Biochemical and molecular characterization of glucoamylase produced by the Aspergillus niger strain HPD-2: Biochemical and molecular characterization of glucoamylase

Abstract: Aspergillus niger HPD-2 has interesting growth characteristics, it grows at a temperature of 38 ºC and pH of 3, it is also known that it produces various enzymes of commercial interest such as glucoamylase, which is present in the medium even under non-inducible conditions and has importan...

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Detalles Bibliográficos
Autores: Pérez Rodríguez, Fernando, Pliego-Arreaga, Raquel, Silva-Martínez, Guillermo Antonio, Cervantes-Montelongo, Juan Antonio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:México
Institución:UNIVERSIDAD DE SONORA
Repositorio:Biotecnia
Idioma:inglés
OAI Identifier:oai:oai.biotecnia.unison.mx:article/2024
Acceso en línea:https://biotecnia.unison.mx/index.php/biotecnia/article/view/2024
Access Level:acceso abierto
Palabra clave:Glucoamylase
A. niger
Biochemical characterization
Molecular characterization
Enzyme kinetic
Glucoamilasa
caracterización molecular
caracterización bioquímica
cinética enzimática
Descripción
Sumario:Abstract: Aspergillus niger HPD-2 has interesting growth characteristics, it grows at a temperature of 38 ºC and pH of 3, it is also known that it produces various enzymes of commercial interest such as glucoamylase, which is present in the medium even under non-inducible conditions and has important activity characteristics such as an optimum temperature of 70 ºC and an optimum pH of 3-4. These features are very important because they will help to minimize microbial contamination risk in industrial hydrolysis processes. For the characterization of A. niger HPD-2 glucoamylase, the presence and activity of the enzyme were verified in a non-inducing medium. The apparent kinetic parameters Km, Ki and Vmax were determined, 6.66 mM, 0.601 M and 66.5 mM/min respectively. As well as its optimum pH and temperature activity (pH 3 and 70 °C). Comparatively speaking, these data are competitive against those reported for similar purified enzymes. On the other hand, DNA sequence analysis of A. niger HPD-2 glucoamylase gene showed no changes in the promoter region or starch-binding domains. Therefore, the presence of the enzyme in a non-inducing medium could be related to changes in a repressor protein CreA.