Identification of the Predominant Bacillus, Enterococcus, and Staphylococcus Species in Meju, a Spontaneously Fermented Soybean Product

메주 발효 관련 Bacillus, Enterococcus, Staphylococcus 속 우점종 확인

  • Jang, Mihyun (Department of Food Science and Biotechnology, Kyonggi University) ;
  • Jeong, Do-Won (Department of Food and Nutrition, Dongduk Women's University) ;
  • Lee, Jong-Hoon (Department of Food Science and Biotechnology, Kyonggi University)
  • 장미현 (경기대학교 식품생물공학과) ;
  • 정도원 (동덕여자대학교 식품영양학과) ;
  • 이종훈 (경기대학교 식품생물공학과)
  • Received : 2019.02.08
  • Accepted : 2019.02.25
  • Published : 2019.09.28


Meju is a spontaneously fermented soybean product produced in Korea. We isolated the bacteria of the genera Bacillus, Enterococcus, and Staphylococcus from 12 meju samples collected from five regions of Korea using selective media, and we identified them based on the sequence analysis of 16S ribosomal RNA and gmk (guanylate kinase) genes. Bacillus and Enterococcus strains were identified from all samples and the numbers of Bacillus strains in the 11 samples were >15% of the total cell number. Therefore, the genus Bacillus was confirmed as the predominant bacterial group of meju. Staphylococcus strains were identified from six samples. The identified 151 Bacillus isolates predominated in the following order: B. velezensis, B. sonorensis, B. subtilis, and B. licheniformis. Among the 165 Enterococcus isolates, 163 strains were identified as E. faecium. Eighty-two Staphylococcus isolates were classified into six species of coagulase-negative Staphylococcus group and S. xylosus was the predominant species.


Meju;Bacillus velezensis;Bacillus sonorensis;Enterococcus faecium;Staphylococcus xylosus


