• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.648-660
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• 2014

Doenjang, a traditional Korean fermented soybean paste, is made by mixing and ripening meju with high salt brine (approximately 18%). Meju is a naturally fermented soybean block prepared by soaking, steaming, and molding soybean. To understand living bacterial community migration and the roles of bacteria in the manufacturing process of doenjang, the diversity of culturable bacteria in meju and doenjang was examined using media supplemented with NaCl, and some physiological activities of predominant isolates were determined. Bacilli were the major bacteria involved throughout the entire manufacturing process from meju to doenjang; some of these bacteria might be present as spores during the doenjang ripening process. Bacillus siamensis was the most populous species of the genus, and Bacillus licheniformis exhibited sufficient salt tolerance to maintain its growth during doenjang ripening. Enterococcus faecalis and Enterococcus faecium, the major lactic acid bacteria (LAB) identified in this study, did not continue to grow under high NaCl conditions in doenjang. Enterococci and certain species of coagulase-negative staphylococci (CNS) were the predominant acid-producing bacteria in meju fermentation, whereas Tetragenococcus halophilus and CNS were the major acid-producing bacteria in doenjang fermentation. We conclude that bacilli, LAB, and CNS may be the major bacterial groups involved in meju fermentation and that these bacterial communities undergo a shift toward salt-tolerant bacilli, CNS, and T. halophilus during the doenjang fermentation process.

• Preventive Nutrition and Food Science
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• 제17권3호
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• pp.217-222
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• 2012

This study was carried out to investigate the isolation and characterization of lactic acid bacteria (LAB) from naturally fermented sauce-type kimchi. Sauce-type kimchi was prepared with fresh, chopped ingredients (Korean cabbage, radish, garlic, ginger, green onion, and red pepper). The two isolated bacteria from sauce-type kimchi were identified as Pediococcus pentosaceus and Lactobacillus brevis by 16S rDNA sequencing and tentatively named Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2, respectively. Pediococcus sp. IJ-K1 was isolated from the early and middle fermentation stages of sauce-type kimchi whereas Lactobacillus sp. IJ-K2 was isolated from the late fermentation stage. The resistance of Pediococcus sp. IJ-K1 and Lactobacillus sp. IJ-K2 to artificial gastric and bile acids led to bacterial survival rates that were 100% and 84.21%, respectively.

• 한국미생물·생명공학회지
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• 제34권1호
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• pp.74-77
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• 2006

A lactic acid bacterial strain resistant to several antibiotics such as oxytetracycline, tylosin, neomycin and sulfathiazole, which have been often used as a therapeutic agent in livestock, was isolated from the porcine gastrointestinal tract. The isolate YB-55 was identified as belonging to the genus Pediococcus with the highest similarity to P. pentosaceus on the basis of its 16S rRNA sequence and biochemical properties. The isolated strain showed viability of over 85% at pH 3.0 and was resistant to bile salt. The strain produced lactic acid of 12.3 g/L by jar fermentation and maintained its viability in the presence of antibiotics at dosage related therapeutic effect, suggesting P. pentosaceus YB-55 may of ffr potential as a probiotics for livestock.

• 미생물학회지
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• 제50권3호
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• pp.227-232
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• 2014

본 연구에서는 bacterial cellulose를 생산하는 감귤에서 분리된 Gluconacetobacter sp. gel_SEA623-2를 이용하여 초기 초산농도 및 Lactobacillus plantarum KCCM 80077 유산균을 접종한 mixed culture가 bacterial cellulose 생산성에 미치는 영향을 알아보았다. 0.5%의 초산을 첨가한 mixed culture의 경우 초기 생균수가 $2.4{\times}10^6CFU/ml$에서 14일 동안 배양한 이후에 $1.1{\times}10^7CFU/ml$까지 증가하였고 total acidity가 0.5%의 초산을 첨가한 single culture와 비교하여 0.3% 가량 높게 측정되어 유산균에 의해 추가적으로 젖산이 생성된 것으로 판단된다. Single culture에서는 초기 초산농도가 0.0 및 0.5%일 때 1.0% 농도와 비교하여 상대적으로 높은 bacterial cellulose 생산성을 나타내기는 하였으나 유의적인 차이는 보이지 못하였다. 하지만 mixed culture에서는 0.5%의 초산을 첨가하였을 때 $37.83{\pm}6.81g/L$의 dry weight과 $10.33{\pm}0.58mm$의 thickness를 나타냄으로써 1%의 초산을 첨가한 single culture의 $28.40{\pm}1.23g/L$와 $7.50{\pm}0.50mm$의 생산량과 비교하여 유의적인 차이를 나타내었다(P<0.05).

