• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.810-817
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• 2009

The effect of cryoprotectants (maltodextrin+glycerol) and cryoprotectants+antioxidant [ascorbic acid and/or butylated hydroxytoluene (BHT)] mixtures on the survival, electrolyte leakage, and lipid degradation of freeze-dried Weissella paramesenteroides LC11 during storage was investigated and compared with that of the control (cells without additives) over a 90-day storage period at 4 or $20^{\circ}C$ in glass tubes with water activity ($a_w$) of 0.23. The survival, electrolyte leakage, and lipid degradation were evaluated through colony counts, electrical conductivity, and thiobarbituric acid reactive substances (TBARS) content, respectively. The fatty acids composition was determined by gas chromatography, in both the total lipid extract and the polar lipid fraction, and compared with that of the control after the 90-day storage period. As the storage proceeded, increases in leakage value and TBARS content, as well as a decrease in viability, were observed. After 90 days of storage, the major fatty acids found in both the total lipid extract and the polar lipid fraction were palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids. The survival, leakage value, TBARS content and 18:2/16:0 or 18:3/16:0 ratio were the greatest for the protected strain held at $4^{\circ}C$. Cells with the cryoprotectants+BHT mixture showed the highest percentage of survival and 18:2/16:0 or 18:3/16:0 ratio in both lipid extracts, as well as the lowest leakage value and TBARS content after the 90-day storage period. Drying cells with the cryoprotectants+BHT mixture considerably slowed down polar lipid degradation and loss of membrane integrity, resulting in improved viability during storage.

• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.585-591
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• 2014

To evaluate the potential utility of pretreatment of raw biomass with a complex microbial system, we investigated the degradation of rice straw by BMC-9, a lignocellulose decomposition strain obtained from a biogas slurry compost environment. The degradation characteristics and corresponding changes in the bacterial community were assessed. The results showed that rapid degradation occurred from day 0 to day 9, with a peak total biomass bacterium concentration of $3.3{\times}10^8$ copies/ml on day 1. The pH of the fermentation broth declined initially and then increased, and the mass of rice straw decreased steadily. The highest concentrations of volatile fatty acid contents (0.291 mg/l lactic acid, 0.31 mg/l formic acid, 1.93 mg/l acetic acid, and 0.73 mg/l propionic acid) as well as the highest xylanse activity (1.79 U/ml) and carboxymethyl cellulase activity (0.37 U/ml) occurred on day 9. The greatest diversity among the microbial community also occurred on day 9, with the presence of bacteria belonging to Clostridium sp., Bacillus sp., and Geobacillus sp. Together, our results indicate that BMC-9 has a strong ability to rapidly degrade the lignocelluloses of rice straw under relatively inexpensive conditions, and the optimum fermentation time is 9 days.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1532-1536
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• 2015

To investigate the memory-enhancing effect of lactic acid bacteria, we selected the probiotic mixture KF, which consisted of Lactobacillus plantarum KY1032 and Lactobacillus curvatus HY7601 (1 × 10¹¹ CFU/g of each strain), and investigated its antilipidemic and memoryenhancing effects in aged Fischer 344 rats. KF (1 × 10¹⁰ CFU/rat/day), which was administered orally once a day (6 days per week) for 8 weeks, significantly inhibited age-dependent increases of blood triglyceride and reductions of HDL cholesterol (p < 0.05). KF restored agereduced spontaneous alternation in the Y-maze task to 94.4% of that seen in young rats (p < 0.05). KF treatment slightly, but not significantly, shortened the escape latency daily for 4 days. Oral administration of KF restored age-suppressed doublecortin and brain-derived neurotrophic factor expression in aged rats. Orally administered KF suppressed the expression of p16, p53, and cyclooxygenase-2, the phosphorylation of Akt and mTOR, and the activation of NF-κB in the hippocampus of the brain. These findings suggest that KF may ameliorate age-dependent memory deficit and lipidemia by inhibiting NF-κB activation.

