• Title/Summary/Keyword: Lactococcus lactis subsp

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Studies on the Characteristics of Kefir Grains Collected from Korean (한국에서 수집된 케퍼 그레인의 특성에 대한 연구)

  • 박선정;주영철;장윤현;차성관
    • Food Science of Animal Resources
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    • v.23 no.3
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    • pp.262-268
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    • 2003
  • Kefir is a traditional fermented milk in Caucasusian area and is made mainly of milk fermented with lactic acid bacteria and yeasts. Six typical kefir grains were selected from ten kefir grains collected from different locals in Korea. Kefir grains were gelatinous in texture and had various shapes of villi, grapes, leaves, hulled millets, and towels. To investigate predominant microflora of kefir grains, SPC, MRS, M17, Rogosa, and APT agar media were used for viable cell count MRS, SPC, and Rogosa media were most acceptable for bacterial cell counts of the selected kefir grains. From one or two of the SPC agar plates which contained around 25∼50 colonies, all grown colonies were isolated and identified. Most predominant bacteria was identified as Lactobacillus fermentum by API 50 CHL kit. The proportions of Lb. fermentum and Lb. brevis among the total identified bacteria were around 41~88% and M4%, respectively. To select the best preservation method for kefir grains, refrigeration, freezing, and freeze drying were compared. Freeze drying was found most suitable for the preservation of kefir grains, based upon their acid-producing activities and production of off-flavors.

Comparison of Bioconversion Ability and Biological Activities of Single and Multi-Strain Probiotics for an Active Molecule in Roasted Tartary Buckwheat (단일 및 복합 프로바이오틱스 균주에 의한 쓴메밀 내 Rutin의 Quercetin으로의 생물전환 및 이의 생리활성 비교)

  • Song-in Kim;Eunbee Cho;Kyohee Cho;Chang Kwon;Seok-hee Lim;Jong Won Kim;Myung Jun Chung;Su Jeong Kim;Sanghyun Lim
    • Microbiology and Biotechnology Letters
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    • v.51 no.4
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    • pp.465-473
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    • 2023
  • In this study, we aimed to evaluate the bioconversion ability of single (Lactiplantibacillus plantarum CBT LP3, Lactococcus lactis subsp. lactis CBT SL6, Streptococcus thermophilus CBT ST3) and multi-strain probiotics to convert rutin to quercetin in roasted tartary buckwheat, and to assess their biological activities. To evaluate the bioconversion efficiency, each strain was cultured for 24 h in MRS media with 5% roasted tartary buckwheat 'Hwangguem-Miso' powder. After then, rutin and quercetin contents were determined by HPLC. Additionally, the biological activities were compared before and after bioconversion of an ingredient. Anti-oxidant effects were measured by DPPH and ABTS assays. Anti-inflammatory effects were determined by measuring NO production, and levels of iNOS, TNF-α, IL-6 and IL-4 using an LPS-induced Raw 264.7 cell model. The bioconversion rate under the combination of three species of probiotics significantly increased more than single species. Antioxidant efficacy results showed the highest activity when the combination of three species of probiotics cultured. The pro-inflammatory factors such as nitric oxide, iNOS, TNF-a, and IL-6 were significantly decreased when the three types of probiotics were combined than single strain was cultured. In addition, level in the anti-inflammatory factor IL-4 was increased. The multi-strain probiotics showed increased bioconversion efficiency, effects of anti-oxidant and anti-inflammatory compared to the single strain. These findings suggest that the fermentation of tartary buckwheat by probiotics may be a valuable candidate for developing functional foods with anti-oxidation and anti-inflammation.