• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 Proceedings of the 17th Symposium on Plant Biology Environmental Stress and Photosynthesis
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• pp.55-67
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• 1999

A puc -deleted cell of Rhodobacter sphaeroides grows with a doubling time longer than 160 h under the light-limiting photoheterotrophic ( 3 Watts [W]/㎡) conditions due to an absence of the peripheral light-harvesting B800-850 complex. A spontaneous fast-growing mutant, R.sphaeroides SK101 was ioslate dto have∼40-h doubling at 3 Watts/㎡, while the growth of the mutant was not distinguished from its parental strain during both aerobic and light-saturating photoheterotrphic (10W/㎡) growth. The B875 complex of SK101 under the light-limiting conditions was elevated by 20 to 30% compared with that of the puc -deleted cell, reflecting parallel increase of bacteriochlorophyll and carotenoid contents of the mutant. The formation of B875 complex of SK101 under the anaerobic dark conditions with dimethylsulfoxide was the same as that of the puc-deleted cell. suggesting that the mutation of SK101 result in the altered control of B875 complex formation by light. When puc is restored in SK101 , it is not B875 complex but B800-850 complex which formation is elevated. The mutation of SK101 affected the bchF transcription most drastically to show two to tenfold increase during both aerobic and photoheterotrophic growth. The mutated phenotype of SK101 was complemented with pW2, which contains approximately 100-kb HNA of the photosynthetic gene clusters. The complementing DNA was narrowed down to a 1.1-kb DNA containing orfQ and pufKBA . The mutation of SK101 appeared to be exerted through the mutation of the orfQ gene encoding a putative bacteriochlorophyll -mobilizing protein.

• Journal of Microbiology and Biotechnology
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• 제33권12호
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• pp.1681-1691
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• 2023

Flavin mononucleotide-binding proteins or domains emit cyan-green fluorescence under aerobic and anaerobic conditions, but relatively low fluorescence and less thermostability limit their application as reporters. In this work, we incorporated the codon-optimized fluorescent protein from Chlamydomonas reinhardtii with two different linkers independently into the redox-responsive split intein construct, overexpressed the precursors in hyperoxic Escherichia coli SHuffle T7 strain, and cyclized the target proteins in vitro in the presence of the reducing agent. Compared with the purified linear protein, the cyclic protein with the short linker displayed enhanced fluorescence. In contrast, cyclized protein with incorporation of the long linker including the myc-tag and human rhinovirus 3C protease cleavable sequence emitted slightly increased fluorescence compared with the protein linearized with the protease cleavage. The cyclic protein with the short linker also exhibited increased thermal stability and exopeptidase resistance. Moreover, induction of the target proteins in an oxygen-deficient culture rendered fluorescent E. coli BL21 (DE3) cells brighter than those overexpressing the linear construct. Thus, the cyclic reporter can hopefully be used in certain thermophilic anaerobes.

• Environmental Engineering Research
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• 제13권2호
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• pp.51-65
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• 2008

The increasing demand for energy in the near future has created strong motivation for environmentally clean alternative energy resources. Microbial fuel cells (MFCs) have opened up new ways of utilizing renewable energy sources. MFCs are devices that convert the chemical energy in the organic compounds to electrical energy through microbial catalysis at the anode under anaerobic conditions, and the reduction of a terminal electron acceptor, most preferentially oxygen, at the cathode. Due to the rapid advances in MFC-based technology over the last decade, the currently achievable MFC power production has increased by several orders of magnitude, and niche applications have been extended into a variety of areas. Newly emerging concepts with alternative materials for electrodes and catalysts as well as innovative designs have made MFCs promising technologies. Aerobic bacteria can also be used as cathode catalysts. This is an encouraging finding because not only biofouling on the cathode is unavoidable in the prolonged-run MFCs but also noble catalysts can be substituted with aerobic bacteria. This article discusses some of the recent advances in MFCs with an emphasis on the performance, materials, microbial community structures and applications beyond electricity generation.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2007년도 추계학술발표회
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• pp.185-185
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• 2007

20세기에 들어 산업, 군사 및 다양한 목적으로 비인화성 용매인 PCE와 TCE의 사용량이 증대하였다. 주의를 필요로 하는 물질임에도 불구하고 부주의한 사용과 보관으로 인해 토양, 퇴적토, 지하수에 심각하게 오염되었다. High-chlorinated ethenes은 호기성 박테리아의 oxygenation에 의해 분해되지 않는다. PEC및 TCE의 완전한 탈염소화는 혐기성조건에서만 관찰되어지며, 지난 10연년간의 연구에 의해서 탈염소화 혐기성 미생물의 수의 보고는 증가되었다. 혐기성 조건에서 탈염소화 미생물에 의해 PCE와 TCE는 less-chlorinated ethenes 또는 무해한 ethene으로 전환이 가능하다. 본 연구는 lactate를 electron donor로 이용해 PCE에서 ethene까지 완전히 탈염소화하는 혐기성 배양을 수행했다. PCE로 오염된 퇴적토 시료로부터 혐기성 미생물 배양을 성공했다. PCE가 ethene까지 완전히 분해되는 것이 관찰되었다. 추가적으로 혐기성 미생물 배양액에서 1,2-cis-dichloroethene (cis-DCE)와 vinyl chloride (VC)의 축적이 일어남을 관찰하였다. 혐기성 미생물 배양액에서 Dehalococcoides 16S rRNA gene sequences에 특이적으로 반응하는 primer를 이용한 DGGE를 통해 미생물 군집을 분석하였다. 결론적으로, 우리의 연구에서 PCE를 감소시키는 배양액을 배양했으며, 이 배양엑에는 Dehalococcoides sp. 존재하는 것을 확인하였다.

