• Animal Bioscience
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• v.35 no.4
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• pp.556-566
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• 2022

Objective: This study aimed to determine the appropriate supplementation level of lactic acid bacteria (LAB; Lactobacillus plantarum and Bacillus clausii), yeast (Saccharomyces cariocanus and Wickerhamomyces anomalus) for degrading free gossypol and glucosinolate in the fermented total mixed ration (TMR) containing cottonseed meal (CSM) or rapeseed meal (RSM), to improve the utilization efficiency of these protein sources. Methods: For LAB, L. plantarum or B. clausii was inoculated at 1.0×10⁸, 1.0×10⁹, 1.0×10¹⁰, and 1.0×10¹¹ colony-forming unit (CFU)/kg dry matter (DM), respectively. For yeast, S. cariocanus or W. anomalus was inoculated at 5×10⁶, 5×10⁷, 5×10⁸, and 5×10⁹ CFU/kg DM, respectively. The TMR had 50% moisture and was incubated at 30℃ for 48 h. After fermentation, the chemical compositions, and the contents of free gossypol and glucosinolate were determined. Results: The results showed that the concentration of free gossypol content was reduced (p<0.05), while that of the crude protein content was increased (p<0.05) in the TMR containing CSM inoculated by B. clausii (1×10⁹ CFU/kg DM) or S. cariocanus (5×10⁹ CFU/kg DM). Similarly, the content of glucosinolate was lowered (p<0.05) and the crude protein content was increased (p<0.05) in TMR containing RSM inoculated with B. clausii (1×10¹⁰ CFU/kg DM) or S. cariocanus (5×10⁹ CFU/g DM). Conclusion: This study confirmed that inclusion of B. clausii with 1.0×10⁹ or 1.0×10¹⁰ CFU/kg DM, or S. cariocanus (5×10⁹ CFU/kg DM) to TMR containing CSM/RSM improved the nutritional value and decreased the contents of anti-nutritional factors.

• Korean Journal of Veterinary Service
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• v.45 no.2
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• pp.117-124
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• 2022

In the event of an outbreak of a livestock epidemic, it has been considered that the existing burial-centered carcass disposal method should be improved ecofriendly for prevention of leachate and odors from burial basically in regard of pathogen inactivation. Therefore, the aim of this study is whether it was possible to treat the carcass of cattle and chickens using the chemical carcass treatment method. It was conducted to establish detailed treatment standards for the chemical treatment method of cattle and chicken carcasses based on the results of the proof of the absence of infectious diseases in cattle chickens. After inoculating cattle carcass with 10 pathogens (foot and mouth disease virus, bovine viral diarrhea virus, Mycobacterium bovis, Mycobacterium avium subsp. Paratuberculosis, Brucella abortus, Bacillus anthracis, Clostridium chauvoei, Clostridium perfringens, Escherichia coli, and Salmonella Typhimurium) and chicken carcasses with low pathogenic avian influenza virus, Clostridium perfringens type C, E. coli and Salmonella Typhimurium, these were treated at 90℃ for 5 hours in a potassium hydroxide liquid solution corresponding to 15% of the body weight. This method liquefies all cadaveric components and inactivates all inoculated pathogens by PCR and culture. Based on these results, it was possible to prove that chemical treatment of cattle and chicken carcasses is effective in killing pathogens and is a safe method without the risk of disease transmission. The chemical treatment method of livestock carcasses can be suggested as an alternative to the current domestic burial-centered livestock carcass treatment method, preventing environmental pollution, and contributing to public health.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.182-187
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• 2023