Supported by : National Research Foundation of Korea (NRF), Kyonggi University


  1. Choi KK, Cui CB, Ham SS, Lee DS. 2003. Isolation, identification and growth characteristics of main strain related to meju fermentation. J. Korean Soc. Food Sci. Nutr. 32: 818-824.
  2. Kang MJ, Kim SH, Joo HK, Lee GS, Yim MH. 2000. Isolation and identification of microorganisms producing the soy proteinhydrolyzing enzyme from traditional mejus. J. Korean Soc. Agric. Chem. Biotechnol. 43: 86-94.
  3. Kwon OJ, Kim JK, Chung YK. 1986. The characteristics of bacteria isolated from ordinary Korean soy sauce and soybean paste. J. Korean Agri. Chem. Soc. 29: 422-428.
  4. Yoo SK, Cho WH, Kang SM, Lee SH. 1999. Isolation and identification of microorganisms in Korean traditional soybean paste and soybean sauce. Korean J. Appl. Microbiol. Biotechnol. 27: 113-117.
  5. Cho KM, Seo WT. 2007. Bacterial diversity in Korean traditional soybean fermented foods (doenjang and ganjang) by 16S rRNA gene sequence analysis. Food Sci. Biotechnol. 16: 320-324.
  6. Jeong DW, Kim HR, Jung G, Han S, Kim CT, Lee JH. 2014. Bacterial community migration in the ripening of doenjang, a traditional Korean fermented soybean food. J. Microbiol. Biotechnol. 24: 648-660.
  7. Jung JY, Lee SH, Jeon CO. 2014. Microbial community dynamics during fermentation of doenjang-meju, traditional Korean fermented soybean. Int. J. Food Microbiol. 185: 112-120.
  8. Jung WY, Jung JY, Lee HJ, Jeon CO. 2016. Functional characterization of bacterial communities responsible for fermentation of doenjang: a traditional Korean fermented soybean paste. Front. Microbiol. 7: 827.
  9. Kim TW, Lee JH, Kim SE, Park MH, Chang HC, Kim HY. 2009. Analysis of microbial communities in doenjang, a Korean fermented soybean paste, using nested PCR-denaturing gradient gel electrophoresis. Int. J. Food Microbiol. 131: 265-271.
  10. Shin D, Jeong D. 2015. Korean traditional fermented soybean products: Jang. J. Ethnic Foods 2: 2-7.
  11. Park KY, Hwang KM, Jung KO, Lee KB. 2002. Studies on the standardization of doenjang (Korean soybean paste). J. Korean Soc. Food Sci. Nutr. 31: 343-350.
  12. Kim YS, Jeong DY, Hwang YT, Uhm TB. 2011. Bacterial community profiling during the manufacturing process of traditional soybean paste by pyrosequencing method. Korean J. Microbiol. 47: 275-280.
  13. Kim YS, Kim MC, Kwon SW, Kim SJ, Park IC, Ka JO, et al. 2011. Analyses of bacterial communities in meju, a Korean traditional fermented soybean bricks, by cultivation-based and pyrosequencing methods. J. Microbiol. 49: 340-348.
  14. Lee JH, Kim TW, Lee H, Chang HC, Kim HY. 2010. Determination of microbial diversity in meju, fermented, cooked soya beans, using nested PCR-denaturing gradient gel electrophoresis. Lett. Appl. Microbiol. 51: 388-394.
  15. Lee SY, Kim HY, Lee S, Lee JM, Muthaiya MJ, Kim BS, et al. 2012. Mass spectrometry-based metabolite profiling and bacterial diversity characterization of Korean traditional meju during fermentation. J. Microbiol. Biotechnol. 22: 1523-1531.
  16. Nam YD, Lee SY, Lim SI. 2012. Microbial community analysis of Korean soybean pastes by next-generation sequencing. Int. J. Food Microbiol. 155: 36-42.
  17. Chang M, Chang HC. 2007. Characteristics of bacterial-koji and doenjang (soybean paste) made by using Bacillus subtilis DJI. Korean J. Microbiol. Biotechnol. 35: 325-333.
  18. Cho MJ, Shim JM, Lee JY, Lee KW, Yao Z, Liu X, et al. 2016. Properties of meju fermented with multiple starters. Microbiol. Biotechnol. Lett. 44: 109-116.
  19. Hong Y, Jung HJ, Han SK, Kim HY. 2016. Potentiality of Bacillus amyloliquefaciens KFCC11574P isolated from Korean traditional doenjang as a starter in the production of functional soya bean paste. Int. J. Food Sci. Technol. 51: 105-113.
  20. Ji WD, Yang SH, Choi MR, Kim JK. 1995. Volatile components of Korean soybean paste produced by Bacillus subtilis PM3. J. Microbiol. Biotechnol. 5: 143-148.
  21. Lee KH, Choi HS, Hwang KA, Song J. 2016. Quality changes in doenjang upon fermentation with two different Bacillus subtilis strains. J. East Asian Soc. Diet. Life 26: 163-170.
  22. Yoo SK, Kang SM, Noh YS. 2000. Quality properties on soy bean pastes made with microorganisms isolated from traditional soy bean paste. Korean J. Food Sci. Technol. 32: 1266-1270.
  23. Dunlap CA, Kwon SW, Rooney AP, Kim SJ. 2015. Bacillus paralicheniformis sp. nov., isolated from fermented soybean paste. Int. J. Syst. Evol. Microbiol. 65: 3487-3492.
  24. Dunlap CA, Kim SJ, Kwon SW, Rooney AP. 2016. Bacillus velezensis is not a later heterotypic synonym of Bacillus amyloliquefaciens; Bacillus methylotrophicus, Bacillus amyloliquefaciens subsp. plantarum and 'Bacillus oryzicola' are later heterotypic synonyms of Bacillus velezensis based on phylogenomics. Int. J. Syst. Evol. Microbiol. 66: 1212-1217.
  25. Fan B, Blom J, Klenk HP, Borriss R. 2017. Bacillus amyloliquefaciens, Bacillus velezensis, and Bacillus siamensis form an "Operational Group B. amyloliquefaciens" within the B. subtilis species complex. Front. Microbiol. 8: 22.
  26. Lane DJ. 1991. 16S-23S rRNA sequencing, pp. 115-175. In Stackebrandt E, Goodfellow M (eds.), Nucleic Acid Techniques in Bacterial Systematics. Wiley, New York.
  27. Madhaiyan M, Poonguzhali S, Kwon SW, Sa TM. 2010. Bacillus methylotrophicus sp. nov., a methanol-utilizing, plant-growth-promoting bacterium isolated from rice rhizosphere soil. Int. J. Syst. Evol. Microbiol. 60: 2490-2495.
  28. Pal misano MM, Nakamura LK, Duncan KE, Istock CA, Cohan FM. 2001. Bacillus sonorensis sp. nov., a close relative of Bacillus licheniformis, isolated from soil in the Sonoran Desert, Arizona. Int. J. Syst. Evol. Microbiol. 51: 1671-1679.
  29. Jeong DW, Lee B, Lee H, Jeong K, Jang M, Lee JH. 2018. Urease characteristics and phylogenetic status of Bacillus paralicheniformis. J. Microbiol. Biotechnol. 28: 1992-1998.
  30. Resch M, Nagel V, Hertel C. 2008. Antibiotic resistance of coagulase-negative staphylococci associated with food and used in starter cultures. Int. J. Food Microbiol. 127: 99-104.