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Registros recuperados: 25 | |
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Sánchez Portillo, Juan Fernando. |
El nematodo agallador Meloidogyne incognita Kofoid y White, 1919, Chitwood, 1949, distribuido en 23 de los 32 estados del país y Nacobbus aberrans Thorne 1935, Thorne and Allen, 1944, distribuido en 10 de 32 estados de la República Mexicana, su combate para ambas especies, casi siempre se hace aplicando diferentes agroquímicos, los cuales algunos ya tienen problemas de registro. Se necesita evaluar nuevos productos que sean otra alternativa a su manejo y mas amigables al ambiente. En el presente trabajo se evaluó el efecto de quitina-quitosano con diferentes grados de desacetilación, biopolímeros naturales que poseen propiedades nematicidas y utilizados como reguladores de la población de estos fitonematodos; los estudios se hicieron in vitro, sobre la... |
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Palavras-chave: Biopolímero natural; Meloidogyne incognita; Nacobbus aberrans; Desacetilación; Control; Quitina; Quitosano; Chitin; Chitinase; Natural biopolymer; Chitosan; Deacetylation; Fitopatología; Maestría. |
Ano: 2010 |
URL: http://hdl.handle.net/10521/55 |
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Sánchez Portillo, Juan Fernando. |
El nematodo agallador Meloidogyne incognita Kofoid y White, 1919, Chitwood, 1949, distribuido en 23 de los 32 estados del país y Nacobbus aberrans Thorne 1935, Thorne and Allen, 1944, distribuido en 10 de 32 estados de la República Mexicana, su combate para ambas especies, casi siempre se hace aplicando diferentes agroquímicos, los cuales algunos ya tienen problemas de registro. Se necesita evaluar nuevos productos que sean otra alternativa a su manejo y mas amigables al ambiente. En el presente trabajo se evaluó el efecto de quitina-quitosano con diferentes grados de desacetilación, biopolímeros naturales que poseen propiedades nematicidas y utilizados como reguladores de la población de estos fitonematodos; los estudios se hicieron in vitro, sobre la... |
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Palavras-chave: Biopolímero natural; Meloidogyne incognita; Nacobbus aberrans; Desacetilación; Control; Quitina; Quitosano; Chitin; Chitinase; Natural biopolymer; Chitosan; Deacetylation; Fitopatología; Maestría. |
Ano: 2010 |
URL: http://hdl.handle.net/10521/55 |
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Dahiya,Neetu; Tewari,Rupinder; Tiwari,Ram P; Singh Hoondal,Gurinder. |
Enterobacter sp. NRG4 was shown to excrete chitinase into the culture supernatant when cultivated in medium containing chitin. A 60 kDa extracellular chitinase was purified to homogeneity and characterized. The enzyme hydrolyzed swollen chitin, colloidal chitin, regenerated chitin and glycol chitin but did not hydrolyze chitosan. The chitinase exhibited Km and Vmax values of 1.43 mg ml-1 and 83.33 µM µg-1 h-1 for swollen chitin, 1.41 mg ml-1 and 74.07 µM µg-1 h-1 for colloidal chitin, 1.8 mg ml-1 and 40 µM µg-1 h-1 for regenerated chitin and 2.0 mg ml-1 and 33.33 µM µg-1 h-1 for glycol chitin, respectively. The optimal temperature and pH for activity were 45ºC and pH 5.5, respectively. Mg2+, K+ and Ca2+ stimulated chitinase activity by 13, 16 and 18%,... |
Tipo: Journal article |
Palavras-chave: Chemical modification; Chitinase; Enterobacter sp. NRG4; Purification; Substrate binding. |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000200003 |
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Meng,Huimin; Wang,Zhangxun; Meng,Xiangyun; Xie,Ling; Huang,Bo. |
Entomopathogenic fungi can produce a series of chitinases, some of which function synergistically with proteases and other hydrolytic enzymes to degrade the insect cuticle. In the present study, the chitinase gene Ifu-chit2 from Isaria fumosorosea was investigated. The Ifu-chit2 gene is 1,435-bp long, interrupted by three short introns, and encodes a predicted protein of 423 amino acids with a 22 residue signal peptide. The predicted Ifu-Chit2 protein is highly homologous to Beauveria bassiana chitinase Bbchit2 and belongs to the glycohydrolase family 18. Ifu-Chit2 was expressed in Escherichia coli to verify chitinase activity, and the recombinant enzyme exhibited activity with a colloidal chitin substrate. Furthermore, the expression profiles of Ifu-chit2... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Isaria fumosorosea; Chitinase; Prokaryotic expression; Quantitative real-time PCR. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000300381 |
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Costa,Juliana R V da; Rossi,Juliana R; Marucci,Suzana C; Alves,Eliane C da C; Volpe,Haroldo X L; Ferraudo,Antonio S; Lemos,Manoel V F; Desidério,Janete A. |
