• 방사선산업학회지
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• 제6권2호
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• pp.177-180
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• 2012

The acid and bile tolerance changes of 5 different lactic acid bacteria (LAB; Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus debruekii) with gamma irradiation were evaluated. The abilities of LAB to survive in the acidic conditions at the stomach and the bile acidic conditions at the beginning of the small intestine are the key functions for applying LAB to probiotics. In the results, all of LAB survived more than 50% after incubation in PBS (pH 2.5) for 2 hr, which indicated more than half of LAB are possible to pass through the stomach. However, gamma irradiation decreased the acid tolerances of LAB. The bile tolerances of all bacteria except Lactobacillus acidophilus were observed to survive at a 3% oxgall concentration in MRS, and 1 kGy of gamma irradiation to LAB did not affect any bile tolerances changes. But gamma irradiated Lactobacillus casei and Lactobacillus casei (3 kGy) showed decreasing survival rate with oxgall added MAS agar. In conclusion, gamma irradiation should be applied to yogurt or fermented foods with care because LAB could be changes their properties on acid and bile tolerances.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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• pp.349-352
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• 2004

Twelve strains of Lactobacillus acidophilus isolated from feces of human or animal sources were tested for probiotic properties such as cholesterol assimilation, bile and acid tolerances, and CLA production. Although the cultures showed some variation with respect to each test, the 12 strains could be classified into 3 groups based on their ability to assimilate cholesterol. The cholesterol assimilation showed positive correlation with bile tolerance and negative correlation with acid tolerance. The cholesterol assimilation of L. acidophilus strains may not be related to the deconjugation activity, but may in fact be attributed to its bile tolerance. CLA production by lactic acid bacteria (LAB) exhibited a wide variation that ranged from 2.69 to 7.64 mg/g fat. CLA production of Bifidobacterium longum ATCC 15707 was the highest among the LAB tested, but there was no evidence for differences in CLA production between genus and species.

• 한국축산식품학회지
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• 제32권4호
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• pp.409-413
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• 2012

This study aimed to compare the probiotic characteristics of twelve strains of Lactobacillus acidophilus including cholesterol assimilation and conjugated linoleic acid (CLA) production. Cholesterol assimilation exhibited some variation among L. acidophilus strains, which could be classified into three groups based on their assimilation levels (p<0.05). The high cholesterol assimilation group exhibited a significantly higher tolerance to 0.3 and 0.5% bile acid than the low cholesterol assimilation group (p<0.05). Cholesterol assimilation showed positive correlation with 0.5% bile tolerance, and a negative correlation with acid tolerance (p<0.01). Glycocholate deconjugation activity showed no relationship with cholesterol assimilation, whereas taurocholate deconjugation activity was shown to have negative correlation with cholesterol assimilation (p<0.05). CLA production by L. acidophilus strains exhibited a wide variation, ranging from 2.69 to 5.04 mg/g fat. CLA production of L. acidophilus GP1B was the highest among the tested strains, but there was no evidence for differences in CLA production in strain specificity. Based on these results, the cholesterol assimilation of L. acidophilus strains may not be related to deconjugation activity, but may in-fact be attributed to their bile-tolerance.

• 한국축산식품학회지
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• 제35권4호
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• pp.551-556
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• 2015

The aim of this study was to evaluate the functional properties of lactic acid bacteria from various sources and to identify strains for use as probiotics. Ten Lactobacillus strains were selected and their properties such as bile tolerance, acid resistance, cholesterol assimilation activity, and adherence to HT-29 cells were assessed to determine their potential as probiotics. Lactobacillus sp. JNU 8829, L. casei MB3, L. sakei MA9, L. sakei CH8, and L. acidophilus M23 were found to show full tolerance to the 0.3% bile acid. All strains without L. acidophilus M23 were the most acid-tolerant strains. After incubating the strains at pH 2.5 for 2 h, their viability decreased by 3 Log cells. Some strains survived at pH 2.5 in the presence of pepsin and 0.3% bile acid. Lactobacillus sp. JNU 8829, L. acidophilus KU41, L. acidophilus M23, L. fermentum NS2, L. plantarum M13, and L. plantarum NS3 were found to reduce cholesterol levels by ＞50% in vitro. In the adhesion assay, Lactobacillus sp. JNU 8829, L. casei MB3, L. sakei MA9, and L. sakei CH8 showed higher adhesion activities after 2 h of co-incubation with the intestinal cells. The results of this comprehensive analysis shows that this new probiotic strain named, Lactobacillus sp. JNU 8829 could be a promising candidate for dairy products.

