• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1510-1518
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• 2015

In this work, we wanted to develop a probiotic from famous longevity villages in Korea. We visited eight longevity villages in Korea to collect fecal samples from healthy adults who were aged above 80 years and had regular bowel movements, and isolated lactic-acid-producing bacteria from the samples. Isolated colonies that appeared on MRS agar containing bromophenol blue were identified by means of 16S rRNA sequencing, and 102 of the isolates were identified as lactic-acid-producing bacteria (18 species). Lactobacillus fermentum was the most frequently found species. Eight isolates were selected on the basis of their ability to inhibit the growth of six intestinal pathogens (Escherichia coli O157:H7, Salmonella enterica subsp. enterica Typhimurium, Salmonella enterica subsp. enterica Enteritidis, Enterococcus faecalis, Staphylococcus aureus, and Listeria monocytogenes) and their susceptibility to 15 antimicrobial agents. Among these eight isolates, four Lactobacillus fermentum isolates were found not to produce any harmful enzymes or metabolites. Among them, Lactobacillus fermentum isolate no. 24 showed the strongest binding to intestinal epithelial cells, the highest immune-enhancing activity, anti-inflammation activity, and anti-oxidation activity as well as the highest survival rates in the presence of artificial gastric juice and bile solution. This isolate, designated Lactobacillus fermentum PL9988, has all the characteristics for a good probiotic.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.207-213
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• 2015

High-quality protein ingredients have been used in nursery diets, in spite of expensive ingredients, to minimize nutritional deficiency and disease problems. Recent dramatic increases in prices of protein products for nursery diets have exacerbated the challenge. Spray-dried egg may be a part of the solutions. Therefore, this review describes the value of spray-dried egg in nursery diets as a high-quality protein source. Spray-dried egg is egg by-product and is produced by only eggs without shell that are below the USDA Grade B standards. Spray-dried egg is an excellent nutrient source: 1) highly digestible, 2) excellent balance of amino acids, 3) rich content of fat, and 4) high metabolizable energy. These can be attributed to growth of nursery pigs. Beyond the provision of bioavailable nutrients, spray-dried egg also may provide specific physiological benefits. Spray-dried egg contains 1) immunoglobulin antibodies (IgY: IgG in egg yolk) that may attach to intestinal pathogens and excrete them and 2) lysozymes antimicrobial protein that can damage bacteria cell wall. Thereby feeding spray-dried egg may reduce concentration of intestinal pathogen and thus improve potential gut health or enteric disease resistance in nursery pigs. This is important for physiologically immature weaned pigs. Based on these benefits, spray-dried egg is believed to have the same benefits as spray-dried plasma protein and milk products in diets for nursery pigs. Therefore, it is suggested that spray-dried egg has a great potential as a valuable protein source in nursery diets.

• Journal of Life Science
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• v.22 no.5
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• pp.605-612
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• 2012

Spore-forming bacteria are being used as probiotic supplements for human and animal use, due to their low pH stability and ability to survive the gastric barrier. In this study, the BCNU 9028 strain was screened from meju, a Korean fermented soybean food starter. Biochemical and physiological characteristics, as well as 16S rDNA sequence analyses, indicate that this strain belongs to the genus $Bacillus$. $Bacillus$ sp. BCNU 9028 showed a 92% survivability at pH 2.5 and could also withstand 0.3% ox bile. Furthermore, it was postulated that $Bacillus$ sp. BCNU 9028 could prevent biofilm formation and adherence of food-borne pathogens such as $Listeria$ $monocytogenes$, $S.$ $aureus$ and $E.$ $coli$ on the basis of its autoaggregation and coaggregation capacity with food-borne pathogens. It was shown that BCNU 9028 has good abilities to adhere to the intestinal tract from its hydrophobic character (63.3%). The $Bacillus$ sp. BCNU 9028 strain especially elicited antibacterial activity against both Gram-positive and -negative pathogens. These findings suggested that the $Bacillus$ sp. BCNU 9028 strain could be used as a potential probiotic.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.1-12
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• 2010

The immune system is generally divided into the innate and the adopted immune systems, both protecting the body from pathogens. Recently, allergies, a disease associated with an imbalanced immune system, have increased rapidly in developed countries. Prevailing symptoms of allergic diseases are eczema, allergic rhinitis, asthma, inflammatory bowel disease, and food allergy. Probiotic bacteria, mainly consisting of lactic acid bacteria, are used in the prevention and treatment of allergic diseases. The function of them is to stimulate the intestinal immune cells and form a complex signal network to activate other immune cells. Beneficial health effects of probiotics are based on the hygiene hypothesis, which suggests that sanitary environment is important for health, but limited exposure to environmental factors increases allergic diseases. An immunoregulatory effect of probiotic bacteria is demonstrated by controlled trial, animal model, in vitro, in vivo and ex vivo designs. However, the immunoregulatory effect of probiotic bacteria is controversial because it depends on probiotic strains, a dose and a type of diseases. In this review, we discussed clinical evidences on immunoregulatory effects of probiotic bacteria.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1353-1362
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• 2005

