• Journal of Microbiology
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• 제44권2호
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• pp.171-176
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• 2006

A strictly aerobic, non-motile, ovoid-shaped Alphaproteobacteria, designated strain $JC2049^T$ was isolated from a tidal flat sediment sample. The results of 16S rRNA gene sequence analysis indicated that this isolate belonged to the genus Thalassobius, with a sequence similarity of 96.9-97.3% to other valid Thalassobius spp. The cells required 1-7% NaCl for growth (optimum 2%) and accumulated $poly-\beta-hydroxybutyrate$. Nitrite was reduced to nitrogen, but nitrate was not reduced to nitrite. No genetic potential for aerobic anoxygenic photosynthesis was detected. The primary isoprenoid quinone (Ubiquinone-10), predominant cellular fatty acids $(C_{18:1}{\omega}7c,\;11\;methyl\;C_{18:1}\omega7c\;and\;C_{16:0})$ and DNA G+C content (61 mol %) were all consistent with the assignment of this isolate to the genus Thalassobius. Several phenotypic characteristics clearly distinguished our isolate from other Thalassobius species. The degree of genomic relatedness between strain $JC2049^T$ and other Thalassobius species was in a range of 20-43 %. The polyphasic data presented in this study indicates that our isolate should be classified as a novel species within the genus Thalassobius. The name Thalassobius aestuarii sp. novo is therefore proposed for this isolate; the type strain is $JC2049^T(=IMSNU\;14011^T=KCTC\;12049^T=DSM\;15283^T)$.

• 한국식품영양과학회지
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• 제17권3호
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• pp.215-219
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• 1988

신선돈육의 등심부위를 절단하여 2% 초산용액을 분무하고 $4^{\circ}C$의 냉장고에 보관하면서 무처리구와 경시적으로 미생물학적, 이화학적, 육색의 변화등을 검토하여 저장성 증대의 가능성을 검토하였다. 초산용액의 분무는 신선육표면에 존재하는 aerobic bacteria 및 coliform bactereia의 생육억제에 상당한 효과가 있었다. pH, 단백질변패도(YBN), 지방산패도(TBA)의 측정치는 초산처리구가 대체로 낮게 나와 초산용액이 돈육의 부패를 지연시킬수 없음을 나타내었으며 이들의 값은 미생물의 생육변화와 유사한 양상을 나타내었다. 육색의 변화는 초산용액처리 직후에는 무처리구 보다 검게 나왔으나 저장 2일째 이후부터는 초산용액 처리구가 선홍색쪽에 가까왔다.

• Preventive Nutrition and Food Science
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• 제15권3호
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• pp.239-243
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• 2010

The antimicrobial effects of a commercially available, buffered sodium citrate (BSC) were evaluated for the reduction of total aerobic bacteria count, Salmonella Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in a liquid medium and ground beef. BSC at 0, 1, 2 and 4.8% (wt/vol) or 0, 3, and 4.8% (wt/wt) was mixed into inoculated brain heart infusion (BHI) broth and ground beef (80% lean), respectively. BSC at concentrations of 1 and 2% did not inhibit growth of the pathogens tested in BHI broth. E. coli O157:H7 in BHI broth with 4.8% BSC was significantly reduced (p<0.05) by 3～4 log CFU/mL compared with the control for up to 4 days. At 4.8%, BSC treatment of ground beef most significantly reduced (p<0.05) total aerobic count and E. coli O157:H7 by 2.1 and 2.0 log CFU/g, respectively. This study indicates that the legally allowable level of 1.3% (wt/wt) BSC is not effective for reducing the pathogens tested in ground beef stored at $7^{\circ}C$.

• 한국유기농업학회지
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• 제7권2호
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• pp.153-161
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• 1999

No-till direct-sown rice-wheat relaying cropping system has major advantages such as labor and cost saving by eliminating tillage and preparation of seed bed and transplanting. In this system, rice sowing was done simultaneously wheat harvesting. A paddy field experiment was conducted to evaluate effects of no-till years on soil microbial changes and soil physico-chemical characteristics with rice growth and development. Chemical fertilizers and agricultrual chemicals was not applied in no-till system. As the year in no-till direct-sown system the air permeability was increased and after water submerging soluble nitrogen was released Aerobic microbial-n was highest in May and then decreased after water irrigation. The population of aerobic soil microorganisms were steeply decreased after water submerging Soil microorganisms was decreased with the increased the soil depth. A month was needed for the seedling establishment in a no-tillage rice-wheat cropping system. Increased cropping years improved leaf greenness and leaf area index(LAI). But stomatal conductance(Gc) was higher in conventional cultivation system than no-till system. Stomatal conductance at panicle initiation stage was increased higher in conventional condition of leaves but the difference between conventional and no-till system was increased at heading stage. In no-till 4 years condition rice grain yield was spikelet numbers per panicle.

