Strain improvement of Aspergillus sojae for increased l-leucine aminopeptidase and protease production
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Conventional random mutagenesis was implemented to improve l-leucine aminopeptidase (LAP) and protease production in Aspergillus sojae. Through successive mutagenesis by ethyl methanesulfonate (EMS), UV, and 1-methyl-2-nitro-1-nitrosoguanidine (NTG), EMS25, EU36, and EUN13 mutants from each mutagenesis process were screened using a newly developed quick and easy screening method. The mutant EUN13 exhibited a 9.6-fold increase in LAP [50.61 ± 4.36 U/g-initial dried substrate (IDS)] and a 3.8-fold increase in protease production (13.36 ± 0.31 U/g-IDS) on solid-state fermentation. This mutant showed more frequent branching and higher lap1 mRNA expression as compared to the parent strain SMF 131, which at least in part contributed to the increased LAP and protease production. The mutant EUN13 can be used as a starter organism for diverse industrial soybean fermentation processes for the production of conventional products such as meju, doenjang, and ganjang as well as for the production of new fermented soybean-based sauces.
Keywordsl-leucine aminopeptidase (LAP) Protease Aspergillus sojae Random mutagenesis Soybean fermentation
This study was supported by the World-Class 300 project, and by the Partnership programs of Strengthening technological competency for Small and Medium Enterprise (S2483241) funded by the Ministry of SMEs and Startups (MSS, Korea).
- Abdullah R, Ikram-Ul-Haq I, Iftikhar T, Butt Z, Khattak M. Random mutagenesis for enhanced production of alpha-amylase by Aspergillus oryzae IIB-30. Pak. J. Bot. 45: 269–274 (2013)Google Scholar
- Chien H-CR, Lin L-L, Chao S-H, Chen C-C, Wang W-C, Shaw C-Y, Tsai Y-C, Hu H-Y, Hsu W-H. Purification, characterization, and genetic analysis of a leucine aminopeptidase from Aspergillus sojae. Biochim. Biophys. Acta Gene Struct. Expr. 1576: 119–126 (2002)Google Scholar
- Le Crom S, Schackwitz W, Pennacchio L, Magnuson JK, Culley DE, Collett JR, Martin J, Druzhinina IS, Mathis H, Monot F. Tracking the roots of cellulase hyperproduction by the fungus Trichoderma reesei using massively parallel DNA sequencing. Proc. Natl. Acad. Sci. 106: 16151–16156 (2009)CrossRefGoogle Scholar
- Liu G, Zhang L, Qin Y, Zou G, Li Z, Yan X, Wei X, Chen M, Chen L, Zheng K, Zhang J, Ma L, Li J, Liu R, Xu H, Bao X, Fang X, Wang L, Zhong Y, Liu W, Zheng H, Wang S, Wang C, Xun L, Zhao G-P, Wang T, Zhou Z, Qu Y. Long-term strain improvements accumulate mutations in regulatory elements responsible for hyper-production of cellulolytic enzymes. Sci. Rep. 3: 1–7 (2013)Google Scholar
- Sempio FC. Yondu. Korea Trademark 4,012,227,080,000 (2016)Google Scholar
- Simpson I, Caten C. Recurrent mutation and selection for increased penicillin titre in Aspergillus nidulans. Microbiology 113: 209–217 (1979)Google Scholar
- Wösten HA, Moukha SM, Sietsma JH, Wessels JG. Localization of growth and secretion of proteins in Aspergillus niger. Microbiology 137: 2017–2023 (1991)Google Scholar