Fifteen samples of dried laver Pyropia tenera were collected from markets and processing plants in Korea for an assessment of their microbial and chemical hazards, in accordance with the Korean food code. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine other pathogenic bacteria (Staphylococcus aureus, Salmonella spp., Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, Enterohemorrhagic Escherichia coli, Yersinia enterocolitica, Bacillus cereus, and Campylobacter jejuni) were evaluated The concentrations of heavy metals (lead, cadmium, total mercury, and total arsenic) and radioactive isotopes (¹³¹I, and ¹³⁴Cs+¹³⁷Cs) in the laver samples were also determined. The total viable count of bacteria was 2.62±0.80 (1.48-4.45) CFU/g. The contamination levels of lead, cadmium, total mercury, and total arsenic were 0.024±0.005 (0.018-0.035), 0.090±0.038 (0.041-0.146), 0.008±0.005 (0.003-0.018) and 1.315±0.372 (0.814-1.930) mg/kg, respectively. All samples tested negative for significant levels of radioactivity, the nine pathogenic bacteria, coliforms, and E. coli (<1.00 CFU/g). We assume that ensuring the microbiological and chemical safety of dried laver can increase the demand for its exportation. The present study may serve as a basis for microbiological and chemical hazard assessment of dried lavers.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.347-353
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• 2022

In this study, the effect of a synbiotic mixture of probiotics and 3% inulin on the growth, non-specific immune response, and mortality due to disease resistance of Paralichthys olivaceus was investigated. The results revealed that an 8-week diet of synbiotic-added feed, had no significant effect on the growth of P. olivaceus, Analysis of the hematological parameters revealed that there was a significant difference in the content of AST, total protein, and cholesterol among the groups, whereas there was no significant difference in the ALT and glucose contents. Further, there was no significant difference in the lysozyme activity of the synbiotic and control group after 8 weeks' feeding. In addition, when the symbiotic mixture was used rather than probiotics alone, the NBT activity of the synbiotic group increased compared to that of the control group. Moreover, when only probiotics were used, the cytokine expression in the spleen of the samples was significantly lower than that in the control group, whereas the expression was significantly higher in the spleen of the synbiotics group. However, there was no significant difference in the cytokine expression in the liver, intestine, and kidney of the three groups. Lastly, after injection for 2 weeks, the mortality rates of the control group towards Edwardsiella tarda, Streptococcus parauberis, and Streptococcus iniae were 95, 85 and 85%, respectively; those of the probiotics group were 85, 80, and 80%, respectively; and those of the synbiotics group were 80, 80, and 85%, respectively.

• The Korean Journal of Food And Nutrition
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• v.36 no.1
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• pp.33-41
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• 2023

To increase antioxidant and antibacterial activities of seasoned soy sauce, five kinds of oriental medicinal plant(Scutellaria baicalensis (P1), Coptis japonica makino (P2), Citriunshius pericarpium (P3), Zizyphi spinosi semen (P4), Crataegus pinnatifida(P5)) and four kinds of medicinal mushrooms(Inonotus obliquus (M1), Hericium erinaceus (M2), Phellinus linteus (M3), Lentinula edodes(M4)) were added to seasoned soy sauce. Soluble solid content, pH, salinity, total polyphenol & flavonoid contents were determined. DPPH & ABTS radical scavenging activities, SOD-like activity, and antibacterial activity were analyzed. Experimental sauces showed decreased pH but significant increases of soluble solid content and salinity. Total polyphenol content was 12.76 ㎍ GAE/g in the control. However, M1 and P1 sauce had significantly higher polyphenol contents at 352.14 and 528.25 ㎍ GAE/g, respectively. Total flavonoids content also showed the same pattern. DPPH free radical scavenging activity was the lowest in the control at 15.75%. It was the highest at 81.80% in M1 and 68.88% in P1. ABTS free radical scavenging activity and SOD-like activity showed the same tendencies. They were higher in the experimental groups than in the control. As for the antibacterial activity analyzed by the paper-disc method, the activity increased the most in P1 and P2. In particular, P2 had the strongest antibacterial activity. Its activity against different microorganisms was in the order of Staphylococcus aureus > Bacillus cereus > Escherichia coli > Salmonella typhimurium. In conclusion, these new sauces show increased antioxidative and antioxidant activities. Therefore, they are expected to be used in various ways as a functional soy sauce.