Aedes aegypti (L.), the main vector of dengue fever in Brazil, has been controlled with the use of massive chemical products, contributing to the development of resistance and decreasing the insect control efficiency. The control of dipterans with bioinsecticides based on Bacillus thuringiensis has been satisfactory, due to the production of insecticidal proteins denominated Cry (crystal), Cyt (cytolytic) toxins and Chi (chitinase), and to the synergistic effects among them. The present work aimed to select B. thuringiensis isolates efficient against A. aegypti larvae. A bacterial collection containing 1,073 isolates of B. thuringiensis, obtained from different locations of Brazilian territory, had the DNA isolated and submitted to PCR amplifications using... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biological control; Cry; Cyt; Chitinase; Dengue fever. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2010000500015 |
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Yan,PM; Zhang,HF; Wang,Q; Yan,XY; Sun,Y. |
Isozymes of peroxidase (POD), catalase (CAT), esterase (EST) and superoxide dismutase (SOD) were analyzed on transgenic maize (with external chitinase gene) and its parent by vertical polyacrylamide gel electrophoresis (PAGE). This study was made using shoots at the fourth leaf stage. Results showed that: POD and EST were detected in 6 bands. POD-2 and POD-3 were present at the bud and seedling stages. POD-1, POD-4, POD-5 and POD-6 were only present at the seedling stage. POD-6 expressed stronger in the transgenic maize with chitinase than in its parent. EST-2 was present only at the bud stage, and its expression in transgenic maize was stronger than that in its parent. EST-5 only existed at the seedling stage. EST-4 did not exist in the parent maize... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitinase; Isozyme; Maize; Antioxidant enzyme system. |
Ano: 2010 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-56572010000200002 |
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Vasconcellos,Rafael Leandro Figueiredo de; Silva,Mylenne Calciolari Pinheiro da; Ribeiro,Carlos Marcelo; Cardoso,Elke Jurandy Bran Nogueira. |
Actinobacteria are capable of playing several different roles in soil ecosystems. These microorganisms affect other organisms by producing secondary metabolites and are responsible for the degradation of different complex and relatively recalcitrant organic compounds. In our survey of actinobacteria isolated from the rhizosphere of Araucaria angustifolia, five culture media (AI, WYE, YCED, MSSC and LNMS) were compared for their effectiveness in isolating these microorganisms. When summing up all the isolates randomly obtained, we got 103 isolates. After isolation, the phosphate-solubilizing ability and the "in vitro" production of indole-acetic acid and chitinases were evaluated. The AI medium was ineffective for actinobacteria isolation, when it was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brazil Pine; Selective culture media; Indole-acetic acid; Chitinase; Phosphate solubilization. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000600019 |
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Galante,Rafaela S.; Taranto,Alex G.; Koblitz,Maria G.B.; Góes-Neto,Aristóteles; Pirovani,Carlos P.; Cascardo,Júlio C.M.; Cruz,Sandra H.; Pereira,Gonçalo A.G.; Assis,Sandra A. de. |
The enzyme chitinase from Moniliophthora perniciosa the causative agent of the witches' broom disease in Theobroma cacao, was partially purified with ammonium sulfate and filtration by Sephacryl S-200 using sodium phosphate as an extraction buffer. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes were obtained: ChitMp I, ChitMp II, ChitMp III and ChitMp IV. ChitMp I had an optimum temperature at 44-73ºC and an optimum pH at 7.0-8.4. ChitMp II had an optimum temperature at 45-73ºC and an optimum pH at 7.0-8.4. ChitMp III had an optimum temperature at 54-67ºC and an optimum pH at 7.3-8.8. ChitMp IV had an optimum temperature at 60ºC and an optimum pH at 7.0. For the computational... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitinase; Moniliophthora perniciosa; Kinetic characterization; Purification; Isoenzymes; Heat stability; 3D structure; Comparative modeling. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000200016 |
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Vargas,Lúcia Rosane Bertholdo; Rossato,Marcelo; Ribeiro,Rute Terezinha da Silva; Barros,Neiva Monteiro de. |
