• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.577-583
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• 2014

In this study, we evaluated fermentation characteristics of microorganism with antimicrobial activity in makgeolli made from various kinds of koji and nuruk during fermentation. The pH of nuruk groups decreased compared to the koji groups after 3 days of fermentation. Acidity and alcohol contents of nuruk groups significantly increased compared to the koji groups. The total sugar contents of the koji groups were significantly higher than those of the nuruk groups after 15 days of fermentation. Sensory scores of koji groups (DKB) were higher than those of other samples. Antimicrobial activities of nuruk group (GND and ANF) against Salmonella enterica, Bacillus subtilis, Escherichia coli, and Bacillus cereus were significantly higher compared to the koji group. ST-1, isolated from (Geumjeonggu nuruk D), showed the highest antimicrobial activity and was identified as Paenibacillus polymyxa strain RCP6 based on 16S rRNA sequencing. Our result suggest that Paenibacillus polymyxa from nuruk group produces a bacteriocin-like substrate with antimicrobial activity.

• Journal of Life Science
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• v.18 no.2
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• pp.287-290
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• 2008

In order to obtain yeast cells producing a bacteriocin, Subpeptin JM4-A or Subpeptin JM4-B, the 48 bp oligonucleotides corresponding to Subpeptin JM4-A and Subpeptin JM4-B genes including codon for start and stop were chemically synthesized and cloned into pAUR123, an yeast expression vector. Transformed yeast cells exhibited growth inhibition of Bacillus subtilis, Escherichia coli and Pseudonomas aeruginosa. This result indicates that yeast cells producing Subpeptin JM4-A or Subpeptin JM4-B possess bacteriocidal properties against both Gram positive B. subtilis and Gram negative E. coli and P. aeruginosa cells. The recombinant yeast strains constructed in this study can be applied in the food preservative or. animal foodfeed.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.101-105
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• 2008

In order to obtain yeast cells producing a bacteriocin OR-7, the 180 bp polynucleotide corresponding to the OR-7 gene including codons for start and stop was chemically synthesized and cloned into pAUR123, an yeast expression vector. Transformed yeast cells exhibited growth inhibition of Bacillus subtilis, Campylobacter jeuni, Escherichia coli and Pseudomonas aeruginosa. This result indicates that yeast cells producing OR-7 possess bacteriocidal properties against both Gram positive B. subtilis and Gram negative C. jejuni, E. coli and P. aeruginosa cells. The recombinant yeast strain constructed in this study can be applied in the food preservative or animal feed.

• Food Engineering Progress
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• v.13 no.1
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• pp.64-69
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• 2009

From the 25 fresh fruits and vegetable products, 1,250 isolates grown on MRS agar media were screened for the inhibitory activity on the growth of Escherichia coli 0157:H7, Listeria monocytogenes, and Bacillus cereus as well as Lactobacillus plantarum, L. casei, and Lactococcus lactis subsp. lactis. Among them, 607 isolates (49% of total isolates) from 23 different foods produced growth inhibitory activity on the E. coli 0157:H7, L. monocytogenes, or B. cereus. When these isolates were screened for the inhibitory activity on the growth of L. plantarum, L. casei, and Lactococcus lactis subsp., 24 isolates (3% of total isolates) from 7 food samples showed bacteriocin-like activity. These isolates had typical physiological characteristics of lactic acid bacteria, which indicated these isolates were strains of lactic acid bacteria. The inhibitor from 3 out of 24 revealed as nicin. From the RAPD-PCR profiles, 24 strains was classified and it was also indicated that most of the strains isolated from same produce showed similar phylogenetic profile.

• Journal of Microbiology
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• v.39 no.2
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• pp.146-148
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• 2001

Lactobacillus crispatus ATCC 33820 and L. gasseri ATCC 33323 were grown in MRS broth (pH 6.5) at 37$^{\circ}C$ for 24 h and the antibacterial activities of cell free culture supernatants were determined by the agar well diffusion method. The culture supernatants were inhibitory to Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Pediococcus acidilacticii, and Lactobacillus helveticus. The supernatants did not show any lysozyme activity. Addition of catalase did not affect the antibacterial activities of the supernatants. The antibacterial substances were heat stable (100$^{\circ}C$ for 60 min) and sensitive to proteases.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.666-670
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• 2021

Paenibacillus konkukensis sp. nov., SK3146 is a novel strain isolated from a pig feed. Here, we present complete genome sequence of SK3146. The genome consists of a single circular genome measuring 7,968,964 bp in size with an average guanine + cytosine (G+C) content of 53.4%. Genomic annotation revealed that the strain encodes 151 proteins related to hydrolases (EC3), which was higher than those in Bacillus subtilis and Escherichia coli. Diverse kinds of hydrolases including galactosidase, glucosidase, cellulase, lipase, xylanase, and protease were found in the genome of SK3146, coupled with one bacteriocin encoding gene. The complete genome sequence of P. konkukensis SK3146 indicates the immense probiotic potential of the strain with nutrient digestibility and antimicrobial activity functions.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.9-18
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• 2016

