In this work, the optimization of hydrogen production by photo-fermentation bacteria immobilized on agar gel granule was systematic investigated in batch culture. Experiment focus on the effect of some important affec...In this work, the optimization of hydrogen production by photo-fermentation bacteria immobilized on agar gel granule was systematic investigated in batch culture. Experiment focus on the effect of some important affecting factors on photo-hydrogen production. Results indicated that immobilized Rhodopseudomonas faecalis RLD-53 exhibited the highest hydrogen yield of 3.15 mol H2/mol acetate under follow optimal condition: agar granule diameter of 2.5 mm, inoculum age of 24 h, agar concentration of 2%, biomass of 4 mg/ml in agar and light intensity of 9000 lux. More importantly, immobilized photo-fermentation bacteria not only can enhance hydrogen production but can increase acids-tolerance capacity, even at pH 5.0 hydrogen also was produced, and thus hopefully immobilized photo-fermentation bacteria can be applied in the combination of dark and photo-fermentation for hydrogen production with high yield.展开更多
One of the most important solutions to overcome energy and environmental problems and to replace the fossil fuel-based economy could be the use of photosynthetic microorganisms.The use of photosynthetic microorganisms...One of the most important solutions to overcome energy and environmental problems and to replace the fossil fuel-based economy could be the use of photosynthetic microorganisms.The use of photosynthetic microorganisms is a potential alternative to energy generation from fossil fuels because they efficiently produce hydrogen(H_(2)).Immobilization of photosynthetic microorganisms is used for many biotechnological applications such as H_(2) production.This method appears attractive because it restricts cell movement in an entrapped matrix.Immobilization of Rhodopseudomonas sp.S16-VOGS3 cells is a promising way to improve H_(2) production.In this work,the ability of immobilized Rhodopseudomonas sp.S16-VOGS3 cells to produce H_(2) was investigated in two types of PBRs.The PBRs used in this work were a cylindrical one with 0.2 L working volume(C-PBR)and a flat Roux type with 0.6 L working volume(FRT-PBR).The calcium alginate beads prepared were resistant to culture mixing and showed little leakage of cells,and the immobilized cells continued the photofermentation process in both PBRs.The immobilized cells in the C-PBR produced 936.8 mL of H_(2) with an average H_(2) production rate of 2.99 mL/h.The average productivity was 126.4μL(H_(2))/mg(cells)/h or 14.96 mL(H_(2))/L(culture)/h,and the light conversion efficiency was 2.37%.The immobilized cells in the FRT-PBR produced a total of 662.2 mL of H_(2) with an average H_(2) production rate of 1.55 mL/h.The average productivity was 31.1μL(H_(2))/mg(cells)/h or 2.58 mL(H_(2))/L(culture)/h,and the light conversion efficiency was 0.52%.The more uniform and therefore more efficient degree of bacterial cell mixing achieved in the C-PBR with cylindrical configuration played an important role compared to the FRT-PBR.In the FRT-PBR,the beads were aggregated at the bottom,which limited light penetration and resulted in low H_(2) production efficiency.展开更多
The electronic singlet vertical excited states of photosynthetic reaction center (PSRC) in Rhodopseudomonas (Rps.) viridis were investigated by ZINDO and INDO/S methods. The effects of the interactions of pigment-pigm...The electronic singlet vertical excited states of photosynthetic reaction center (PSRC) in Rhodopseudomonas (Rps.) viridis were investigated by ZINDO and INDO/S methods. The effects of the interactions of pigment-pigment and pigment-protein on the electronic excitations were examined. The calculation results showed that the interactions of pigment-pigment and pigment-protein play an important role in reasonably assigning the experimental absorption and circular dichroism (CD) spec-tra of PSRC in Rps. virids. By comparing the theoretically computed excited states with the experi-mental absorption and CD spectra, satisfactory assignments of the experimental spectroscopic peaks were achieved.展开更多