• Fisheries and Aquatic Sciences
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• v.25 no.11
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• pp.579-586
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• 2022

Research on the potential biological activity of red alga Symphyocladia spp. has been limited to Symphyocladia latiuscula, which is widely used as a food ingredient in Korea. Here, we examined the biological activity of another species, Symphyocladia linearis, which is found in Korea and was reported as a new species in 2013. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antibacterial properties of a 70% ethanol extract of S. linearis. Antioxidant activity, which was evaluated using radical scavenging assays, revealed half maximal inhibitory concentration values for 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) of 34.57 and 11.70 ㎍/mL algal extract, respectively. Anti-inflammatory activity of the S. linearis ethanolic extract was evaluated using RAW 264.7 cells by measuring the inhibition of lipopolysaccharide-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. The potential cytotoxicity of NO and PGE₂ was first examined, confirming no toxicity at concentrations ranging from 10-100 ㎍/mL. NO production was inhibited 61.1% and 78.0% at 50 and 100 ㎍/mL S. linearis extract, respectively; and PGE₂ production was inhibited 69.1%, 83.2%, and 94.8% at 25, 50, and 100 ㎍/mL S. linearis extract, respectively. Thus, the S. linearis extract showed very strong efficacy against PGE₂ production. The cellular production of reactive oxygen species, measured using 2',7'-dichlorofluorescin diacetate fluorescence, was inhibited 48.8% by the addition of 100 ㎍/mL S. linearis extract. Antibacterial activity was evaluated using the disc diffusion method and minimum inhibitory concentration (MIC). S. linearis was effective only against gram-positive bacteria, exhibiting antibacterial activity against Staphylococcus aureus with a MIC of 256 ㎍/mL extract and against Bacillus cereus with a MIC of 1,024 ㎍/mL extract. Based on these results, we infer that a 70% ethanolic extract of S. linearis possesses strong anti-inflammatory properties, and therefore has the potential to be used in the prevention and treatment of inflammatory and immune diseases.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.51-60
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• 2023

The foodborne illness is the important public health concerns, and the livestock feces are known to be one of the major reservoirs of foodborne pathogens. Also, it was reported that 45.5% of foodborne illness outbreaks have been associated with the animal products contaminated with the livestock feces. In addition, it has been known that the persistence of a pathogens depends on many potential virulent factors including the various virulent genes. Therefore, the first step to understanding the public health risk of livestock feces is to identify and describe microbial communities and potential virulent genes that contribute to bacterial pathogenicity. We used the whole metagenome shotgun sequencing to evaluate the prevalence of foodborne pathogens and to characterize the virulence associated genes in pig and chicken feces. Our data showed that the relative abundance of potential foodborne pathogens, such as Bacillus cereus was higher in chickens than pigs at the species level while the relative abundance of foodborne pathogens including Campylobacter coli was only detected in pigs. Also, the microbial functional characteristics of livestock feces revealed that the gene families related to "Biofilm formation and quorum sensing" were highly enriched in pigs than chicken. Moreover, the variety of gene families associated with "Resistance to antibiotics and toxic compounds" were detected in both animals. These results will help us to prepare the scientific action plans to improve awareness and understanding of the public health risks of livestock feces.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.219-227
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• 2023

