• 생태와환경
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• 제36권3호통권104호
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• pp.304-310
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• 2003

수심이 얕고 부영양 호소인 L. Kasumigaura를 대상으로 퇴적층으로부터 유기물 용출특성을 조사하였다. 퇴적물의 함수율은 약 80%이상을 차지하고 있었으며 공극수의 DOC농도는 표층에서 높고 깊어질수록 감소하는 경향을 나타냈다. 특히 조사기간중 공극수의 DOC농도(104mg C/l)가 크게 증가하여 공극수로부터 수체로 용출 가능성이 높을 것으로 추정되었다. DOC 용출실험결과, 호기조건에서는 Labile-DOC (L-DOC)용출이 거의 관측되지 않았고 Refractory-DOC (R-DOC)만 관측되었으며, 혐기조건에서는 L-DOC와 R-DOC 모두 용출되는 것으로 나타났다. 이러한 결과는 퇴적층의 상부수층에 DO가 충분히 유지되면 L-DOC는 용출되어도 호기성 bacteria에 의해 쉽게 분해되기 매문에 R-DOC만 용출되는 것으로 조사되었으며, 혐기조건하에서는 혐기성 bacteria의 유기물 분해능력의 감소로 L-DOC와 R-DOC모두 용출되는 것으로 나타났다. 결과적으로 내부생성기원의 유기물중 퇴적층으로부터 R-DOC 용출은 수체의 유기물 농도를 증가시키는 주요 원인으로 나타났으며, 수중 유기물의 대부분을 차지하고 있는 R-DOC는 유기물순환에 중요한 역할을 담당하고 있다는 사실이 확인되었다.

• 한국수산과학회지
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• 제31권6호
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• pp.920-926
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• 1998

본 연구는 C. polykrikoides 적조 구제로 살포한 황토가 저층에 퇴적된 후, 적조생물이 분해되는 동안 미생물군집과 호흡 전자전달계 활성에 미치는 영향을 알아보기 위하여 마산만과 진해만의 퇴적물로 배양실험을 행한 결과이다. 종속영양세균수는 두 개 정점의 실험구 모두 황토첨가와 무관하게 $10^7$ cells/dry g의 범위로 12시간만에 최고 치에 도달하였고 유사한 변동을 보여주었다. 종조성의 변동 또한 황토첨가로 인한 뚜렷한 영향을 보여주지 않았으며, Vibrio spp.는 배양기간 동안 계속 출현하였다. 그러나 황산염환원세균은 배양 8일째 마산만의 황토를 첨가하지 않은 퇴적물에서 $3.8\times10^7$cells/dry g로 1:1(1:2) 비율의 황토첨가 실험구에 비하여 120 (350)배 정도 높았고, 진해만의 퇴적물에서는 $5.5\times10^6$cells/dry g로 1:1 (1 : 2) 비율의 황토첨가 실험구보다 160(420)배 정도 높았다. 또한, ETA는 두 개의 정점 모두 호기적 조건에서는 각 실험구의 평균치가 6.8$\~$7.6 $\mu$g formazan $h^{-1}$ dry $g^{-1}$ 의 범위로서 황토의 첨가와 무관하게 비슷한 활성을 나타내었지만, 혐기적조건의 정점 A의 퇴적물에서 황토를 첨가하지 않은 실험구는 평균 10.4$\mu$g formazan $h^{-1}$ dry $g^{-1}$ 로 황토첨가 비율이 높을수록 7.3 (1:1), 3.4(1 : 2) $\mu$g formazan $h^{-1}$ dry $g^{-1}$으로 낮은 활성을 나타내었고, 정점 B의 퇴적물도 황토를 첨가한 비율이 높을수록 활성이 낮았다. 따라서 황토첨가가 해양환경에 나쁜 영향을 미치는 혐기적분해 및 황산염환원세균의 성장을 저지하는 효과가 있는 것으로 사료된다. 본 실험 결과는 모델실험에 의한 것으로 보다 자세한 황토의 영향을 알기 위해서는 현장에서 미생물군집의 변동과 활성의 조사가 필요할 것이다.

