was the major site of virus replication at the early stage of infection, while the virus mainly accumulated in the brain at the late stage. In addition, susceptibility of mice to CA16 infection was found to be age dependent. Moreover, different CA16 strains could exhibit varied virulence in vivo . Importantly, we demonstrated that post-exposure treatment with an anti-CA16 monoclonal antibody fully protected mice against lethal CA16 infection. Collectively, these results indicate the successful development of a CA16 infection mouse model for anti-viral evaluation.
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a combination vaccine comprising of inactivated enterovirus 71 and coxsackievirus a16 elicits balanced protective immunity against both viruses
Vaccine, 2014Co-Authors: Zhiqiang Ku, Qibin Leng, Zhong HuangAbstract:Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are the two major causative agents of hand, foot and mouth disease (HFMD), which is an infectious disease frequently occurring in children. A bivalent vaccine against both EV71 and CA16 is highly desirable. In the present study, we compare monovalent inactivated EV71, monovalent inactivated CA16, and a combination vaccine candidate comprising of both inactivated EV71 and CA16, for their immunogenicity and in vivo protective efficacy. The two monovalent vaccines were found to elicit serum antibodies that potently neutralized the homologous virus but had no or weak neutralization activity against the heterologous one; in contrast, the bivalent vaccine immunized sera efficiently neutralized both EV71 and CA16. More importantly, passive immunization with the bivalent vaccine protected mice against either EV71 or CA16 lethal infections, whereas the monovalent vaccines only prevented the homologous but not the heterologous challenges. Together, our results demonstrate that the experimental bivalent vaccine comprising of inactivated EV71 and CA16 induces a balanced protective immunity against both EV71 and CA16, and thus provide proof-of-concept for further development of multivalent vaccines for broad protection against HFMD.
Wenyan Zhang - One of the best experts on this subject based on the ideXlab platform.
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optimization and characterization of candidate strain for coxsackievirus a16 inactivated vaccine
Viruses, 2015Co-Authors: Jingliang Li, Junliang Chang, Jiaxin Yang, Wenyan Zhang, Xiao Fang YuAbstract:Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine.
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coxsackievirus a16 infection induces neural cell and non neural cell apoptosis in vitro
PLOS ONE, 2014Co-Authors: Zhaolong Li, Elana S Ehrlich, Jingliang Li, Xiao Fang Yu, Jinghua Yu, Hong Wang, Wenyan ZhangAbstract:Coxsackievirus A16 (CA16) is one of the main causative pathogens of hand, foot and mouth disease (HFMD). Viral replication typically results in host cell apoptosis. Although CA16 infection has been reported to induce apoptosis in the human rhabdomyosarcoma (RD) cell line, it remains unclear whether CA16 induces apoptosis in diverse cell types, especially neural cells which have important clinical significance. In the current study, CA16 infection was found to induce similar apoptotic responses in both neural cells and non-neural cells in vitro, including nuclear fragmentation, DNA fragmentation and phosphatidylserine translocation. CA16 generally is not known to lead to serious neurological symptoms in vivo. In order to further clarify the correlation between clinical symptoms and cell apoptosis, two CA16 strains from patients with different clinical features were investigated. The results showed that both CA16 strains with or without neurological symptoms in infected patients led to neural and muscle cell apoptosis. Furthermore, mechanistic studies showed that CA16 infection induced apoptosis through the same mechanism in both neural and non-neural cells, namely via activation of both the mitochondrial (intrinsic) pathway-related caspase 9 protein and the Fas death receptor (extrinsic) pathway-related caspase 8 protein. Understanding the mechanisms by which CA16 infection induces apoptosis in both neural and non-neural cells will facilitate a better understanding of CA16 pathogenesis.
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protection from lethal challenge in a neonatal mouse model by circulating recombinant form coxsackievirus a16 vaccine candidates
Journal of General Virology, 2014Co-Authors: Jingliang Li, Junliang Chang, Xiao Fang Yu, Jiaxin Yang, Wenyan ZhangAbstract:Circulating coxsackievirus A16 (CA16) is a major cause of hand, foot and mouth disease (HFMD) in South-east Asia. At present, there is no vaccine against CA16. Pathogenic animal models that are sensitive to diverse circulating CA16 viruses would be desirable for vaccine development and evaluation. In this study, we isolated and characterized several circulating CA16 viruses from recent HFMD patients. These CA16 viruses currently circulating in humans were highly pathogenic in a newly developed neonatal mouse model; we also observed and analysed the pathogenesis of representative circulating recombinant form CA16 viruses. An inactivated CA16 vaccine candidate, formulated with alum adjuvant and containing submicrogram quantities of viral proteins, protected neonatal mice born to immunized female mice from lethal-dose challenge with a series of CA16 viruses. Further analysis of humoral immunity showed that antibody elicited from both the immunized dams and their pups could neutralize various lethal viruses by a cytopathic effect in vitro. Moreover, viral titres and loads in the tissues of challenged pups in the vaccine group were far lower than those in the control group, and some were undetectable. This lethal-challenge model using pathogenic CA16 viruses and the vaccine candidates that mediated protection in this model could be useful tools for the future development and evaluation of CA16 vaccines.