Two Bacillus strains, CJW15 and SSD8, with strong antibacterial activities were isolated from cheonggukjang. Both were identified as B. amyloliquefaciens strains after gene sequencing of rRNA and recA. CJW15 strongly inhibited the growth of B. cereus (ATCC14579), Listeria monocytogenes (ATCC19111), and Lactococcus lactis (ATCC11454). In comparison, SSD8 inhibited the growth of B. cereus (ATCC14579) and Enterococcus faecium (ATCC19953). The antibacterial activities of the two strains were not affected when exposed to a temperature of $100^{\circ}C$ for 15 min and were quite stable in acidic (pH 3) and alkaline (pH 12) pH conditions. Enzymatic treatments (trypsin, pepsin, proteinase K, and protease) had no effect on the activity of CJW15, but reduced the activity of SSD8 by half. Both isolates possess genes involved in the synthesis of lipopeptides (e.g. surfactin, fengycin, iturin, and iturin A), and genes encoding subtilin, a bacteriocin. Moreover, both isolates have fibrinolytic activities as well.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.84-97
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• 2016

Isolates from Korean fermented soybean paste were identified as Enterococcus faecium SBP12, Pediococcus halophilus SBP20, Lactobacillus fermentum SBP33, Leuconostoc mesenteroides SBP37, Pediococcus pentosaceus SBP41, Lactobacillus brevis SBP49, Lactobacillus acidophilus SBP55, and Enterococcus faecalis SBP58 according to conventional morphological and biochemical characteristics, carbohydrate fermentation profiling, and 16S rRNA sequence comparison. Strain SBP20, SBP33, SBP49, and SBP55 showed very resistance to simulated gastric and intestinal juices with final populations exceeding 6 log CFU/ml, whereas cells of SBP12 and SBP58 after exposure to low pH were dramatically decreased within 2 h. Among 4 strains having good tolerance to gastrointestinal conditions, the high adhesive ability to HT-29 cells, antibiotic resistance, and antimicrobial activity against food-borne pathogens Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 were observed with SBP49 and SBP55, therefore, these two strains were confirmed as putative probiotic candidates. There was no significant difference between the sourdoughs fermented with SBP49 and SBP55 with respect to the values of pH, total titratable acidity, and viable cell count. During sourdough fermentation, SBP49 strain produced significantly greater amounts of lactic acid than SBP55 strain, which secreted large quantities of hydrogen peroxide. SBP49 and SBP55 strains producing the antimicrobial substances such as lactic acid, hydrogen peroxide, and bacteriocin effectively inhibited B. cereus and S. aureus inoculated in the sourdough.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.903-911
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• 2011

In this study, Bacillus polyfermenticus CJ6 harboring antibacterial activity was isolated from meju. The antibacterial activity of Bacillus polyfermenticus CJ6 was stable in the pH range of 3.0~9.0, but it disappeared after culture at $70^{\circ}C$ for 24 hr. Antibacterial activity was inactivated by proteinase K, protease, and ${\alpha}$-chymotrypsin, indicating its proteinaceous nature. The growth inhibitory effects of B. polyfermenticus CJ6 culture on food-borne pathogens such as Staphylococcus aureus, Salmonella Typhi, Listeria monocytogenes, and Escherichia coli O157:H7 were examined in this study. Approximately 6~6.2 log CFU/mL of each pathogen was co-cultured with B. polyfermenticus CJ6 in a 50 mL culture volume for 24 hr. Growth of S. aureus and L. monocytogenes was completely inhibited after 3 hr of incubation. Growth of S. Typhi and E. coli O157:H7 was also completely inhibited after 6 hr of incubation. The antibacterial compounds from B. polyfermenticus CJ6 were purified by solid phase extraction (C18 Sep-pak cartridge), recycling preparative HPLC, and analytical HPLC. Ultra-high performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compounds, which were confirmed to be five peptides (757.4153 Da, 750.3444 Da, 1024.5282 Da, 1123.6083 Da, and 1617.8170 Da).

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.815-822
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• 2005

In order to extend the shelf-life of packaged or coated foods, an antibacterial edible film was developed from soybean meal that had been fermented with Bacillus subtilis under the optimum condition of pH 7.0-7.5 and $33^{\circ}C$ for 33 h. The water vapor permeability of the fermented film ($86.0 mg/cm^2{\cdot}h$) was higher than those of normal soybean films ($66.9 mg/cm^2{\cdot}h$). Protein solubility of the fermented film was also higher than ordinary soy protein film at the pH range of 3 -10. The fermented soybean film had higher tensile strength and lower $\%$ elongation (elongation rate) than the ordinary soybean film, mainly because partial hydrolysis of proteins in the soybean film occurred during fermentation. Antimicrobial properties of the fermented film on foodstuffs were measured by placing the films on surime, jerked beef, and mashed sausage media; containing $10^2-10^3$ CFU/plate of foodborne pathogenic bacteria, and showed significantly higher inhibitory effects on the growths of all the indicating bacteria. The film could be used as a packaging material in the food industry. However, before direct application of the fermented film to the commercial food industry, its poor mechanical and antibacterial properties need to be improved.