title: Culture-based and denaturing gradient gel electrophoresis analysis of the bacterial community from Chungkookjang, a traditional Korean fermented soybean food.
abstract: The bacterial community of Chungkookjang and raw rice-straw collected from various areas in South Korea was investigated using both culture-dependent and culture-independent methods. Pure cultures were isolated from Chungkookjang and raw rice-straw on tryptic soy agar plates with 72 to 121 colonies and identified by 16S rDNA gene sequence analysis, respectively. The traditional culture-based method and denaturing gradient gel electrophoresis analysis of PCR-amplified 16S rDNA confirmed that Pantoea agglomerans and B. subtilis were identified as predominant in the raw rice-straw and Chungkookjang, respectively, from Iljuk district of Gyeonggi province, P. ananatis and B. licheniformis were identified as predominant in the raw rice-straw and Chungkookjang from Wonju district of Gangwon province, and Microbacterium sp. and B. licheniformis were identified as predominant in the raw rice-straw and Chungkookjang from Sunchang district of Jeolla province. Other strains, such as Bacillus, Enterococcus, Pseudomonas, Rhodococcus, and uncultured bacteria were also present in raw rice-straw and Chungkookjang.
  
  
  CONCLUSIONS
  A comprehensive analysis of these microorganisms would provide a more detailed understanding of the biologically active components of Chungkookjang and help improve its quality. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis can be successfully applied to a fermented food to detect unculturable or more species than the culture-dependent method. This technique is an effective and convenient culture-independent method for studying the bacterial community in Chungkookjang. In this study, the bacterial community of Chungkookjang collected from various areas in South Korea was investigated using both culture-dependent and culture-independent methods.
authors.affiliation: Division of Biological Science and Technology, Yonsei University, Wonju, Gangwon 220-710, Republic of Korea.
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Hong
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Kun Sub
authors.initials: KS
authors.lastname: Chung
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis / Q000379:methods*; D005285:Fermentation; D007529:Isoflavones / Q000378:metabolism*; D012275:Oryza / Q000382:microbiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D056910:Republic of Korea; D017422:Sequence Analysis, DNA; D030262:Soybean Proteins / Q000378:metabolism*; D013025:Glycine max / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D007529:Isoflavones; D012336:RNA, Ribosomal, 16S; D030262:Soybean Proteins; C525760:chungkookjang