Organic triazophos wastewater was continuously treated with Rhodopseudomonas capsulatus and activated carbon and activated sludge system(PACT AS) in a plug bioreactor. A kinetic model of PACT AS wastewater trea...Organic triazophos wastewater was continuously treated with Rhodopseudomonas capsulatus and activated carbon and activated sludge system(PACT AS) in a plug bioreactor. A kinetic model of PACT AS wastewater treatment system was established to provide an useful basis for further simulate scale up treatment of toxic organic wastewater.展开更多
Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudom...Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.展开更多
In the process of cultivating Rhodobater sphaeroides R26.1, some of which turned from blue to pink due to the irradiation of a beam of leaking white light. The mutant strains were named ＇pinky＇ strains, which were c...In the process of cultivating Rhodobater sphaeroides R26.1, some of which turned from blue to pink due to the irradiation of a beam of leaking white light. The mutant strains were named ＇pinky＇ strains, which were cultivated in the red light and in the dark for a comparative study. It turned out that the strains did not grow in the dark, so they might be photosynthetic bacteria. The electronic absorption spectrum of the ＇pinky＇ strains was measured, which shows they contained two main photosynthetic pigments, carotenoids（Cars） and bacteriochlorophylls（BChls）. And then they were extracted and analyzed. It proves that Bchls included Bchl a and Bchl a＇. Nuclear magnetic resonance （NMR） spectra were exploited to determine the chemical structure of Cars. The results indicate that there were seven kinds of Cars, including lycopene, rhodopin, anhydrorhodovibrin, 3,4-dihydroanhydrorhodovibrin, 3,3,4- dihydrospirilloxanthin, 3,4,3＇,4＇-tetrahydrospirilloxanthin and spirilloxanthin. Based on the above results, it was found that most identified Cars formed via spirilloxanthin biosynthesis pathway. The analyzed results of 16S rRNA gene show that the homology of ＇pinky＇ strains with Rhodopseudomonas palusteris was 99%. Rhodopseudomonas palusteris has been cultivated in our laboratory. Because of its strong vitality, it did not become extinct with so many years passing. When Rhodobater sphaeroides R26.1 was cultivated, it got rejuvenated under the appropriate conditions and caused Rhodobater sphaeroides R26.1 to be contaminated.展开更多
文摘In this work, the optimization of hydrogen production by photo-fermentation bacteria immobilized on agar gel granule was systematic investigated in batch culture. Experiment focus on the effect of some important affecting factors on photo-hydrogen production. Results indicated that immobilized Rhodopseudomonas faecalis RLD-53 exhibited the highest hydrogen yield of 3.15 mol H2/mol acetate under follow optimal condition: agar granule diameter of 2.5 mm, inoculum age of 24 h, agar concentration of 2%, biomass of 4 mg/ml in agar and light intensity of 9000 lux. More importantly, immobilized photo-fermentation bacteria not only can enhance hydrogen production but can increase acids-tolerance capacity, even at pH 5.0 hydrogen also was produced, and thus hopefully immobilized photo-fermentation bacteria can be applied in the combination of dark and photo-fermentation for hydrogen production with high yield.