The characterization of entomopathogenic microorganisms is important for the selection of more effective strains for use in integrated pest-control programs. Five Nomuraea rileyi strains (SA86101, GU87401, SR86151, CG128 and VA9101) were characterized using random amplified polymorphic DNA (RAPD) analysis, virulence studies and assessment of chitinolytic and proteolytic activity. RAPD analysis divided the strains into two groups with a similarity coefficient of 0,76%, group 1 consisting of strains SA86101, GU87401 and SR86151 and group 2 of strains CG128 and VA9101. The LT50 varied from 165h with strain VA9101 to 246h with strain GU87401. Chitinolytic and proteolytic activity of the fungi after 144h growth in minimal medium were tested using colloidal... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nomuraea rileyi; Anticarsia gemmatalis; Chitinase; Protease; RAPD; Virulence. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132003000100003 |
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Thimoteo,S.S.; Glogauer,A.; Faoro,H.; de Souza,E.M.; Huergo,L.F.; Moerschbacher,B.M.; Pedrosa,F.O.. |
Chitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4) present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading to the isolation and identification of a chitinase gene named metachi18A. The metachi18A gene was subcloned and overexpressed in Escherichia coli BL21 and the MetaChi18A chitinase was purified by affinity chromatography as a 6xHis-tagged fusion protein. The MetaChi18A enzyme is a 92-kDa protein with a conserved active site domain of glycosyl hydrolases family 18. It hydrolyses colloidal chitin with an optimum pH of 5 and temperature of 50°C. Moreover, the enzyme... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitinase; Metagenomic; Aeromonas; Kinetics. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017000100602 |
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Aliabadi,Nasrin; Aminzadeh,Saeed; Karkhane,Ali Asghar; Haghbeen,Kamahldin. |
Abstract Twelve bacterial strains isolated from shrimp farming ponds were screened for their growth activity on chitin as the sole carbon source. The highly chitinolytic bacterial strain was detected by qualitative cup plate assay and tentatively identified to be Cohnella sp. A01 based on 16S rDNA sequencing and by matching the key morphological, physiological, and biochemical characteristics. The cultivation of Cohnella sp. A01 in the suitable liquid medium resulted in the production of high levels of enzyme. The colloidal chitin, peptone, and K2HPO4 represented the best carbon, nitrogen, and phosphorus sources, respectively. Enzyme production by Cohnella sp. A01 was optimized by the Taguchi method. Our results demonstrated that inoculation amount and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biochemical characterization; Chitinase; Cohnella sp. A01; Isolation; Thermostable. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822016000400931 |
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Firmino,Alexandre A.P.; Ulhoa,Cirano J.; Sousa,Marcelo V.; Ferreira Filho,Edivaldo X.; Ricart,Carlos A.O.. |
The effect of G protein modulators and cyclic AMP (cAMP) on N-acetylglucosaminidase (NAGase) production was investigated during 84 h of growth of a Trichoderma harzianum strain in chitin-containing medium. Caffeine (5 mM), N6--2'-O-dibutyryladenosine 3'5'-cyclic monophosphate sodium salt (dBcAMP) (1 mM) and 3-isobutyl-1-methylxanthine (IBMX) (2 mM) decreased extracellular NAGase activity by 80%, 77% and 37%, respectively. AlCl3/KF (100 µM/10 mM and 200 µM/ 20 mM) decreased the activity by 85% and 95%, respectively. Cholera (10 µ/mL) and pertussis (20 µ/mL) toxins also affected NAGase activity, causing a decrease of approximately 75%. Upon all treatments, protein bands of approximately 73 kDa, 68 kDa and 45 kDa had their signals diminished whilst a 50 kDa... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Trichoderma; N-acetylglucosaminidase; Chitinase; CAMP; G protein. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000200015 |
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Dhawan,Manish; Joshi,Neelam. |
Abstract Beauveria bassiana, an entomopathogenic fungus, is the alternative biocontrol agent exploited against major economic crop pests. Pieris brassicae L. is an emerging pest of the Brassicaceae family. Therefore, in the present study, fungal isolates of Beauveria bassiana, viz. MTCC 2028, MTCC 4495, MTCC 6291, and NBAII-11, were evaluated for their virulence against third instar larvae of P. brassicae. Among all these fungal isolates, maximum mortality (86.66%) was recorded in B. bassiana MTCC 4495 at higher concentration of spores (109 conidia/ml), and the minimum mortality (30.00%) was recorded in B. bassiana MTCC 6291 at a lower concentration (107 conidia/ml) after ten days of treatment. The extracellular cuticle-degrading enzyme activities of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitinase; Entomopathogenic fungi; Lipase; Mortality; Protease. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000300522 |
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Registros recuperados: 25 | |
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