• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.22-31
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• 2018

Isoflavone itself is less available in the body without the aid of intestinal bacteria. In this study, we searched for isoflavone-transforming bacteria from human fecal specimens (n = 14) using differential selection media. Isoflavone-transforming activity as the production of dihydrogenistein and dihydrodaidzein was assessed by high-performance liquid chromatography and we found Lactobacillus rhamnosus, named L. rhamnosus vitaP1, through 16S rDNA sequence analysis. Extract from Pueraria lobata (EPL) and soy hypocotyl extract were fermented with L. rhamnosus vitaP1 for 24 and 48 h at $37^{\circ}C$. Fermented EPL (FEPL) showed enhanced anti-tyrosinase activity and antioxidant capacities, important suppressors of the pigmentation process, compared with that of EPL (p < 0.05). At up to $500{\mu}g/ml$ of FEPL, there were no significant cell cytotoxicity and proliferation on B16-F10 melanoma cells. FEPL ($100{\mu}g/ml$) could highly suppress the content of melanin and melanosome formation in B16-F10 cells. In summary, Lactobacillus rhamnosus vitaP1 was found to be able to biotransform isoflavones in EPL. FEPL showed augmented anti-melanogenic potential.

• Journal of Microbiology and Biotechnology
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• v.24 no.2
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• pp.133-143
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• 2014

The development of the gut is controlled and modulated by different interacting mechanisms, such as genetic endowment, intrinsic biological regulatory functions, environment influences and last but no least, the diet influence. In this work, we compared the fecal microbiota of breast-fed (BF), formula-fed (FF), and mixed-fed (MF) infants from Hebei Province, China. By using high-throughput 16S rDNA sequencing analyses, we found some differences in gut microbiota in the three groups. Firmicutes and Proteobacteria were the dominant bacteria at the phylum level in the three groups, where FF infants showed a significant depletion in Bacteroidetes (p < 0.001) and Actinobacteria (p < 0.05). Enterobacteriaceae was the dominant bacteria at the family level in the three groups, but FF infants showed higher Enterobacteriaceae enrichment than BF and MF infants (p < 0.05); the abundance of the Bifidobacteriaceae was only 8.16% in the feces of BF infants, but higher than in MF and FF infants (p < 0.05). The number of genera detected (abundance >0.01%) in BF, MF, and FF infants was only 15, 16, and 13, respectively. This study could provide more accurate and scientific data for the future study of infant intestinal flora.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.8-12
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• 1998

Two experiments were conducted to determine the effects of $MnSO_4$ on controlling harmful microorganisms in vitro and in vivo. The in vitro experiment was conducted to examine the effects of manganese sulfate $(MnSO_4)$ on the reduction of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by growth stimulation of Pediococcus acidilactici (P. acidilactici; lactic acid bacteria). Manganese ion (0.003 %) was found to stimulate the growth of P. acidilactici in the In Vitro system. When E. coli and S. aureus were grown in a mixture with P. acidilactici, their numbers were reduced. This may be the result of a reduction of pH in the medium as a result of better growth of P. acidilactici due to stimulation by the Mn ion. The in vivo experiment was conducted to determine the effects of $MnSO_4$ in diets on controlling harmful microorganisms in fecal samples of pigs. There were no significant differences for the microbial numbers (i.e., total microorganisms, E. coli, lactic acid bacteria and S. aureus) in feces of pigs fed $MnSO_4$ compared to feces of pigs fed the control diet through 7 days. However, on day 7 of experiment, the pH of feces in pigs fed $MnSO_4$ (0.1%) decreased faster than pigs fed the control diet.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.197-201
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• 2014

