• Journal of Animal Science and Technology
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• 제63권3호
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• pp.603-613
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• 2021

This research improved the growth potential of Bifidobacterium animalis subsp lactis strain JNU306, a commercial medium that is appropriate for large-scale production, in yeast extract, soy peptone, glucose, L-cysteine, and ferrous sulfate. Response surface methodology (RSM) was used to optimize the components of this medium, using a central composite design and subsequent analyses. A second-order polynomial regression model, which was fitted to the data at first, significantly lacked fitness. Thus, through further analyses, the model with linear and quadratic terms plus two-way, three-way, and four-way interactions was selected as the final model. Through this model, the optimized medium composition was found as 2.8791% yeast extract, 2.8030% peptone soy, 0.6196% glucose, 0.2823% L-cysteine, and 0.0055% ferrous sulfate, w/v. This optimized medium ensured that the maximum biomass was no lower than the biomass from the commonly used blood-liver (BL) medium. The application of RSM improved the biomass production of this strain in a more cost-effective way by creating an optimum medium. This result shows that B. animalis subsp lactis JNU306 may be used as a commercial starter culture in manufacturing probiotics, including dairy products.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1870-1875
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• 2020

Probiotics are often infused into functional foods or encapsulated in a supplement form to maintain a healthy balance between the gut microbiota and their host. Because there are milk-based functional foods such as yogurt and cheese on the market, it has been suggested that milk-based probiotics could be incorporated into skim milk proteins in a liquid capsule. Skim milk is mainly composed of casein and whey protein, which create a strong natural barrier and can be used to encapsulate probiotics. In this study, we compared the encapsulated probiotics prepared with milk-based concentrated cell mixtures using commercial probiotics. Probiotic capsules were emulsified with skim milk proteins using vegetable oil to form a double coating layer. The product was heat-stable when tested using a rheometer. The survival rate of the milk-based probiotic cells in the lower gastric environment with bile was significantly higher than commercial probiotics. Thus, milk-encapsulated probiotics exhibited greater efficacy in the host than other types of probiotics, suggesting that the former could be more viable with a longer shelf life under harsh conditions than other form of probiotics. Our findings suggested that, compared with other types of probiotics, milk-based probiotics may be a better choice for producers and consumers.

• 한국축산식품학회지
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• 제41권2호
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• pp.300-311
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• 2021

The objective of the present study was to evaluate the cholesterol-assimilation ability of lactic acid bacteria (LAB), which were isolated from kimchi, a Korean traditional fermented cabbage. The isolated strain, using modified MRS medium, showed 30.5% cholesterol assimilation activity and was named Pediococcus acidilactici LRCC5307. Types and concentrations of bile were investigated for their effects on increasing the cholesterol assimilation ability of the LRCC5307 strain, a 74.5% decrease in cholesterol was observed when 0.2% bile salts were added. In addition, the manufacture of low-cholesterol butter using LRCC5307 was examined. After fermentation, LRCC5307 with butter showed 8.74 Log CFU/g viable cells, pH 5.43, and a 11% decrease in cholesterol. These results suggest that LRCC5307 could help in the production of healthier butter by decreasing cholesterol and including living LAB.

• 한국해양바이오학회지
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• 제14권2호
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• pp.112-123
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• 2022

Photosynthetic bacteria (PSB) play an important role in water purification, and their application is beneficial for sustainable aquaculture. However, maintaining the microbial stability of PSB from subculturing to preservation is a challenging task. Since improvement in the microbial stability of PSB is a crucial parameter, optimized conditions for cell immobilization and lyophilization were investigated. In PSB immobilization, 0.1-M CaCl₂ was found to be the most effective divalent metal ion solution in terms of cost-effectiveness, resulting in beads with a 4-mm diameter and high loading (1.91×10⁹ CFU/mL) of viable cells. Maintenance of cell viability, external appearance, and color of PSB beads was best in 3.5% NaCl during storage. In lyophilization, the addition of skim milk (9%) and dextrose (2%) as cryoprotective additives allowed the highest cell viability. Over an 18-week shrimp breeding period, when optimally manufactured beads and lyophilized powder of PSB were applied to shrimp aquaculture water, NH⁴⁺, NO₃^-, and NO₂^- were more effectively removed by 55%, 100%, and 100%, respectively, compared to controls. Thus, microbial stability of PSB through optimized cell immobilization and lyophilization was successfully enhanced, enabling a wide application.

