Abstract
The growing popularity of traditional Korean alcoholic beverages has led to a demand for quality enhancement of the traditional starter culture nuruk, which consists primarily of wheat. Therefore, this study focused on mycoflora characterization and the temporal variations in traditional wheat-based nuruks fermented at two representative traditional temperature conditions for 30 days. Nuruk A was fermented at a constant temperature of 36°C for 30 days and nuruk B was fermented at a high initial temperature of 45°C for 10 days followed by 35°C for 20 days. The average mycoflora load in the two different nuruk conditions did not vary significantly between the 0 and 30 day cultures, and a maximum load of 8.39 log CFU/g was observed for nuruk A on culture day 3 and 7.87 log CFU/g for nuruk B on culture day 30. Within two samples, pH was negatively correlated with temporal changes in mycoflora load. The pH of nuruk A was significantly lower than that of nuruk B at all of the time points evaluated. Culture-dependent characterization led to the identification of 55 fungal isolates belonging to 9 genera and 15 species, with the most prominent genera comprising Lichtheimia, Penicillium, Trametes, Aspergillus, Rhizomucor, and Mucor. A total of 25 yeast isolates were characterized belonging to 6 genera and 7 species, the most prominent among which were Rhodotorula, Pichia, Debaryomyces, Saccharomycopsis, and Torulospora. Mycofloral community dynamics analysis revealed that both samples A and B varied considerably with respect to the fungal communities over a span of 30 days.
Similar content being viewed by others
References
Boekhout, T. and Robert, V. 2003. Yeasts in food: Beneficial and detrimental aspects, Behr, Hamburg, Germany.
Buglass, A.J. (ed.). 2011. Handbook of alcoholic beverages: Technical, analytical and nutritional aspects, Wiley, USA.
Coton, E. and Leguerinel, I. 2014. Ecology of bacteria and fungi in foods, pp. 577–586. In Batt, C.A. and Robinson, R.K. (eds.), Encyclopedia of food microbiology, Elsevier Science, USA.
Degola, F., Berni, E., Dall’Asta, C., Spotti, E., Marchelli, R., Ferrero, I., and Restivo, F.M. 2007. A multiplex RT-PCR approach to detect aflatoxigenic strains of Aspergillus flavus. J. Appl. Microbiol. 103, 409–417.
Díaz, C., Molina, A.M., Nähring, J., and Fischer, R. 2013. Characterization and dynamic behavior of wild yeast during spontaneous wine fermentation in steel tanks and amphorae. Biomed Res. Int. 2013, 13.
Feron, G., Bonnarme, P., and Durand, A. 1996. Prospects for the microbial production of food flavours. Trends Food Sci. Tech. 7, 285–293.
Ho, C.J., Yeo, S.H., Park, J.H., Choi, H.S., Gang, J.E., Kim, S.I., Jeong, S.T., and Kim, S.R. 2013. Isolation of aromatic yeasts (non-Saccharomyces cerevisiae) from Korean traditional nuruks and identification of fermentation characteristics. Agricultural Sciences 4, 136–140.
Im, S.Y., Choi, J.H., Baek, S.Y., Cho, Y.S., Jeong, S.T., Kim, M.D., and Yeo, S.H. 2014. Quality characteristics and establishment of manufacturing process for traditional nuruk. Abstr. P12-015, p. 397. Abstr. 81st Annu. Meet. of Korean Soc. Food Sci. Tech.
King, A.D.Jr., Hocking, A.D., and Pitt, J.I. 1979. Dichloran-rose bengal medium for enumeration and isolation of molds from foods. Appl. Environ. Microbiol. 37, 959–964.
Kurtzman, C.P. 2011. Phylogeny of the ascomycetous yeasts and the renaming of Pichia anomala to Wickerhamomyces anomalus. Antonie van Leeuwenhoek 99, 13–23.
Lee, D.Y., Lee, S.J., Kwak, H.Y., Jung, L., Heo, J., Hong, S., Kim, G.W., and Baek, N.I. 2009. Sterols isolated from nuruk (Rhizopus oryzae ksd-815) inhibit the migration of cancer cells. J. Microbiol. Biotechnol. 19, 1328–1332.
