title: Optimization of ellagitannase production by Aspergillus niger GH1 by solid-state fermentation.
abstract: Ellagic acid is one of the most bioactive antioxidants with important applications in pharmaceutical, cosmetic, and food industries. However, there are few biotechnological processes developed for its production, because it requires precursors (ellagitannins) and the corresponding biocatalyst (ellagitannase). The aim of this study was to optimize the culture conditions for ellagitannase production by Aspergillus niger in solid-state fermentation (SSF). The bioprocess was carried out into a column bioreactor packed with polyurethane foam impregnated with an ellagitannins solution as carbon source. Four strains of Aspergillus niger (PSH, GH1, HT4, and HC2) were evaluated for ellagitannase production. The study was performed in two experimental steps. A Plackett-Burman design was used to determine the influencing parameters on ellagitannase production. Ellagitannins concentration, KCl, and MgSO4 were determined to be the most significant parameters. Box-Behnken design was used to define the interaction of the selected parameters. The highest enzyme value was obtained by A. niger PSH at concentrations of 7.5 g/L ellagitannins, 3.04 g/L KCl, and 0.76 g/L MgSO4. The methodology followed here allowed increasing the ellagitannase activity 10 times over other researcher results (938.8 U/g ellagitannins). These results are significantly higher than those reported previously and represent an important contribution for the establishment of a new bioprocess for ellagic acid and ellagitannase production.
authors.affiliation: a Department of Food Science and Technology, School of Chemistry , Universidad Autónoma de Coahuila , Saltillo , Coahuila , México.
authors.forename: Reynaldo
authors.initials: R
authors.lastname: de la Cruz
authors.forename: Juan A
authors.initials: JA
authors.lastname: Ascacio
authors.forename: Juan
authors.initials: J
authors.lastname: Buenrostro
authors.forename: Leonardo
authors.initials: L
authors.lastname: Sepúlveda
authors.forename: Raúl
authors.initials: R
authors.lastname: Rodríguez
authors.forename: Arely
authors.initials: A
authors.lastname: Prado-Barragán
authors.forename: Juan C
authors.initials: JC
authors.lastname: Contreras
authors.forename: Antonio
authors.initials: A
authors.lastname: Aguilera
authors.forename: Cristóbal N
authors.initials: CN
authors.lastname: Aguilar
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D001234:Aspergillus niger / Q000201:enzymology*; D019149:Bioreactors; D002265:Carboxylic Ester Hydrolases / Q000096:biosynthesis*; D003470:Culture Media; D004610:Ellagic Acid / Q000378:metabolism*; D005285:Fermentation; D011140:Polyurethanes / Q000737:chemistry
chemical_list: D000975:Antioxidants; D003470:Culture Media; D011140:Polyurethanes; D004610:Ellagic Acid; C028279:polyurethane foam; D002265:Carboxylic Ester Hydrolases
keywords: Aspergillus niger; ellagic acid; ellagitannase; ellagitannins; solid-state fermentation