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| Registros recuperados: 25 | |
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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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| Freitas,Cleverson D. T. de; Souza,Diego P. de; Araújo,Eliane S.; Cavalheiro,Mariana G.; Oliveira,Luciana S.; Ramos,Márcio V.. |
| In this study, proteins extracted from laticifer cells of three plants were examined by electrophoresis, mass spectrometry (MALDI-TOF) and characterized in respect of proteolytic, chitinolytic and anti-oxidative activities by means of zymography and colorimetric assays. Acidic proteins with molecular masses between 12.5 and 74.5 kDa predominated in laticifers of P. rubra. This profile was not found in laticifers of C. grandiflora and E. tirucalli. The later was poor in respect of proteins. Strong anti-oxidative activity of superoxide dismutase (E.C. 1.15.1.1) was detected in P. rubra and C. grandiflora latices, and to a lesser extent ascorbate peroxidase (E.C. 1.11.1.1) and isoforms of peroxidase were seen. Catalase (E.C. 1.11.1.6) was detected only in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Catalase; Chitinase; Cysteine proteinase; Latex; Peroxidase. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100002 |
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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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| Zarei,Mandana; Aminzadeh,Saeed; Zolgharnein,Hossein; Safahieh,Alireza; Daliri,Morteza; Noghabi,Kambiz Akbari; Ghoroghi,Ahmad; Motallebi,Abbasali. |
| Chitinases have the ability of chitin digestion that constitutes a main compound of the cell wall in many of the phytopathogens such as fungi. In the following investigation, a novel chitinase with antifungal activity was characterized from a native Serratia marcescens B4A. Partially purified enzyme had an apparent molecular mass of 54 kDa. It indicated an optimum activity in pH 5 at 45ºC. Enzyme was stable in 55ºC for 20 min and at a pH range of 3-9 for 90 min at 25ºC. When the temperature was raised to 60ºC, it might affect the structure of enzymes lead to reduction of chitinase activity. Moreover, the Km and Vmax values for chitin were 8.3 mg/ml and 2.4 mmol/min, respectively. Additionally, the effect of some cations and chemical compounds were found to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antifungal; Characterization; Chitinase; Serratia marcescens B4A. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000300022 |
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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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| 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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| 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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| 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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| 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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| 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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| Registros recuperados: 25 | |
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