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circulating coxsackievirus a16 identified as recombinant type a human enterovirus china
Emerging Infectious Diseases, 2011Co-Authors: Ke Zhao, Guanjun Wang, Wei Hu, Wenyan Zhang, Xiao Fang YuAbstract:To determine the relationship of coxsackievirus A16 (CA16) to prototype CA16-G10, we conducted a phylogenetic analysis of circulating CA16 strains in China. Complex recombinant forms of CA16-related viruses involving multiple human enteroviruses, subgroup A (CA4, CA16, and enterovirus 71), are prevalent among patients with hand, foot, and mouth disease.
Toshio Omori - One of the best experts on this subject based on the ideXlab platform.
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characterization of the replication maintenance and transfer features of the incp 7 plasmid pcar1 which carries genes involved in carbazole and dioxin degradation
Applied and Environmental Microbiology, 2006Co-Authors: Masaki Shintani, Hiroshi Habe, Toshio Omori, Hirokazu Yano, Hisakazu Yamane, Masataka Tsuda, Hideaki NojiriAbstract:ABSTRACT Isolated from Pseudomonas resinovorans CA10, pCAR1 is a 199-kb plasmid that carries genes involved in the degradation of carbazole and dioxin. The nucleotide sequence of pCAR1 has been determined previously. In this study, we characterized pCAR1 in terms of its replication, maintenance, and conjugation. By constructing miniplasmids of pCAR1 and testing their establishment in Pseudomonas putida DS1, we show that pCAR1 replication is due to the repA gene and its upstream DNA region. The repA gene and putative oriV region could be separated in P. putida DS1, and the oriV region was determined to be located within the 345-bp region between the repA and parW genes. Incompatibility testing using the minireplicon of pCAR1 and IncP plasmids indicated that pCAR1 belongs to the IncP-7 group. Monitoring of the maintenance properties of serial miniplasmids in nonselective medium, and mutation and complementation analyses of the parWABC genes, showed that the stability of pCAR1 is attributable to the products of the parWAB genes. In mating assays, the transfer of pCAR1 from CA10 was detected in a CA10 derivative that was cured of pCAR1 (CA10dm4) and in P. putida KT2440 at frequencies of 3 × 10−1 and 3 × 10−3 per donor strain, respectively. This is the first report of the characterization of this completely sequenced IncP-7 plasmid.
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enhanced degradation of carbazole and 2 3 dichlorodibenzo p dioxin in soils by pseudomonas resinovorans strain CA10
Chemosphere, 2002Co-Authors: Jaka Widada, Hideaki Nojiri, Takako Yoshida, Hiroshi Habe, Toshio OmoriAbstract:Abstract We studied the degradation of carbazole (CAR) and 2,3-dichlorodibenzo-p-dioxin (2,3-DCDD) in soils inoculated with carbazole- and dioxin-degrader Pseudomonas resinovorans strain CA10. By using Tn5-based transposon delivery systems, this bacterium was chromosomally marked with a tandem green fluorescent protein (gfp) gene. Real-time competitive PCR and direct counting using the (gfp) marker were employed to monitor the total number of carbazole 1,9a-dioxygenase gene (carAa) and survival of CA10 cells in the soil and soil slurry microcosms. Bioaugmentation studies indicated that the survival of the marked CA10 cells in soil microcosms was strongly influenced by pH and organic matter. While the number of the marked CA10 cells decreased rapidly in pH 6 with low organic matter, a high cell density was maintained in pH 7.3 with 2.5% organic matters up to 21 days after inoculation. In pH 7.3 soil, the period needed for complete degradation of CAR (100 μg kg−1) was markedly shortened from 21 to 7 days by the inoculation with the CA10 cells. Single inoculation of CA10 cells into the soil slurry system of 2,3-DCDD-contaminated soil enhanced the degradation of 2,3-DCDD from 25.0% to 37.0%. In this system, the population density of CA10 cells and the total number of carAa gene were maintained up to 14 days after inoculation. By repeated inoculation (every 2 days) with CA10 cells each at a density of 109 CFU g−1 of soil, almost all of the 2,3-DCDD (1 μg kg−1) was degraded within 14 days. Results of these experiments suggest that P. resinovorans strain CA10 may be an important resource for bioremediation of CAR and chlorinated dibenzo-p-dioxin in contaminated soils.