The stressful physiological and environmental conditions around weaning often promote the proliferation of pathogens in the digestive tract of piglets resulting in diarrhoea and reduced daily weight gain. Typical dietary practices to maintain growth performance and health have led to an increased use of antimicrobial growth promoters. Due to the advanced ban of antibiotics in pig production, new concepts have been developed to secure animal health and growth performance, feed efficiency, and product quality as well. Several naturally occurring compounds seem to beneficially affect the composition and activity of the microflora in the gastrointestinal tract (GIT) of pigs. These are, among others, organic acids, probiotics, prebiotics, and enzymes. Organic acids are already widely used, especially in pigs, due to their positive effects on GIT health and growth performance. Probiotics have been shown to be effective against diarrhoea though effects may be dependent on diet composition and environmental conditions. Prebiotics may influence composition and activity of the intestinal microflora. Additionally, pre- and probiotics may exert positive influences on immune response, whereas enzymes may enhance feed digestibility by breaking down anti-nutritional factors. In the following, the focus will be directed to the role of organic acids, probiotics, prebiotics, and feeding enzymes as potential modulators of GIT health.

• Toxicological Research
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• v.26 no.4
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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.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.631-640
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• 2011

Milk oligosaccharides are the complex mixture of six monosaccharides namely, D-glucose, D-galactose, N-acetyl-glucosamine, N-acetyl-galactosamine, L-fucose, and N-acetyl-neuraminic acid. The mixture is categorized as neutral and acidic classes. Previously, 25 oligosaccharides in bovine milk and 115 oligosaccharides in human milk have been characterized. Because human intestine lacks the enzyme to hydrolyze the oligosaccharide structures, these substances can reach the colon without degradation and are known to have many health beneficial functions. It has been shown that this fraction of carbohydrate can increase the bifidobacterial population in the intestine and colon, resulting in a significant reduction of pathogenic bacteria. The role of milk oligosaccharides as a barrier against pathogens binding to the cell surface has recently been demonstrated. Milk oligosaccharides have the potential to produce immuno-modulation effects. It is also well known that oligosaccharides in milk have a significant influence on intestinal mineral absorption and in the formation of the brain and central nervous system. Due to its structural resemblance, bovine milk is considered to be the most potential source of oligosaccharides to produce the same effect of oligosaccharides present in human milk. This review describes the characteristics and potential health benefits of milk oligosaccharides as well as the prospects of oligosaccharides in bovine milk for use in functional foods.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.595-598
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• 2000

Aeromonas hydrophila is a pathogen to fish as well as human. It is a food-borne disease, and causes severe mortality in fish, and sometimes severe septicemia in human. In this study, a rapid detection method using latex agglutination has been developed for A. hydrophila. Polyclonal antibodies were raised against membrane and whole cells of three isolates from rainbow trout. Among these, latex particles coated with antibodies raised against whole cells of isolate No. 2 showed the best sensitivity. With latex particles coated with this antibody, we could detect $5{\times}10^4$ CFU of A. hydrophila in 5 min. The cross-reactivity with bacteria constituting the normal intestinal microflora and other pathogens for rainbow trout was insignificant. This latex agglutination assay method produced positive reaction with all clinical isolates of A. hydrophila which were identified by species-specific PCR for 16S rRNA in A. hydrophila.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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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.

• Korean Journal of Veterinary Research
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• v.59 no.1
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• pp.33-36
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• 2019

This study examined complex infections with various enteropathogens and the genetic diversity of bovine norovirus (BNoV) in 932 fecal samples from diarrheic calves in South Korea. Overall, seventeen (1.8%) of the samples tested positive for BNoV following RT-PCR examination. All BNoV-positive samples were co-infected with other intestinal pathogens, including bovine Rotavirus, Giardia, Cryptosporidium, and Escherichia coli. The genetic diversity of the BNoVs shared high nucleotide identity (98.1-99.5%) and amino acid homology (93.5-98.1%) with genotype 2 BNoV (GIII.2) strains. In conclusion, BNoV infections with GIII genotypes were detected in complex infections of diarrheic calves in South Korea.