• 한국환경보건학회지
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• 제34권1호
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• pp.70-75
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• 2008

The Chinese cabbage kimchi, baechoo-kimchi, is the most popular type of kimchi in Korea. This study was performed to investigate the changes of index microorganisms (aerobic bacteria, psychrotrophilic bacteria, coliforms, and Escherichia coli), lactic acid bacteria, pH, and acidity of kimchi during the long-term fermentation and ripening. A homemade-style traditional Korean baechoo-kimchi, was prepared from Chinese cabbage, red pepper, green onion, garlic, ginger, and salt-fermented anchovy sauce, and then incubated at $10^{\circ}C$ for 28 days. In the baechoo-kimchi, the number of aerobic bacteria increased with time. The number of psychrotrophilic bacteria maintained their numbers $(10^4CFU/g)$ in the kimchi during the fermentation. Coliforms and E. coli were not detected in the kimchi. The pH of kimchi decreased and the acidity of kimchi increased over time. Lactic acid bacteria, which are representative of fermentative microorganisms in the kimchi process showed rapid growth in the earlier stage of fermentation and increased steadily after 7 days. The counts of lactic acid bacteria were at a level of $10^4CFU/g$ early in the fermentation stage, reaching a level of $10^8CFU/g$ after 14 days, and at this point pH was 4.18 and acidity reached 0.63, indicating that the optimal state of kimchi fermentation. This study suggests that the lactic acid bacteria which were proliferated in kimchi during the ripening and fermentation could contribute to improving the taste and flavor of kimchi and inhibit the growth of pathogenic microorganisms that might exist in kimchi.

• Environmental Engineering Research
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• 제12권4호
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• pp.129-135
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• 2007

This study evaluated microbial risk that could develop within soil microbial communities after amended with organic fertilizers from stabilized swine manure waste. For this purpose, we assessed the occurrences and competitiveness of antibiotic resistance and pathogenicity in soil microbial communities that were amended with swine manure wastes stabilized by a traditional lagoon fermentation process and an autothermal thermophilic aerobic digestion process, respectively. According to laboratory cultivation detection analysis, soil applications of the stabilized organic fertilizers resulted in increases in absolute abundances of antibiotic resistant bacteria and of two tested pathogenic bacteria indicators. The increase in occurrences might be due to the overall growth of microbial communities by the supplement of nutrients from the fertilizers. Meanwhile, the soil applications were found to reduce competitiveness for various types of antibiotic resistant bacteria in the soil microbial communities, as indicated by the decrease in relative abundances (of total viable heterotrophic bacteria). However, competitiveness of pathogens in response to the fertilization was pathogens-specific, since the relative abundance of Staphylococcus was decreased by the soil applications, while the relative abundance of Salmonella was increased. Further testes revealed that no MAR (multiple antibiotic resistance) occurrence was detected among cultivated pathogen colonies. These findings suggest that microbial risk in the soil amended with the fertilizers may not be critical to public health. However, because of the increased occurrences of antibiotic resistance and pathogenicity resulted from the overall microbial growth by the nutrient supply from the fertilizers, potential microbial risk could not be completely ruled out in the organic-fertilized soil samples.

• KSBB Journal
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• 제21권6호
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• pp.493-497
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• 2006

볏짚 가수분해물의 조성과 유사한 xylose/glucose 혼합배지를 이용하여 Candida mogii ATCC 18364에 의한 xylitol 생산성 및 수율에 관한 연구를 수행하였다. 통기량을 생육단계 (약 10시간)는 호기적인 2 vvm, 300 rpm에서, 생산단계는 반호기적 조건인 1 vvm, 300 rpm으로 조절한 결과 균체의 농도가 10시간 만에 약 $4.7\;g/{\ell}$까지 증가하여 농축균을 사용한 것과 같은 효과를 얻을 수 있었으며, 4일 후에 $0.58\;g/{\ell}$의 수율과 $0.25\;g/{\ell}{\cdot}h$의 생산성으로 약 $24\;g/{\ell}$의 자일리톨이 생산되어 농축균을 이용한 것보다 약간 더 우수하였다. 또한 생산단계에서 xylose를 이용한 세포의 성장을 감소시키기 위해 생산단계에서 포도당을 $6.8\;g/{\ell}{\cdot}day$로 공급한 결과 4일 후에 0.8 g/g의 수율과 $0.31\;g/{\ell}{\cdot}h$의 생산성으로 약 $29.4\;g/{\ell}$의 자일리톨을 생산하여, 포도당 공급을 하지 않았을 때보다 약 $20{\sim}30%$의 증가를 보여주었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.205-210
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• 2006