• 한국축산식품학회지
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• 제31권5호
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• pp.719-726
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• 2011

Pediococcus pentosaceus JWS 939 (JWS 939) is a nonpathogenic bacteriocin-producing probiotic isolated from the duck intestine. This study assessed the immunomodulatory effects of JWS 939 and compared them with those of Lactobacillus rhamnosus GG (LGG), a well-known immune enhancer. The immune-enhancing effects of JWS 939 were measured by measuring the production of nitric oxide (NO) and cytokines in C57BL/6 mouse peritoneal macrophages. In addition, to assess the immune enhancement abilities of JWS 939, in vivo, a Listeria monocytogenes challenge mice model was used. The results showed that heat-killed JWS 939 induced more NO and interleukin (IL)-$1{\beta}$ production in mouse peritoneal macrophages than in LGG, and that oral administration of viable JWS 939 in mice increased more NO, IL-$1{\beta}$, and tumor necrosis factor (TNF)-${\alpha}$ level than in LGG in serum upon L. monocytogenes challenge. In addition, mice fed with JWS 939 had a longer survival time after lethal challenge with L. monocytogenes, and these effects were stronger than those induced by LGG. Collectively, P. pentosaceus JWS 939 is a remarkable strain that, by releasing bacteriocin and enhancing host immune responses, may have potential as a duck feed additive to suppress pathogens.

• 생명과학회지
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• 제9권1호
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• pp.111-120
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• 1999

우리 고유의 전통 발효 음식인 김치로부터 bacteriocin 생성능이 우수한 Lactococcus sp. J-105균주를 분리하였다. Lactococcus sp. J-105의 생육 및 bacteriocin 생성에 대한 최적 조건을 검토한 결과 bacteriocin 생성은 대수 증식기 말기에서 정지기 초기에 가장 많이 생성되었다. Lactococcus sp. J-105의 생육 및 bacteriocin 생성 최적 탄소원 및 질소원은 각각 maltose와 polypeptone이었다. 균의 생육 및 bacteriocin 생성 최적 온도는 $25^{\circ}C$였으며 생육 최적 pH는 pH 8 부근이었다. bacteriocin 생성 또한 pH 8에서 최고를 나타내었다. 한편 NaCl은 오히려 균체 증식과 bac-tericoin 생성을 저해하였다. Lactococcus sp. J-105가 생산하는 bacteriocin의 pH 및 열에 대한 안정성을 검토한 결과 pH 2~4, $121^{\circ}C$ 15분에서 각각 안정하였다. 또한 J-105의 항균 spectrum을 검토한 결과 Lactobacillus sp. Leuconostoc s 그리고 Bacillus subtilis 등의 Gram 양성균에 대해서 항균활성 나타내었으며 Gram 음성균인 Acetobacter acid에 대해서도 항균 활성을 나타내었으나 E. coli에 대해서는 항균 활성을 나타내지 않았다. 본 bacteriocin은 trypsin, protease와 같은 peptide 분해효소에 대해서는 안정한 반면, pepsin에 의해서는 활성이 상실되는 특이한 성질을 나타내었다

• 한국축산식품학회지
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• 제32권5호
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• pp.635-643
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• 2012

As an appraisal for the application of a new starter culture, more than 200 lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains showing excellent growth and acid production ability in 10% skim milk media were selected and identified as Lactobacillus casei based on the results of their API carbohydrate fermentation patterns, as well as 16S rDNA sequence analysis. To assess the effect of L. casei strains on irritable bowel disease (IBD), the inhibitory effect of the selected strains against the nitric oxide (NO) production of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was measured. Among the tested L. casei strains, L. casei MCL was observed to have the greatest NO inhibitory activity. Additionally, L. casei MCL was found to inhibit mRNA expression of pro-inflammatory cytokines (interleukin-$1{\beta}$, IL-6, TNF-${\alpha}$), as well as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) involved in pathophysiologic processes such as inflammation. The mRNA expression of anti-inflammatory cytokines, including IL-10 and transforming growth factor-$1{\beta}$ (TGF-${\beta}$) of L. casei MCL, was confirmed using quantitative real-time PCR. In conclusion, L. casei MCL showed decreases in the expression of pro-inflammatory cytokines and up-regulated expression of the anti-inflammatory cytokine.