• 대한임상검사과학회지
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• 제49권4호
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• pp.407-412
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• 2017

본 연구에서는 계대배양과 세균 동정 시험에 소요되는 시간을 단축하고, 혈류감염의 새로운 검사 방법을 모색하여 간단하고 신속 정확한 동정 결과를 도출할 목적으로 질량분석기를 이용하여 다음과 같은 결과를 얻었다. 혈액배양에서 한 가지 세균만 배양된 검체는 총 254개였으며, Vitek 2에서 208주(81.8%)의 세균을 동정되었으며, 45주는 동정되지 않았다. 동정된 세균 중 그람양성 세균이 146개(57.5%), 그람음성 세균이 108개(42.5%)이었다. 전체적으로 233개는 종(species) 수준까지 동정 되었으며, 21개는 속(genus)수준까지 동정 되었다. 동정 오류는 Propionibacterium acnes를 Clostridium bifermentans로 동정 되었다. 균종별로는 enterobacteriaceae, glucose non-fermentative bacilli (GNFB), staphylococci의 정확도는 각각 81/83 (97.6%), 12/15 (80.0%), 72/85 (84.7%)로 나타났다. Vitek 2에 의한 표준법과 Vitek MS에 의한 직접법에 의한 동정의 일치율은 81.8%이었으며, 45주는 동정되지 않았다. 동정되지 않은 세균들의 대부분은 그람양성 세균(n=37)이었고, 그람양성 세균은 streptococci (14), coagulase-negative staphylococci (CNS) (11), enterococci (3), Staphylococcus aureus (2), Micrococcus spp. (2), Bacillus spp. (2) 그리고 Actinomyces odontolyticus, Finegoldia mag na, Peptostreptococcus spp.가 각각 1건씩 이었다. 결과 보고 시간은 기존의 검사 방법보다 24~72시간까지 단축되었다. 산소성 배양과 무산소성 배양 사이의 동정률의 차이는 없었으나 무산소성 배양을 사용하면 용해 과정이 필요 없어 검체 준비 시간을 단축할 수 있었다. 이상의 연구 결과로 혈액배양병에서 직접 동정하는 방법은 정확하고 결과 보고 시간이 신속하여 환자의 치료에 매우 유용할 것이라 생각된다. 향후 추가적인 연구에서는 본 연구에서 정확성이 부족했던 사슬알균(streptococci)과 혈장응고효소 음성 포도알균(CNS)을 동정하기 위한 방법을 더욱 개선할 필요가 있을 것으로 사료된다.

• Journal of Applied Biological Chemistry
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• 제52권3호
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• pp.121-125
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• 2009

고추역병에 대한 길항미생물로 선발된 Bacillus subtilis AH18과 Bacillus licheniformis K11의 토양미생물 생태에 미치는 영향을 조사하기 위하여 이들 미생물을 단독 또는 복합으로 토양에 처리한 후 토양미생물상의 변화를 관찰하였다. 토양미생물 생태의 변화는 토양에서 인지질 지방산을 추출한 후 전체 지방산과 지표 지방산의 상대적 비율로 분석하였다. 전체적 인지질 지방산 구성과 각 지표 지방산 분석에 의해서 B. subtilis AH18 처리구는 무처리 대조구와 완전히 구분되었다. 전체 토양미생물상을 B. subtilis AH18 처리가 바꾸었고 세균 비율을 감소시켰으며, 곰팡이세균 비율을 높였으며, 그램음성균/그램양성균의 비율을 낮추었으며, 혐기성균/호기성균의 비율은 증가시켰다. 또한 불량환경 적응성을 의미하는 cy19:0/18:$1{\omega}7c$ 지방산비율과 단불포화지방산/포화지방산 비율도 B. subtilis AH18 처리구가 증가시켰다. 이에 반하여 B. licheniformis K11 처리나 두 미생물의 동시 처리는 전술한 토양미생물 지표에 큰 영향을 미치지 않았다. 따라서 지방산 분석을 토양미생물상 분석에서 B. subtilis AH18의 단용처리는 미생물을 처리하지 않은 대조구에 비하여 토양미생물상을 뚜렷이 바꾸었지만, B. subtilis AH18가 B. licheniformis K11와 혼용되었을 때는 토양미생물상 변화에 미치는 영향이 적었다. 따라서 이들 두 미생물을 동시에 처리할 경우 고추역병 방제와 토양미생물 생태 보존의 두 목적을 동시에 이룰 수 있을 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권12호
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• pp.1744-1751
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• 2011

