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http://dx.doi.org/10.4014/jmb.1610.10013

Characterization of Aspergillus sojae Isolated from Meju, Korean Traditional Fermented Soybean Brick  

Kim, Kyung Min (Department of Bio and Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University)
Lim, Jaeho (Department of Bio and Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University)
Lee, Jae Jung (Sempio Fermentation Research Center, Sempio Foods Company)
Hurh, Byung-Serk (Sempio Fermentation Research Center, Sempio Foods Company)
Lee, Inhyung (Department of Bio and Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University)
Publication Information
Journal of Microbiology and Biotechnology / v.27, no.2, 2017 , pp. 251-261 More about this Journal
Abstract
Initially, we screened 18 Aspergillus sojae-like strains from Aspergillus spp. isolated from meju (Korean traditional fermented soybean brick) according to their morphological characteristics. Because members of Aspergillus section Flavi are often incorrectly identified because of their phylogenetic similarity, we re-identified these strains at the morphological and molecular genetic levels. Fourteen strains were finally identified as A. sojae. The isolates produced protease and ${\alpha}-amylase$ with ranges of 2.66-10.64 and 21.53-106.73 unit/g-initial dry substrate (U/g-IDS), respectively, which were equivalent to those of the koji (starter mold) strains employed to produce Japanese soy sauce. Among the isolates and Japanese koji strains, strains SMF 127 and SMF 131 had the highest leucine aminopeptidase (LAP) activities at 6.00 and 6.06 U/g-IDS, respectively. LAP plays an important role in flavor development because of the production of low-molecular-weight peptides that affect the taste and decrease bitterness. SMF 127 and SMF 131 appeared to be non-aflatoxigenic because of a termination point mutation in aflR and the lack of the polyketide synthase gene found in other A. sojae strains. In addition, SMF 127 and SMF 131 were not cyclopiazonic acid (CPA) producers because of the deletion of maoA, dmaT, and pks/nrps, which are involved in CPA biosynthesis. Therefore, A. sojae strains such as SMF 127 and SMF 131, which have high protease and LAP activities and are free of safety issues, can be considered good starters for soybean fermentations, such as in the production of the Korean fermented soybean products meju, doenjang, and ganjang.
Keywords
Aspergillus sojae; starter mold; soybean fermentation; protease; leucine aminopeptidase;
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1 Cupp-Enyard C. 2008. Sigma's non-specific protease activity assay - casein as a substrate. J. Vis. Exp. 19: e899.
2 Tan PST, Konings WN. 1990. Purification and characterization of an aminopeptidase from Lactococcus lactis subsp. cremoris Wg2. Appl. Environ. Microbiol. 56: 526-532.
3 Lee JH, Jo EH, Hong EJ, Kim KM, Lee I. 2014. Safety evaluation of filamentous fungi isolated from industrial doenjang koji. J. Microbiol. Biotechnol. 24: 1397-1404.   DOI
4 Jorgensen TR. 2007. Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae. J. Food Prot. 70: 2916-2934.   DOI
5 Murakami H. 1971. Classification of the koji mold. J. Gen. Appl. Microbiol. 17: 281-309.   DOI
6 Laforgue R, Guerin L, Pernelle JJ, Monnet C, Dupont J, Bouix M. 2009. Evaluation of PCR-DGGE methodology to monitor fungal communities on grapes. J. Appl. Microbiol. 107: 1208-1218.   DOI
7 Lee C-Z, Liou G-Y, Yuan G-F. 2006. Comparison of the aflR gene sequences of strains in Aspergillus section Flavi. Microbiology 152: 161-170.   DOI
8 Watson AJ, Fuller LJ, Jeenes DJ, Archer DB. 1999. Homologs of aflatoxin biosynthesis genes and sequence of aflR in Aspergillus oryzae and Aspergillus sojae. Appl. Environ. Microbiol. 65: 307-310.
9 Chang P-K, Horn BW, Dorner JW. 2009. Clustered genes involved in cyclopiazonic acid production are next to the aflatoxin biosynthesis gene cluster in Aspergillus flavus. Fungal Genet. Biol. 46: 176-182.   DOI
10 Sardjono, Zhu Y, Knol W. 1998. Comparison of fermentation profiles between lupine and soybean by Aspergillus oryzae and Aspergillus sojae in solid-state culture systems. J. Agric. Food Chem. 46: 3376-3380.   DOI
11 Felsenstein J. 1985. Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39: 783-791.   DOI
12 Tamura K, Stecher G, Peterson D, Filipski A, Kumar S. 2013. MEGA6: molecular evolutionary genetics analysis version 6.0. Mol. Biol. Evol. 30: 2725-2729.   DOI
13 Tominaga M, Lee Y-H, Hayashi R, Suzuki Y, Yamada O, Sakamoto K, et al. 2006. Molecular analysis of an inactive aflatoxin biosynthesis gene cluster in Aspergillus oryzae RIB strains. Appl. Environ. Microbiol. 72: 484-490.   DOI
14 Chang P-K, Bhatnagar D, Cleveland TE, Bennett JW. 1995. Sequence variability in homologs of the aflatoxin pathway gene aflR distinguishes species in Aspergillus section Flavi. Appl. Environ. Microbiol. 61: 40-43.
