title: Secretomic Insight into Glucose Metabolism of Aspergillus brasiliensis in Solid-State Fermentation.
abstract: The genus Aspergillus is ubiquitous in nature and includes various species extensively exploited industrially due to their ability to produce and secrete a variety of enzymes and metabolites. Most processes are performed in submerged fermentation (SmF); however, solid-state fermentation (SSF) offers several advantages, including lower catabolite repression and substrate inhibition and higher productivity and stability of the enzymes produced. This study aimed to explain the improved metabolic behavior of A. brasiliensis ATCC9642 in SSF at high glucose concentrations through a proteomic approach. Online respirometric analysis provided reproducible samples for secretomic studies when the maximum CO2production rate occurred, ensuring consistent physiological states. Extracellular extracts from SSF cultures were treated by SDS-PAGE, digested with trypsin, and analyzed by LC-MS/MS. Of 531 sequences identified, 207 proteins were analyzed. Twenty-five were identified as the most abundant unregulated proteins; 87 were found to be up-regulated and 95 were down-regulated with increasing glucose concentration. Of the regulated proteins, 120 were enzymes, most involved in the metabolism of carbohydrates (51), amino acids (23), and nucleotides (9). This study shows the high protein secretory activity of A. brasiliensis under SSF conditions. High glucose concentration favors catabolic activities, while some stress-related proteins and those involved in proteolysis are down-regulated.
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa , San Rafael Atlixco 186, Col. Vicentina, Distrito Federal, C.P. 09340, México.
authors.forename: Tania
authors.initials: T
authors.lastname: Volke-Sepulveda
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa , San Rafael Atlixco 186, Col. Vicentina, Distrito Federal, C.P. 09340, México.
authors.forename: Daniel
authors.initials: D
authors.lastname: Salgado-Bautista
authors.affiliation: Complex Carbohydrate Research Center , 315 Riverbend Road, Athens, Georgia 30605, United States.
authors.forename: Carl
authors.initials: C
authors.lastname: Bergmann
authors.affiliation: Complex Carbohydrate Research Center , 315 Riverbend Road, Athens, Georgia 30605, United States.
authors.forename: Lance
authors.initials: L
authors.lastname: Wells
authors.affiliation: Complex Carbohydrate Research Center , 315 Riverbend Road, Athens, Georgia 30605, United States.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Gutierrez-Sanchez
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa , San Rafael Atlixco 186, Col. Vicentina, Distrito Federal, C.P. 09340, México.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Favela-Torres
mesh_terms: D001230:Aspergillus / Q000201:enzymology / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D013058:Mass Spectrometry; D008660:Metabolism / Q000187:drug effects; D040901:Proteomics / Q000379:methods
chemical_list: D002245:Carbon Dioxide; D005947:Glucose
keywords: Aspergillus brasiliensis; glucose; secretome; solid-state fermentation