• 한국축산식품학회지
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• 제24권2호
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• pp.164-170
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• 2004

건강한 성인의 분변으로부터 담즙산 분해능이 우수한 젖산균의 분리를 위하여 무작위 선별법과 도말법을 사용하여 층 120주의 젖산균을 1차 분리하였고, 그중 5종의 젖산균을 최종 선발하였다. 유용한 젖산균이 갖추어야할 중요한 성질인 내산성, 내담즙산성, 대장균 저해능을 시험한 결과 Lactobacillus sp. CK 102이 가장 우수한 균주로 나타났다. Lactobacillus sp. CK 102 균주는 pH 2.0에서 68％ 이상의 내성과 1.0％ 담즙산이 함유된 배지에서 90％이상의 내성을 나타냈으며 MRS 배지에서 대장균과 혼합 배양시 18시간 이내에 대장균을 100％ 사멸시켰다. 젖산균제로써 기능이 가장 우수한 균주인 Lactobacillus sp. CK 102를 API kit와 16S rRNA sequencing 방법을 사용하여 동정한 결과 Lactobacillus platarum 으로 밝혀졌다. 이상의 결과에서 분리한 Lactobacillus sp. CK 102는 생균제로서 안전하게 이용할 수 있는 것으로 나타났다.

• Journal of Dairy Science and Biotechnology
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• 제36권3호
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• pp.171-177
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• 2018

In this study, we aimed to investigate the effects of low-temperature encapsulation on the viability of Weissella cibaria CMU under harsh conditions and in freeze-dried foods during storage. The capsules were prepared by gelation of sodium caseinate at different concentrations (5%, 6%, 7%, and 8%) with a combination of 0.5% gellan gum and 2% $glucono-{\delta}-lactone$. The size distribution of the capsules was determined using a Mastersizer 3000 laser diffraction particle size analyzer. Scanning and transmission electron microscopy revealed that the capsule with 6% sodium caseinate had a smooth and rounded external surface, with reproducibility. The acid, bile, and heat tolerances of the encapsulated cells were significantly higher than those of the control under prolonged acid (5 h), bile (12 and 24 h), and heat (2 h) exposure, respectively. During storage for up to 6 months at $4^{\circ}C$ or $25^{\circ}C$, the viability of encapsulated Weissella cibaria CMU in beef and vegetable rice porridge was effectively improved.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.131-136
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• 2006

During lactic acid bacteria (LAB) transit through the gastrointestinal tract, ingested microorganisms were exposed to successive stress factors, including low pH in the human stomach and in bile acid. These stress factors can be used as criteria for the selection of a viable probiotic strain. Four such strains (Lactobacillus helveticus SGU 0011, Lactobacillus pentosus SGU 0010, Streptococcus thermophilus SGU 0021 and Lactobacillus casei SGU 0020) were isolated from raw milk. When the identified LAB were exposed to synthetic gastric juice, whereas L. casei SGU 0020 and S. thermophilus SGU 0021 exhibited a 0% survival rate, L. helveticus SGU 0011 and L. pentosus SGU 0010 exhibited 60% and 95% survival rates. L. casei SGU 0020 and S. thermophilus SGU 0021 could not be examined with regard to their tolerances to artificial bile juice, as they uniformly died upon exposure. However, L. helveticus SGU 0011 and L. pentosus SGU 0010 individually survived at rates of 39% and 93%. Also, all four of these strains were confirmed to be tolerant of ten different antibiotics.

• 한국식품과학회지
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• 제39권6호
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• pp.681-687
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• 2007