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organization and transcriptional characterization of catechol degradation genes involved in carbazole degradation by pseudomonas resinovorans strain CA10
Bioscience Biotechnology and Biochemistry, 2002Co-Authors: Hideaki Nojiri, Takako Yoshida, Hiroshi Habe, Masaki Shintani, Kana Maeda, Hiroyo Sekiguchi, Masaaki Urata, Toshio OmoriAbstract:Pseudomonas resinovorans strain CA10 assimilates catechol, which is an intermediate of carbazole degradation, by ortho cleavage pathway enzymes encoded by the catR, catBCA operon. Cat proteins of strain CA10 were very similar to those of P. putida, although the relatedness in non-coding regions was not high. It was found that catBCA genes were induced in carbazole-grown cells as a single transcriptional unit.
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preliminary examinations for applying a carbazole degrader pseudomonas sp strain CA10 to dioxin contaminated soil remediation
Applied Microbiology and Biotechnology, 2001Co-Authors: Hiroshi Habe, Jaka Widada, Hideaki Nojiri, Takako Yoshida, Kazuki Ide, M Yotsumoto, Hirokazu Tsuji, Hiroyuki Hirano, Toshio OmoriAbstract:A method for bioremediation of chlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) by a carbazole-utilizing bacterium, Pseudomonas sp. strain CA10, was developed. CA10 cells transferred to carbon- and nitrogen-free mineral medium supplemented with 1 mg carbazole (CAR)/ml grew rapidly during the first 2 days; and the cells at the end of this rapid growth period showed the highest 2,3-dichlorodibenzo-p-dioxin (2,3-Cl2DD)-degrading activity. The CA10 cells pre-grown for 2 days efficiently degraded 2,3-Cl2DD in aqueous solution at either 1 ppm or 10 ppm. The effect of inoculum density on the efficiency of 2,3-Cl2DD degradation was investigated in a soil slurry microcosm [ratio of soil:water = 1:5 (w/v)]. The results showed that a single inoculation with CA10 cells at densities of 107 CFU/g soil and 109 CFU/g soil degraded 46% and 80% of 2,3-Cl2DD, respectively, during the 7-day incubation. The rate of degradation of each CDD congener, 2-ClDD, 2,3-Cl2DD, and 1,2,3-Cl3DD (1 ppm each) by strain CA10 in the soil slurry system was not significantly influenced by the coexistence of the other congeners. Using this soil slurry system, we tried an experimental bioremediation of the actual dioxin-contaminated soil, which contained mainly tetra- to octochlorinated dioxins. Although the degradation rate of total CDD and CDF congeners by a single inoculation with CA10 cells was 8.3% after a 7-day incubation, it was shown that strain CA10 had a potential to degrade tetra- to hepta-chlorinated congeners including the most toxic compound, 2,3,7,8-tetrachlorinated dibenzo-p-dioxin.
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biodegradation of carbazole by pseudomonas spp ca06 and CA10
Bioscience Biotechnology and Biochemistry, 1993Co-Authors: Naoki Ouchiyama, Toshio Omori, Yan Zhang, Tohru KodamaAbstract:Two bacterial strains, CA06 and CA10, that assimilate carbazole (CAR) as the sole source of carbon and nitrogen were isolated from 202 farm soil samples and 4 activated sludge samples, and identified as Pseudomonas spp. Growth conditions for strains CA06 and CA10 on CAR were examined. Anthranilic acid (AN) and catechol (CAT) were identified as the main metabolites of CAR by high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). When strains CA06 and CA10 were cultivated in a medium containing 17mM CAR, 1.4mM AN, and 0.1 mM CAT were accumulated in the culture broth, but AN disappeared after 140 h of incubation. An initial oxidation product, 2ʹ -aminobiphenyl-2,3-diol, and a meta-cleavage product, 2-hydroxy-6-oxo-6-(2ʹ -aminophenyl)hexa-2,4-dienoic acid, were tentatively identified in the culture broth of CAR by GC-MS. When AN was used for a substrate in culture by these strains, CAT and a small amount of cis, cis-muconate was detected by HPLC. This conversion sugges...
