• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.209-217
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• 2022

In this study, Enterococcus faecalis BMSE-HMP005 isolated from human breast milk demonstrated antimicrobial effects against multidrug-resistant (MDR) bacterial strains. The bacteriocin produced by E. faecalis BMSE-HMP005 was fractionated using reverse-phase high-performance liquid chromatography. This fraction showed antimicrobial effects against both gram-positive and gram-negative MDR bacteria. No hemolytic reactions were observed. E. faecalis BMSEHMP005 was resistant to vancomycin; however, kanamycin, ampicillin, and erythromycin showed minimum inhibitory concentrations that were lower than the acceptable range provided by the European Food Safety Authority. For artificial gastric juice and bile acid, the survival rates were 98.67% and 95.70%, respectively. These results show the potential utility of E. faecalis BMSE-HMP005 as a probiotic with remarkable antimicrobial effects against MDR bacteria.

• Animal Bioscience
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• v.36 no.5
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• pp.720-730
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• 2023

Objective: This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Methods: Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. Results: The MIX diets had lower (p<0.05) acid detergent fiber with higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber compared to the CON diets. In terms of fermentation characteristics, the MIX diets had higher (p<0.05) acetate than the CON diets. The MIX diets had extended (p<0.05) lactic acid bacteria growth at 4 to 7 d of aerobic exposure and showed lower (p<0.05) yeast growth at 7 d of aerobic exposure than the CON diets. In terms of rumen fermentation, the MIX diets had higher (p<0.05) total fermentable fraction and total volatile fatty acid, with lower (p<0.05) pH than those of CON diets. The interaction (p = 0.036) between inoculant and diet level was only found in the immediately fermentable fraction, which inoculant was only effective on LOW diets. Conclusion: Application of corn silage with inoculant on FTMR presented an antifungal effect by inhibiting yeast at aerobic exposure and a carboxylesterase effect by improving nutrient digestibility. It also indicated that fermented feedstuffs could be used as microbial source for FTMR. Generally, the interaction between inoculant and diet level had less effect on this FTMR study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1769-1775
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• 2011

This study was carried out to investigate the changes in the quality characteristics of Kimchi with mashed red pepper (Capsicum annuum L.) added during 12 days of fermentation at $20^{\circ}C$. The moisture content of Kimchi increased according to the addition of mashed red pepper, whereas the crude protein, crude lipid, and crude ash content decreased. The total bacterial and lactic acid bacterial counts of Kimchi with additional mashed red pepper sharply increased until the 2 day mark, then gradually increased thereafter. The initial pH and total acidity of Kimchi with additional mashed red pepper showed a range of 5.67~5.88 and 0.18~0.21, respectively. The pH and total acidity rapidly changed within a range of 4.26~4.72 and 0.50~0.70%, respectively, until the 2 day mark. The reducing sugar content sharply decreased until the 2 day mark, then gradually decreased afterwards. It decreased with increasing levels of mashed red pepper. A sensory evaluation indicated that Kimchi with 50% or 75% additional mashed red pepper was better than that of other Kimchi.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1552-1559
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• 2011

