• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.2
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• pp.70-78
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• 1989

This experiment was carried out to develop the preparation method of chitosan which has strong antimicrobial activity, and also tried to investigate as a natural food preservative with this chitosan. The antimicrobial activity of chitosan was the strongest when deacetylation of chitin was conducted at $146^{\circ}C$ for 8 hours with $50\%$ sodium hydroxide. The growth of Escherichia coil was completely inhibited by adding this low molecular weight chitosan (M. W, 35,000) at the level of concentration of 75ppm to the medium. The antimicrobial activity was strong enough against such Gram positive bacteria as Staphylococcus sp. and Bacillus sp.. The growth of these strains was inhibited by the concentration of 50ppm but it was varied in its kinds against Gram negative bacteria. The concentration of chitosan re-quired for growth inhibition of microorganisms was 100ppm against Pseudomonas sp. and Vibrio sp., 2,000ppm against Salmonella sp.. The growth of Saccharomyces sp. was inhibited by the concentration of 100ppm, but Hansenula sp., Aspergillus sp., Penicillium sp. and Mu-cor sp. did not inhibited by even more than the concentration of 5,000ppm. The shelf life of Mulkimchi (pickle type Kimchi), containing $0.2\%$ chitosan was 10 days longer than control stored at $5^{\circ}C$.

• Korean Journal of Veterinary Service
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• v.20 no.1
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• pp.19-26
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• 1997

The present study was conducted to investigate the general epidemiological situations with 18-pullorum infected chickens from Kyongbuk provinces during the period from June 1995 to January 1996. On the Salmonella pullorum isolation tests by rectal swab culture method from infected chickens (386-samples), any Salmonella spp was not isolated from infected live-birds. But 2-S pullorum were isolated of 2-dead chickens(33.3% ) from 6-dead chickens which were positively reacted by serological tests. On the other hand, we could not isolated any Salmonella spp. in any parts of egg-contents ; egg-shell, egg-white and egg-yolks with 25-infected bird eggs. On the tests of antibiogram, 2-S pullorum strains were highly sensitive to GM, AM, SXT, CZ, K, FIM, ENR, C, AN, N, NN, LIN＋SP, CF, TE and PB, respectively and intermediate sensitive to the CB, CFP, CL, S, P and XNL. But 2-strains were resistant to CC, DP, E, L, OX, TLA and TyLO. In the serological tests, pullorum antibody titers of 18-infected birds was from 2.76 to 9.18 with average by the microplate test. During the 6-months, pullorum antibody average titers were not changed generally. To validate the effects of the antimicrobial agent treatments to the serological antibody titers, infected 6-chickens was medicated with 0.5%-futazolidone. The titer of premeditated birds was average 4.26 but after medication with furazolidone, the titers of treated 6-birds was average 4.08.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.164-166
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• 2018

Salmonella enterica subsp. enterica is a foodborne pathogen that has been detected throughout the world. Here, we present the complete genome sequence of Salmonella Enteritidis isolated from a commercial kimbap that caused foodborne illness in the Republic of Korea in 2014. Complete genome sequence analysis of Salmonella Enteritidis MFDS1004839 revealed a 4,679,649 bp chromosome and a 96,994 bp plasmid, with G + C contents of 52.2% and 49.3%, respectively. The chromosome and plasmid genome included 4,482 predicted protein-coding sequences, 84 tRNAs and 22 rRNAs genes.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.151-159
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• 1997

This study was carried out to isolate of causative agents from CMT-positive and mean somatic cell count(SCC) $\geq$500,000 cells/ml mastitic milk, and evaluate to antimicrobial susceptibility of isolates in Iksan branch area from January to November, 1996. 1. The CMT-positivity(SCC 500,000 cells/ml) of 610 heads was 36.2% (221), and of 2,373 quarter milks was 16.1% (383). 2. The Gram-positive isolates were 153 strains which was Staphylococcus sp (115), Micrococcus sp (18), Streptococcus sp (10), Listeria monocytogenes (5) and Enterococcus faecalis(5). 3. The Gram-negative isolates were 66 strains including E coli(14), Yersinia sp (13), Shigella sp(8), Enterobacillus sp(8), Cedecea sp(5), Pseudomonas aeruginosa(5), Proteus sp(5), Klebsiella sp(4), Salmonella sp(2), kluyvera ascorbate(1) and Tatumella ptyseos (1). 4. The Gram positive strains of isolates were moderately susceptible to T/s, Cp, Fd, Imp, Aug, Rif, Cft and Va. And the Gram negative strains of Isolates were moderately susceptible to T/s, Cp, Imp, Pi and Ti, In order. 5. Multiple antimicrobial resistant patterns were encountered 62 and 36 from Gram positive and negative isolates, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.765-769
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• 2002

Improvement of hygienic quality of powdered raw grains and vegetables by fermentation was investigated. Luc-tobacillus sp. isolated from kimchi was used as a starter. The cell counts of coliform group and SS enteric bacteria on the SS agar plate in raw grains and vegetables were 2.3$\times$103 cfu/mL and 8.6$\times$10$^3$ cfu/mL, respectively. The starlet, Lactobacillu sp., reached 10$^{7}$ cfu/mL after 48 hr in fermentation. At that time, the coliform group and enteric bacteria on the SS agar plate were gradually inactivated and eliminated after 60 hr of fermentation. During the fermentation process, pH of the suspension was lowered and acidity increased. Antimicrobial activity of the acidic supernatant of fermented raw grains and vegetal]les against the E. coli sp. and Salmonella sp. was higher than that of lactic acid solution or neutralized supernatant. Therefore, it was considered that antimicrobial effect of the fermented raw grains and vegetal]les might be accelerated by tile synergic effect of acid and bacteriocin, and liquid fermentation of powdered raw grains and vegetables will be effective for inactivation of hygienic microorganisms.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.445-451
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• 1996