• 한국환경과학회지
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• 제24권12호
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• pp.1609-1616
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• 2015

The objective of this study was to make a SBR+MBR complex process to evaluate the possible use of the advanced water treatment system for ships (SBR+MBR complex process) in accordance with the amendments MAPOL 73/78 that went into effect. The conditions 1 and 2 did not show the quick reduction in anaerobic condition while in the precipitation and stirring stages of the SBR treatment which was determined to be ineffective denitrification, same as with the ORP. Removal of organic matters such as $BOD_5$ and $COD_{Cr}$ in the SBR treatment was observed to happen smoothly and going through the MBR treatment as well would provide a stable water quality. However, the results were not satisfactory in accordance with $BOD_5$ 25 mg/L and $COD_{Cr}$ 125 mg/L. Thus, the operating conditions improvement is deemed necessary. Likewise for the nutrients (T-N and T-P), the nitrification in bioreactor, denitrification and phosphorus absorption in aerobic tank due to phosphorus release in anaerobic tank had not been proceeded effectively. It was concluded that the improved operating conditions and structural changes would provide more effective treatments since the removal rates of T-N and T-P were less than 70% and 80%, respectively, which were standards specified by the MEPC. 227(64).

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1210-1215
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• 2006

The properties related to the temperature and oxygen stability of the cytoplasmic hydrogenases from the fermentative strict anaerobic bacterium, Clostridium butyricum NCIB 9576 (Cl. butyricum), and purple sulfur phototrophic bacterium, Thiocapsa roseopersicina NCIB 8347 (T. roseopersicina), were compared. The optimum temperatures for the growth of Cl. butyricum and T. roseopersicina were 37$^{\circ}C$ and 25$^{\circ}C$, respectively, whereas those for the H$_2$ evolution of the cytoplasmic hydrogenases prepared from Cl. butyricum (C-H$_2$ase) and T. roseopersicina (T-H$_2$ase) were 45$^{\circ}C$ and 65$^{\circ}C$, respectively. The T-H$_2$ase was more thermostable than the C-H$_2$ase and retained its full activity for 5 h at 50$^{\circ}C$ under anaerobic conditions and 90% of its activity at 60$^{\circ}C$, whereas the C-H$_2$ase lost its activity drastically at 50$^{\circ}C$. The optimum pHs for H$_2$ oxidation of the C-H$_2$ase and T-H$_2$ase were 9.0 and 7.5, respectively. Both enzymes showed a maximum H$_2$ evolution activity at pH 7.0. Under aerobic conditions, 80% of the T-H$_2$ase activity was retained for 10 h at 30$^{\circ}C$, and 50% of the activity remained after 6 days under the same experimental conditions. However, the C-H$_2$ase was labile to oxygen and lost its activity immediately on exposure to air. Therefore, these properties of the T-H$_2$ase are expected to be advantageous for application in in vitro biological H$_2$ production systems.

• 한국임상수의학회지
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• 제32권1호
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• pp.41-44
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• 2015

이 연구는 더러브렛 말에서 호이산화탄소성 Streptococcus equi subsp equi 에 기인한 선역의 발생에 관한 보고이다. 3개의 다른 농장에서 선역의 전형적인 증상인 림프절 화농이 있거나 없는 29두의 말에서 17 균주의 S equi subsp equi를 분리하였다. 이들 중 임상증상이 있는 1두에서 분리한2균주는 호기배양에서 분리되었으나, 임상증상이 있는 6두에서 분리한 7균주와 임상증상이 없는 22두에서 분리한 8균주는 호기조건에서 배양되지 않았다. 이 15 분리균주는 일반 호기배양기에서는 증식하지 않았으며, 5% $CO_2$배양기, 산소분압을 낮추는 candle jar 및 GasPak을 이용한 혐기배양에서 증식하는 호이산화탄소성, 산소민감성 또는 이산화탄소 요구성 S. equi subsp. equi로 판명되었다. 이 연구는 호이산화탄소성 S. equi subsp. equi 에 의한 선역발생에 관한 최초의 보고이다.