Real time PCR was used in this study to determine the effect of triticale dried distillers grains with solubles (TDDGS) as a replacement for grain or barley silage in finishing diets on the presence of six classical ruminal bacterial species (Succinivibrio dextrinosolvens, Selenomonas ruminantium, Streptococcus bovis, Megasphaera elsdenii, Prevotella ruminicola and Fibrobacter succinogenes) within the rumen contents of feedlot cattle. This study was divided into a step-wise adaptation experiment (112 days) that examined the effects of adaptation to diets containing increasing levels of TDDGS up to 30% (n = 4), a short-term experiment comparing animals (n = 16) fed control, 20%, 25% or 30% TDDGS diets over 28 days, and a rapid transition experiment (56 days) where animals (n = 4) were rapidly switched from a diet containing 30% TDDGS to a barley-based diet with no TDDGS. It was found that feeding TDDGS as replacement for barley grain (control vs. 20% TDDGS) decreased 16S rRNA copy numbers of starch-fermenting S. ruminantium and S. bovis (p<0.001 and p = 0.04, respectively), but did not alter 16S rRNA copy numbers of the other rumen bacteria. Furthermore, feeding TDDGS as a replacement barley silage (20% vs. 25% and 30% TDDGS) increased 16S rRNA copy numbers of S. ruminantium, M. elsdenii and F. succinogenes (p<0.001; p = 0.03 and p<0.001, respectively), but decreased (p<0.001) the 16S rRNA copy number of P. ruminicola. Upon removal of 30% TDDGS and return to the control diet, 16S rRNA copy numbers of S. ruminantium, M. elsdenii and F. succinogenes decreased (p = 0.01; p = 0.03 and p = 0.01, respectively), but S. dextrinosolvens and S. bovis increased (p = 0.04 and p = 0.009, respectively). The results suggest that replacement of TDDGS for grain reduces 16S rRNA copy numbers of starch-fermenting bacteria, whereas substitution for barley silage increases 16S rRNA copy numbers of bacteria involved in fibre digestion and the metabolism of lactic acid. This outcome supports the contention that the fibre in TDDGS is highly fermentable.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.1
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• pp.1-5
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• 2024

Understanding changes in fermentation characteristics and microbial populations of forage silage during ensiling is of interest for improving the nutrient value of the feed for ruminants. This study was conducted to investigate the changes in fermentation characteristics and bacterial communities of whole crop rice (WCR) silage during the ensiling period. The chemical compositions, pH, organic acids and bacterial communities were evaluated at 0, 3, 6, and 12 months after ensiling. The bacterial communities were classified at both the genus and species levels. The dry matter content of WCR silage decreased with the length of storage (p<0.05), but there was no significant difference in crude protein and NDF contents. Following fermentation, the pH level of WCR silage was lower than the initial level. The lactic acid content remained at high levels for 3 to 6 months after ensiling, followed by a sharp decline at 12 months (p<0.05). Before fermentation, the WCR was dominated by Weissella (30.8%) and Pantoea (20.2%). Growth of Lactiplantibacillus plantarum (31.4%) was observed at 3 months after ensiling. At 6 months, there was a decrease in Lactiplantibacillus plantarum (10.2%) and an increase in Levilactobacillus brevis (12.8%), resulting in increased bacteria diversity until that period. The WCR silage was dominated by Lentilactobacillus buchneri (71.2%) and Lacticaseibacillus casei (27.0%) with a sharp reduction in diversity at 12 months. Overall, the WCR silage maintained satisfactory fermentation quality over a 12-month ensiling period. Furthermore, the fermentation characteristics of silage were found to be correlated to bacterial microbiome.

• Journal of Life Science
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• v.22 no.2
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• pp.251-258
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• 2012

The purpose of this study was to investigate the probiotic properties of lactic acid bacterial strains isolated from animal feces. BCNU 9041 and BCNU 9042 isolates were assigned to Lactobacillus brevis on the basis of their physiological properties and 16S ribosomal DNA sequences analysis. They were confirmed as safe bioresources because of their non-hemolytic activities and non-production of harmful ${\beta}$-glucosidase, ${\beta}$-glucuronidase, tryptophanase, or urease. These isolates were also highly resistant to acid (at pH 2.5) and bile acids (at concentration of 0.3%, 0.6%, and 1% oxgall). In addition, they exhibited good antibacterial activity against food-borne bacteria, especially Bacillus cereus, Listeria monocytogenes, and Shigella sonnei. Furthermore, it was demonstrated that they have the highest levels of hydrophobicity and that they showed bile salt hydrolytic and cholesterol assimilation activity. These results suggest that BCNU 9041 and 9042 have good potential for application in functional foods and health-related products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.671-675
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• 2008

Based on information about the major microbial composition of kimchi and its relation to the taste, Leuconostoc mesenteroides K2M5 and Lactobacillus sakei K5M3 were selected as kimchi starter candidates. These two strains were found to be safe for industrial use because they showed neither harmful characteristics like ${\beta}$-hemolysis, ammonia and indole formation, and gelatin liquefaction, nor enzymatic activities like phenylalanine deaminase, ${\beta}$-glucuronidase, ${\beta}$-glucosidase, 7${\alpha}$-dehydroxylase and nitroreductase. Starter kimchi made with these strains were better in taste than the conventional kimchi when they are evaluated both by laboratory personnel and the public. Also microbial analysis of starter kimchi showed only starter bacteria after they were fermented to have the optimum acidity. Starter kimchi prepared with these two strains were not much different in physicochemical properties to the conventional kimchi except in that the starter kimchi were much higher in volatile organic acid content such as lactic acid. These results suggest that kimchi quality can be controlled to have consistent properties, both in taste and microbial composition, by using bacterial starters.

