• Journal of Animal Science and Technology
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• 제46권4호
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• pp.687-700
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• 2004

요구르트의 제조 시 기능성 성분을 함유한 첨가제로서 구기자, 구기엽 및 지골피를 기질로 하여 요구르트를 제조하여 젖산균주에 따른 발효특성을 시험하였고, 각 부위를 첨가한 요구르트의 cholestol 저하 효과 및 병원성 균주의 성장 억제 효과를 시험하였다. 상업용 starter를 사용한 모든 처리구에서 발효 후 pH가 4.06 이하로 나타나 발효 촉진 효과가 있었고, 산 생성은 S. salivarius ssp. thermophilus와 L. delbrueckii ssp. bulgaricus에서 높아 발효촉진 효과가 우수하였으며 젖산균수는 S. salivarius ssp. thermophilus와 L. delbrueckii ssp. bulgaricus를 이용한 구기자 extract 첨가구에서 9시간째 2.62${\times}$$10^9$ cfu/$m\ell$로서 최대 균수를 나타내었다. 유당분해율은 S. salivarius ssp. thermophilus와 L. dilbrueckii ssp. bulgaricus를 이용한 구기자, 구기엽, 지골피 extract 처리구에서 36.11%, 37.76% 및 32.70%를 나타내어 높았고, 유기산 생성은 S. salivarius ssp. thermophilus와 L. delbrueckii ssp. bulgaricus 균주를 stsrter로 사용한 요구르트의 경우에만 isobutylic acid가 34.39${\sim}$37.72 mM로 높은 유기산을 생성하였다. 점도는 L. acidophilus, B. longum과 S. salivarius ssp. thermophilus를 starter로 사용하였을 때 1,615${\sim}$2,030 cP로서 모든 첨가구에서 높은 점도를 나타내었고, 관능검사 결과 대조구가 3.27${\sim}$3.44인데 비하여 구기자와 구기엽 extractffm 첨가한 요구르트의 관능검사 결과는 1.77${\sim}$2.58로서 상당히 낮은 기호도를 나타내었다. 그러나 지골피 extract 첨가구에서 L. casei와 L. acidophilus. B. longum 및 S. salivarius ssp. thermophilus를 starter로 사용한 요구르트 기호도의 경우는 3.34${\sim}$3.77로 나타나 기호성이 좋았다. 구기자, 구기엽 및 지골피 extract 첨가에 의한 cholesterol 저하 효과는 인체 유래의 각 젖산균과 상업용 starter 균주를 이용한 모든 처리구에서 17.38${\sim}$32.08%의 콜레스테롤 저하 효과를 나타내었다. 그 중 L. acidophilus KCTC315.와 L. salivarius subsp. salivarius CBU27 젖산균은 25.75${\sim}$32.08%의 높은 콜레스테롤 저하 효과를 보였다. 구기자, 구기엽 및 지골피 extract 첨가 요구르트의 식중독 유발 살모넬라 균주에 대한 성장 억제 효과는 S. typhimurium M-15 균주에서 약간의 억제 효과를 보였고, 설사와 식중독을 유발하는 것으로 알려진 대장균 중 E. coli KCTC1021와 리스테리아증을 유발하는 L. monocytogenes에 대해서는 높은 성장 억제 효과를 보여 구기자, 구기엽, 지골피를 기질로 한 요구르트가 살모렐라, 대장균 및 리스테리아 유발 병원성 균주에 대한 탁월한 억제 효과가 있었다.

• 한국식품영양학회지
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• 제17권1호
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• pp.8-17
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• 2004

Chlorella 추출물을 첨가한 yoghurt를 개발하기 위한 기초 연구로 chlorella 추출물의 첨가가 yoghurt starter의 산 생성 및 증식에 미치는 영향을 조사하였다. Str. themophilus, Lac. acidophilus, Lac. casei, Lac. bulgaricus를 단독 균주 및 혼합 균주로 접종하여 배양하면서 생균 수와 pH 및 적정산도를 측정하였다. 단독 균주의 경우 chlorella 추출물 분말의 첨가 농도(0.5%, 1.0%, 2.0%, 3.0%)를 달리 하였을 때 Str. thermophilus, Lac. casei와 Lac. bulgaricus는 chlorella 추출물 분말 0.5% 첨가 시 9시간 배양에서, 그리고 Lac. acidophilus는 1.0% 첨가 시 15시간 배양에서 최대 균수를 나타내었으며, 이들 중 Lac. casei가 0.5% 첨가 시 배양 9시간에 3.63${\times}$$10^{9}$ CFU/mL로 가장 높은 생균 수를 보였다. 또한 이들 유산균의 산 생성도 chlorella 추출물 분말을 0.5% 첨가하였을 때 가장 많이 증가하였다. 혼합균주의 경우 chlorella 추출물 분말을 0.25%, 0.5%, 1.0%, 2.0%로 첨가하였을 때 저농도(0.25∼0.5%)의 chlorella 추출물 분말 첨가에 의해 모든 유산균 혼합 균주의 증식이 촉진되었고, pH가 크게 하락하였으며 적정산도가 크게 상승하였다. Str. thermophilus와 Lac. casei를 혼합 배양하였을 때 chlorella 추출물 분말 0.25% 첨가 시 12시간 배양 후 1.13${\times}$$10^{8}$ CFU/mL로 생균수 가 가장 높아 4.12 의 log cycle 증가를 나타내었다. 따라서 chlorella 추출물 첨가 yoghurt 제조 시 chlorella 추출물 분말을 0.25% 첨가하여 혼합 starter로 Str. thermophilus와 Lac. casei 혼합균주를 사용하는 것이 이들 유산균의 생육이 촉진되어 가장 적합한 것으로 나타났다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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• pp.246.1-246
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• 1979

