• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.46-55
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• 2022

Clostridioides difficile infection (CDI) is a significant cause of hospital-acquired and antibiotic-mediated intestinal diseases and is a growing global public health concern. Overuse of antibiotics and their effect on normal intestinal flora has increased the incidence and severity of infections. Thus, the development of new, effective, and safe treatment options is a high priority. Here, we report a new probiotic strain, Bacillus amyloliquefaciens (BA PMC-80), and its in vitro/in vivo anti-C. difficile effect as a prospective novel candidate for replacing conventional antibiotics. BA PMC-80 showed a significant anti-C. difficile effect in coculture assay, and its cell-free supernatant (CFS) also exhibited a considerable anti-C. difficile effect with an 89.06 ㎍/ml 50% minimal inhibitory concentration (MIC) in broth microdilution assay. The CFS was stable and equally functional under different pHs, heat, and proteinase treatments. It also exhibited a high sensitivity against current antibiotics and no toxicity in subchronic toxicity testing in hamsters. Finally, BA PMC-80 showed a moderate effect in a hamster CDI model with reduced infection severity and delayed death. However, further studies are required to optimize the treatment condition of the hamster CDI model for better efficacy and identify the antimicrobial compound produced by BA PMC-80.

• 한국수산과학회지
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• 제56권1호
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• pp.89-98
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• 2023

We evaluated the effects of prebiotic (mannan oligosaccharides, Mos) and probiotic diet supplements on growth performance, innate immunity, antioxidant activity, and intestinal changes in the microbial flora of red seabream Pagrus major. A basal diet (Con) was formulated to meet the nutrient requirement of red seabream. The dietary starch in Con was replaced with 0.6% Mos, Lactobacillus plantarum, Bacillus subtilis, B. licheniformis and probiotic mixture (labeled as Mos, Pro-LP, Pro-BS, Pro-BL and Pro-Mix, respectively). We stocked 450 fish in 18 polypropylene tanks (400 L) in triplicate groups per dietary treatment. The fish were fed one of the diets twice (08:30, 18:30 h) a day for 63 days. Lysozyme activity was significantly higher in all the supplemented groups than that of the Con group. The immunoglobulin level of Pro-Mix, anti-protease activity of Pro-BL, and glutathione peroxidase and superoxide dismutase activity of Pro-BS, Pro-BL and Pro-Mix groups were significantly higher than those of the Con group. The ratio of total Vibrio/heterotrophic marine bacteria counts was significantly lower in Pro-LP, Pro-BL and Pro-Mix groups than that of the Con group. Therefore, dietary supplementation of Mos and probiotics to improves immune response and antioxidant enzyme activity and inhibits Vibrio bacteria in the intestine.

• 한국임상수의학회지
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• 제28권5호
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• pp.516-518
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• 2011

한국 황새복원센터에서 사육중인 황새의 정상 장내 세균총을 검사하기 위한 조사를 실시하였다. 44마리의 건강한 황새의 총배설강으로부터 44개의 분변시료를 채취하여 호기 및 혐기조건에서 배양하였다. 배양된 미생물의 16Sribosomal RNA 및 heat shock protein 60 유전자의 염기서열을 조사하였다. 호기조건 하에서는 Enterococcus faecalis, Escherichia coli, Bacillus spp., Enterococcus avium, Enterococcus gallinarum, Pseudomonas spp., Alcaligenes spp., Enterobacter spp., Corynebacterium spp., Proteus mirabilis가 동정되었다. 혐기조건 하에서는 E. coli, Clostridium tertium, En. faecalis, P. mirabilis가 동정되었다. 모든 시료에서 E. coli, En. faecalis 혹은 두 가지 모두가 분리되었다. 이러한 정상 황새의 장내 미생물 정보는 향후 분변 배양 결과의 해석에 도움이 될 것으로 판단된다.

