Heterologous expression and characterisation of the Aspergillus aspartic protease involved in the hydrolysis and decolorisation of red‐pigmented proteins. (31st March 2016)

• Record Type: Journal Article
• Authors: Takenaka, Shinji; Umeda, Mayo; Senba, Hisanori; Koyama, Dai; Tanaka, Kosei; Yoshida, Ken‐ichi; Doi, Mikiharu
• Is Part Of: Journal of the science of food and agriculture. Volume 97:Number 1(2017)
• Page Start: 95
• Page End: 101
• Publication Date: 2016-03-31
• Subjects: Aspergillus repens -- aspartic protease -- decolorisation -- pigmented protein -- katsuobushi -- heterologous expression; Food -- Periodicals; Agriculture -- Periodicals; 664
• DOI: 10.1002/jsfa.7688
• Languages: English
• ISSNs: 0022-5142

Abstract

Abstract: BACKGROUND: Aspergillus repens strain MK82 produces an aspartic protease (PepA_MK82) that efficiently decolorises red‐pigmented proteins during dried bonito fermentation. However, further expansion of the industrial applications of PepA_MK82 requires the high‐level production and efficient preparation of the recombinant enzyme. RESULTS: The genomic DNA and cDNA fragments encoding the protease were cloned from strain MK82 and sequenced. Phylogenetic analysis of PepA_MK82 and comparisons with previously reported fungal aspartic proteases showed that PepA_MK 82 clusters with different groups of these enzymes. Heterologous expression of PepA_MK82 in Pichia pastoris yielded preparations of higher purity than obtained with an Escherichia coli expression system. Total protease activity in a 100‐mL culture of the P. pastoris transformant was 14 times higher than that from an equivalent culture of A. repense MK82. The recombinant PepA_MK82 was easily obtained via acetone precipitation; the final recovery was 83%. PepA_MK82 and its recombinant had similar characteristics in terms of their optimal pH, thermostability, and decolorisation activity. The recombinant was also able to decolorise flaked, dried bonito and to bleach a blood‐stained cloth. CONCLUSION: Given its ability to hydrolyse and decolorise red‐pigmented proteins, recombinant PepA_MK8 can be exploited in the food industry and as a stain‐removal agent in laundry applications. © 2016 Society of Chemical Industry