A glucose-limited “pH-stat” continuous culture study of Lactobacillus bulgaricus NLS-4 in an anaerobic condition showed the marked effects of environmental pH on end products, fermentation blances and bioenergetic aspects of the organism. Lactic acid was the major end product of fermentation with minor products, such as acetic acid, formic acid and ethanol throughout the pH range tested. In acidic conditions below pH 6.5, a typi-cal pattern of homofermentation was revealed whereas in alkaline conditions, the metabolic pattern was changed from homofermentation to heterofermentation and led to acquire much energy. This metabolic change was likely due to the pH-dependent lactate dehydrogenase activity. Molar growth yields (Yglc=35.5-44.4) and YATP, $18.5\pm2.5$ in average which was 80％ higher than the value ever postulated seemed to be accounted for less requirement of maintenance energy of the organism in the culture conditions.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 제36차 추계 학술발표대회
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• pp.306-309
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• 2005

본 연구는 기능성 발효유로서 티벳산 발효유에서 분리한 효모(Kluyveromyces marxianus)와 유산균(Lactobacillus bulgaricus)의 혼합스타터를 이용한 발효유를 제조하여 배양 기간별 균수측정, pH, 적정산도, Alcohol 함량, 항암활성에 대해 알아보았다. 배양은 산도 0.68%, 최종 pH가 4.5가 되는 시점에서 마치게 되는데 이때의 배양 온도는 $30^{\circ}C$, 배양기간은 36시간이었다. 이때의 균수는 K. marxianus는 $5.3{\times}10^9$) CFU/mL, L. bulgaricus는 $3.2{\times}10^9$ CFU/mL였고 Alcohol 함량은 0.35%까지 증가하였다. 36시간 배양하여 제조된 발효유의 항종양 활성은 Hep-2에 대해서는 90.5%, HEC-1B는 86.6%, SW-156은 60.3%, SK-MES-1은 57.14%의 높은 항종양활성을 나타내었다. 이상의 결과 기존의 유산균 발효유에 효모를 첨가한 알코올 발효유의 제조가 가능하며, 제품의 항종양 활성의 측면에서도 높은 기능성을 나타내는 것으로 나타났다.

• 한국축산식품학회지
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• 제39권5호
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• pp.704-724
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• 2019

This study mainly investigated the improvement effect of nitroso-hemoglobin (NO-Hb) and four lactic acid bacteria (LAB) (Streptococcus thermophiles, Lactobacillus bulgaricus, Lactobacillus casei, and Montessori enterococcus) on the color and microbiological qualities of raw beef. Three strains of Escherichia coli, Staphylococcus, Salmonella, and Pseudomonas were used as pathogenic bacteria. The results showed that both NO-Hb and LAB could enhance the color stability and scavenged the spoilage bacteria in a minced beef model. But the improvement effect of NO-Hb was more significant than LAB. This suggested that NO-Hb, as a novel ingredient, could be used as a promising substitute for nitrite in meat products to improve the color and safety of meat products. In addition, low field (LF)-NMR method has been established to be practicable to identify changes in the relaxation times of water and fat caused by different type of bacteria and the storage periods. The number of relaxation components in minced beef was affected by bacteria and increase of the storage period.