基金supported by European Union's Horizon Europe-the Framework Programme for Research and Innovation[grant number 101093150]project LIBRA(Light Based Multisensing Device for Screening of Pathogens and Nutrients in Bioreactors)。
文摘One of the most important solutions to overcome energy and environmental problems and to replace the fossil fuel-based economy could be the use of photosynthetic microorganisms.The use of photosynthetic microorganisms is a potential alternative to energy generation from fossil fuels because they efficiently produce hydrogen(H_(2)).Immobilization of photosynthetic microorganisms is used for many biotechnological applications such as H_(2) production.This method appears attractive because it restricts cell movement in an entrapped matrix.Immobilization of Rhodopseudomonas sp.S16-VOGS3 cells is a promising way to improve H_(2) production.In this work,the ability of immobilized Rhodopseudomonas sp.S16-VOGS3 cells to produce H_(2) was investigated in two types of PBRs.The PBRs used in this work were a cylindrical one with 0.2 L working volume(C-PBR)and a flat Roux type with 0.6 L working volume(FRT-PBR).The calcium alginate beads prepared were resistant to culture mixing and showed little leakage of cells,and the immobilized cells continued the photofermentation process in both PBRs.The immobilized cells in the C-PBR produced 936.8 mL of H_(2) with an average H_(2) production rate of 2.99 mL/h.The average productivity was 126.4μL(H_(2))/mg(cells)/h or 14.96 mL(H_(2))/L(culture)/h,and the light conversion efficiency was 2.37%.The immobilized cells in the FRT-PBR produced a total of 662.2 mL of H_(2) with an average H_(2) production rate of 1.55 mL/h.The average productivity was 31.1μL(H_(2))/mg(cells)/h or 2.58 mL(H_(2))/L(culture)/h,and the light conversion efficiency was 0.52%.The more uniform and therefore more efficient degree of bacterial cell mixing achieved in the C-PBR with cylindrical configuration played an important role compared to the FRT-PBR.In the FRT-PBR,the beads were aggregated at the bottom,which limited light penetration and resulted in low H_(2) production efficiency.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.20203009 and 20432010)Hubei Province Science Foundations(Nos.2004ABC002 and 2005ABB012(a Grant for Young Distinguished Scholar))+1 种基金a Grant from the Ministry of Science and Technology of China(No.2004CCA00100)the China Scholarship Council.
文摘The electronic singlet vertical excited states of photosynthetic reaction center (PSRC) in Rhodopseudomonas (Rps.) viridis were investigated by ZINDO and INDO/S methods. The effects of the interactions of pigment-pigment and pigment-protein on the electronic excitations were examined. The calculation results showed that the interactions of pigment-pigment and pigment-protein play an important role in reasonably assigning the experimental absorption and circular dichroism (CD) spec-tra of PSRC in Rps. virids. By comparing the theoretically computed excited states with the experi-mental absorption and CD spectra, satisfactory assignments of the experimental spectroscopic peaks were achieved.
文摘Organic triazophos wastewater was continuously treated with Rhodopseudomonas capsulatus and activated carbon and activated sludge system(PACT AS) in a plug bioreactor. A kinetic model of PACT AS wastewater treatment system was established to provide an useful basis for further simulate scale up treatment of toxic organic wastewater.
基金supported by the National Key R&D Program of China(2022YFD1400700)the Key Research and Development Program of Hunan Province,China(2022NK2014)+2 种基金the Hunan Natural Science Foundation,China(2022JJ40234)the Agricultural Science and Technology Innovation Fund Project of Hunan Province,China(2022CX1)the Changsha Natural Science Foundation,China(kq2202338).
文摘Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.
文摘In the process of cultivating Rhodobater sphaeroides R26.1, some of which turned from blue to pink due to the irradiation of a beam of leaking white light. The mutant strains were named ＇pinky＇ strains, which were cultivated in the red light and in the dark for a comparative study. It turned out that the strains did not grow in the dark, so they might be photosynthetic bacteria. The electronic absorption spectrum of the ＇pinky＇ strains was measured, which shows they contained two main photosynthetic pigments, carotenoids（Cars） and bacteriochlorophylls（BChls）. And then they were extracted and analyzed. It proves that Bchls included Bchl a and Bchl a＇. Nuclear magnetic resonance （NMR） spectra were exploited to determine the chemical structure of Cars. The results indicate that there were seven kinds of Cars, including lycopene, rhodopin, anhydrorhodovibrin, 3,4-dihydroanhydrorhodovibrin, 3,3,4- dihydrospirilloxanthin, 3,4,3＇,4＇-tetrahydrospirilloxanthin and spirilloxanthin. Based on the above results, it was found that most identified Cars formed via spirilloxanthin biosynthesis pathway. The analyzed results of 16S rRNA gene show that the homology of ＇pinky＇ strains with Rhodopseudomonas palusteris was 99%. Rhodopseudomonas palusteris has been cultivated in our laboratory. Because of its strong vitality, it did not become extinct with so many years passing. When Rhodobater sphaeroides R26.1 was cultivated, it got rejuvenated under the appropriate conditions and caused Rhodobater sphaeroides R26.1 to be contaminated.
