• 한국수소및신에너지학회논문집
• /
• 제15권4호
• /
• pp.309-316
• /
• 2004

Chlamydomonas reinhardtii UTEX 90 was cultivated with continuous supply of 2% $CO_2$ using TAP media at $25^\circ{C}$ and produced biomass 1.18 g of dry cell weight/L for 4 days. C. reinhardtii algal biomass(CAB) was concentrated to 20 times by volume and converted into hydrogen and organic acids by anaerobic fermentation using Clostridium butyricum. Organic acids in the fermentate of CAB were consecutively used to produce hydrogen by Rhodobacter sphaeroides KD 131 under the light condition. Approximately 52% of starch in the concentrated CAB which had 4-5.8, 24-26 and 6-7 g/L of starch, protein and fat, respectively was degraded by Cl. butyricum at $37^\circ{C}$. During this process, hydrogen and some organic acids, such as formate, acetate, propionate, and butyrate, respectively were produced. Further conversion of the organic acids in anaerobic fermentate of CAB by Rb. sphaeroides KD131 produced hydrogen from the anaerobic fermentate under the illumination of 8 klux using halogen lamp at $30^\circ{C}$. The result showed that hydrogen was evolved by the anaerobic conversion using Cl. butyricum and then by the photosynthetic fermentation using Rb. sphaeroides KD131. It indicated that the two-step conversion process produced the maximum amount of hydrogen from algal biomass which contained carbohydrate, protein, and fat via organic acids.

• 생명과학회지
• /
• 제16권4호
• /
• pp.632-639
• /
• 2006

본 연구에서는 lacZ transcriptional fusion plasmid를 이용하여 광합성 세균인 Rhodobacter sphaeroides에서의 7가지 광합성유전자 (puf, puc, puhA, bchC, bchE, bchF, bchI) 발현의 경향과 조절을 조사하였다. R. sphaeroides에서 puhA와 bchI를 제외한 모든 광합성유전자들이 호기적 조건과 비교했을 때 혐기적 조건에서 더욱 강하게 발현되었다. puhA 유전자는 bchFNBHLM-RSP0290과 operon을 형성하며, bchI 유전자는 crtA와 operon을 이루는 것으로 나타났다. 광합성 조건에서 자란 R. sphaeroides의 puf, puc, bchCXYZ operon의 발현은 빛의 세기에 비례하는 반면, bchFNBHLM(RSP0290 puhA) operon의 발현은 빛의 세기에 반비례 하였다. bchEJG의 발현은 $10\;W/m^2$의 빛이 조사된 광합성 조건에서 제일 낮았으며, $100\;W/m^2$의 빛의 광합성 조건에서 가장 높았다. R. sphaeroides의 산소인지와 빛 인지에 관련된 세 가지 주요 조절기작에 의한 광합성유전자 조절은 다음과 같다. puf와 bchC는 PpsR repressor와 PrrBA two-component system에 의해 조절된다. 그리고 puc operon은 PpsR, FnrL, PrrBA system에 의해 조절된다. bchE의 발현은 FnrL과 PrrBA system에 의해 조절되는 반면, bchF는 오로지 PpsR에 의해서만 조절된다. PpsR repressor는 강한 세기의 빛 조건에서 bchf 발현억제의 원인이 되며, FnrL은 그 자체가 산소를 인지하는 기능 이외에도 세포질의 산화/환원 상태의 인지에 관련될 것으로 보인다.

• Bulletin of the Korean Chemical Society
• /
• 제32권4호
• /
• pp.1361-1364
• /
• 2011

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
• /
• pp.231.3-232
• /
• 2000

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
• /
• 제30권5호
• /
• pp.717-725
• /
• 2020

The use of plant growth-promoting rhizobacteria is economically viable and environmentally safe for mitigating various plant stresses. Abiotic stresses such as flood and drought are a serious threat to modern agriculture. In the present study, the indole-3-acetic acid-producing rhizobacterium R. sphaeroides KE149 was selected, and its effects on the growth of adzuki bean plants under flood stress (FS) and drought stress (DS) were investigated. IAA quantification of bacterial pure culture revealed that KE149 produced a significant amount of IAA. Moreover, KE149 inoculation notably decreased stress-responsive endogenous abscisic acid and jasmonic acid and increased salicylic acid in plants under DS and FS. KE149 inoculation also increased proline under DS and methionine under FS. In addition, KE149 inoculation significantly increased the levels of calcium (Ca), magnesium (Mg), and potassium (K) while lowering the sodium (Na) content in the plant shoot under stress. KE149-treated plants had markedly greater root length, shoot length, stem diameter, biomass, and higher chlorophyll content under both normal and stressed conditions. These results suggest that KE149 could be an efficient biofertilizer for mitigating water stress.

