• Journal of Microbiology
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• 제44권4호
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• pp.461-465
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• 2006

The occurrence of thioredoxin reductase (NAD(P)H: oxidized-thioredoxin reductase, EC 1.6.4.5, TrxR) in five mesophilic species of Deinococcus was investigated by PAGE. Each species possessed a unique TrxR pattern, for example, a single TrxR characterized D. radiopugnans while multiple forms of TrxR occurred in other Deinococcal spp. Most of TrxRs occurring in Deinococcus showed dual cofactor specificity, active with either NADH or NADPH, although the NADPH specific-TrxR was observed in D. radiophilus and D. proteolytic us.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 제36차 추계 학술발표대회
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• pp.225-228
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• 2005

The aim of this study is to evaluate the microbial safety and physical qualities of Korean jerky, and the effect of nisin during storage. Jerky processed packages with or without nisin (100 IU or 500 IU) were stored at room temperature (25 $^{\circ}C$) for 60 days, and samples measured for quality at regular intervals throughout this storage period. In the case of 25$^{\circ}C$ storage, the number of mesophilic microorganisms in seasonedbeef packages without nisin increased markedly, but with nisin there was no observed increase. B. cereus cells showed similar trends, although coliform was not detected in all samples. At 25$^{\circ}C$ storage, changes in the cutting force of packages containing nisin showed no significant change, packages without nisin decreased markedly.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2005년도 제36차 추계 학술발표대회
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• pp.319-323
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• 2005

Lactic acid bacteria are dominant microflora in many kinds of fermented foods. In this study, dominant microflora, especially lactic acid bacteria were isolated from salted sea food, and we determined physiological characteristics, and assayed specific property such as bacteriocin activity. The population of lactic acid bacteria as well as aerobic mesophilic counts was at the level of $10^7$ cfu /g. Total 17 strains of LAB were isolated from salted sea food sample. The phenotypic characteristics of these strains were determined followed by Bergey's Manual. And genotypic and bacteriocin activity were tested by Schillinger and $L{\ddot{u}}cke^{(7)}$.

• Genomics & Informatics
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• 제9권2호
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• pp.79-84
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• 2011

Two initial models of cold-adapted lipase PsLip1 have been constructed, based on homology with the bacterial lipases Chromobacterium viscosum (CvLip) and Pseudomonas cepacia (PcLip), whose X-ray structures have been solved and refined to high resolution. The mature polypeptide chains of these lipases have 84% similarity. The models of Mod1 and Mod2 have been compared with the tertiary structures of CvLip and PcLip, respectively, and analyzed in terms of stabilizing interactions. Several structural aspects that are believed to contribute to protein stability have been compared: the number of conserved salt bridges, aromatic interactions, hydrogen bonds, helix capping, and disulfide bridges. The 3-dimensional structural model of PsLip1 has been constructed in order to elucidate the structural reasons for the decreased thermostability of the enzyme in comparison with its mesophilic counterparts.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.811-813
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• 2008

To see the effect of magnesium on adhesion to natural zeolites, a series of batch tests were performed in this research. Mixed bacteria were sampled from the digestion tank at a local sewage treatment plant in Seoul. Magnesium-zeolites were synthesized by mixing natural zeolites with 0.096 M, 0.24 M, and 0.48 M of MgCl2 solution. For comparison, manganese and trivalent ferric zeolites were also prepared. Two grams of 0.2 mm $\sim$ 0.3 mm sized zeolites(non-treated, Mg, Mn and Fe(III) treated zeolites) and 20 mL of water were mixed in a Corex 25 mL tube. Five milliliters of culture solution including bacteria was added to the tube. The tubes were equilibrated in a shaking incubator at mesophilic temperature $(30{\pm}2^{\circ}C)$. The bacterial concentrations were measured with a Microluminometer (New Horizons 3550i) and total organic carbon (TOC) spectrophotometer (Multi NC-3100).

• 한국자기공명학회논문지
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• 제19권1호
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• pp.42-48
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• 2015

The mannitol transporter Enzyme $II^{Mtl}$ of the bacterial phosphotransferase system has two cytoplasmic phosphoryl transfer domains $IIA^{Mtl}$ and $IIB^{Mtl}$. The two domains are linked by a flexible peptide linker in mesophilic bacterial strains, whereas they are expressed as separated domains in thermophilic strains. Here, we carried out backbone assignment of $IIA^{Mtl}$ from thermophilic Thermoanaerobacter Tencongensis using a suite of heteronuclear triple resonance NMR spectroscopy. We have completed 94% of the backbone assignment, and obtained secondary structural information based on torsion angles derived from the chemical shifts. $IIA^{Mtl}$ of Thermoanaerobacter Tencongensis is predicted to have six ${\beta}$ strands and six ${\alpha}$ helices, which is analogous to $IIA^{Mtl}$ of Escherichia coli.