This study was conducted to compare the effects of feeding dry or fermented (aerobically or anaerobically with or without lactic acid bacteria) restaurant food residue mixture-containing diets on animal performance and blood profiles. Rats were used as the model animal for the simulation of laboratory rodents, rabbit or horse feeding and fed for 4 wks. The results were compared with feeding a dry diet (control) with the same ingredient composition as diets processed by aerobic and anaerobic methods. Feeding all the fermented diets tended to increase (p>0.05) average daily gain of rats resulting in improved (p<0.01) feed efficiency. Apparent digestibility of NDF was increased (p<0.05) by feeding the fermented diets, although digestibilities of DM, OM, CP, and NFC were not affected (p>0.05). Compared with the aerobically fermented diet, digestibility of ADF was increased (p<0.05) for the anaerobically fermented diet and for the 0.5% LAB culture plus anaerobically fermented diet. The digestibility of crude ash tended to increase (p>0.05) with feeding of the fermented diets. Feeding either of the fermented diets had little effects on serum nutrients, electrolytes, enzymes and blood cell profiles of rats except sodium and uric acid concentrations. These results showed that compared with feeding a dry food residue-containing diet, feeding aerobically or anaerobically fermented diets showed better animal performance as indicated by higher feed efficiency and rat growth rate. These improvements were attributed to the desirable dietary protein conservation during the food residue fermentation process and to higher total tract digestibilities of NDF and crude ash in the fermented food residue diets.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.39-45
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• 2001

Extremophiles are unique microorganisms that are adapted to survive in ecological niches such as high or low temperatures, extremes of pH, high salt concentrations and high pressure. These unusual microorganisms have unique biochemical features which can be exploited for use in the biotechnological industries. Due to the high biodiversity of extremophilic archaea and bacteria and their existence in various biotopes a variety of biocatalysts with different physicochemical properties have been discovered. The extreme molecular stability of their enzymes, membranes and the synthesis of unique organic compounds and polymers make extremophiles interesting candidates for basic and applied research. Some of the enzymes from extremophiles, especially hyperthermophilic marine microorganisms (growth above $85^{\circ}C$), have already been purified in our laboratory. These include the enzyme systems from Pyrococcus, Pyrodictium, Thermococcus and Thermotoga sp. that are involved in polysacharide modification and protein bioconversion. Only recently, the genome of the thermoalkaliphilic strain. Anaerobranca gottschalkii has been completely sequenced providing a unique resource of novel biocatalysts that are active at high temperature and pH. The gene encoding the branching enzyme from this organism was cloned and expressed in a mesophilic host and finally characterized. A novel glucoamylase was purified from an aerobic archaeon which shows optimal activity at $90^{\circ}C$ and pH 2.0. This thermoacidophilic archaeon Picrophilus oshimae grows optimally at pH 0.7 and $60^{\circ}C$. Furthermore, we were able to detect thermoactive proteases from two anaerobic isolates which are able to hydrolyze feather keratin completely at $80^{\circ}C$ forming amino acids and peptides. In addition, new marine psychrophilic isolates will be presented that are able to secrete enzymes such as lipases, proteases and amylases possessing high activity below the freezing point of water.

• Animal Bioscience
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• 제34권9호
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• pp.1479-1490
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• 2021

Objective: Our recent findings confirmed the effectiveness of sodium metabisulfite (SMB) in controlling the growth of undesirable microorganisms in fruit and vegetable discards (FVD); however, lactic acid bacteria (LAB) are susceptible to its antibacterial effects. Two series of experiments were conducted to enable the survivability of LAB during silage fermentation of a total mixed ration (TMR) containing SMB-treated FVD. Methods: In Exp. 1, the objective was to isolate a strain of LAB tolerable to the toxic effect of SMB. In Exp. 2, the SMB load was minimized through its partial replacement with a chemical mixture (CM) based on sodium benzoate (57%), potassium sorbate (29%), and sodium nitrite (14%). FVD was treated with SMB + CM (2 g each/kg biomass) and added to the TMR at varying levels (0%, 10%, or 20%), with or without KU18 inoculation. Results: The KU18 was screened as a presumptive LAB strain showing superior tolerance to SMB in broth medium, and was identified at the molecular level using 16S rRNA gene sequence analysis as Lactobacillus plantarum. Inoculation of KU18 in TMR containing SMB was not successful for the LAB development, biomass acidification, and organoleptic properties of the resultant silage. In Exp. 2, based on the effectiveness and economic considerations, an equal proportion of SMB and CM (2 g each/kg FVD) was selected as the optimal loads for the subsequent silage fermentation experiment. Slight differences were determined in LAB development, biomass acidification, and sensorial characteristics among the experimental silages, suggesting the low toxicity of the preservatives on LAB growth. Conclusion: Although KU18 strain was not able to efficiently develop in silage mass containing SMB-treated FVD, the partial substitution of SMB load with the CM effectively alleviated the toxic effect of SMB and allowed LAB development during the fermentation of SMB + CM-treated FVD in TMR.