• 한국식생활문화학회지
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• 제27권6호
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• pp.743-750
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• 2012

A tissue cultured wild ginseng (TCWG) suspension was inoculated with lactic acid bacteria and fermented to improve the functionality of TCWG. The utilization of TCWG was increased directly using the freeze-dried powder. The optimal ratio of TCWG powder and water for fermentation was 1:19 (5%), which was selected by measuring the fluidity and viable cell count according to concentration. The effects on ADH activation and immune cell activation by each ferments with 10 kinds of Lactobacillus sp. strains were examined. The ferments with the Lactobacillus casei KFRI 692 strain showed 5.4 times higher ADH activity and 1.3 times higher ALDH activity than the non-fermented TCWG powder (control). The level of NO production and cytotoxicity was also measured by Raw 264.7 cells. The ferment with the Lac. casei KFRI 692 strain showed the highest level of NO production and lower cytotoxicity than the others. Therefore, the Lac. casei KFRI 692 strain was selected as a strain for fermentation of a TCWG suspension to maximize its functionality. To identify the optimal fermentation time of the selected Lac. casei KFRI 692 strain on the 5% TCWG suspension, the viable cell count of lactic acid bacterial and the changes in pH were observed for 72 hours. 24-hrs was found to be the optimal fermentation time. In this way, fermented TCWG with lactic acid bacteria showed higher ADH activation efficacy and immune cell activation than non-fermented TCWG.

• 한국수산과학회지
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• 제48권5호
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• pp.596-603
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• 2015

This study investigated the effects of adding oyster shell powder (OSP) from Crassostrea gigas on the food quality of Chinese cabbage Kimchi (CCK). We monitored the changes in microbial levels, pH, acidity and sensory evaluation during the fermentation of CCK treated with various contents of OSP. The microbial assay showed that adding OSP to CCK inhibited the growth of viable cells, total coliforms, and lactic acid bacteria, with the greatest growth inhibition against lactic acid bacteria over the fermentation period. After fermentation for 18 days, the lactic acid bacterial counts in CCK treated with OSP (0.3%, 0.5% and 1%) were at least 1 log CFU/g lower than those of control CCK. In addition, the pH and acidity of CCK treated with OSP were lower than in control CCK over the fermentation period. The overall sensory evaluation of CCK with 0.3% OSP was better than that of control CCK after fermentation for 24 days. In conclusion, OSP treatment, especially 0.3% OSP, enhances the food quality and extends the self-life of CCK, while minimizing the detrimental effects on its sensory characteristics.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.220-233
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• 2019

Bacterial lysates have become a common ingredient for natural health care. Lactic acid bacteria (LAB) could serve as potential candidates for lysate production: the lactic acids produced by LAB have been utilized for their moisturizing, antimicrobial, and rejuvenating effects, while other substances provide topical benefits and health effects for the skin. Our study aimed to obtain lysate from a LAB S. macedonicus MBF 10-2 through an optimized fermentation using the Response Surface Methodology. Strain MBF10-2 was cultivated in a 2L fermenter tank in de Man Rogosa and Sharpe (MRS) medium and in plant-based peptone modified MRS, i.e. Soy-peptone and Vegitone. The duration and the medium composition (dextrose and soy peptone or proteose peptone) were adjusted to obtain an optimum production of cell lysate. Central Composite Design was employed for Design Expert 7.0.0 by adjusting 3 factors: dextrose (1%, 1.5%, 2%, 2.5%, 3%), soy or proteose peptone (0.5%, 0.75%, 1%, 1.25% and 1.5%), and duration of fermentation (8, 10, 12 14, and 16 h for MRS-Soy peptone and 15, 17, 19, 21, and 23 h for MRS Vegitone). Bacteriocin-Like Inhibitor Substance activity of lysate and pH were used as indicators. The optimum condition for lysate production using MRS Soy Peptone and Vegitone are as follows: dextrose concentration 2.5%, plant-based peptone 1.25%, while optimum fermentation duration were 11.18 h (MRS Soy Peptone) and 17 h (MRS Vegitone) with a starter concentration of 10% at $OD_{600nm}$ $0.2{\pm}0.05$. However, the standard MRS medium produced better quality lysate compared to MRS plant-based peptones.

