• 한국식품영양과학회지
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• 제26권6호
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• pp.1237-1245
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• 1997

Interspecific fusants were made from the cells of two strains of Lactobacillus genus, a streptomycin resistant Lactobacillus sp. JC-7 and a kanamycin resistant L. acidophilus 88. The morphological and physiological properties of the fusants were examined by determining bacteriocin productivity, acid-producing activity, ability of carbohydrates utilization and three important enzyme activities. The fusants produced a bacteriocin against indicator strains and fusant No. 1, 4 exhibited a larger inhibition zone compared to that of L. acidophilus 88. $\beta$-Galactosidase, phospho-$\beta$-galactosidase, lipase activities and resistance to NaCl of Lactobacillus sp. JC-7 were better than those of L. acidophilus 88. Fusant No. 3 and 7 exhibited excellent lipase activities. Protease activity and acid productivity of L. acidophilus 88 were better than those of Lactobacillus sp. JC-7. Proteasse activities of all fusants were higher than those of parental strains, and expecially fusant No. 5 and 7 exhibited excellent proteolysis ability.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.143-151
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• 1994

In the course of the study on strain inprovement by protoplast fusion, Lactobacillus acidophilus 88 protoplasts production and regeneration conditions were investigated. This strain produced a bacteriocin that revealed strong inhibitory activity against various indicator strains, especially L. helveticus CNRZ 1096. Protoplasts of L. acidophilus 88 strains were very efficiently obtained by treatment with 125 $\mu $g/ml lysozyme in a protoplast forming buffer containing 20 mM N-2 hydroxy-ethtl-piperazine-N'-2-ethane-sulfonic acid(HEPES, pH 7.0) and 1M sucrose at 37$\circ $C for 30 min. Hovever, treatment with mutanolysin was not effective for the production of L. acidophilus 88 protoplasts under the same conditions. High protoplast yield was obtained form the cells at the middle to late logarithmic growth phase in the de Man, Rogosa and Sharpe(MRS) medium. Regeneration was efficiently accomplished with the MRS medium containing 10% sucrose.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.121-128
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• 1997

A lactic acid bacterium was isolated from kimchi. The isolated strain was identified as the genus Lactobacillus through its morphological, cultural, and physiological characteristics and named as Lactobacillus sp. JC-7. The optimum conditions for the electrofusion between streptomycin (2.5 mg/ml) resistant mutant of Lactobacillus acidophilus 88 and kanamycin (600 $\mu$g/ml) resistant mutant of Lactobacillus sp. JC-7 were evaluated. The highest number of fusants were obtained at a capacitance value of 120 msec (1670 $\mu$F), a field strength of 100 V/cm, and a pulse controller setting of 72$\Omega$. The optimum pH of electroporation buffer was 7.5 and the concentration of divalent cation was 1 mM Mg$^{2+}. Electrofusants were efficiently obtained by addition 20% polyethylene glycol to elec- troporation buffer. The yield of fusion was better than that of using polyethylene glycol mediated chemical induction.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.25-31
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• 1997

Protoplast fusion between L. casei KCTC 1121 and L. acidophilus 88 was attempted to obtain improved strains. The fusants produced a bacteriocin against indicator strains, making a smaller inhibition zone compared to that of L. acidophilus 88. After culturing for 2 months on selective medium, the selected fusants were still stable without segregation. Fusants showed higher lipase activity compared to those of the two parent strains. Fusant No.4, 11, and 15 exhibited excellent lactic acid productivity. Fusant No.4 and 15 exhibited improved proteolysis ability compared to the two parent strains. Whereas L. casei possessed both ${\beta}-galactosidase$ and $phospho-{\beta}-galactosidase$ activities, and L. acidophilus 88 had only ${\beta}-galactosidase$ activity, the fusants had both the intermediate enzyme activities. Cell size of the fusants was greater than that of the parents.

• 한국식품영양과학회지
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• 제25권1호
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• pp.143-149
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• 1996

균주개량 방법의 일환으로 electrofusion 법을 이용하여 protease 화성, lipase 활성, 내열성, 내산성 등이 우수한 L. bulgaricus와 bacteriocin을 생산하는 L. acidophilus 간의 융합조건을 검토하였다. Electrofusion에 의해 생성된 융합주는 식별하기 위해 streptomycin(2mg/ml)과 lincomycin(5$\mu\textrm{g}$/ml)에 내성을 나타내는 L. bulgaricus 변이주이와 kanamucin (600$\mu\textrm{g}$/ml)에 내성을 나타내는 L. acidophilus 88 변이주를 분리하였다. Electrofusion을 500V/cm, 100mses(49phms, 2300 capacotance)에서 수행했을 때 가장 융합이 잘 일어났으며 전기장의 세시와 시간이 증가할수록 융합요율이 현저히 감소하였다. 2가 양이온은 대체적으로 융합효율을 감속시키는 경향을 나타내었으나 1mM MgCl$_2$에서 융합 효율이 약간 증가하였다. PEG 400을 elec-trogusion buffer에 30%되도록 첨가했을 때, 가장 양호한 융합효율을 나타내었으며 그 이상에서는 오히려 융합 효율이 감소하였다. Electrofusion법과 PEG 매개에 의한 융합법의 융합 효율을 비교한 결과, 거의 비슷한 융합 효율을 나타내었으나 electrofusion 법과 PEG매개에 의한 융합법을 혼합하였을 때 가장 양호한 융합 효율을 나타내었다.