Lettuce is one of the most consumed vegetables worldwide. However, it has potential risks associated with pathogenic bacterial contamination because it is usually consumed raw. In this study, we investigated the changes in the bacterial community on lettuce (Lactuca sativa L.) in Chungcheong-do, South Korea, and the prevalence of foodborne pathogens on lettuce in different seasons using 16S rRNA gene-based sequencing. Our data revealed that the Shannon diversity index showed the same tendency in term of the number of OTUs, with the index being greatest for summer samples in comparison to other seasons. Moreover, the microbial communities were significantly different between the four seasons. The relative abundance of Actinobacteriota varied according to the season. Family Micrococcaceae was most dominant in all samples except summer, and Rhizobiaceae was predominant in the microbiome of the summer sample. At the genus level, the relative abundance of Bacillus was greatest in spring samples, whereas Pseudomonas was greatest in winter samples. Potential pathogens, such as Staphylococcus and Clostridium, were detected with low relative abundance in all lettuce samples. We also performed metagenome shotgun sequencing analysis on the selected summer and winter samples, which were expected to be contaminated with foodborne pathogens, to support 16S rRNA gene-based sequencing dataset. Moreover, we could detect seasonal biomarkers and microbial association networks of microbiota on lettuce samples. Our results suggest that seasonal characteristics of lettuce microbial communities, which include diverse potential pathogens, can be used as basic data for food safety management to predict and prevent future outbreaks.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.264-274
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• 2023

To evaluate functional biomaterials of 5 invasive alien plants, total polyphenol and flavonoid contents, antioxidant activity, anti-inflammatory activity, and antibacterial effect were measured. The total polyphenol and flavonoid contents of the extracts were in the order of Rumex acetosella L. > Hypochaeris radicata L. ≥ Lactuca scariola L. > Humulus japonicus Siebold & Zucc. ≥ Solanum viarum Dunal. The DPPH and ABTS radical scavenging activities of the extract were the highest in R. acetosella and correlated well with the total polyphenol contents. In RAW 264.7 cells stimulated with lipopolysaccharide (LPS), nitric oxide (NO) and prostaglandin E₂ (PGE₂) production inhibitory effect of the extracts (100 ㎍ SE/mL) were 20~60% and 10~70%, respectively, showing the highest inhibitory effect in R. acetocella. The extracts of R. acetosella, H. japonicus and S. viarum showed antibacterial activity against food poisoning-causing microorganisms such as Bacillus subtilis, Escherichia coli, Vibrio parahaemolyticus and Vibrio vulnificus. Furthermore, the H. japonicus extract was found to have effective antibacterial activity against oral microorganisms such as Enterococcus faecalis, Lacticaseibacillus casei, Rothia dentocariosa, Staphylococcus epidermidis and Streptococcus mutans, and its major active ingredients were predicted to be pentadecylic acid, palmitic acid and clionasterol. These results suggest that alien plants have potential as biomaterials with antioxidant, anti-inflammation and antibacterial effects.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.26-30
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• 2023

In this study, we analyzed the microbial contamination level of ultraviolet sterilizer (UVS) chambers and suggested plans to improve hygiene management. In this study, UVS chambers targeted 98 UVS in some childcare centers in Jeollanam-do, Korea. Total aerobic bacteria and coliform bacteria were tested according to the Korean Food Code. Of the 98 UVS chambers, total aerobic bacteria were detected in 67 (68.4%) and coliform bacteria in 5 (5.1%). Six kinds of food-poisoning bacteria, including Salmonella spp., were not detected, but Bacillus cereus was detected in 1 (2.8%) out of 98 UVS chambers. According to the UV lamp replacement period, the detection rate of total aerobic bacteria was 3 (50%) out of 6 UVS within 3 months, 3 (60%) out of 5 UVS in 3 to 6 months, and 61 (70.1%) out of 87 UVS over 6 months. The detection rate of coliform bacteria according to the UV lamp replacement period was not detected within 6 months, however, they were detected in 5 (5.7%) out of 87 chambers after more than 6 months. The level of microbial contamination in the UVS chambers was higher as the lamp replacement period was longer. Considering these results, it was determined that the UVS chambers should be kept dry and clean, and the UV lamp should be replaced periodically. In addition, it is necessary to provide the staff catering for childcare centers with continuous education regarding the cleaning of UVS chambers and the replacement of UV lamps.