• 한국생활과학회지
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• 제20권6호
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• pp.1213-1222
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• 2011

This research evaluated antibacterial and growth inhibition effects on three kinds of lactic acid bacteria and five kinds of food poisoning bacteria using Backryencho powder, hot water, 70% ethanol, and 95% ethanol extracts. Antibacterial activity was shown against Leu. mensenteroides for 8 and 10 mg/disc of the 95% ethanol extract solution and strong proliferation inhibition effects were displayed against B. subtilis, Stap. aureus, E. coli, and S. typhimurium. High antibacterial activity according to certain clear zone formations was shown especially for the 10 mg/disc. A 3% concentration of the 95% ethanol extract showed high growth inhibition effects against lactic acid bacteria, L. brevis, L. plantarum, and Leu. mesenteroids. The measurement of viable cell counts of S. aureus, E. coli, B. subtilis, and S. typhimurium indicated suppression effects by the 3% concentration of the 95% ethanol extract, at 49.60%, 41.54%, 35.95%, 28.82%, and 26.60% respectively. The antibacterial activities of the hot water, 70% ethanol, 95% ethanol extract of Backryencho against food poisoning bacteria and Kimchi fermentation lactic acid bacteria were confirmed through various methods of antibiotic measurement. Based on these results, Backryencho extract is considered a good source for a range of applications as a natural anti-bacterial agent for the storage ability of Kimchi and as a possible food preservative.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.76-84
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• 2013

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at $4^{\circ}C$ and $10^{\circ}C$. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at $4^{\circ}C$. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at $4^{\circ}C$ and $10^{\circ}C$. Lc. gelidum was detected as the dominant LAB at $4^{\circ}C$ in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At $4^{\circ}C$, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased.

• 한국식품과학회지
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• 제37권2호
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• pp.241-246
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• 2005

동치미의 저장기간을 연장할 목적으로 항균력을 갖는 허브를 동치미에 첨가하였을 때에 허브가 동치미의 젖산발효 및 품질특성에 미치는 효과가 조사되었다. 8종의 서양 및 자생 허브 중에서 marta rosemary가 7종의 젖산균에 대해서 우수한 항균 활성을 보였으며 허브향을 내는 삼백초와 pepper mint, 감미를 갖는 stevia도 균주에 따라 약간의 항균작용을 나타내었다. 향신료는 젖산균의 생육을 억제하지 못하였다 .상기 4종의 허브와 3종의 젖산균을 스타터로 사용하여 동치미를 $25^{\circ}C$에서 6일 동안 담금한 바, 허브 무첨가구와 삼백초, stevia, pepper mint 허브 첨가구의 동치미 액은 담금 직후부터 pH가 급감하여 12시간에 pH 4 부근에 도달하고 그 후 점차 감소하여 pH 3.60-3.35 범위를 유지하였다. Marta rosemary를 첨가한 동치미 액의 pH는 초기에는 pH 6.06까지 증가하다가 36시간 이후 감소하여 6일까지 동치미 최적 pH범위인 3.8-4.2 이상을 유지하였다. 따라서 marta rosemary의 첨가는 젖산균의 초기발효를 진행시키고 그 후 유산균을 적절하게 억제하여 유기산의 과다생성을 방지하므로 동치미의 가식기간을 크게 연장시키는 것이 가능한 것으로 판단되었다.