• 한국조리학회지
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• 제13권1호
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• pp.55-61
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• 2007

L. acidophilus KCCM 32820과 P. freudenreichii KCCM 31227의 성장곡선 및 5%와 10% 유청 배지를 고압증기멸균 및 저온살균하여 L. acidophilus KCCM 32820과 P. freudenreichii KCCM 31227을 혼합배양시 생성되는 propionic acid와 acetic acid 양을 측정하였다. L. acidophilus KCCM 32820의 대수기는 $6\sim21$시간, P. freudenreichii KCCM 31227의 대수기는 $36\sim108$시간으로 나타났다. 혼합배양시 propionic acid의 생성량은 5% 유청 배지보다는 10% 유청 배지에서, 고압증기 멸균보다는 저온살균에서 많은 양이 생성되었다. Propionic acid의 최대 생산량은 10% 유청 배지를 저온살균하였을 때 배양 120시간에 7.88 mg/mL이었다. Acetic acid도 5%보다는 10% 유청 배지에서 높은 생성량을 나타냈고 그 생성량은 배양시간이 경과함에 따라 propionic acid 생성량의 $2:1\sim3:1$이었다.

• 한국식품영양과학회지
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• 제25권1호
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• pp.150-156
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• 1996

유산균의 균주개량방법의 일환으로 photoplast fu-sion 기법과 electrofusion법을 이용하여 protease 활성, lipase 활성, 내열성, 내산성 등이 우수한 L. bulgaricus와 bacteriocin을 생산하는 L. acidophilus 간의 융합시켜 얻은 융합주들의 생리학적 성질을 검토하였다. 산 생성능, 내열성, 내산성 protease, lipase 활성 등 L. bulgaricus가 L. acidophilus보다 우수하였다. L. bulgaricus는 lactose와 sorbos를 이용하였으나. mal-tose 와 dorbitol을 이용하지 못하는 반면 , L. acidophilus는 matose를 이용하고 lactose 와 sorbose를 이용하지 못하였다. 융합주 가운데서는 367810번이 모균주의 발효능 특성을 함께 지님으로서 재조합체임을 확인 할 수 있었으며, sorbitol의 경우 모균주에서는 발효능이 전혀 나타나지 않았음에도 불구하고 융합주 4, 7번이 발효능을 나타내어 융합과정에서 새로운 형질을 획득하기도 한다는 사실을 알 수 있었다. Lactase 활성은 모균주 모두 높은 $\beta-galactosidase$ 활성을 보였으나, $phospho-\beta-galactosidase$ 활성은 거의 없었으며 융합주들도 다소 차이는 있었지만 모균주와 유사한 효소활성을 나타내었다. 발효에 있어서 key enzyme으로 작용하는 protease. lipase 등의 효소활성도 모균주의 활성보다 우수한 융합주도 존재하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1790-1797
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• 2002

Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at $37^{\circ}C$, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken.

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.721-730
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• 2019

The probiotic Lactobacillus acidophilus KBL409 was encapsulated with alginate (Al) and alginate-chitosan (Al/Chi) through extrusion method. The sizes and zeta potentials of microspheres were measured to confirm encapsulation. To evaluate the protective effect of microspheres against gastrointestinal fluids, all the samples were exposed to simulated gastric fluids (SGFs, pH 1.5) at $37^{\circ}C$ for 1 or 2 h, followed by incubation with simulated intestinal fluids (SIFs, pH 6.5) for 2 h. The mucoadhesive ability of microspheres was evaluated using the intestinal epithelial cell line HT29-MTX. To extend the shelf-life of probiotics, lyoprotectants such as disaccharide and polysaccharide were mixed with free or encapsulated cells during the freeze-drying process. The size of the microspheres demonstrated a narrow distribution, while the zeta potentials of Al and Al/Chi-microspheres were $-17.9{\pm}2.3$ and $20.4{\pm}2.6mV$, respectively. Among all the samples, Al/Chi-encapsulated cells showed the highest survival rate even after exposure to SGF and SIF. The mucoadhesive abilities of Al and Al/Chi-microspheres were higher than 94%, whereas the free L. acidophilus showed 88.1% mucoadhesion. Ten percent of sucrose showed over 80% survival rate in free or encapsulated cells. Therefore, L. acidophilus encapsulated with Al and Al/Chi-microspheres showed higher survival rates after exposure to the gastrointestinal tract and better mucoadhesive abilities than the free cells. Also, sucrose showed the highest protective effect of L. acidophilus during the freeze-drying process.

• Journal of Ginseng Research
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• 제38권3호
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• pp.167-172
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• 2014

Background: Roles of immune reaction and toll-like receptor-4 (TLR-4) have widely been established in the pathogenesis of alcoholic liver disease (ALD). Methods: We evaluated the biologic efficacy of Korean Red Ginseng (KRG), urushiol, and probiotics (Lactobacillus rhamnosus R0011 and Lactobacillus acidophilus R0052) in mouse models of ALD. Sixty C57BL/6 mice were equally divided into six feeding groups for 10 weeks: normal diet, alcohol, control, alcohol + KRG, alcohol + urushiol, and alcohol + probiotics. Alcohol was administered via a LiebereDeCarli liquid diet containing 10% alcohol. TLR-4 expression, proinflammatory cytokines, and histology, as well as the results of liver function tests were evaluated and compared. Results: No between-group differences were observed with regard to liver function. TLR-4 levels were significantly lower in the KRG, urushiol, and probiotics groups than in the alcohol group ($0.37{\pm}0.06ng/mL$, $0.39{\pm}0.12ng/mL$, and $0.33{\pm}0.07ng/mL$, respectively, vs. $0.88{\pm}0.31ng/mL$; p < 0.05). Interleukin-$1{\beta}$ levels in liver tissues were decreased among the probiotics and KRG groups. The tumor necrosis factor-${\alpha}$ level of liver tissue was decreased in the KRG group. Conclusion: The pathological findings showed that alcohol-induced steatosis was significantly reduced by KRG and urushiol. As these agents improve immunologic capacity, they may be considered in potential anti-ALD treatments.