• Toxicological Research
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• 제26권4호
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• pp.301-313
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• 2010

Growth promoters including hormonal substances and antibiotics are used legally and illegally in food producing animals for the growth promotion of livestock animals. Hormonal substances still under debate in terms of their human health impacts are estradiol-$17\beta$, progesterone, testosterone, zeranol, trenbolone, and melengestrol acetate (MGA). Many of the risk assessment results of natural steroid hormones have presented negligible impacts when they are used under good veterinary practices. For synthetic hormonelike substances, ADIs and MRLs have been established for food safety along with the approval of animal treatment. Small amounts of antibiotics added to feedstuff present growth promotion effects via the prevention of infectious diseases at doses lower than therapeutic dose. The induction of antimicrobial resistant bacteria and the disruption of normal human intestinal flora are major concerns in terms of human health impact. Regulatory guidance such as ADIs and MRLs fully reflect the impact on human gastrointestinal microflora. However, before deciding on any risk management options, risk assessments of antimicrobial resistance require large-scale evidence regarding the relationship between antimicrobial use in food-producing animals and the occurrence of antimicrobial resistance in human pathogens. In this article, the risk profiles of hormonal and antibacterial growth promoters are provided based on recent toxicity and human exposure information, and recommendations for risk management to prevent human health impacts by the use of growth promoters are also presented.

• 미생물학회지
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• 제27권2호
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• pp.155-161
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• 1989

Lactobacillus sporogenes를 NTG로 처리하여 rifampicin에 내성인 돌연변이 균주를 얻었으며, 이중 58 종이 rifampicin에 현저한 내성을 보였다. 9종의 mutants를 선발하여 그 생화학적 특성을 검토한 결과, 포자형성능, 산생성능, E. coli 생육억제능 면엣 parent와 유사한 특성을 나타내었다. In vitro 시험을 통해ㅐ, 내성균주들에 의해 rifampicin이 불활성화 되지 않음이 밝혀졌다. 따라서 이들 mutants를 유산균 제제원으로 사용할 수 있으며, 그 제제는 rifampicin과 병용투여시, 효과적인 정장제로 사용될 수 있을 것으로 사료된다.

• Journal of Dairy Science and Biotechnology
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• 제18권1호
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• pp.47-60
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• 2000

Over decades of work, the probiotic research has grown rapidly with a number of new cultures, which is claimed a variety of benefit. However, many of the specific effects attributed to the ingestion of probiotics remain convoluted and scientifically unsubstantiated. Accordingly, the scientific community faces a greater challenge and must objectively seek cause and effect relationships for many potential and currently investigated probiotic species. Rational selection and design of probiotics remains an important challenge and will require a solid information about the physiology and genetics of candidate strains relevant to their intestinal roles, functional activities, and interaction of with other resident micro flora. As far as beneficial culture of lactic acid bacteria (LAB) is concerned, simple, cost-effective, and exact identification of candidate strains is of foremost importance among others. Until recently, the relatedness of bacterial isolates has been determined sorely by testing for one or several phenotyphic markers, using methods such as serotyping, phage-typing, biotyping, and so forth. However, there are problems in the use of many of these phenotype-based methods. In contrast, some of newer molecular typing methods involving the analysis of DNA offer many advantages over traditional techniques. These DNA-based methods have the greater discriminatory power than that of phenotypic procedures. This review focuses on the importance and the basis of molecular typing methods along with some considerations on de-sign and selection of probiotic culture for human consumption.

• 한국미생물·생명공학회지
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• 제46권4호
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• pp.334-345
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• 2018