• 한국포장학회지
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• 제4권1호
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• pp.33-40
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• 1997

The microbial growth of fresh, vacuum packaged, cook-in-bag uncured beef patties was determined in two film structures, a commercial (PE/EVOH), and super barrier ($SiO_2$ coated polyester) material. Packaged samples were cooked to internal temperature of 71 and $82^{\circ}C$ for 30 minutes, and stored in temperature abused ($23{\pm}2^{\circ}C$) and refrigerated storage ($4-6^{\circ}C$). Barrier properties had a significant effect (p<0.001) on aerobic and mesophilic growth in the abused condition. Cooking temperatures had a statistically significant effect (p<0.05) on aerobic growth in the refrigerated condition. The growth of anaerobes and psychrophiles were not significantly effected by either variables. Storage times had the most significant effect (p<0.001) for all groups of microorganisms. The physical properties of the commercial film (strength, thickness, and shrinkage) were changed after exposure to thermal treatment, while the super barrier package had actually no change.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1368-1371
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• 2008

In this study, 50 rump samples of raw beef obtained from local Korean supermarkets were analyzed to survey microbial distributions. As results, mesophilic microorganisms ranged from $(1.4{\pm}0.01){\times}10^2$ to $(1.6{\pm}0.05){\times}10^5\;CFU/g$, and total coliforms ranged from 0 to $(1.3{\pm}0.04){\times}10^4\;CFU/g$. Major foodborne pathogens, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp., were not found among the samples. However, Staphylococcus aureus was isolated with 4% frequency. Other isolated microorganisms included Enterobacter amnigenus (4%), Enterobacter cloacae (24%), E. coli (24%), Listeria innocua (8%), Staphylococcus saprophyticus (56%), Staphylococcus xylosus (10%), and Staphylococcus warneri (8%).

• 산업기술연구
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• 제39권1호
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• pp.21-25
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• 2019

This work experimentally determined the effect of microaerobic condition on anaerobic digestion of thickened waste activated sludge in semi-continuous mesophilic digesters at hydraulic retention time of 20 days. The concentration of hydrogen sulfide was $7{\pm}2ppm$ at the microaerobic condition and $14{\pm}2ppm$ at the anaerobic condition. Removal efficiency of volatile solid was not significantly different between microaerobic ($40{\pm}8%$) and anaerobic ($38{\pm}8%$) conditions. There was no important difference between microaerobic ($1,352{\pm}98ml/d$) and anaerobic ($1,362{\pm}104ml/d$) conditions in the biogas production, either. Therefore, it could be concluded that the application of the microaerobic condition was an efficient method of the hydrogen sulfide removal from the biogas.

• 한국축산시설환경학회지
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• 제10권2호
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• pp.111-118
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• 2004

본 연구는 양돈 분뇨를 고온호기산화장치(TAO)를 이용하여 처리하였을 때, 고온 미생물 의 첨가에 의한 온도 상승과 시스템의 내부 미생물 변화 그리고 유해 미생물의 불활성화에 대하여 연구하였다. 실험은 총 용량 $18 m^3(3.0\times2.5\times2.4 m)$의 반응기에 양돈 분뇨 $6 m^3$을 투입하고 5$\~$7일간 운전하였다. 대조구는 양돈 분뇨만을 투입하였고 처리구는 6 $\iota$의 고온 미생물(Bacillus. sp)을 투입하였다. 반응기의 내부 미생물의 변화를 검토하기 위해서 호기성 중온균, 고온균 그리고 일반 세균을 분석하였다. 또한, 유해 미생물의 불활성화를 검토하기 위하여 E. coil, Salmonella. sp, Crytosporidium parvum, Giardia lamblia를 분석하였다. 대조구와 처리구의 운전기간 동안 반응기 내부의 온도 범위는 $18\~66^{\circ}C$로 $55^{\circ}C$ 이상의 높은 온도를 유지하였다. 미생물 변화에 있어서 대조구의 중온균과 고온균은 $3.1\times10^6\~1.2\times10^2$ CFU/ml, $1.0\times10^4\~8.0\times10^1$ CFU/ml로 감소하였으나 처리구의 경우, 중온균은 $3.0\times10^8\~8.6\times10^5$ CFU/ml로 감소하였으나 고온균은 $2.0\times10^6\~1.2\times10^8$ CFU/ml로 증가하는 경향을 보였다. Salmonella와 Giardia는 처리 전$\cdot$후에 검출되지 않았으며 E. coil와 Crytosporidium은 처리전 양성반응을 나타내었으나 처리 후 불활성화 되었다. 이상의 결과를 통해서, 우리는 TAO system에 고온 미생물을 첨가함으로써 유해한 미생물이 사멸된 액상비료를 생산할 수 있었고 분뇨로부터 기인하는 2차 오염을 방지할 수 있을 것으로 판단된다.