• 한국수소및신에너지학회논문집
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• 제21권1호
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• pp.12-18
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• 2010

Photobiological hydrogen production using Rhodobacter sphaeroides KD131 was studied on the effect of light intensities and nitrogen sources. Media containing malate and glutamate were shown higher hydrogen production rate than that containing succinate and $(NH_4)_2SO_4$ at the $110\;W/m^2$ illumination by halogen lamp at $30^{\circ}C$. Media lacking glutamate as the nitrogen source exhibited higher hydrogen production than that containing glutamate. Initial cell concentration was optimized to 1.0 at the absorbance of 660 nm. Hydrogen production was increased by increasing the light intensity from 0 to $216\;W/m^2$ but the increasing rate declined over $108\;W/m^2$.

• 미생물학회지
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• 제30권4호
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• pp.265-268
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• 1992

홍색 비유황 고아합성세균들중에 몇종을 선택하여 bacteriocin 생산실험을 실시하였다. 그 결과, Rhodobacter capsulatus, Rhodobacter sphaeroides 그리고 Phodocylus gelatinosus의 세균들이 bacteriocin을 분비하는 것으로 나타났으며 특히 Rhodobacter capsulatus ATCC 17016은 cell-bound bacteriocin도 생산하는 것으로 나타났다. 대부분의 경우, 근연종들간에 bacteriocin이 분비되는 것으로 나타났으나, 비교적 우연관계가 먼 Phodocylus gelatinosus와 Rhodopseudomonas sulfoviridis간에도 bacteriocin이 분비되는 것으로 나타났다.

• 미생물학회지
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• 제24권1호
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• pp.62-66
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• 1986

김해 대저 근교의 양지바른 수계 혐기층에서 수소 생성능을 가진 광합성 세균을 분리하였다. 그 중 수소 생성능이 가장 우수한 균주 230을 선택하여, 여러가지 형태적, 생리적 특성과 배양상의 특정을 조사한 결과, 균주 230은 그람 음성이고, 막대형으로 운동성이 있었으며, benzoate와 propionate는 진자공여체로 이용하지 못하고, 황화합 물은 전혀 이용하지 못하였으며. biotin, thiamine, nicotinic acid를 growth factor로 요구하고, 박테리오 클로필 a와 group II 카로티노이드계색소를 가지고 있었으으로 Rhodopuudomonas sphaeroides로 동정되었다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
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• pp.159-160
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• 2003

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 추계 학술대회
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• pp.5-7
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• 2000

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2003년도 제39회 학술심포지움
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• pp.13-18
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• 2003

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 International Meeting 2000
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• pp.4-8
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• 2000

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.179-185
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• 1991

We examined optimum culture conditions of Rhodopseudomonas sphaeroides B5 for effective utilization of substrate and sunlight for hydrogen production. The optimum concentration range of DL-lactate as electron donor for hydrogen production by resting cells was from 5 to 50mM, and optimun CN ratio (lactate/glutamat) for maintenence of hydrogen production activity by growing cultures was from 5 to 6. Hydrogen production by the cultures of low cell density (0.36mg/ml dry cells) was saturated with 10 Klux light intensity. Under constant illumination of 50Klux which was set up as the average medium value of annual variation of sunlight intensity, hydrogen production with various cell densities in the culture resulted in highest production rate (132${\mu}$l/hr/mg dry cells) up to 0.64mg/ml dry cells. However, the amount of total hydrogen production was saturated with cell density of 2.1mg/ml dry cells. In addition to these, the optimum inner thickness pervious to light of the culture vessel for hydrogen production which was measured under sunlight was 5 cm.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.959-966
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• 2016

Chlorophyll synthase (ChlG) and bacteriochlorophyll synthase (BchG) have a high degree of substrate specificity. The BchG mutant of Rhodobacter sphaeroides, BG1 strain, is photosynthetically incompetent. When BG1 harboring chlG of Synechocystis sp. PCC 6803 was cultured photoheterotrophically, colonies arose at a frequency of approximately 10^-8. All the suppressor mutants were determined to have the same mutational change, ChlG_I44F. The mutated enzyme ChlG_I44F showed BchG activity. Remarkably, BchG_F28I, which has the substitution of F at the corresponding 28^th residue to I, showed ChlG activity. The K_m values of ChlG_I44F and BchG_F28I for their original substrates, chlorophyllide (Chlide) a and bacteriochlorophyllide (Bchlide) a, respectively, were not affected by the mutations, but the K_m values of ChlG_I44F and BchG_F28I for the new substrates Bchlide a and Chlide a, respectively, were more than 10-fold larger than those for their original substrates, suggesting the lower affinities for new substrates. Taken together, I44 and F28 are important for the substrate specificities of ChlG and BchG, respectively. The BchG activity of ChlG_I44F and the ChlG activity of BchG_F28I further suggest that ChlG and BchG are evolutionarily related enzymes.

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