Spore-forming Bacillus species are commercially available probiotic formulations for application in humans. They have health benefits and help prevent disease in hosts by combating entero-pathogens and ameliorating antibiotic-associated diarrhea. However, the molecular and cellular mechanisms of these benefits remain unclear. Here, we report the draft genome of a potential probiotic strain of Bacillus clausii B106. We mapped and compared the probiotic profile of B106 with other reference genomes. The draft genome analysis of B106 revealed the presence of ADI pathway genes, indicating its ability to tolerate acidic pH and bile salts. Genes encoding fibronectin binding proteins, enolase, as well as a gene cluster involved in the biosynthesis of exopolysaccharides underscored the potential of B106 to adhere to the intestinal epithelium and colonize the human gut. Genes encoding bacteriocins were also detected, indicating the antimicrobial ability of this isolate. The presence of genes encoding vitamins, including Riboflavin, Folate, and Biotin, also indicated the health-promoting ability of B106. Resistance of B106 to multiple antibiotics was evident from the presence of genes encoding resistance to chloramphenicol, ${\beta}$-lactams, Vancomycin, Tetracycline, fluoroquinolones, and aminoglycosides. The findings indicate the significance of B. clausii B106 administration during antibiotic treatment and its potential value as a probiotic strain to replenish the health-promoting and disease-preventing gut flora following antibiotic treatment.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1207-1210
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• 2021

Lactobacillus amylovorus are known to exist in the intestinal flora of healthy cattle or pigs. The L. amylovorus strain 1394N20 was isolated from the feces of the Hanwoo calf (Bos taurus coreanae). The genome of strain 1394N20 consists of a single circular chromosome (2,176,326 bp) with overall guanine + cytosine content of 37.8 mol%. Moreover, 2,281 protein-coding sequences, 15 rRNAs, and 65 tRNAs genes were identified in the chromosome based on the results of annotation. The bacterium has a gene encoding endoglucanase, an enzyme that hydrolyzes the 1,4-β-D-glycosidic linkages in cellulose, hemicellulose, lichenin, and cereal β-D-glucans. Genomic sequencing of L. amylovorus strain 1394N20 reveals the immense potential of the strain as a probiotic with nutrient digestibility.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.856-864
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• 2019

Objective: The objective of this study was to investigate effects of mixed organic acids (MOA) on nutrient digestibility, volatile fatty acids composition and intestinal microbiota in growing-finishing pigs fed high wheat bran diet. Methods: Six crossbred barrows ($Duroc{\times}Landrace{\times}Yorkshire$), with an average body weight $78.8{\pm}4.21kg$, fitted with T-cannulas at the distal ileum, were allotted to a double $3{\times}3$ Latin square design with 3 periods and 3 diets. Each period consisted of a 5-d adjustment period followed by a 2-d total collection of feces and then a 2-d collection of ileal digesta. The dietary treatments included a corn-soybean-wheat bran basal diet (CTR), mixed organic acid 1 diet (MOA1; CTR+3,000 mg/kg OA1), mixed organic acid 2 diet (MOA2; CTR+2,000 mg/kg OA2). Results: Pigs fed MOA (MOA1 or MOA2) showed improved (p<0.05) apparent total tract digestibility (ATTD) of gross energy, dry matter and organic matter, and pigs fed MOA2 had increased (p<0.05) ATTD of neutral detergent fiber compared to CTR. Dietary MOA supplementation decreased (p<0.05) pH value, and improved (p<0.01) concentrations of lactic acid and total volatile fatty acids (TVFA) in ileum compared to CTR. Pigs fed MOA showed higher (p<0.05) concentration of acetic acid, and lower (p<0.05) content of formic acid in feces compared to CTR. Pigs fed MOA1 had increased (p<0.05) concentration of TVFA and butyric acid in feces. Pigs fed MOA1 showed higher concentration of Lactobacillus and lower concentration of Escherichia in feces compared to CTR. Conclusion: Dietary supplementation of MOA 1 or 2 could improve nutrients digestibility, TVFA concentration and intestinal flora in growing-finishing pigs fed high fiber diet.

