• 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.

• Research in Plant Disease
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• v.12 no.3
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• pp.189-196
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• 2006

Crown gall on lower stem of weeping fig(Ficus benjamina Roxb.) was first observed at Daejon in 2003. Tumors were about 15 cm in size and semi-round with rough surface texture of dark brown color. Two virulent isolates among ten bacteria isolated from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge, and white or tannish cream in color on potato dextrose agar supplemented with 0.5% $CaCO_3$. They were rod shape with peritrichous flagellae, gram-negative, aerobic growth, oxidase-positive, and grew on D1M agar. The isolates were identified as Agrobacterium larrymoorei and A. tumefaciens based on biochemical and physiological characteristics, fatty acid profiles and substrate utilization patterns. Seedlings of some host plants excepting grapevine produced typical galls two to three weeks after inoculation with cell suspensions of the virulent strains. This is the first report on crown gall of weeping fig in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.266-274
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• 2000

Understanding of microbial community structure in soil-root system is necessary to use beneficial soil and rhizosphere microbes for improvement of crop production and biocontrol. The knowledge of behavior and function of microbes in soil-root system plays a key role for the application of beneficial inocula. Because the majority of the intact bacteria in soil are unable to grow on nutrient media, both culturable and nonculturable bacteria have to be studied together. In our study, culture-independent survey of bacterial community in the soil-root system of red pepper fields was conducted by the sequence analysis of three universal clone libraries of genes which code for small-subunit rRNA (rDNA). Universal small subunit rRNA primers were used to amplify DNA extracted from each sample and PCR products were cloned into pGEM-T. Out of 27 clones sequenced, 25 clones were from domain bacteria. Two of the rDNA sequences were derived from eukaryotic organelles. Within the domain bacteria, several kingdoms were represented : the Proteobacteria (16 clones). Cytophyga-Flexibacter-Bacteroides group (2 clones). the high G+C content gram-positive group(1 clone) and 4 unknown clones.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.221-228
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• 2020

Ochrobactrum anthropi is a non-fermentative oxidative gram-negative bacillus that produces oxidase. Distinguishing a mixed culture with non-fermenting bacteria having a similar appearance and oxidase-positive is difficult, and there is a limit to accurate identification with a biochemical identification system. This paper proposes that the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Platform (MALDI-TOF) method is useful for classifying bacteria that are difficult to identify using biochemical testing methods. As a result of analyzing five cases of O. anthropi examined using MicroScan, it took 6.5 days to the final report, which was 3.5 days more than the 3.0 days of E. coli. The pus sample in patient 5 was a mixed infection with Achromobacter xylosoxidans, and it took 11.3 days because of multiple subculture and retests. Four patients were over 60 years old with an underlying disease, and the possibility of opportunistic and nosocomial infections could not be excluded. Among them, samples collected after 92 days of hospitalization were resistant to imipenem and meropenem. Therefore, an examination using the MALDI-TOF method will be useful for the rapid and adequate treatment of patients with difficult identification, such as O. anthropi.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.218-223
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• 2001

This study was conducted to evaluate the functional properties of onion, rosemary and thyme extracts which are the ingredients of onion Kimchi. Onion extract showed a significant difference in antioxidative effect based on peroxide value and thiocyanate method. Antioxidative activity of rosemary extract was similar to those of BHA and BHT. but thyme extract did not show any antioxidative effect.. Onion, rosemary, and thyme extracts showed antimicrobial activities against gram positive bacteria but onion and thyme extracts did not against E. coli, Candida, and molds. Rosemary extract demonstrated a strong activity against L. plantarum which is a major lactobacillus in Kimchi fermentation, and Micrococcus luteus. Onion, rosemary, and thyme extracts showed an effect or hangover relief effect by lowering the alcohol concentration of blood in rat. Blood pressure of the male spontaneous hypertensive rat was suppressed by onion extract after 3 days of feeding, but rosemary and thyme extracts were not effective for lowering blood pressure.

• Fisheries and Aquatic Sciences
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• v.23 no.8
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• pp.20.1-20.18
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• 2020

Background: Olive flounder, Paralichthys olivaceus, is an economically important aquaculture species in Korea. Olive flounders have been heavily damaged by streptococcal infections every year and are treated with antibiotics. However, antibiotic abuse is causing the emergence of resistant strains, and to overcome this, research has shown that new antibiotics must be applied. Tylosin is a relatively safe antibiotic and has good activity against Gram-positive bacteria and mycoplasma. We studied the therapeutic effects and side effects of tylosin on Streptococcus parauberis-infected olive flounder. Methods: After artificial infection of olive flounder with S. parauberis SPOF18J3, an appropriate dose of tylosin was confirmed by intramuscular injection (I.M.) at 2.5, 5, 10, and 15 mg/kg, and oral administration at 10 and 20 mg/kg. After I.M. and oral administration dosing of tylosin, side effects were confirmed by serological analysis, histopathological analysis, and median lethal dose (LD₅₀) analysis at both an appropriate concentration and a high concentration. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: The appropriate I.M. and oral administration concentration of tylosin administered to olive flounder infected with S. parauberis SPOF18J3 was found to be 10 mg/kg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were showed not significantly different between the control group and the experimental groups. The histopathologic results showed mild inflammatory responses in muscle and tubular vacuolization and tubular atrophy appeared, but there were no significant differences between the groups. The LD₅₀ was confirmed to be 461 mg/kg. Conclusion: In this study, an effective treatment method was provided by verifying the treatment effects and side effects of tylosin in olive flounder infected with S. parauberis, which can be applied directly to aquaculture sites. In addition, these results may be used as a reference for evaluation required upon request to obtain approval for tylosin antibiotics as fishery antibiotics in Korea. After approval, it is possible that a fishery disease manager will be able to prescribe and sell the antibiotic tylosin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.583-588
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• 2002