• 농업과학연구
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• 제48권2호
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• pp.273-281
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• 2021

These days, different types of yogurt are being manufactured by adding various starters and functional ingredients for health. The purpose of this study was to prepare yogurt added with rice followed by fermentation with two types of starters and to examine its attributes. Ten percent of skim milk powder and 0, 2.5, 5.0, 7.5, or 10% rice were mixed in water (w/v) and then inoculated with two types of starter: 1) Type A, Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus as starter; and 2) Type B, Streptococcus thermophiles, Lactobacillus acidophilus, and Bifidobacteium animalis ssp. lactis as starter. The pH of B type yogurt was lower (p < 0.05) than that of A type yogurt from 6 hours to 14 hours after fermentation. The number of microorganisms in all fermented milk showed maximum increases at 2 and 6 hours of fermentation (p < 0.05). The number of microorganisms in fermented milk peaked at 6 hours after fermentation and maintained this level thereafter. There was no effect of rice addition on microbial growth or acidity of the fermented milk. Sensory attributes of yogurt samples with and without added rice were not significantly different. This experiment showed that the production efficiency of yogurt with added rice was not different when two different types of starters were used to manufacture yogurt.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.280-289
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• 2021

Genetic markers currently used for the discrimination of Lactobacillus delbrueckii subspecies have low efficiency for identification at subspecies level. Therefore, our objective in this study was to select novel genetic markers for accurate identification and discrimination of six L. delbrueckii subspecies based on pangenome analysis. We evaluated L. delbrueckii genomes to avoid making incorrect conclusions in the process of selecting genetic markers due to mislabeled genomes. Genome analysis showed that two genomes of L. delbrueckii subspecies deposited at NCBI were misidentified. Based on these results, subspecies-specific genetic markers were selected by comparing the core and pangenomes. Genetic markers were confirmed to be specific for 59,196,562 genome sequences via in silico analysis. They were found in all strains of the same subspecies, but not in other subspecies or bacterial strains. These genetic markers also could be used to accurately identify genomes at the subspecies level for genomes known at the species level. A real-time PCR method for detecting three main subspecies (L. delbrueckii subsp. delbrueckii, lactis, and bulgaricus) was developed to cost-effectively identify them using genetic markers. Results showed 100% specificity for each subspecies. These genetic markers could differentiate each subspecies from 44 other lactic acid bacteria. This real-time PCR method was then applied to monitor 26 probiotics and dairy products. It was also used to identify 64 unknown strains isolated from raw milk samples and dairy products. Results confirmed that unknown isolates and subspecies contained in the product could be accurately identified using this real-time PCR method.

• 약학회지
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• 제29권3호
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• pp.159-164
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• 1985

To investigate the susceptibility and resistance in case of simultaneous administrations of Lactobacilli and Clostridia prekparations with antituberculosis agents and antibiotics, five strains of Lactobacilli, i.e., Lactobacillus bulgaricus, L. casei, L. helveticus, L. acidophilus, L. sporogenes, and Clostridium butyricum were isolated from commercially available preparation. Minimal inhibitory concentrations (MIC) of nine antituberculosis agents and 21 antibiotics against these strains were determined. The results shwoed that these strains were very sensitive only to rifampicin among antituberculosis agents, and sensitive to other antibiotics. Since the simultaneous oral administration of rifampicin and other antibkiotics with these sensitive strains is ineffective, development of new resistant mutants is desirable.

• 한국식품영양과학회지
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• 제28권5호
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• pp.1022-1028
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• 1999

The solvent extracts of Ulmi cortex, which were extracted by using several solvents with different polarities, were prepared for utility as a natural preservatives. The antimicrobial activities and cell growth inhibitions were investigated to each strain with the different concentrations of Ulmi cortex extracts. Methanol extract showed the highest antimicrobial activity. The methanol extract was represented the broad antimicrobial activities for the gram positive and negative strains. Minimum inhibitory concentrations (MIC) for each strains were appeared to around 0.3mg/ml at each of Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus. The cell growth inhibitions were not shown on Lactobacillus bulgaricus, Lac tobacillus plantarum, and Bifidobacterium bifidum, but greatly on the Clostridium butyricum. The meth anol extracts were further reextracted sequentially with hexane, chloroform, ethyl acetate, and butanol for purifying crude methanol extracts. The extract, which was reextracted by butanol, showed the highest antimicrobial activity.

• 한국식품영양학회지
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• 제6권3호
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• pp.208-210
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• 1993

In order to know the influences of heat treatment of yoghurt on pH, $\beta$-galactosidase and viable cells, yoghurt sample was made by general method with Lactobacillus bulgaricus and Streptococcus thermophilus, and the changes in pH, $\beta$-galactosidase-activity and viable cell-count were determined during heating at 55$^{\circ}C$ and 7$0^{\circ}C$. The pH of yoghurt was not changed when the yoghurt was heated at 7$0^{\circ}C$, but at 55$^{\circ}C$ it decreased slightly. The stability of $\beta$-galactosidase was not affected markedly by heat treatment at 55$^{\circ}C$, but was rapidly inactivated at 7$0^{\circ}C$. The heat treatment of yoghurt at 55$^{\circ}C$ had the halb of viable cell in 1 hour, but the heat treatment at 7$0^{\circ}C$ had considerable effect on viable cell in 5 minutes.