• 한국식품과학회지
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• 제41권6호
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• pp.673-680
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• 2009

본 연구에서는 비만의 원인 중 하나인 장내균총의 변화를 개선하고자 in vitro 상에서 천연소재를 탐색하였고 선발된 소재인 오미자로 항균활성과 기능성을 분석하고 세포에 대한 독성 및 동물 실험을 수행하였다. 나아가 풍미증진과 기능성 가미를 위한 오미자 열수추출물을 첨가한 음료로의 개발 가능성을 확인하고자 하였다. 96 well plate법을 이용하여 screening한 결과, 유익균인 B. fragilis와 B. spp.의 활성을 증진시키고, 유해균인 E. limosum과 C. perfringens을 억제시키는 오미자를 선발하였다. 오미자 열수 추출물의 항균활성을 paper disc method를 이용하여 실험한 결과 E. limosum, B. fragilis, C. perfringens, C. difficile에 대한 항균력을 가지고 B. bifidum에 대한 항균력은 나타내지 않았다. 이 결과를 바탕으로 MIC를 측정한 결과, E. limosum, B. fragilis, C. perfringens, C. difficile를 오미자 열수 추출물 $1\;{\mu}g/mL$의 농도에서 최소 저해 하였다. 기능성을 가진 오미자 열수추출물을 이용한 음료로의 제품화를 위해 과채류 주스의 살균온도인 $96^{\circ}C$, 15초를 기준으로 $60-100^{\circ}C$에서 $10^{\circ}C$씩 변화를 주어 10분씩 처리하여 실험한 결과, 항균활성의 경우 대체로 안정하였고 큰 항균력을 위해서는 $80^{\circ}C$ 이상 살균 처리하는 것이 좋을 것으로 사료된다. 또한 열처리에 따른 총 폴리페놀 함량과 전자공여능을 이용한 항산화력의 변화를 측정한 결과 대체로 안정하였다. 이는 음료 개발에 있어서 중요한 이점이 될 것으로 사료된다. 또한 열처리에 따른 항균활성과 항산화를 나타내는 폴리페놀 함량과 전자공여능을 비교해봤을 때 서로 비례하는 것으로 보아 폴리페놀 함량과 전자공여능의 함량이 항균활성에 관련이 있을 것으로 사료된다. 소장상피세포에 대한 독성 유무를 확인하기 위해 소장상피 정상세포인 Caco-2에 대한 오미자 열수 추출물의 독성 영향을 MTT assay를 통해 확인하였다. 그 결과 고농도인 $5\;{\mu}g/mL$에서도 세포에 영향을 주지 않았다. 이 결과를 통해 미루어 볼 때 동물 실험하기 전, in vitro 상에서 오미자 추출물이 세포에 영향을 주는지 여부를 판단한 것으로 다음 진행되는 동물 실험에 대한 오미자 추출물의 안정성을 확인하였다. 동물 실험은 high-fat-diet rats에 오미자 열수 추출물을 0.5 mg/kg/day 투여한 경우 체중증감에 영향을 미치지 않았다. 장내미생물 균총 변화에서 control군과 extract 투여군을 비교한 결과, in vitro 실험결과와 같이 Bifidobacterium spp.를 7.62% 증진시키고 Clostridium spp.를 12.39% 감소시켰다. 또한 비만과 관련된 Eubacterium을 억제시켰다. 이는 오미자가 유익균을 증진시키고, 유해균은 감소시키는 장내 균총을 유익한 균총으로 개선시키는 식품소재로 이용이 가능할 것으로 기대된다. 오미자 추출물을 첨가한 음료의 관능평가 결과 인체 내에 부족하기 쉬운 미량 영양소를 보충해주는 자작 나무수액에 장내 균총 변화에 영향을 주는 오미자 추출물과 기능성 올리고당인 자일리톨을 첨가하여 관능평가한 결과 전반적 기호도는 자작나무수액 100%, 오미자추출물 5%, 자일리톨 5%을 첨가한 sample C가 6.68로 다른 sample에 비해 높은 점수를 받았다(p<0.05). 그러므로 5% xylitol, 5% 오미자 열수 추출물을 첨가한 sample C가 관능적으로 우수함을 보여 앞으로 맛과 기능성, 풍미를 가미한 음료로의 개발이 가능할 것으로 생각된다.