The widespread use and distribution of chloroethylene organic compounds is of serious concern owing to their carcinogenicity and toxicity to humans and wildlife. In an effort to develop active bacterial consortia that could be useful for bioremediation of chloroethylene-contaminated sites in Africa, 16 combinations of 5 dichloroethylene (DCE)-utilizing bacteria, isolated from South Africa and Nigeria, were assessed for their ability to degrade cis- and trans- DCEs as the sole carbon source. Three combinations of these isolates were able to remove up to 72% of the compounds within 7 days. Specific growth rate constants of the bacterial consortia ranged between 0.465 and $0.716\;d^{-1}$ while the degradation rate constants ranged between 0.184 and $0.205\;d^{-1}$ with $86.36{\sim}93.53\;and\;87.47{\sim}97.12%$ of the stoichiometric-expected chloride released during growth of the bacterial consortia in cis- and trans-DCE, respectively. Succession studies of the individual isolates present in the consortium revealed that the biodegradation process was initially dominated by Achromobacter xylosoxidans and subsequently by Acinetobacter sp. and Bacillus sp., respectively. The results of this study suggest that consortia of bacteria are more efficient than monocultures in the aerobic biodegradation of DCEs, degrading the compounds to levels that are up to 60% below the maximum allowable limits in drinking water.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.54-56
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• 2006

Single-well-gas-sparging tests were developed and evaluated for assessing the feasibility of in-situ aerobic cometabolism of trichloroethylene (TCE), using propane as a growth substrate. To evaluate transport characteristics of dissolved solutes [sulfur hexafluoride (SF6) or bromide (non-reactive tracers), propane (a growth substrate), ethylene, propylene (nontoxic surrogates to probe for CAH transformation activity), and DO], push-pull transport tests were performed. Mass balance showed about 90% of the injected bromide and about 80% of the injected SF6 were recovered, and the recoveries of other solutes were comparable with bromide and slightly higher than SF6. A series of Gas-Sparging Biostimulation tests were performed by sparging propane/oxygen/argon/SF6 gas mixtures, and temporal ground water samples were obtained from the injection well under natural gradient 'drift' conditions. The decreased time for propane depletion and the longer time to deplete SF6 as a conservative tracer indicate the progress of biostimulation. Gas-Sparging Activity tests were performed. .Propane utilization, DO consumption, and ethylene and propylene cometabolism were well demonstrated. The stimulated propane-utilizers cometabolized ethylene and propylene to produce ethylene oxide and propylene oxide, as cometabolic by-products, respectively. Gas-Sparging Acetylene Blocking tests were performed by sparging gas mixtures including acetylene to demonstrate the involvement of monooxygenase enzymes. Gas substrate degradation was essentially completely Inhibited in the presence of acetylene, and no production of the corresponding oxides was also observed. The Gas-Sparging tests supports the evidences that the successive stimulation of propane-oxidizing microorganisms, cometabolic transformation of ethylene and propylene by the enzyme responsible for methane and propane degradation.

• Archives of Pharmacal Research
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• 제19권3호
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• pp.178-182
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• 1996

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxidative stresses induced by 0.1 mM of copper ion $(Cu^{++})$ was studied. In aerobic culture condition, yeasts lacking MnSOD (mitochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared withwild type were observed under anaerobic condition. It was found that, under aerobic condition, the supplementation of 0.1 mM copper ioh:(Cu") into culture medium caused the remarkable increase of CuZnSOD but not so significant change in MnSOD. It was also observed that catalase activities appeared to be relatively high in the presence of copper ion in spite of the remarkable reduction of glutathion peroxidase in CuZnSOD-deficient yeasts, but the slight increments of catalase and glutathion peroxidase were detected in MnSOD-deficient strains. It implies that the lack of cytoplasmic SOD could be compensated mainly by catalase. However, these phenomena resulted in the significantincrease of cellular lipid peroxides content in CuZnSOD-deficient yeasts and the slight increment of lipid peroxides in MNSOD-deficient cells. In anaerobic cultivation supplementing copper ion, the cellular enzyme activities of catalase and glutathion peroxidase in SOD-deficient yeasts were slightly increased without any significant changes of lipid peroxides in cell membrane. It suggests that a little amount of free radicals generated by copper ion under anaerobic condition could be sufficiently overcome by catalase as well as glutathion peroxidase.dase.