• Korean Journal of Veterinary Research
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• v.24 no.2
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• pp.149-162
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• 1984

The research was conducted(1) to confirm the agent(s) responsible for the antimicrobial activity contained in the fermented tomato juice with L. acidophilus(2) to extract and purify the antimicrobial agent(s)(3) to find the biological, physical and chemical properties of the agent(s). The following results were obtained and summarized as followings; 1. The agent responsible for the inhibitory activity was confirmed by both well assay method using fermented tomato juice with L. acidophilus and turbidimetric technique using the cell-free filtrate or neutralized filtrate of tomato acidohilus culture and found exerted antimicrobial agent other than lactic acid. 2. The procedures of purification : The isolation and purification of antimicrobial agent from the lyophilized acidophilus tomato culture were carried out by (1) methanol extraction (2) acetone extraction, (3) Sephadex G-50 gel filtration (4) paper chromatography and (5) thin layer chromatography. 3. The biological, physical and chemical properties of antimicrobial agent: The biological, physical, chemical properties of the purified antimicrobial agent were: (1) The antimicrobial activity was strong against test organisms; Bacillus subtilis(ATCC 6633), Escheichia coli(ATCC 25922), Staphylococcus aureus(ATCC 167), Pseudomonas fluorescens(KFCC 32394), Proteus vulgaris and Shigella dysenteriae. (2) The pH value of the agent was 2.0 and the inhibitory activity was lost when it was neutralized at 7.0 of pH and the agent was heat stable at $121^{\circ}C$ for 60 minutes. (3) The ultraviolet light absorption spectra of methanol-acetone extract and TLC fraction exhibited a maximum absorption at 260nm and 224nm respectively. (4) The most purified agent from TLC plate increased about 130-fold in activity. (5) The agent isolated from TLC plate was free from $H_2O_2$ or lactic acid. 4. Bioautographic assy: By means of bioautography of the agent on silica gel of TLC plate a strong inhibitory activity against B. subtilis was demonstrated. 5. Mass spectrometry: The agent obtained from TLC plate was analyzed by mass spectrometry which show the parent peak at m/e 264 suggesting the molecular weight of the compound and molecular group such as [$C_2H{^+}_4$], [CO], [CH=NH], [$C_3{H^}4_7$], [$\begin{array}{rcl}O\\{\parallel}\\CH_3-C\\\end{array}$], [$C_6-H{^+}_{11}$], [$C_5H{^+}_{11}$], [$\begin{array}{rcl}O\\{\parallel}\\C_5H_7-C^+\\\end{array}$] were suggested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.692-696
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• 2001

To develop natural food preservatives, ethanol and water extracts were prepared from the coriander (Coriandrum sativum L.) and antimicrobial activities were examined against 10 microorganisms which were food borne pathogens and/or food poisoning microorganisms and food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activities for the microorganisms tested, but not on lactic acid bacteria and yeast. Especially, minimum inhibitory concentrations (MIC) for Bacillus subtilis and Bacillus cereus were as low as 0.25mg/mL. antimicrobial activity of the ethanol extract was not destroyed by the heating at 121$^{\circ}C$ for 15min and not affected by pH. The ethanol extract of coriander exhibiting high antimicrobial activities was fractionated in the order of hexane, chloroform, ethylacetate and butanol fractions to test antimicrobial activity. The highest antimicrobial activity adjust bacteria tested was found in the ethylacetate fraction.

• Food Science and Preservation
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• v.24 no.3
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• pp.325-333
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• 2017

This study aimed to investigate the various biological activities of Geranium thunbergii such as antimicrobial activity and protective effect against oxidative damage. To evaluate its antioxidant and antimicrobial activities, we first performed methanol extraction; this methanol extract was further partitioned using various solvents. And then, its antioxidant activity was measured using various assays including total phenolic content and protection against oxidative DNA damage, and antimicrobial activities were examined using minimum inhibiting concentration (MIC) test, and paper disc method. In addition, high-performance liquid chromatography was performed to analyze the major chemical components of ethyl acetate fraction. The G. thunbergii fraction with ethyl acetate exhibited higher antioxidant and antimicrobial activities than the other fractions. The results showed that G. thunbergii ethyl acetate fraction at $50{\mu}g/mL$ had strong DPPH and ABTS radical scavenging activities of 80.88% and 80.12%, respectively. In addition, the ethyl acetate fraction protected DNA from the oxidative damage induced by ferrous ion and hydroxyl radicals and showed high antimicrobial activity with diameter of inhibition zones ranging from 13.33 to 15.67 mm. High-performance liquid chromatography analysis revealed the major phenolic compounds of G. thunbergii to be ellagic acid and gallic acid. These results suggest that G. thunbergii might protect DNA against oxidative stress induced by reactive oxygen species and can be utilized as a natural source of antioxidant and antimicrobial agent in the food industry.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.88-89
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• 2006