• 한국축산식품학회지
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• 제28권1호
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• pp.1-8
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• 2008

최근까지 박테리오신 생산균주의 분리, 분자생물학적 메커니즘, 정제, 구조 및 작용기작, 산업적인 적용 등의 논문 등이 보고되고 있다. 또한 50개국 이상에서 치즈, 통조림식품 등에서 식품보존제로서 승인되어 있다. 박테리오신의 여러 장점으로 인해 현재 추진되고 있는 축산업 분야의 HACCP의 범위인, 사육장에서부터 식품제조에 이르기까지 항생물질, 인공적인 방부제나 식품첨가물이 적게 들어가거나 첨가되지 않은 자연식품을 선호하고 있는 실정에 적합하다. 향후 축산업에서 항생제 대체방안의 하나로서 박테리오신의 사용은 확대되리라 기대된다. 경제적인 가격 경쟁력을 갖기 위해, 대량생산에 대한 연구가 이루어져야 하며, 적절한 제형으로 보다 구체적인 적용실험이 수행되어 산업화를 앞당겨야 한다.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.603-608
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• 2005

We recently isolated a novel probiotic strain, Lactobacillus fermentum PL9005 (KCCM-10250), from infant feces and showed that it had a potential immunoenhancing effect. In the present study, a safety assessment of the bacteria was performed using a BALB/c mouse model. Mice were administered with L. fermentum PL9005 daily for 28 days. There were no detectable changes in body weight, feed intake, or clinical signs, and no significant difference in hematological parameters or blood biochemistry between the L. fermentum PL9005-fed and control groups. Bacterial translocation was detected in the mesenteric lymph nodes, liver, and spleen of some mice with and without L. fermentum PL9005 feeding, however, the organisms were not related to ingestion of L. fermentum PL9005; this was confirmed by PCR using a species-specific primer. No gross lesions were detected in the liver, spleen, or intestine of L. fermentum PL9005-fed or control mice. Mucosal thickness in the ileum, cecum, and colon of L. fermentum PL9005-fed mice was not significantly different from that of corresponding organs in control mice. No inflammation or epithelial cell degeneration in the intestines was observed in any mice. These results indicate that ingestion of L. fermentum PL9005 is safe in mice and can be applied in the functional food market.

• Journal of Microbiology
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• 제45권5호
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• pp.373-378
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• 2007

Based on observations that lactic acid bacteria have the ability to activate macrophages, we assessed the potential effects of eight different Lactobacillus strains treated with gastrointestinal enzymes on the production of nitric oxide and various cytokines in macrophages. RAW 264.7 murine macrophage cells were cultured with either precipitates or supernatants of Lactobacillus strains digested with pepsin followed by pancreatin. The increased production of nitric oxide and interleukin $(IL)-1{\beta}$, IL-6, IL-12 and tumour necrosis factor $(TNF)-{\alpha}$ were observed when cultured with precipitates, and this effect was largely strain-dependent. In contrast, the exposure of RAW 264.7 cells to supernatants produced weaker or nearly undetectable effects in comparison to the effects of exposure to precipitates. The induction of nitric oxide appeared to be unaffected. These results demonstrate that nitric oxide and cytokines were effectively induced when the bacterial precipitate was treated with macrophages. The results of the present study also indicate that Lactobacillus strains treated with digestive enzymes are capable of stimulating the production of nitric oxide and cytokines in macrophages, which may modulate the gastrointestinal immune function of the host when it is given as a feed additive.

• 한국식품과학회지
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• 제29권5호
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• pp.1038-1044
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• 1997

Gram 음성 및 Gram 양성균, 효모와 곰팡이의 총9종의 균주에 대해 탄소수 8-12의 저급지방간 모노글리세라이드와 아디핀산의 항균력을 조사하였다. Gram 음성균에 대해서 저급지방산 모노글리는 단독으로 거의 항균효과를 나타내지 않았으나 AP와 혼합첨가시 적은 농도에서 강한 항균효과를 나타내었으며 동일한 농도의 AP에 대해서 MG C8이 MG C10보다 높은 항균력을 나타내었다. Gram 양성균은 저급지방산 모노글리세라이드 단독으로도 항균효과가 있었으나 높은 농도가 첨가되어야 하며 AP를 혼합첨가하면 Gram 음성균과 마찬가지로 적은 농도에서도 강한 항균작용을 나타내었으나 유산균에 대해서는 항균효과가 적었다. 또한 효모 및 곰팡이는 AP보다는 모노글리세라이드가 강한 항균작용을 나타내었다. Gram 양성균과 효모 및 곰팡이는 Gram 음성균과는 달리 모노글리세라이드중 MG C10이 MG C8보다 강한 항균작용을 나타내었다.