• Journal of Life Science
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• v.30 no.10
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• pp.896-904
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• 2020

The purpose of this study was to investigate the probiotic characteristics and immune activities of selected lactic acid bacterial (LAB) strains as feed additives in livestock. 301 LAB strains isolated from traditional fermented foods were first assessed for their antibacterial activity potential. Of the 301 isolates, five showed antibacterial activity against five livestock pathogens (Esherichia coli KCCM11234, Listeria monocytogens KCTC3710, Salmonella Typhimurium KCTC1926, Staphylococcus aureus KCCM11593, and Shigella flexneri KCTC2517). The probiotic characteristics of the five selected strains were also investigated by antioxidative activity, hemolysis, bile salt hydrolase, acid resistance and bile tolerance. The SRCM102607 strain was found to have superior probiotic properties and was selected for further experimentation. 16S rRNA gene sequencing showed that SRCM102607 is Pediococcus acidilactici, which was labeled as P. acidilactici SRCM102607 (KCCM 12246P). The survival characteristics of P. acidilactici SRCM102607 in artificial gastrointestinal conditions were assessed under exposed acidic (pH 2.0) and bile (0.5% and 1.0%) conditions. P. acidilactici SRCM102607 was also confirmed to have resistance to various antibiotics, including amikacin, gentamicin, vancomycin, and etc. The TNF-α production by P. acidilactici SRCM102607 was 171.86±4.00 ng/ml. These results show that P. acidilactici RCM102607 has excellent potential for use as a probiotic livestock feed additive.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.75-82
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• 2015

Chitosan provides beneficial effects such as decrease in cholesterol, weight loss, and antioxidative effects. The manufacture of Maribo cheese containing powdered chitosan (CP) or nanopowdered chitosan (NCP) is not yet established. Thus, this study was conducted to determine the effect of CP and NCP on Maribo cheese's physicochemical properties. The curd was added with 0.2 and 0.5% of CP and NCP, respectively, after the second whey drainage. The pH changed and the lactic acid bacterial population decreased in all treatments. Additionally, WSN and TBA gradually increased during the ripening of cheese. The TP of control cheese was higher than that of another group. On the basis of the obtained results, consumer preference test on overall acceptability of 0.2% NCP was good-41%, great good 13%. It was concluded that the quality of Maribo cheese was not affected by adding chitosan. Furthermore, 0.2% NCP was preferred during cheese ripening and observed the possibility of functional cheese than another group.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.262-268
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• 2003

Kefir is a traditional fermented milk in Caucasusian area and is made mainly of milk fermented with lactic acid bacteria and yeasts. Six typical kefir grains were selected from ten kefir grains collected from different locals in Korea. Kefir grains were gelatinous in texture and had various shapes of villi, grapes, leaves, hulled millets, and towels. To investigate predominant microflora of kefir grains, SPC, MRS, M17, Rogosa, and APT agar media were used for viable cell count MRS, SPC, and Rogosa media were most acceptable for bacterial cell counts of the selected kefir grains. From one or two of the SPC agar plates which contained around 25∼50 colonies, all grown colonies were isolated and identified. Most predominant bacteria was identified as Lactobacillus fermentum by API 50 CHL kit. The proportions of Lb. fermentum and Lb. brevis among the total identified bacteria were around 41~88% and M4%, respectively. To select the best preservation method for kefir grains, refrigeration, freezing, and freeze drying were compared. Freeze drying was found most suitable for the preservation of kefir grains, based upon their acid-producing activities and production of off-flavors.