Two microorganisms isolated from soybean curd residue (biji) were identified as Enterococcus faecium (51% homology) and Lactobacillus rhamnosus (99.5% homology) by using gram positive identification (GPI) card and API 50 CHL kit, respectively. Ent. faecium grew well in micronized full-fat soyflour (MFS) milk, indicating pH 4.9, 0.38% acidity and 1.8$\times$10$^{9}$ CFU/$m\ell$ of viable cell counts after fermentation for 20 hr. L. rhamnosus LL showed pH 6.5 and 4.6$\times$10$^{8}$ CFU/$m\ell$ viable cell counts, but enhanced acid production in MFS milk mixture fortified with skim milk or by the addition of 1% of glucose and lactose. On the other hand, Ent. faecium LL did not show increased acid production in MFS/skim milk and MFS milk fortified with sugar. The MFS/skim milk fermented by L. rhmnosus LS and Ent. faecium LL showed 600 mg% and 350 mg% lactic acid, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.818-824
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• 2003

This study was carried out to select Meju of a good quality through general composition analysis, organoleptic evaluation, and to conduct isolation, identification, and growth characteristics of main strain related to fermentation from selected Meju. Moisture and crude protein of Meju were 7.2∼28.8% and 32.7∼42.3%, respectively. The amino nitrogen contents of Kyongbuk and Chonbuk Mejus were 770.8 mg% and 239.9 mg%, respectively. And also, free amino acid and glutamic acid contents of Doenjangs made from Chonbuk and Kyongbuk Mejus were 4,169.6 mg% and 499.4 mg%, respectively. The result of sensory evaluation of Mejus collected from several regions showed Kyongbuk was the most suitable Meju in items of color, flavor, appearance and overall (p<0.05). The typical properties of B. lichenifomis NH20 strain isolated from Kyongbuk Meju showed gram positive, aerobic rod cell and motility. As major component among its cellular fatty acid composition, $C_{15:0}$ anteiso fatty acid, $C_{15:1}$ iso fatty acid, $C_{17:0}$ anteiso fatty acid, and $C_{17:0}$ iso fatty acid were 30.7, 28.9, 13.3 and 11.2%, respectively. It showed the same identification coefficient (0.653) compared to the standard strain. Therefore, it was identified to be B. licheniformis NH20 according to Bergey's Manual of Systematic Bacteriology and its fatty acid profiles. The optimum pH, temperature, salt content, and culture time of B. licheniformis NH20 were 7.0, 32$^{\circ}C$, 2%, and 9 hours, respectively.ctively.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.118-123
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• 2012

In order to develop environment friendly fungicide for the control of citrus green mold (Penicillium digitatum) using endophytic bacteria, the 21 bacterial isolates were isolated from citrus leaves in seven different orchards in Jeju Province. Among the 21 bacterial isolates, 5 bacterial isolates presented antifungal activity against green mold pathogen P. digitatum. The CB3 isolate, which showed the most strong antagonistic effect, was selected through opposite culture against the pathogen. The rod-shaped, gram-positive bacterium CB3 was identified as Bacillus velezensis based on morphological, physiological characteristics, 16S rDNA, and gyr A gene sequence analysis. The isolate CB3 showed strong antifungal activity against two citrus postharvest pathogen P. digitatum. Citrus fruits were treated by wound inoculation with P. digitatum pathogen, and the control efficacy of CB3 culture broth was 66.7% ($1{\times}10^8$ cfu/ml). In conclusion, The stability of CB3 and its strong antifungal activity also lead us to believe that it has potential for application as an environment friendly biological control agent.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.58-62
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• 2009

From the course of screening of useful enzyme producing microorganism from marine sedimentary layer, we isolated 2 lipase producing strains and their lipase producing activities were tested. 16S rDNA sequence analysis showed that they were Gram-positive bacteria grouped on Janibacter sp. An excellent lipase producing strain, Janibacter sp. LI-68 and J. sp. LI-80 identified by 16S rDNA analysis and biochemical methods (BIOLOG), was further studied its lipase producing characteristics. The optimum initial pH, temperature and the optimum cultral time for the enzyme production on MA medium were 8, $30{\sim}40^{\circ}C$ and 96 h, respectively.