Production, purification and characterization of an aspartic protease from Aspergillus foetidus. (November 2017)

• Record Type: Journal Article
• Authors: Souza, Paula Monteiro; Werneck, Gabriela; Aliakbarian, Bahar; Siqueira, Felix; Ferreira Filho, Edivaldo Ximenes; Perego, Patrizia; Converti, Attilio; Magalhães, Pérola Oliveira; Junior, Adalberto Pessoa
• Is Part Of: Food and chemical toxicology. Volume 109:Part 2(2017)
• Page Start: 1103
• Page End: 1110
• Publication Date: 2017-11
• Subjects: Acid protease -- Aspergillus foetidus -- Purification -- Submerged fermentation; Toxicology -- Periodicals; Food poisoning -- Periodicals; Food Poisoning -- Periodicals; Toxicology -- Periodicals; Toxicologie -- Périodiques; Intoxications alimentaires -- Périodiques; Food poisoning; Toxicology; Periodicals; Electronic journals; 615.9
• DOI: 10.1016/j.fct.2017.03.055
• Languages: English
• ISSNs: 0278-6915

Abstract

Abstract: An acidic thermostable protease was extracellularly produced either in shake flask or in stirred tank bioreactor by an Aspergillus foetidus strain isolated from the Brazilian savanna soil using different nitrogen sources. Its maximum activity (63.7 U mL -1 ) was obtained in a medium containing 2% (w/v) peptone. A cultivation carried out in a 5.0 L stirred-tank bioreactor provided a maximum protease activity 9% lower than that observed in Erlenmeyer flasks, which was obtained after a significantly shorter (by 16–29%) time. Protease purification by a combination of gel-filtration chromatography resulted in a 16.9-fold increase in specific activity (248.1 U g -1 ). The estimated molecular weight of the purified enzyme was 50.6 kDa, and the optimal pH and temperature were 5.0 and 55 °C, respectively. The enzyme was completely inhibited by pepstatin A, and its activity enhanced by some metals. According to the inhibition profiles, it was confirmed that the purified acid protease belongs to the aspartic protease type. These results are quite promising for future development of large-scale production of such protease, which can be useful in biotechnological applications requiring high enzyme activity and stability under acidic conditions. Highlights: Novel thermostable aspartic protease was purified from Aspergillus foetidus strain. Enzyme production was observed on different nitrogen source. Maximum protease activity in lab-scale bioreactor is 55.8 U/mL. The 50.6 kDa protease presented optimal catalytic activity at pH 5.0 and 55 °C. This acid protease may find food industry applications.