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

• 한국버섯학회지
• /
• 제16권3호
• /
• pp.225-230
• /
• 2018

본 연구는 느타리버섯 수확후배지를 배지자원으로 재사용하기 위하여 미생물처리에 의한 수확후 배지의 총질소함량 증진효과를 조사하였다. Bacillus sp. GM20-4 와 Rhodobacter sphaeroides(RS) 배양액 30%를 함께 접종하여 5일간 상온에서 배양 시 총질소 함량이 가장 크게 증가하였다. 농가의 수확후배지 조성에 따른 GM20-4와 RS처리에 의한 T-N함량 변화를 조사하기 위하여 경기 지역 버섯재배농가 세 곳의 수확후배지(spent mushroom substrates, SMS A, B, C)를 수집하여 GM20-4 와 RS 배양액 30%를 처리한 결과, 무처리구에 비해 건조 SMS B에서 T-N함량이 20%p로 가장 크게 증가하였고, 건조 SMS A는 17%, C는 12% 증가하였다. 반면에 생수확후 배지에서는 미생물 처리에 의한 T-N 함량 증가 효과가 크지 않았다. 또한 아미노산 조성별 함량 변화는 건조된 SMS A, B, C 모두 GM20-4와 RS 처리로 aspatic acid와 glutamic acid가 상대적으로 높게 증가한 결과를 보였고, 특히 건조 SMS B의 처리구에서 두 아미노산의 함량이 무처리구보다 2.9배 증가를 보임으로서 미생물처리가 수확후배지의 총질소 및 아미노산 함량의 증진효과를 확인하였다.

• 생명과학회지
• /
• 제22권8호
• /
• pp.1009-1017
• /
• 2012

Rodobacter sphaeroides에서 orf282 유전자는 cbb3 terminal oxidase를 암호화하는 ccoNOQP 오페론과 혐기적 활성자인 FnrL을 암호화하는 fnrL 유전자 사이에 있으며, 아직은 기능이 잘 알려지지 않았다. orf282 유전자의 기능을 알기 위해 우리는 orf282의 일부를 삭제함으로써 유전자를 붕괴시켜 orf282-minus mutant를 제조하였다. 두개의 FnrL 결합 부위가 orf282의 upstream에 존재한다는 것이 밝혀져 있으며, orf282 유전자가 FnrL에 의해 양성적으로 조절된다는 것이 증명되었다. orf282 유전자는 B875와 B800-850 spectral complexes의 형성과 관련이 없다. orf282 mutant에서의 cbb3 oxidase 활성을 wild type와 비교해보면 orf282 유전자가 ccoNOQP 오페론의 조절과 cbb3 cytochrome c oxidase의 생합성과 무관하다는 것을 알 수 있다. orf282 mutant의 구조 유전자인 nifH와 조절유전자인 nifA의 프로모터 활성이 증가한 것은 orf282 유전자 산물이 nifH와 nifA의 발현에서 음성적 effector로 작용한다는 것을 시사한다.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.295-296
• /
• 2000

Effect of light intensity on ALA production was, investigated. The culture condition and medium optimization were also examined for the biosynthesis of ALA using Rhodobacter sphaeroides, non-sulfur bacteria, and investigated for enhancement of the production of ALA. In the dark condition, extracellular ALA formation and cell growth were not observed. Optimum light intensity for cell growth and ALA production were 4 kLux and 5 kLux, respectively.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제5권6호
• /
• pp.413-417
• /
• 2000

In this study, a direct detection system for triazine derivative herbicides was developed using the photosynthetic reaction center (RC) from the purple bacterium, Rhodobacter sphaeroides, and surface plasmon resonance (SPR) apparatus. The histidine-tagged RCs were immobilized on an SPR gold chip using nickel-nitrilotriacetic acid groups as a binder for one of the triazine herbicide, atrazine. The SPR responses were proportional to the sample concentrations of atrazine in the range 0.1-1 $\mu\textrm{g}$/mL. The sensitivity of the direct detection of atrazine using the RC-assembled sensor chip was higher than that using the antibody-immobilized chip. The other types of herbicides, DCMU or MCPP, were not detected with such high sensitivity. The results indicated the high binding selectivity of the RC complex.