Li, X.R., Ma, E.B., Yan, L.Z., Han Meng, H., Du, X.W., and Quan, Z.X. 2013. Bacterial and fungal diversity in the starter production process of fen liquor, a traditional chinese liquor. J. Microbiol. 51, 430–438.
Park, J.W., Lee, K.H., and Lee, C.Y. 1995. Identification of filamentous molds isolated from Korean traditional nuruk and their amylolytic activities. Korean J. Appl. Microbiol. Bioeng. 23, 737–746.
Ponnusamy, K., Lee, S., and Lee, C.H. 2013. Time-dependent correlation of the microbial community and the metabolomics of traditional barley nuruk starter fermentation. Biosci. Biotechnol. Biochem. 77, 683–690.
Quatrini, P., Marineo, S., Puglia, A., Restuccia, C., Caggia, C., Randazzo, C., Spagna, G., Barbagallo, R., Palmeri, R., and Giudici, P. 2008. Partial sequencing of the β-glucosidase-encoding gene of yeast strains isolated from musts and wines. Ann. Microbiol. 58, 503–508.
Rousk, J., Brookes, P.C., and Bååth, E. 2009. Contrasting soil pH effects on fungal and bacterial growth suggest functional redundancy in carbon mineralization. Appl. Environ. Microbiol. 75, 1589–1596.
Song, S.H., Lee, C., Lee, S., Park, J.M., Lee, H.J., Bai, D.H., Yoon, S.S., Choi, J.B., and Park, Y.S. 2013. Analysis of microflora profile in Korean traditional nuruk. J. Microbiol. Biotechnol. 23, 40–46.
Swangkeaw, J., Vichitphan, S., Butzke, C., and Vichitphan, K. 2009. The characterisation of a novel Pichia anomala β-glucosidase with potentially aroma-enhancing capabilities in wine. Ann. Microbiol. 59, 335–343.
Tamang, J.P. 2012. Plant-based fermented foods and beverages of asia, p. 74. In Hui, Y.H. and Evranuz, E.Ö. (eds.), Handbook of plant-based fermented food and beverage technology, Taylor & Francis, United Kingdom.
Tataridis, P., Kanelis, A., Logotetis, S., and Nerancis, E. 2013. Use of non-Saccharomyces Torulaspora delbrueckii yeast strains in winemaking and brewing. Zb. Matitse Srp. Prir. Nauke. 124, 415–426.
Uchimura, T., Takagi, S., Watanabe, K., and Kozaki, M. 1990. Absidia sp. in the Chinese starter (nuruk) in Korea. J. Brew. Soc. Jpn. 85, 888–894.
Vajzovic, A., Bura, R., Kohlmeier, K., and Doty, S.L. 2012. Novel endophytic yeast Rhodotorula mucilaginosa strain ptd3 ii: Production of xylitol and ethanol in the presence of inhibitors. J. Ind. Microbiol. Biotechnol. 39, 1453–1463.
White, T., Bruns, T., Lee, S., and Taylor, J. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics, pp. 315–322. In Innis, M., Gelfand, D., Shinsky, J., and White, T. (eds.), PCR protocols: A guide to methods and applications, Academic Press, USA.
Yang, S., Lee, J., Kwak, J., Kim, K., Seo, M., and Lee, Y.W. 2011. Fungi associated with the traditional starter cultures used for rice wine in Korea. J. Korean Soc. Appl. Biol. Chem. 54, 933–943.
Yu, T.S., Kim, J., Kim, H.S., Hyun, J.S., Ha, H.P., and Park, M.G. 1998. Bibliographical study on microorganisms of traditional Korean nuruk (since 1945). J. Korean Soc. Food Nutr. 27, 789–799.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bal, J., Yun, SH., Song, HY. et al. Mycoflora dynamics analysis of Korean traditional wheat-based nuruk . J Microbiol. 52, 1025–1029 (2014). https://doi.org/10.1007/s12275-014-4620-0
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12275-014-4620-0