This study was performed to identify and assess food hazards during dry laver processing. Samples including raw materials, intermediates, and finished products during dried-laver processing were collected from seven dried-laver processing facilities, and microbial analyses were conducted. Microbial levels such as total coliforms and total viable cell count (TVC) increased as the processing steps progressed. TVC and total coliforms ranged from <30 to $9.1{\times}10^7$ CFU/g and <18 to 27,600 MPN/100 g for intermediates and finished products obtained during dried-laver processing, respectively. However, no fecal coliform was detected in the samples. Additionally, food-borne bacteria including Bacillus cereus, Listeria monocytogenes, Salmonella sp., Staphylococcus aureus, and Vibrio parahaemolyticus were not identified in finished products. For heavy metal content, arsenic ranged from 30.18 to 39.05 mg/kg, mercury from 0.005 to 0.009 mg/kg, and cadmium from 0.076 to 0.318 mg/kg dry mass in all finished products. However, lead was not detected in samples tested in this study. In conclusion, dried-laver products were safe based on the levels of food-borne bacteria and heavy metal contents. However, it is important to reduce total viable cell counts and total coliforms during dried-laver processing.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.1-6
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• 2011

We are aim to evaluate antimicrobial effects of the extract of Galla rhois (GR) on the health status and performance of growing and finishing pigs. This study was conducted on the growing and finishing pigs (n = 200) for 130 days in a swine husbandry. The animals were divided with two groups; GR treated group (n = 100) and commercial diet feeding group (n = 100). GR treated animals had provided with commercial diet adding the extract of GR as 0.2%. During the study period, we compared clinical signs, weight increase rate, diet consumption amount, fecal scores, gross findings, necropsy findings, histopathological findings between the treated group and non treated group. After necropsy, bacteria isolation and PCR analysis were conducted with the clinical samples. As the results of this long-term clinical trial, GR showed the antimicrobial effects on respiratory disease and diarrhea. We were identified that GR had the anti-bacterial and anti-viral effects.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1610-1616
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• 2020

Objective: This study was to evaluate the effect of husbandry systems and strains on cecum microbial diversity of Jingyang chickens under the same dietary conditions. Methods: A total of 320 laying hens (body weight, 1.70±0.15 kg; 47 weeks old) were randomly allocated to one of the four treatments: i) Silver-feathered hens in enrichment cages (SEC) with an individual cage (70×60×75 cm), ii) Silver-feathered hens in free range (SFR) with the stocking density of 1.5 chickens per ten square meters, iii) Gold-feathered hens in enrichment cages (GEC), iv) Gold-feathered hens in free range (GFR). The experiment lasted 8 weeks and the cecum fecal samples were collected for 16S rDNA high throughput sequencing at the end of experiment. Results: i) The core microbiota was composed of Bacteroidetes (49% to 60%), Firmicutes (21% to 32%) and Proteobacteria (2% to 4%) at the phylum level. ii) The core bacteria were Bacteroides (26% to 31%), Rikenellaceae (9% to 16%), Parabacteroides (2% to 5%) and Lachnoclostridium (2% to 6%) at the genus level. iii) The indexes of operational taxonomic unit, Shannon, Simpson and observed species were all higher in SFR group than in SEC group while in GEC group than in GFR group, with SFR group showing the greatest diversity of cecum microorganisms among the four groups. iv) The clustering result was consistent with the strain classification, with a similar composition of cecum bacteria in the two strains of laying hens. Conclusion: The core microbiota were not altered by husbandry systems or strains. The free-range system increased the diversity of cecal microbes only for silver feathered hens. However, the cecum microbial composition was similar in two strain treatments under the same dietary conditions.

• KSBB Journal
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• v.32 no.1
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• pp.22-28
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• 2017

Bacteria are among the most common causes of severe diseases in both plants and animals. Salmonella spp. has deleterious effects and is the cause of various transmittable diseases. Because of strains resistivity, side effects and high prices of synthetic antibiotics, it has become essential to explore safe and economical natural sources of antibiotics. In this study, growth inhibitory effects of natural antibiotics present in crude extracts of Galla rhois, Thujae semen, Paeonia japonica, and Armeniacae semen were investigated both in vivo and iv vitro. Ethanol extracts of the above-mentioned plants were prepared and tested against seven serovars of Salmonella and Escherichia coli by disc diffusion method. In addition, the antibacterial effects of the plant extracts were determined in vivo using ducks as model animals. Reverse transcription-polymerase chain reaction was performed using blood and fecal samples of control, infected, and treated groups of the ducks to determine the gene expression levels of the bacteria. Our results confirmed that the Galla rhois ethanol extract had the highest antibacterial activity among the plant extracts when they were used individually. However, the Galla rhois, Thujae semen, and P. japonica ethanol extracts showed stronger antibacterial effects against all the bacterial species used when the extracts were combined at a ratio of 3:3:2, respectively.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.71-82
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• 2013