Fowl cholera is an infectious disease caused by .Pasteurella multocida, affecting domesticated and wild birds. It usually appears as a septicemia of sudden onset with high morbidity and mortality, but chronic conditions that characterized by localized infections often occur. 13wks broiler breeders were submitted to the Kyung-pook national university for diagnosis. Clinical signs included approximately 1% mortality, severe lameness, ruffled feathers and swollen and/or cloudy eyes. At necropsy, the outstanding lesions were seen swollen hock joint, which were suppurative or caseous exudates, inflammation of conjunctiva, severe pneumonia and epicarditis. The causative agent was isolated from the hock joint, liver, sinus and sternum of the chickens, and performed physiological and biochemical test. To identify the serotype of P. multocida, capsular serotyping was conducted by multiplex polymerase chain reaction (PCR). In the antimicrobial susceptibility test, the isolates were resistance to the aminoglycosides. In this study, we confirmed chronic fowl cholera (FC) caused by P. multocida in broiler breeders in Korea.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.149-155
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• 2000

The allelopathic effects of Artemisia lavandulaefolia were studied using several test plants and microbes. Aqueous extracts and volatile compounds of A. lavandulaefolia inhibited seed germination, seedling and root growth of the test species such as Achyranthes japonica. Lactuca sativa, Artemisia princeps var. orientalis. Oenothera odorata, Plantago asiatica. Aster yomena, Elsholtzia ciliata, and Raphanus sativus var. hortensis for. acanthiformis. The root growth of test species was more affected than shoot growth by allelochemicals of A. lavandulaefolia. Essential oil of A. lavandulaefolia had antibacterial and antifungal effects. However, the antimicrobial activity of the essential oil was dependent upon the microbial species and concentrations. Callus growth of Oryza sativa, Brassica campestris subsp. napus var. pekinensis and Achyranthes japonica was sensitive by the essential oil of A. lavandulaefolia. Twenty three chemicals were identified from A. lavandulaefolia essential oil by gas chromatography. Primary allelochemicals among them were 1, 8-cineole, 1-$\alpha$-terpineol, $\alpha$-terpinene. camphor, 2-buten-1-ol and azulene. We concluded that aqueous extract and essential oil of A. lavandulaefolia were responsible for allelopathic effects.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.427-437
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• 2018

In this study, 23 ethanolic extracts from 20 medicinal plants were evaluated for biological activities. Results revealed that of 23 samples, seven samples have demonstrated good antimicrobial activity. Minimum inhibitory concentrations were 0.4-2.0 mg/mL, while minimum bactericidal concentrations were mostly high 0.8-2.0 mg/mL for selected seven samples. Five samples revealed > 70 mg gallic acid equivalent (GAE)/g of total phenolic contents. Among test samples, six samples exhibited > 80% inhibition of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and only two samples exhibited > 80% inhibition of 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals. A total of five test samples revealed Trolox equivalent antioxidant capacity more than $1000{\mu}m/g$. The MTT assay indicated that eight test samples exhibited > 90% viability of murine macrophage cells (RAW 264.7) at $250{\mu}g/mL$ and suppressed iNOS mRNA expression at transcriptional level when stimulated by lipopolysaccharide (LPS). Some medicinal plants revealed promising results, and so they have prospective for further more inclusive studies.