• 한국미생물·생명공학회지
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• 제26권1호
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• pp.7-14
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• 1998

Bifidobacterium spp.의 내 산소성기작을 밝히기 위하여, 산소에 민감한 B. adolescentis와 상대적으로 산소에 내성이 있는 B. longum을 선정하여 혐기적 조건, 미호기성 조건,호기성 배양 조건 등에서 그 생육,산화 효소들의 활성, 세포 지방산 조성의 변화 등을 연구하였다. B. adolescentis의 생육은 미 호기성 조건에서 민감하게 저해되었으나, B. longum은 같은 조건에서 혐기배양과 같은 정도의 생육을 유지하였다. 이들 조건에서 두 균주의 catalase는 관찰되지 않은 반면, superoxide dismutase는 B. adolescentis와 B. longum모두에서 관찰되었으며 어느 조건에서든 B. adolescentis은 B. longum보다 높은 활성을 나타내었다. NADH oxidase와 NADH peroxidase의 활성은 B. adolescentis에서는 매우 낮은 반면, B. longum에서는 일정한 수준의 활성을 보였으며, 이 활성은 혐기적 배양조건에서 보다는 미호기성 조건에서 3.7-11.4배 증가하였다. 세포의 지방산 분석 결과 두 균주 모두 $C_{l6:0}$과 $C_{l8:1}$이 전체 methylated성분 중 60-70%를 차지했다. B. longum에는 특히 $C_{l9:0 cyclo 9,10}$가 2-14% 함유되어 있었으며, 이는 lactobacillic acid와는 cylization 위치가 다른 cis 9, 10-methylene octadecanoic acid이었고 미호기적 배양과 정지기 세포에서 증가되는 경향을 보였다. 두 균주 모두 혐기균에서만 확인된 세포막의 plasmalogen의 존재로 인한 dimethyl acetals(DMA)을 함유하고 있었는데 이 중 $C_{l8:1}$ DMA는 호기성 조건에서 현저히 감소되었다. 산소 stress환경의 bifidobacteria의 생육에 있어 NADH oxidative enzymes은 중요한 역할을 하며, 이들 효소체계와는 별도로 환경에 적응하기 위한 세포구조적 변화의 일부로 지방산 $C_{l9:0}$ Cyclo와 plasmalogen의 $C_{l8:1}$ 등이 변화한 것으로 생각된다.

• 한국임상수의학회지
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• 제28권5호
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• pp.516-518
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• 2011

한국 황새복원센터에서 사육중인 황새의 정상 장내 세균총을 검사하기 위한 조사를 실시하였다. 44마리의 건강한 황새의 총배설강으로부터 44개의 분변시료를 채취하여 호기 및 혐기조건에서 배양하였다. 배양된 미생물의 16Sribosomal RNA 및 heat shock protein 60 유전자의 염기서열을 조사하였다. 호기조건 하에서는 Enterococcus faecalis, Escherichia coli, Bacillus spp., Enterococcus avium, Enterococcus gallinarum, Pseudomonas spp., Alcaligenes spp., Enterobacter spp., Corynebacterium spp., Proteus mirabilis가 동정되었다. 혐기조건 하에서는 E. coli, Clostridium tertium, En. faecalis, P. mirabilis가 동정되었다. 모든 시료에서 E. coli, En. faecalis 혹은 두 가지 모두가 분리되었다. 이러한 정상 황새의 장내 미생물 정보는 향후 분변 배양 결과의 해석에 도움이 될 것으로 판단된다.

• 한국농공학회논문집
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• 제56권1호
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• pp.1-9
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• 2014

Sediment pollutants have been considered an important source for the eutrophication of estuarine reservoir. In this study, the effects of pollutants released from bottom sediment to water column were investigated. Sediment samples were collected each two station from Namyang and Sukmoon estuarine reservoirs in August 2013. The fractionation result of sediment phosphorus indicated that Adsorbed-P ($36.7{\pm}8.84%$) and Nonapatite-P ($29.3{\pm}12.50%$) are the two dominant phosphorus groups in the sediments. For sediment release test, eight sets of acrylic chamber (0.3 m $diameter{\times}1m$ high, with 0.15 m sediment depth) were used with aerobic and anaerobic environment. Under anaerobic conditions, rates of $NH_4-N$ release from the sediments were highly variable, with final concentrations of $NH_4-N$ in the overlying water varying from between about 0.69~1.04 in Namyang and 2.58~4.23 mg/L in Sukmoon reservoir. The $NH_4-N$ release was active at the upstream around the confluence of tributary compared to downstream near the embankment. The $PO_4-P$ release was more obvious than $NH_4-N$ in anaerobic condition. The final $PO_4-P$ concentrations were approximately from two-fold to eight-fold higher than initial concentration. In terms of reservoir water quality management, not only tributary pollutants but also sediment nutrient loading is necessary to consider the water quality contribution.