title: The complete biodegradation pathway of ellagitannins by Aspergillus niger in solid-state fermentation.
abstract: Our research group has found preliminary evidences of the fungal biodegradation pathway of ellagitannins, revealing first the existence of an enzyme responsible for ellagitannins degradation, which hydrolyzes pomegranate ellagitannins and it was called ellagitannase or elagitannin acyl hydrolase. However, it is necessary to generate new and clear information in order to understand the ellagitannin degradation mechanisms. This work describes the distinctive and unique features of ellagitannin metabolism in fungi. In this study, hydrolysis of pomegranate ellagitannins by Aspergillus niger GH1 was studied by solid-state culture using polyurethane foam as support and pomegranate ellagitannins as substrate. The experiment was performed during 36 h. Results showed that ellagitannin biodegradation started after 6 h of fermentation, reaching the maximal biodegradation value at 18 h. It was observed that ellagitannase activity appeared after 6 h of culture, then, the enzymatic activity was maintained up to 24 h of culture reaching 390.15 U/L, after this period the enzymatic activity decreased. Electrophoretic band for ellagitannase was observed at 18 h. A band obtained using non-denaturing electrophoresis was identified as ellagitannase, then, a tandem analysis to reveal the ellagitannase activity was performed using Petri plate with pomegranate ellagitannins. The extracts were analyzed by HPLC/MS to evaluate ellagitannins degradation. Punicalin, gallagic acid, and ellagic acid were obtained from punicalagin. HPLC/MS analysis identified the gallagic acid as an intermediate molecule and immediate precursor of ellagic acid. The potential application of catabolic metabolism of ellagitannin hydrolysis for ellagic acid production is outlined.
authors.affiliation: Department of Food Research, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, Coahuila, México.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Ascacio-Valdés
authors.affiliation: Department of Food Science and Nutrition, Universidad Autónoma Agraria "Antonio Narro", Buenavista, Saltillo, México.
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Aguilera-Carbó
authors.affiliation: Department of Biotechnology, Universidad Autonoma Metropolitana, Unidad Iztapalapa, Saltillo, Coahuila, México.
authors.forename: José J
authors.initials: JJ
authors.lastname: Buenrostro
authors.affiliation: Department of Biotechnology, Universidad Autonoma Metropolitana, Unidad Iztapalapa, Saltillo, Coahuila, México.
authors.forename: Arely
authors.initials: A
authors.lastname: Prado-Barragán
authors.affiliation: Department of Food Research, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, Coahuila, México.
authors.forename: Raúl
authors.initials: R
authors.lastname: Rodríguez-Herrera
authors.affiliation: Department of Food Research, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, Coahuila, México.
authors.forename: Cristóbal N
authors.initials: CN
authors.lastname: Aguilar
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D004610:Ellagic Acid / Q000737:chemistry / Q000378:metabolism; D004789:Enzyme Activation; D005285:Fermentation; D047348:Hydrolyzable Tannins / Q000737:chemistry / Q000378:metabolism*; D029561:Lythraceae / Q000737:chemistry / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D010936:Plant Extracts / Q000737:chemistry
chemical_list: D047348:Hydrolyzable Tannins; D010936:Plant Extracts; C013515:ellagitannin; D004610:Ellagic Acid; C115642:punicalagin; C115643:punicalin
keywords: Biodegradation; Ellagitannins; Pathway