• Microbiology and Biotechnology Letters
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• v.35 no.1
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• pp.17-25
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• 2007

The kinds and quantity of antimicrobial agents used for cattle (animal industry) may be considerable, suggesting the possibility that pathogenic bacteria which cannot be extirpated by the existing antimicrobial agents could appear. Ten cattle, pig and chicken farms, respectively, were randomly selected from 5 provinces in Korea and the samples were collected from excrement, manure, underground water, farmers' hands and the neishboring environment. h total of 299 samples were examined and 197 of Escherichia coli, 13 of Campylobacter jejun/coli, 223 of Enterococcus faecium/faecalis and 42 of Staphylococcus aureus isolates were collected. All isolates were screened for antimicrobial resistance: 69.4% of E. coli (137/197 strains), 78.6% of S. aureus (33/42 strains), and 82.1% of E. faecium/faecalis (183/223 strains) were resistant to one antimicrobial agent and all of C. jejuni/coli Isolates showed the resistance to one antimicrobial agent. Meanwhile, the multiple resistance ratio for more than 4 lines of antimicrobial agent was 19.2% of E. coli (38/197 strains), 11.9% of S. aureus (5/42 strains), 15.4% of C. jejuni/coli (2/13 strains) and 6.2% of E. faecium/faecalis (14/223 strains). The antimicrobial resistance ratio of bacteria isolated from the cattle farm showed lower than that of bacteria isolated from the pig or chicken farm, which might be related to the quantify of antimicrobial agents consumed. And one strain of vancomycin resistant E..faecium (VREF) were isolated from the excrement of chicken and stream, respectively. Generally, the ratio of VREF collected in animal farm environments is lower than that of VREF collected in medical environment.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.358-366
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• 2013

The aim of this study was to evaluate the antimicrobial activities of Glycyrrhiza uralensis and Glycyrrhiza glabra extracts with various countries of origin. Three samples of licorice with various origins (Korea, China, and Uzbekistan) were evaluated for their antimicrobial activities against six skin microflora. The bioassay applied for determining the antimicrobial effects included the disc diffusion assay, minimum inhibitory concentration, and challenge test. The ethyl acetate fractions of G. uralensis and G. glabra extracts showed significant antimicrobial activities against two gram-positive (Bacillus subtilis, Propionibacterium acnes) and two gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. These samples had much more intensive antimicrobial activities than synthetic preservatives on B. subtilis, P. acnes, and P. aeruginosa, especially. Korean licorice showed the highest antimicrobial activity amongst the samples tested. In view of the observed inhibitory features of these G. uralensis and G. glabra extracts, it is suggested that they could be used as natural antiseptics against bacterial contamination in cosmetics and foods, instead of the common synthetic preservatives currently employed.

• Journal of the Korean Wood Science and Technology
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• v.29 no.2
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• pp.140-145
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• 2001

Antimicrobial and antioxidative activities on heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. Six flavanones including pinostrobin, eriodictyol, naringenin, pinocembrin, taxifolin and verecundin were isolated from Prunus sargentii which has been selected due to its high antimicrobial and antioxidative activities among the tested species. According to the results of antifungal test, pinocembrin was evaluated as the highest antifungal compound among the test compounds, which showed 80% of hyphal growth inhibition rate. Antifungal activity of pinocembrin was similar to hinokitiol(${\beta}$-thujaplicin), strong antimicrobial compound isolated from Thujopsis dolabrata. Naringenin followed pinocembrin in its antifungal activity. However, verecundin did not show any antifungal activity. No compound was effective in antibacterial activities. As a result of the measurement of free radical scavenging activity, antioxidative activities of taxifolin and eriodictyol were 2 times that of ${\alpha}$-tocopherol, and antioxidative index of these compounds were even superior to that of ${\alpha}$-tocopherol. In this regard, it could inferred that high antifungal and antioxidative activities of extractives of P. sargentii were derived from pinocembrin, taxifolin and eriodictyol, respectively.

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.763-767
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• 2000

This study was performed to isolate and identify bacteria from uterus with pyometra and examine their susceptibility to antimicrobial agents. Uterus of 16 bitches with pyometra were surgically removed by ovariohysteroctomy and then bacteria were isolated and identified. Also, susceptibility test to 15 antimicrobial agents was performed. Out of 16 bitches, 11 strains of Escherichia coli, 2 strains of Serratia marcescens, and 1 strain of Staphylococcus aureus and Salmonella spp. were identified. In antimicrobial susceptibility test, the majority of isolates were susceptible to enrofloxacin, norfloxacin, chloramphenicol, nalidixic acid, gentamicin, trimethprim-sulfamethazole, tetracycline, and moderately susceptible to carbenicillin, amikacin, ampicillin, neomycin, but resistant to vancomycin, streptomycin, bacitracin and colistin. In conclusion, E coli was the most common bacteria isolated from bitches with pyometra and those susceptible antimicrobial agents could be recommended to medical therapy of pyometra.