• Fisheries and Aquatic Sciences
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• 제25권10호
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• pp.525-536
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• 2022

Photosynthetic bacteria (PSB) attract considerable interest as useful microorganisms; nevertheless, a generalized culture technique has not been previously reported owing to difficulty in their cultivation. Therefore, a simple culture technique suitable for public use was investigated. Among the PSB tested, the strain Rhodobacter azotoformans EBN-7 was the most suitable for scale-up production because it showed the highest specific growth rate (0.20 h^-1) on basal medium. In scale-up cultivation (500 L), R. azotoformans EBN-7 showed 4.50 × 10¹⁰ colony-forming units mL^-1 (number of viable cells), dry cell weight of 26.8 g/L, and a specific growth rate of 0.15 h^-1. Cultivation using this final culture broth (as seed culture) in a 15 L simple reactor was successful, with maintenance of cell activity evident. For use as seed culture, the maximum allowable preservation period of R. azotoformans EBN-7 at 4℃ was 3 months. When R. azotoformans EBN-7 cultivated in a simple technique was applied to shrimp aquaculture water, NH₄⁺-N was reduced from 0.61 mg/L to 0.24 mg/L (by 60.7%) in 4 days in comparison with the control. Thus, this simple culture technique using R. azotoformans EBN-7 has the potential for a good removal efficiency of NH₄⁺-N, making seed culture easier and suitable for public use.

• 한국결정성장학회지
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• 제7권1호
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• pp.81-92
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• 1997

전극함몰형 태양전지에 후면 부유접합의 도입은 양질의 표면보호를 제공할 수 있어서 효율 향상을 꾀할 수 있다. 이 논문은 PC-1D 모델링을 통하여 후면 부유접합형 태양전지의 효율을 시뮬레이션 분석한 것이다.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1475-1483
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• 2023

This study aimed to evaluate the cholesterol-lowering and antioxidant activities of soymilk fermented with probiotic Lactobacillaceae strains and to investigate the production of related bioactive compounds. Lactiplantibacillus plantarum KML06 (KML06) was selected for the fermentation of soymilk because it has the highest antioxidant, cholesterol-lowering, and β-glucosidase activities among the 10 Lactobacillaceae strains isolated from kimchi. The genomic information of strain KML06 was analyzed. Moreover, soymilk fermented with KML06 was evaluated for growth kinetics, metabolism, and functional characteristics during the fermentation period. The number of viable cells, which was similar to the results of radical scavenging activities and cholesterol assimilation, as well as the amount of soy isoflavone aglycones, daidzein, and genistein, was the highest at 12 h of fermentation. These results indicate that soymilk fermented with KML06 can prevent oxidative stress and cholesterol-related problems through the production of soy isoflavone aglycones.

• 한국미생물·생명공학회지
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• 제43권1호
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• pp.31-37
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• 2015

생미역에 고농도 장시간(50%, 75%, 90%/30분), 고농도 단시간(50%, 75%/1분, 2분), 저농도 장시간(15%, 30%/30분), 저농도 단시간(15%/5분, 10분)의 전해수를 처리하고 증류수로 세척한 뒤 미역의 전체와 표면의 생균수, 대장균군, 곰팡이수, 색도, 관능평가를 실시하였다. 고농도 단시간의 경우 미생물의 생육을 효과적으로 억제하였지만 관능적으로 낮은 점수를 받았고 고농도 단시간의 경우 관능적으로는 다른 처리구에 비해 비교적 우수하지만 대장균군이 검출되어 효과적이지 못한 것으로 나타났다. 저농도 장시간의 경우 대장균군의 생육을 억제시켰으나 장시간 침지에 의해 전해수취가 약간 남에 따라 보다 짧은 시간인 5분과 10분으로 전해수 침지 횟수를 달리하여 실험하였다. 15% 전해수 5분 1회 처리구의 경우 증류수 처리구에 비해 관능적으로는 선호도가 높았지만 미생물의 생육을 효과적으로 억제하지 못하였다. 결론적으로 15% 농도의 전해수를 10분간 1회 처리하는 것이 증류수 처리구와 비교 시 총균수, 대장균군수 및 곰팡이수를 약 1-2 log cycle 정도 억제함으로써 검출되지 않아 미생물 오염을 억제시키는데 효과적이며, 관능평가에서도 미역 원물 자체의 비린맛 및 비린향을 감소시킬 수 있어 최적의 조건임을 확인할 수 있었다. 이러한 연구결과로 미역을 생산단계에서 화학적 처리인 전해수 세척을 이용해 대장균군의 생육을 억제해 보다 위생적이고 안전한 제품을 생산할 수 있을 것으로 사료된다.

