title: Culture conditions dictate protease and tannase production in submerged and solid-state cultures of Aspergillus niger Aa-20.
abstract: Undesirable protease production by Aspergillus niger Aa-20 in submerged culture and solid-state culture was evaluated using different concentrations of tannic acid as sole carbon source in a model system designed for tannase production. Protease production was found to be dependent on the culture system used (submerged culture or solid-state culture) and on the initial tannic acid concentration. Expression of protease activity in submerged culture was higher (up to 10 times) than activity obtained in solid-state culture, using identical culture medium composition. In submerged culture, the lowest final protease activity (0.13 IU) was obtained with the highest tannic acid concentration, while in solid-state culture protease activity was not affected by changes in initial substrate concentration. Absence of detectable proteolytic activity in solid-state culture is related to high production of tannase enzyme. Hence, the use of solid-state culture for fungal enzyme production may allow for higher and more stable enzyme titers present in culture extracts.
authors.affiliation: Food Research Department, Faculty of Chemical Sciences, Universidad Autónoma de Coahuila, Unidad Saltillo, México.
authors.forename: Cristóbal Noé
authors.initials: CN
authors.lastname: Aguilar
authors.forename: Ernesto
authors.initials: E
authors.lastname: Favela-Torres
authors.forename: Gustavo
authors.initials: G
authors.lastname: Viniegra-González
authors.forename: Christopher
authors.initials: C
authors.lastname: Augur
mesh_terms: D001234:Aspergillus niger / Q000187:drug effects / Q000201:enzymology*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002265:Carboxylic Ester Hydrolases / Q000096:biosynthesis*; D003470:Culture Media; D010450:Endopeptidases / Q000096:biosynthesis* / Q000378:metabolism; D004795:Enzyme Stability; D047348:Hydrolyzable Tannins / Q000378:metabolism* / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D013997:Time Factors
chemical_list: D003470:Culture Media; D047348:Hydrolyzable Tannins; D011480:Protease Inhibitors; D002265:Carboxylic Ester Hydrolases; C022711:tannase; D010450:Endopeptidases