• Applied Biological Chemistry
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• v.37 no.4
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• pp.221-225
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• 1994

For producing single cell protein from the agricultural waste, heat treatment and antibiotics on the growth of Cellulomonas sp. KL-6, isolated in rotting leaf and the adjacent soil mixture, were examined. The organism was able to grow until 5 min. at $65^{\circ}C$, 1 min. at $75^{\circ}C$ and 1/4 min. at $85^{\circ}C$ in gradually rising temperatures. It can be Seen that preheating the suspension at $48^{\circ}C$ results in a marked decrease in heat resistance. On heating at temperature of $55^{\circ}C$ for 30 min., strain KL-6 was more resisted in the 0.1 M phosphate buffer when such substrates as casamino acid (1%), yeast extract (1%) or xylose (5%) were added to it whereas this organism was appeared weaker resistances in 0.1 M phosphate buffer when cysteine (0.03 M), sodium citrate (1%) or casein (1%) were in fused into it. Test strain was susceptible to penicillin-G $(1.563\;{\mu}g/ml)$ and ampicillin $(3.125\;{\mu}g/ml)$, but the organism was resisted to kanamycin $(>200\;{\mu}g/ml)$. The treatment of strain KL-6 with sodium dodecyl sulfate (SDS) resulted in the elimination of R-plasmid from the host strain and the elimination rate with SDS $(10{\sim}30\;{\mu}g/ml)$ was about $9.2{\sim}31.2%$, respectively.

• Journal of Embryo Transfer
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• v.25 no.4
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• pp.267-272
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• 2010

The present study was to investigate the source of contamination during semen processing for in vitro uses. In the present study, frozen semen was prepared from liquid semen in our laboratory for in vitro fertilization (IVF) experiments due to lack of fresh semen. Antibiotics were added in the frozen semen extender (kanamycin and gentamicin) and in vitro culture (IVC) medium (gentamicin) for further inhibiting growth of microorganisms. Nevertheless, proliferations of microorganisms were observed in IVC culture drop during culturing of IVF embryos using frozen semen. Randomly 3 samples were taken from the liquid semen, frozen semen and egg yolk. Contaminated IVC medium, frozen-thawed semen, liquid semen and egg yolk were cultured in de Man, Rogosa and Sharpe (MRS) agar medium. Whitish colonies were detected in contaminated IVC drop, frozen-thawed semen samples and egg yolk but no colonies were formed in liquid semen samples. Gram-negative and rod-shaped identical bacteria were found in both frozen-thawed semen sample and contaminated IVC drop and egg yolk samples. Enterobacter cloacae were confirmed by API 20E kit according to manufacturer's instruction with identification value (% ID) 94.3% and T index 0.88. Antibiotic susceptibility tests were done according to Clinical and Laboratory Standards Institute (CLSI) by using ampicillin, amikacin, cephalothin, gentamicin, kanamycin, tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin test. Among them Enterobacter cloacae were resistant to ampicillin, amikacin, cephalothin, gentamicin, kanamycin but susceptible to tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin. From these findings it could be suggested that this contamination sources might be from egg yolk.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.67-73
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• 1988

This study was conducted to isolate etiological agents from the 103 scouring piglets in Gyeongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical served. The incidence of scouring piglet was most prevalent as 81.6% in the age of 2 to 4 weeks after birth, while the rate was less than 10% in the age of 5 to 6 weeks and under 1 week after birch. When compared the isolation frequency of the each etiological agent, enteropathogenic E. coli was most prevalent as 46.6%, thermophilic Campylobacter 26.2% and Salmonellae was 8.7% in order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85 (20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni were belong to type I (50.0%) and II (25.0%), and most strains of C. coli were belong to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C. and each 1 strain was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, wherease about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C.jejuni and C. coli were sensitive to kanamycin and gentamicin.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.180-184
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• 2003

Several bacteria and yeasts were isolated from soil and characterized for the development of functional probiotics which can be used as a livestock feed additive. From the soil, the microbial strains which have acid/bovine resistance, antibiotics resistance and high stability, were isolated. Most strains selected were very tolerable against acids and very stable in a broad range of pH. Some strains could survive 100% at pH 2.5. The growth of the strains was not affected in the presence of bile acid, pathogenic E. coli and several antibiotics such as tetracycline, nisin, kanamycin, streptomycin, ampicillin. Acidogenic capability test showed that all the strains can produce acids. The hydrolytic activities were analysed for amylase, protease, lipase and cellulase to decompose various organic compounds. All the strains were found to be gram negative, round type, non-kinetic and the color is yellow or white.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.94-99
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• 2005

Sixty four bacterial colonies which were able to oxidize the manganese were isolated from soil samples in Mokcheon and Ochang area. Among them, one bacterial strain was selected for this study based on its higher manganese oxidation, and this selected bacterial strain was identified as Aeromonas sp. MN44 through physiological-biochemical test and analysis of its 16s rRNA sequence. Aeromonas sp. MN44 was able to utilize lactose but did not utilize various carbohydrates as a sole carbon source. Aeromonas sp. MN44 showed a very sensitive to antibiotics such as kanamycin, chloramphenicol, ampicillin, tetracycline and spectinomycin, and heavy metal such as cadmium. But this strain showed a high resistance up to mg/ml unit to heavy metals such as lithium and manganese. Optimal manganese oxidation condition of Aeromonas sp. MN44 was pH 7.4 and manganese oxidation activity was inhibited by proteinase K and boiling treatment. So, we concluded that this factor was protein. The manganese oxidizing factor produced by Aeromonas sp. MN44 was partial purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 113 kDa.

