title: Production of Proteolytic Enzymes by a Keratin-Degrading Aspergillus niger.
abstract: A fungal isolate with capability to grow in keratinous substrate as only source of carbon and nitrogen was identified as Aspergillus niger using the sequencing of the ITS region of the rDNA. This strain produced a slightly acid keratinase and an acid protease during cultivation in feather meal. The peak of keratinolytic activity occurred in 48 h and the maximum proteolytic activity in 96 h. These enzymes were partly characterized as serine protease and aspartic protease, respectively. The effects of feather meal concentration and initial pH on enzyme production were evaluated using a central composite design combined with response surface methodology. The optimal conditions were determined as pH 5.0 for protease and 7.8 for keratinase and 20 g/L of feather meal, showing that both models were predictive. Production of keratinases by A. niger is a less-exploited field that might represent a novel and promising biotechnological application for this microorganism.
authors: Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciência de Alimentos (ICTA), Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 9500, 91501-970 Porto Alegre, RS, Brazil.
authors: Fernanda Cortez
authors: FC
authors: Lopes
authors: Lucas André Dedavid E
authors: LA
authors: Silva
authors: Deise Michele
authors: DM
authors: Tichota
authors: Daniel Joner
authors: DJ
authors: Daroit
authors: Renata Voltolini
authors: RV
authors: Velho
authors: Jamile Queiroz
authors: JQ
authors: Pereira
authors: Ana Paula Folmer
authors: AP
authors: Corrêa
authors: Adriano
authors: A
authors: Brandelli