• 농업과학연구
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• 제8권2호
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• pp.238-243
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• 1981

전보(前報)에서 분리(分離)한 R. meliloti M14를 공시(供試)하여 국내산 니탄(泥炭)의 이용(利用) 가용성(可用性)을 구명(究明)하고저, 니탄(泥炭)의 중화(中和) 및 개량(改良), 액체배양물과의 혼합(混合) 및 숙성등(熟成等)에 관(關)하여 실험(實驗)하였고, 니탄배양물(泥炭培養物)을 보관(保管)하는 동안 온도(溫度)와 잔존생균수(殘存生菌數)와의 관계(關係)를 검토(檢討)하여 다음과 같은 결과(結果)를 얻었다. 1. 국내산(國內産) 니탄(泥炭)은 산성(酸性), pH 3.8로서 이를 pH6.4로 조성(調聲)하는데 14%의 calcium carbonate가 소요(所要)되었으며, 목탄(木炭), 활성탄등(活性炭等)을 혼용(混用)할 경우에는 4~8%를 절약(節約)할 수 있었다. 2. stationary phase 초기(初期)의 균체배양액을 살균(殺菌)하지 않은 니탄배지(泥炭培地)에 접종(接種)하여 tray배양(培養)할 경우에 3일후(日後) $7{\sim}9{\times}10^9cells/g$의 배양물(培養物)을 얻었으며, 살균(殺菌)한 배지(培地)를 사용(使用)하여 병배양하는 경우에는 5일후(日後) $1.1{\sim}6.2{\times}10^{10}cells/g$의 것을 얻었다. 3. 니탄배양물(泥炭培養物)을 보관(保管)하는 동안, 온도(溫度)에 따라서 잔존생균수(殘存生菌數)의 차이(差異)가 심(甚)하였으며, 특(特)히 $35^{\circ}C$와 $45^{\circ}C$의 높은 온도(溫度)에서 그 감소율(減少率)을 줄이기 위하여 추가적(追加的) 탄소원(炭素源) 및 습윤제(濕潤劑)로서 sorbitol의 첨가효과(添加效果)가 인정(認定)되었다. 본균주(本菌株)는 glycerol, sorbitol, sodium latate 등(等)을 유일(唯一)한 탄소원(炭素源)으로 이용(利用)할 수 있었으나 glycerol 및 sodium latate에서는 생육(生育)이 다소(多少)낮았고, 이들을 0.5%함유(含有)한 니탄배양물(泥炭培養物)을 $25^{\circ}C$에서 보관(保管)할때의 decimal reduction time은 8~9주(週)이었으며, sorbitol첨가물(添加物)의 생균수(生菌數)는 초기(初期)에는 높았으나 12~15주(週) 사이에서 다른 것보다 낮아지는 결과(結果)를 보였다.

• Tuberculosis and Respiratory Diseases
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• 제40권2호
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• pp.112-122
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• 1993

연구배경 : 진폐증환자의 궁극적인 치료목표는 호흡분진의 독성에 의한 폐섬유화의 진행을 억제 시키는 것이다. Quinolyl piperazine phosphate(QP) chloroquine의 유도체로서 섬유화 억제 효과가 있는 것으로 알려져 있다. 따라서 QP가 흰쥐 규폐증에 미치는 영향, 즉 폐섬유화 억제 정도를 알아보기 실험을 시도하였다. 방법 : 생리식염수 0.5ml에 유리규산 분진이 40mg 함유한 현탁액을 기도내에 주입하여 흰쥐 규폐증을 만들었고, 이중 QP 투여군에서는 QP 10mg을 유리규산 기도내 투여 직후 1주에 한번씩 경구 투여하였고 QP 투여는 쥐를 도살할때까지 계속하였다. 생리식염수군은 1주째에 그리고 유리규산 투여군 및 QP 투여군은 1주, 3주, 8주, 그리고 20주째에 각각 도살하여 시료를 얻었다. 결과: 1) QP 투여군에서는 실험기간에 따라 유리규산 투여군에 비하여 기관지폐포 세척액내 총 세포수가 감소된 경향을 보였으나 유의한 차이는 아니었다. 2) Luminol을 이용한 살아있는 폐포 염증세포의 화학발광은 두 군간에 유의한 차이가 없었다. 3) 좌측폐의 마른 무게는 3주와 8주째에서 유리규산 투여군에 비하여 QP 투여군에서 유의하게 적은 수치를 보였다. 4) 폐내 hydroxyproline 양은 3주째에 유리규산 투여군에 비하여 QP 투여군에서 유의하게 적은 수치를 보였다. 유리규산 투여군은 1주째에 비하여 3주째에 hydroxyproline 양이 현저히 증가한 소견을 보였으나 QP 투여군에서는 1주째에 비하여 hydroxyproline 양의 현저한 증가가 8주에서 관찰되었다. 5) 병리조직학적 소견상 QP 투여군은 유리규산 투여군에 비하여 세기관지 주위의 염증세포 침윤, 규폐결절의 수와 크기에 있어서 유사하였으나 섬유화의 정도는 덜하였다. 특히 유리규산 투여군의 몇 예에서 진행성 괴상성 섬유화가 관찰되었으나 QP 투여군에서는 관찰할 수 없었다. 결론 : Quinolyl piperazine phosphate (QP)는 유리규산 분진의 기도내 투여로 인한 폐장의 섬유화 반응을 현저히 억제시키지는 못하나 지연시키는 효과는 있는 것으로 사료되었다.