Probiotics로서의 사용을 위한 우수 젖산균주 선발을 위해 김치 및 발효유 제품으로부터 분리한 젖산균과 공시 젖산균주를 대상으로 내산성, 내담즙성, 장내 점착능, 병원성균 억제능 등의 probiotics 특성과 장관면역활성, mitogenic activity 및 대식세포 활성화 등의 면역활성을 검토하였다. 내산성 실험의 결과, Lactobacillus acidophilus DDS-1, Lb. acidophilus B-3208, Lb. plantarum과 Leuconostoc mesenteroides ssp. mesenteroides ATCC 8293의 경우 생존률이 50% 이상으로 나타났으며, 특히 Lb. acidophilus DDS-1과 Lb. acidophilus B-3208의 경우에는 70% 정도의 높은 생존률을 나타내었다. 또한 젖산균주의 담즙산 내성에서는 Lactococcus lactis ssp. lactis ATCC 7962를 제외한 모든 균주가 3% oxgall이 함유된 MRS배지에서도 성장이 가능한 것으로 관찰되었다. 젖산균주의 장내 점착능 면에서 볼 때, Lb. acidophilus DDS-1, Lb. acidophilus B-3208과 Bifidobacterium bifidum KCTC 3357의 장내 점착능이 실험에 사용된 다른 젖산균주와 비교하여 우수하다고 관찰되었으며, 특히 Lb. acidophilus DDS-1과 B-3208의 장내점착능이 높게 나타났다. 젖산균주의 병원성균 억제능 실험의 결과, Lb. acidophilus DDS-1, Lb. acidophilus B-3208 및 B. bifidum KCTC 3357은 Staphylococcus aureus를 제외한 Escherichia coli O157:H7 ATCC 43895, Listeria monocytogenes ATCC 59414, 그리고 Salmonella enteritidis ATCC 49313에 대해 높은 증식억제능을 나타내었다. 젖산균의 세포질 획분과 세포벽 획분을 대상으로 면역활성 실험을 실시한 결과, 장관면역 활성은 젖산균의 세포질 획분에서 양성 대조군으로 사용한 LPS와 같은 수준의 면역활성을 나타내었고, 특히 Lb. acidophilus속 균주들의 세포벽 획분의 장관 면역활성이 다른 균주보다 높게 나타났다. 한편 젖산균주의 세포질과 세포벽 성분에 대한 비장 림프구의 증식능은 대조군과 비슷한 수준으로 낮게 관찰되었으나, 이들의 대식 세포증식능은 세포벽 및 세포질 모두의 획분에서 대조군보다 높았으며 특히 세포벽 획분의 경우에는 양성대조군인 LPS 보다 높거나 유사한 정도의 높은 활성을 확인할 수 있었다. 이상의 결과로부터 시험 균주 중에서 Lb. acidophilus 균주인 DDS-1과 B-3208이 프로바이오틱스로서 요구되는 조건을 충족시킨다는 것을 알 수 있었으며, 이들 균주의 상업적 이용 가능성을 재차 확인할 수 있었다.

• 한국수산과학회지
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• 제44권6호
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• pp.605-611
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• 2011

This study examined the suitability of characteristics of potential strains of probiotic bacteria. Among 25 lactic acid bacteria isolated from Korean traditional fermented food, the Hard Clam Meretrix meretrix Shikhae, the SH-10 strain, which exhibited superior resistance to low pH and bile salts, was selected as a potential probiotic bacteria. By examining carbohydrate utilization, morphological properties, and the 16S rRNA gene sequence, the SH-10 strain was identified as Pediococcus pentosaceus (hereafter, P. pentosaceus SH-10). P. pentosaceus SH-10 was resistant to amikacin, cefotetan, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, and vancomycin. Tests of antimicrobial activities against pathogens such as Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis, and Staphylococcus aureus, indicated that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria. These results suggest that P. pentosaceus SH-10 can be developed as a probiotic bacteria.

• 한국식품조리과학회지
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• 제21권2호
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• pp.217-224
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• 2005

The storage characteristics of frozen soy yogurt prepared with hydrolyzed soy protein isolates were evaluated. In order to facilitate lactic fermentation bacteria grow and produce lactic acid as fast rate as possible, soy protein isolate(SPI) was hydrolyzed using two kinds of proteases; bromelain and a-chymotrypsin. The cultural systems employed thereafter for lactic fermentations were Bifidobacterium bifidum or B. bifidum and Lactobacillus bulgaricus. The viable cell counts, normal- and bile acid tolerances from the mixed cultures of B. bifidum and L. bulgaricus decreased sharply during the initial first 3 days of frozen storage and then showed a gradual decrease thereafter. Melt-down percent of the all frozen products have been favorably affected as was shown by less melting at raised testing temperature during 28 days of frozen storage except for the initial 3 days during which a minor change has been observed. Among the various volatile flavor components, the contents of acetaldehyde, acetone, diacetyl and methanol generally increased during the frozen storage. In sensory test, the frozen soy yogurt prepared with a-chymotrypsin and mixed culture of B. bifidum and L. bulgaricus was the most desirable, the highest scores in sourness, bitterness and mouthfeel.