title: Screening and Characterization of Potential Bacillus Starter Cultures for Fermenting Low-Salt Soybean Paste (Doenjang).
abstract: The bacterial strains were screened as potential starters for fermenting low-salt doenjang (a Korean traditional fermented soybean paste) using Korean doenjang based on proteolytic and antipathogenic activities under 6.5-7.5% NaCl conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that they all belonged to the genus Bacillus. Proteolytic and antipathogenic activities against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Aspergillus flavus, as well as fibrinolytic, amylase, and cellulase activities of the 10 strains were quantitatively evaluated. Of these, strains D2-2, JJ-D34, and D12-5 were selected, based on their activities. The functional, phenotypic, and safety-related characteristics of these three strains were additionally investigated and strains D2-2 and D12-5, which lacked antibiotic resistance, were finally selected. Strains D2-2 and D12-5 produced poly-γ-glutamic acid and showed various enzyme activities, including α-glucosidase and β-glucosidase. Growth properties of strains D2-2 and D12-5 included wide temperature and pH ranges, growth in up to 16% NaCl, and weak anaerobic growth, suggesting that they facilitate low-salt doenjang fermentation. Strains D2-2 and D12-5 were not hemolytic, carried no toxin genes, and did not produce biogenic amines. These results suggest that strains D2-2 and D12-5 can serve as appropriate starter cultures for fermenting low-salt doenjang with high quality and safety.
authors.affiliation: Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Hye Hee
authors.initials: HH
authors.lastname: Jeon
authors.affiliation: Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Jung
authors.affiliation: Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Byung-Hee
authors.initials: BH
authors.lastname: Chun
authors.affiliation: Department of Food Science and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea.
authors.forename: Myoung-Dong
authors.initials: MD
authors.lastname: Kim
authors.affiliation: Department of Agrofood Resources, National Institute of Agricultural Sciences, RDA, Wanju-gun 55365, Republic of Korea.
authors.forename: Seong Yeol
authors.initials: SY
authors.lastname: Baek
authors.affiliation: Department of Agrofood Resources, National Institute of Agricultural Sciences, RDA, Wanju-gun 55365, Republic of Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Moon
authors.affiliation: Department of Agrofood Resources, National Institute of Agricultural Sciences, RDA, Wanju-gun 55365, Republic of Korea.
authors.forename: Soo-Hwan
authors.initials: SH
authors.lastname: Yeo
authors.affiliation: Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea.
authors.forename: Che Ok
authors.initials: CO
authors.lastname: Jeon
mesh_terms: D000681:Amylases / Q000096:biosynthesis; D001407:Bacillus / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism; D001679:Biogenic Amines; D019149:Bioreactors; D002480:Cellulase / Q000096:biosynthesis; D005285:Fermentation; D005516:Food Microbiology; D059022:Food Safety; D010802:Phylogeny; D059748:Proteolysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012965:Sodium Chloride / Q000032:analysis*; D045730:Soy Foods / Q000032:analysis / Q000382:microbiology*; D013025:Glycine max / Q000382:microbiology; D000520:alpha-Glucosidases / Q000096:biosynthesis
chemical_list: D001679:Biogenic Amines; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D000681:Amylases; D000520:alpha-Glucosidases; D002480:Cellulase
keywords: Bacillus; Doenjang; antipathogenic activity; fermented soybean paste; protease; starter culture