• Asian-Australasian Journal of Animal Sciences
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• 제26권1호
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• pp.134-142
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• 2013

The effect of modified atmosphere packaging (MAP; 30% $CO_2$+70% $N_2$ or 100% $N_2$) and an additive mixture (500 ppm rosemary extract, 3,000 ppm sodium acetate and 1,500 ppm calcium lactate) on the quality of pre-cooked hamburger patties during storage at $5^{\circ}C$ for 14 d was evaluated. The addition of the additive mixture reduced aerobic and anaerobic bacteria counts in both 30% $CO_2$-MAP (30% $CO_2$+70% $N_2$) and 100% $N_2$-MAP (p<0.05). The 30% $CO_2$-MAP was more effective to suppress the microbial growth than 100% $N_2$-MAP, moreover the 30% $CO_2$-MAP combined with additive mixture resulted in the lowest bacterial counts. The hamburger patties with additive mixture showed lower CIE $L^*$ and CIE $a^*$, and higher CIE $b^*$ than those with no additive mixture. The 30% $CO_2$-MAP tended to decrease the TBARS during storage regardless of the addition of additives. The use of 30% $CO_2$-MAP in combination with additives mixture was effective for maintaining the quality and extending the shelf-life of pre-cooked hamburger patties.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.270-274
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• 2005

A reactor-scale hydrogen (H2) production via the water-gas shift reaction of carbon monoxide (CO) and water was studied using the purple nonsulfur bacterium, Rhodopseudomonas palustris P4. The experiment was conducted in a two-step process: an aerobic/chemoheterotrophic cell growth step and a subsequent anaerobic $H_2$ production step. Important parameters investigated included the agitation speed. inlet CO concentration and gas retention time. P4 showed a stable $H_2$ production capability with a maximum activity of 41 mmol $H_2$ g $cell^{-1}h^{-1}$ during the continuous reactor operation of 400 h. The maximal volumetric H2 production rate was estimated to be 41 mmol $H_2 L^{-1}h^{-1}$, which was about nine-fold and fifteen-fold higher than the rates reported for the photosynthetic bacteria Rhodospirillum rubrum and Rubrivivax gelatinosus, respectively. This is mainly attributed to the ability of P4 to grow to a high cell density with a high specific $H_2$ production activity. This study indicates that P4 has an outstanding potential for a continuous H2 production via the water-gas shift reaction once a proper bioreactor system that provides a high rate of gas-liquid mass transfer is developed.

• 한국임상약학회지
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• 제27권2호
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• pp.83-91
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• 2017

Background: Piperacillin/tazobactam (TZP) is an antibiotic against a broad spectrum of gram-positive, gram-negative, and aerobic and anaerobic strains of bacteria. Due to changes in its pharmacokinetic and pharmacodynamic parameters by TZP-treated patients' renal functions and obesity, it is important to administrate and monitor TZP based on their renal functions and Body Mass Index (BMI) levels. The purpose of this study was to determine the appropriateness of administration doses of TZP based on renal functions of obese cancer patients in a tertiary hospital. Methods: This study was retrospectively conducted with obese cancer patients with $BMI{\geq}30kg/m^2$ in a tertiary hospital, Korea from September 2004 to August 2014. Data were collected through Electronic Medical Record (EMR) which contained laboratory data and TZP dosing of each patient. Results: Among 7,058 patients during the study period, 102 prescriptions were selected based on inclusion and exclusion criteria and classified by their renal functions. Although TZP should be used based on patients' renal functions to adjust its dose, its initial dose and dosing interval were consistently used without considering patients' renal functions on a regular basis. Especially, in the comparison with FDA dosing standard of TZP, approximately twice patients with $20mL/min{\leq}CrCl{\leq}40mL/min$ received domestically 4.5 g instead of 2.25 g as the TZP starting dose. Conclusion: The appropriate doses of TZP were administered to almost all of obese cancer patients; however, the recommended TZP dose was different between Korea and other countries by twice the amount. Further related studies are necessary to clearly determine the results, to optimize TZP treatment for obese patients with cancer in clinical practice, and to design and develop new TZP formulations for them in pharmaceutical industry.