• Journal of fish pathology
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• v.8 no.2
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• pp.99-109
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• 1995

The diseased larvae of the flounder, Paralichthys olivaceus, were sampled several times from a fish hatchery located in Cheju Island between December, 1991 and April, 1992. They turned out to be infected with Vibrio sp. and diagnosed as intestinal necrosis of flounder larvae(INFL) based on morphological, biological, and biochemical examinations. INFL was known to be caused by the live food organism infected with Vibrio sp. The optimal growth conditions of the isolates for temperature, pH, and NaCl concentration were $20\sim30^{\circ}C$, 6~8, and 2~4%, respectively. In the drug sensitivity test, the isolates were sensitive to oxytetracycline, nalidixic acid, kanamycin, and novobiocin, but resistant to ampicillin, erythromycin, spiramycin and sulfa-drug.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.770-772
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• 1999

This study was conducted to provide a basic system to develop a molecular marker for plant cultivar protection using a recombinant DNA technology. Using Nicotiana tabacum L. plants, the potentiality in the utilization of the developed marker was examined. After homology test with several plant genomes, mouse adenosine deaminase (ADA) gene was selected as DNA source of a molecular marker for cultivar protection. As a result of the digestion of ADA gene with BamHI and Pst I, six DNA fragments were obtained, and 513 bp DNA fragment among them was selected as a possible DNA marker for cultivar protection. Selected 513 bp DNA fragment was efficiently inserted into pBI101 plasmid vector for plant transformation by using phagemid vector pBluescript II SK (+/-) as an intermediate vector. The recombinant pBI101, carrying 513 bp DNA fragment, possible markers for cultivar protection, was transformed into A. tumefaciens LBA4404. Nicotiana tabacum was transformed with A. tumefaciens LBA4404 having the recombinant pBI101 and was confirmed the transfer of 513 bp DNA fragment, a possible molecular marker for cultivar protection.

• Korean Journal of Microbiology
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• v.26 no.4
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• pp.305-311
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• 1988

The spectinomycin resistant strain of slow growing R. japonicum R-168 was selected to be participated in conjugation with E. coli WA803/pGS9. Tn5 was introduced from suicide vector pGS9 into R. japonicum R-168 $spr^{r}$ chromosome at the frequency of $1.0\times 10^{-5}-5.0\times 10^{-7}$ and the transconjugante were selected on the yeast extract-mannitol plate containing kanamycin ($50{\mu}$g/ml) and spectinomycin ($100{\mu}$g/ml) after 8-9 days incubation. All transconjugants we tested were found to contain Tn 5 DNA on their genome, which was confirmed by Southern hybridization experiments. R. japonicum RNa75, which had been selected through plant test, was found to be defective in symbiotic nitrogen fixing ability and the production of leghemoglobin in soybean nodules formed by the inoculation of this mutant. In addition, this mutant strain hardly developed nitrogenase activity asymbiotically in contrast with the wild type strain, indicating that some nitrogen fixing gene might be blocked in this strain and the production of leghemoglobin could be decreased by the interference in nitrogen fixing genes.

• Journal of Veterinary Clinics
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• v.4 no.1
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• pp.409-421
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• 1987

For the epidemiological studies of the respiratory infection from 1,918 heads of adult rabbits from January 1980 to December 1985 at an integrated farm, the causative agents were. Isolated samples 92 from of lungs and nasal discharges, and identified by serological and non-serololgical tests, the loss rates by the infection were also investigatyed, and the antimicrobial sensitivities of the isolates were determined. The results obtained were as fellows : 1. The loss rate by respiratory infection was 11.9% among 1,819 heads which raised and 41.7% among 518 heads which lost by diseases, and the rate increased annually. 2. The loss rate of rabbits in Spring (45.0%), Summer (45.5%) and Winter (53.5%) showed significantly higher (P < 0.01) than that in Autumn(29.1%). 3. The loss rate of Rex (56.3%) showed significantly higher (P<0.05) than New Zealand White (40.7%) and Californian (42.0% ). 4. P. multocida.(37.9%), B. brouchiseptica (16.0%), E. coli (10.6%) and so forth were isolated from 92 samples of lungs and nasal discharges. 5. Sixty fours trains of P. multocida were typed by serological or non-serological tests and their all serotypes were A type (62 strains) except 2 strains of untypable. 6. In antimicrobial sensitivity test for 64 isolates of P. multocida, all the strains tested were highly sensitive to chloramphenicol(95.3%), colistin (95.3%), gentamicin (92.2%), kanamycin (90.6%), neomycin (82.8%) and tetracycline (81.3%), but exhibited low sensitivity to streptomycin (26.6%), and all strains were resistant to lincomycin. 7 Twenty seven isolates of B. brouchiseptica showed higher sensitivity to cephalothin (100%), erythromycin (100% ), gentamicin (100%). trimethoprim+sulfamethoxazole (100%), chloramphenicol(88.9%), kanamycin(88.9%), neomycin (88.9%) and colistin (85.2%), but lower sensitivity to nitrofurantoin (18.5%), penicillin(18.5%). streptomycin(18.5%) and ampicillin (14.8%), and all strains were resistant to lincomycin.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.213-214
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• 1998

This study was conducted to provide useful information for improvement on the efficency of transformation mediated by Agrobacterium tumefaciens. The result from the sensitivity test of cotyledon explants of tomato to kanamycin suggested that 50mg/L could be a proper concentration for selection media. Two hundred mg/L of cefotaxime was selected as a proper concentration to remove Agrobacteria from media without any negative effect on explants. Both callus formation and shoot regeneration from cotyledon explants of tomato were significantly suppressed by the cocultivation with Agrobacterium. Three days of cocultivation was effective on callus formation and shoot regeneration in all of tomato cultivars tested. Confirmation of transformation for regenerated shoots was carried out by histochemical GUS assay and PCR analysis using NPTII primer, and transgenic shoots were obtained from all of 3 tomato cultivars tested.