The strain YCH-37, which produces yeast cell wall lytlc enzyme, was isolated from soil. From the microscopic observation, morphological and cultural characteristics, this strain was identified to fungus, Dicyma sp. So, we named this strain as Dicyma sp. YCH-37. The lytic enzyme effectively lysed Salmonella typhimurium among intact living bacteria and Torulopsis, Hansenula, Zygosaccharomyces among intact living yeast, as well as autoclaved yeast strains. The yeast cell wall lytic enzyme was succesively purified to 204 folds with 13% yields through yeast glucan affinity adsorption and DEAE-cellulose column chromatography. The enzyme was identified to monomeric protein with molecular weight of 25,000 daltons from the results of SDS-PAGE and gel filtration. The optimum pH and temperature for the yeast lytic activity were 8.0 and 50$\circ$C, respectively. The enzyme was stable up to 40$\circ$C, and between pH 4.0-pH 10.0.

• Korean Journal of Veterinary Service
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• v.40 no.1
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• pp.1-6
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• 2017

Molecular typing of pathogenic microorganisms is important for epidemiological investigation of infectious disease outbreaks. In this study, we applied Universal Rice Primers (URP) that were originated from repetitive sequences in rice chromosomal DNA to random amplified polymorphic DNA (RAPD) analysis of pathogenic bacteria such as Escherichia coli, Listeria monocytogenes, and Salmonella sp. Of the twelve URP primers examined to date, seven primers (URP-2, -3, -4, -5, -6, -8, and -9) generated reproducible and polymorphic PCR products ranging from 1 to 13 bands. One of them, URP-6 was very effective in differentiating seven E. coli serotypes, seven L. monocytogenes clinical isolates, and eight Salmonella subspecies (ssp.) serovars. The results thus indicate that RAPD analysis using URP primers might be useful in typing bacterial pathogens including E. coli, L. monocytogenes, and Salmonella strains.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.1
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• pp.40-47
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• 2007

Golda farms and depots of selected areas of the different districts of Bangladesh viz. Khulna, Bagerhat, Jessore and Norial area were sampled for the detection of Salmonella sp. and Escherichia coli. Incidence of Salmonella positive samples was 39%, 25%, 50% and 42% in the farms and 30%, 20%, 20% and 30% in the depots of Dumuria under Khulna, Bagerhat Sadar under Bagerhat, Avoynagar under Jessore and Kalia under Norail district respectively. On the other hand, E. coli positive samples was 23%, 42%, 25% and 17% in the farms and 70%, 30%, 50% and 30% in the depots of Dumuria (Khulna), Bagerhat Sadar (Bagerhat), Avoynagar (Jessore) and Kalia (Norail) region respectively. The overall results indicate that the trend of Samonella and E. coli contamination in farms and depots of all the regions is more or less similar although some variations were observed among the farms and depots of different location and region.

• Journal of Microbiology
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• v.38 no.1
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• pp.8-10
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• 2000

In order to rapidly identify and differentiate Salmonella typhimurium from the intestinal gram-negative bacteria, randomly amplified polymorphic DNA (RAPD) fingerprinting of Salmonella typhimurium was carried out using random primers designated OPA-13 (5'-CAGCACCCAC-3'), OPB-10 (5'-CGTCTGGGAC-3'), OPB-18 (5'-CCACAGCAGT-3'), and OPJ-10 (5'-AAGCCCGAGG-3'), and its patterns compared with 6 representive intestinal, gram-negative bacterial strains, Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, Escherichia coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., which are often found in foods. S. typhimurium had unique and distinct fingerprinting patterns. RAPD fingerprinting is thus concluded to be a rapid and sensitive method for the identification of S. typhimurium compared to conventional culturing procedures or immunoassays.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.19-24
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• 1997

Using the PCR(polymerase chain reaction method), gone 1 of phage K11 coding for K11 phage RNA polymerase has been cloned and expressed under the control of lac promoter. K11 phage RNA polymerase was conventionally purified through the DEAE-sephacel and Affigel blue column chromatographies. The 0.2-0.3 M $NH_4Cl$ fractions of DAEA-sephacel column chromatography showed K11 phage RNA polymerase activity and further purification with Affigel blue column chromatography showed nearly single protein band on SDS-polyacryl amide gel. K11 phage RNA polymerase, which is one of the T7 group phage RNA polymerase (E. coil phage T7, T3 and Salmonella tyhimurium phage SP6 RNA polymerase), shares high degrees of homology with the other T7 group phage RNA polymerase. Previously we constructed T7 and SP6 promoter variants and revealed promoter specificity of T7 and SP6 RNA polymerase (Lee and Kang, 1993). To investigate the promoter specificity of K11 RNA polymerase in vitro K11 promoter activity was measured with SP6 promoter variants. The SP6 promoter variant share highest degrees of sequence homology with K11 promoter sequence show strongest promoter activity.