15 Chang P-K. 2004. Lack of interaction between AFLR and AFLJ contributes to nonaflatoxigenicity of Aspergillus sojae. J. Biotechnol. 107: 245-253.   DOI
16 Sato A, Oshima K, Noguchi H, Ogawa M, Takahashi T, Oguma T, et al. 2011. Draft genome sequencing and comparative analysis of Aspergillus sojae NBRC4239. DNA Res. 18: 165-176.   DOI
17 Nampoothiri KM, Nagy V, Kovacs K, Szakacs G, Pandey A. 2005. L-Leucine aminopeptidase production by filamentous Aspergillus fungi. Lett. Appl. Microbiol. 41: 498-504.   DOI
18 Toldra F, Aristoy M-C, Flores M. 2000. Contribution of muscle aminopeptidases to flavor development in dry-cured ham. Food Res. Int. 33: 181-185.   DOI
19 Kim D-H, Kim S-H, Kwon S-W, Lee J-K, Hong S-B. 2013. Mycoflora of soybeans used for meju fermentation. Mycobiology 41: 100-107.   DOI
20 Buyukkileci AO, Tari C, Fernandez-Lahore M. 2011. Enhanced production of exo-polygalacturonase from agrobased products by Aspergillus sojae. Bioresources 6: 3452-3468.
21 Gurkok S, Cekmecelioglu D, Ogel ZB. 2011. Optimization of culture conditions for Aspergillus sojae expressing an Aspergillus fumigatus ${\alpha}$-galactosidase. Bioresour. Technol. 102: 4925-4929.   DOI
22 Oncu S, Tari C, Unluturk S. 2007. Effect of various process parameters on morphology, rheology, and polygalacturonase production by Aspergillus sojae in a batch bioreactor. Biotechnol. Prog. 23: 836-845.   DOI
23 Kitamoto K. 2002. Molecular biology of the koji molds. Adv. Appl. Microbiol. 51: 129-154.
24 Heerd D, Yegin S, Tari C, Fernandez-Lahore M. 2012. Pectinase enzyme-complex production by Aspergillus spp. in solid-state fermentation: a comparative study. Food Bioprod. Process. 90: 102-110.   DOI
25 Lin C-H, Wei Y-T, Chou C-C. 2006. Enhanced antioxidative activity of soybean koji prepared with various filamentous fungi. Food Microbiol. 23: 628-633.   DOI
26 Murakami H, Hayashi K, Ushijima S. 1982. Useful key characters separating three Aspergillus taxa: A. sojae, A. parasiticus, and A. toxicarius. J. Gen. Appl. Microbiol. 28: 55-60.   DOI
27 Chang P-K, Matsushima K, Takahashi T, Yu J, Abe K, Bhatnagar D, et al. 2007. Understanding nonaflatoxigenicity of Aspergillus sojae: a windfall of aflatoxin biosynthesis research. Appl. Microbiol. Biotechnol. 76: 977-984.   DOI
28 Wicklow DT. 1984. Conidium germination rate in wild and domesticated yellow-green aspergilli. Appl. Environ. Microbiol. 47: 299-300.
29 Chang H-Y, Lee Y-B, Bae H-A, Huh J-Y, Nam S-H, Sohn HS, et al. 2011. Purification and characterisation of Aspergillus sojae naringinase: the production of prunin exhibiting markedly enhanced solubility with in vitro inhibition of HMG-CoA reductase. Food Chem. 124: 234-241.   DOI
30 Klich M, Mullaney E. 1989. Use of a bleomycin-containing medium to distinguish Aspergillus parasiticus from A. sojae. Mycologia 81: 159-160.   DOI
31 Glass NL, Donaldson GC. 1995. Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. Appl. Environ. Microbiol. 61: 1323-1330.
32 Hubka V, Kolarik M. 2012. ${\beta}$-Tubulin paralogue tubC is frequently misidentified as the benA gene in Aspergillus section Nigri taxonomy: primer specificity testing and taxonomic consequences. Persoonia 29: 1.   DOI
33 Peterson SW. 2008. Phylogenetic analysis of Aspergillus species using DNA sequences from four loci. Mycologia 100: 205-226.   DOI
34 Saitou N, Nei M. 1987. The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol. Biol. Evol. 4: 406-425.
35 Godet M, Munaut F. 2010. Molecular strategy for identification in Aspergillus section Flavi. FEMS Microbiol. Lett. 304: 157-168.   DOI
36 Kum S-J, Yang S-O, Lee SM, Chang P-S, Choi YH, Lee JJ, et al. 2015. Effects of Aspergillus species inoculation and their enzymatic activities on the formation of volatile components in fermented soybean paste (doenjang). J. Agric. Food Chem. 63: 1401-1418.   DOI
37 Yuan GF, Liu CS, Chen CC. 1995. Differentiation of Aspergillus parasiticus from Aspergillus sojae by random amplification of polymorphic DNA. Appl. Environ. Microbiol. 61: 2384-2387.
38 Miller GL. 1959. Use of dinitrosalicylic acid reagent for determination of reducing sugar. Anal. Chem. 31: 426-428.   DOI
39 Sahnoun M, Kriaa M, Elgharbi F, Ayadi D-Z, Bejar S, Kammoun R. 2015. Aspergillus oryzae S2 alpha-amylase production under solid state fermentation: optimization of culture conditions. Int. J. Biol. Macromol. 75: 73-80.   DOI