Objectives: This study was performed in order to investigate hand hygiene practices among food-service businesses employees based on the awareness of hand-washing and load of indicator bacteria on their hands. It focused on the comparison of full-time and part-time workers in food-service workplaces. Methods: A direct-interview questionnaire survey and microbiological analysis were carried out with sixty workers each. Samples for microbiological analysis were collected through a modified glove-juice method from the hands of the food-service workers and were analyzed for aerobic plate count, total coliform, fecal coliform, Escherichia coli, Staphylococcus aureus, and Salmonella spp. Microbiological analysis was done according to the Food Code of Korea. Results: Significant differences (p<0.01) were found in the survey between the full-time and part-time workers in hand-washing frequency, use of hand-washing agents, and hand-drying methods. More full-time workers responded to washing their hands after preparing food, after visiting outside, after handling raw materials, and before putting on gloves/when changing gloves than did part-time workers (p<0.05). No remarkable difference was found in bacterial load on the hands except in the aerobic plate count between the two groups. The detection of E. coli, S. aureus, and Salmonella spp. on the hands of some food-service workers in both groups revealed poor hand hygiene practices. Conclusions: The results of this study indicate that there is a need for training programs in order to improve hand hygiene practices and strict hand hygiene compliance by food-service workers.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1261-1272
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• 2018

The effects of Queso Blanco cheese containing Bifidobacterium longum KACC 91563 was studied on the intestinal microbiota and short chain fatty acids (SCFAs) in healthy companion dogs. There were three experimental groups with five healthy dogs each: a control group, not fed with any cheese, and groups fed with Queso Blanco cheese with (QCB) or without B. longum KACC 91563 (QC) for 8 weeks. Fecal samples were collected 5 times before, during, and after feeding with cheese. Intestinal microbiota was analyzed using two non-selective agar plates (BL and TS) and five selective agar plates (BS, NN, LBS, TATAC, and MacConkey). SPME-GC-MS method was applied to confirm SCFAs and indole in dog feces. The six intestinal metabolites such as acetic, propionic, butyric, valeric, isovaleric acid and indole were identified in dog feces. Administration of B. longum KACC 91563 (QCB) for 8 weeks significantly increased the beneficial intestinal bacteria such as Bifidobacterium ($8.4{\pm}0.55$) and reduced harmful bacteria such as Enterobacteriaceae and Clostridium (p<0.05). SCFA such as acetic and propionic acid were significantly higher in the QCB group than in the Control group (p<0.05). In conclusion, this study demonstrates that administration of Queso Blanco cheese containing B. longum KACC 91563 had positive effects on intestinal microbiota and metabolites in companion dogs. These results suggest that Queso Blanco cheese containing B. longum KACC 91563 could be used as a functional food for companion animals and humans.

• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.175-182
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• 2023

Antibiotics have been used in livestock production for not only treatment but also for increasing the effectiveness of animal feed, aiding animal growth, and preventing infectious diseases at the time when immunity is lowered due to stress. South Korea and the EU are among the countries that have prohibited the use of antibiotics for growth promotion in order to prevent indiscriminate use of antibiotics, as previous studies have shown that it may lead to increase in cases of antibiotic-resistant bacteria. Therefore, this study evaluated the number of antibiotic resistance genes in piglets staging from pre-weaning to weaning. Fecal samples were collected from 8 piglets just prior to weaning (21 d of age) and again one week after weaning (28 d of age). Total DNA was extracted from the 200 mg of feces collected from the 8 piglets. Whole metagenome shotgun sequencing was carried out using the Illumina Hi-Seq 2000 platform and raw sequence data were imported to Metagenomics Rapid Annotation using Subsystem Technology (MG-RAST) pipeline for microbial functional analysis. The results of this study did not show an increase in antibiotic-resistant bacteria although confirmed an increase in antibiotic-resistant genes as the consequence of changes in diet and environment during the experiment.