Identification of by-products in hydrogen producing bacteria; Rhodobacter sphaeroides O.U. 001 grown in the waste water of a sugar refinery (original) (raw)
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Photoproduction of hydrogen from sugar refinery wastewater by Rhodobacter sphaeroides O.U. 001
International Journal of Hydrogen Energy, 2000
Pretreated sugar re®nery wastewater (SRWW) was used for the production of hydrogen by Rhodobacter sphaeroides O.U.001 in a 0.4 l column photobioreactor. Hydrogen was produced at a rate of 0.001 l hydrogen/h/l culture in 20% dilution of SRWW. To adjust the carbon concentration to 70 mM and nitrogen concentration to 2 mM, sucrose or L-malic acid was added as carbon source and sodium glutamate was added as nitrogen source to the 20% dilution of SRWW. By these adjustments, hydrogen production rate was increased to 0.005 l hydrogen/h/l culture. Continuous hydrogen production was achieved in the same medium for 100 days at three dierent dilution rates. The maximum hydrogen produced was 2.67 l (in 100 days) at a dilution rate of 0.0013 h À1 .
Applied Microbiology and Biotechnology, 2005
Combined dark and photo-fermentation was carried out to study the feasibility of biological hydrogen production. In dark fermentation, hydrogen was produced by Enterobacter cloacae strain DM11 using glucose as substrate. This was followed by a photo-fermentation process. Here, the spent medium from the dark process (containing unconverted metabolites, mainly acetic acid etc.) underwent photo-fermentation by Rhodobacter sphaeroides strain O.U.001 in a column photo-bioreactor. This combination could achieve higher yields of hydrogen by complete utilization of the chemical energy stored in the substrate. Dark fermentation was studied in terms of several process parameters, such as initial substrate concentration, initial pH of the medium and temperature, to establish favorable conditions for maximum hydrogen production. Also, the effects of the threshold concentration of acetic acid, light intensity and the presence of additional nitrogen sources in the spent effluent on the amount of hydrogen produced during photo-fermentation were investigated. The light conversion efficiency of hydrogen was found to be inversely proportional to the incident light intensity. In a batch system, the yield of hydrogen in the dark fermentation was about 1.86 mol H2 mol−1 glucose; and the yield in the photo-fermentation was about 1.5–1.72 mol H2 mol−1 acetic acid. The overall yield of hydrogen in the combined process, considering glucose as the preliminary substrate, was found to be higher than that in a single process.
Comparison of hydrogen production by four representative hydrogen-producing bacteria
Journal of Industrial and Engineering Chemistry, 2008
The characteristics of hydrogen production by four different hydrogen-producing bacteria (Clostridium beijerinckii, Rhodobacter sphaeroides, anaerobic bacteria isolated from sludge digester and Bacillus megaterium) were investigated quantitatively. The mathematical analysis using Gompertz equation showed that C. beijerinckii was the best hydrogen producer from glucose in terms of hydrogen-production potential and specific hydrogen-production rate. However, the bacteria required relatively long lag time at high-initial glucose concentration. The anaerobic bacteria showing the highest maximum hydrogen-production rate and relatively short lag time have a limit of low-hydrogen-production potential because they are mixed culture and produce some amount of methane gas. C. beijerinckii will be used in the actual system for hydrogen production from carbohydrate but the anaerobic bacteria may be a good choice for the production of hydrogen from wastewater containing innumerable compounds.
International Journal of Hydrogen Energy, 2016
In the present study, a new purple non sulfur (PNS) bacterial strain identified as Rhodobacter sphaeroides CNT 2A was investigated for photo fermentative hydrogen production from acetate, butyrate (short chain organic acids), glucose & sucrose (simple and complex sugar) as sole carbon source in presence of sodium glutamate (0.6 g/L) as nitrogen source. Initial medium pH, acetate and butyrate concentration (by using these substrates as sole carbon sources) were optimized. At optimum pH 8, hydrogen yield efficiency obtained from acetate and butyrate were 2.1 ± 0.2 mol H 2 /mole and 2.9 ± 0.2 mol H 2 /mole substrate consumed, respectively. Hydrogen production obtained from glucose and sucrose were; 0.46 ± 0.05 mol H 2 /mole and 2.4 ± 0.2 mol H 2 /mole, respectively. This study imply that CNT 2A encompasses carbohydrate catabolic pathway and thus can utilize carbohydrates (both simple as well as complex sugar) directly.
National Academy Science Letters, 2019
In the present study, highest hydrogen production by Rhodobacter sphaeroides was seen in lactose and mannitol as carbon sources. Glutamic acid and tyrosine induced the highest production of hydrogen. Cyanocobalamine induced the highest production of hydrogen. Enhancement of hydrogen production by 23% was seen after knocking out of the hydrogen reuptake hydrogenase gene. Large-scale production of hydrogen can be tried with this genetically engineered organism, provided some safety aspects are taken into consideration, especially with storage as hydrogen explodes when it comes in contact with air.
Microbial Biotechnology, 2012
Rhodopseudomonas acidophila KU001 was isolated from leather industry effluents and the effect of different cultural conditions on hydrogen production was studied. Anaerobic light induced more hydrogen production than anaerobic dark conditions. Growing cells produced more amounts of hydrogen between 96 and 144 h of incubation. Resting and growing cells preferred a pH of 6.0 Ϯ 0.24 for hydrogen production. Succinate was the most preferred carbon source for the production of hydrogen while citrate was a poor source of carbon. Acetate and malate were also good carbon sources for hydrogen production under anaerobic light. Among the nitrogen sources, R. acidophila preferred ammonium chloride followed by urea for production of hydrogen. L-tyrosine was the least preferred nitrogen source by both growing and resting cells.
Hydrogen production from tofu wastewater by Rhodobacter sphaeroides immobilized in agar gels
International Journal of Hydrogen Energy, 1999
Hydrogen production from the wastewater of tofu factory was examined by using anoxygenic phototrophic bacterium Rhodobacter sphaeroides immobilized in agar gels[ The maximum rate of hydrogen production observed from the wastewater was 1[0 l h −0 m 1 gel which was even slightly higher than that from a glucose medium "as control#[ The hydrogen production lasted up to 49 h[ The yield of hydrogen was 0[8 ml:ml wastewater or 9[13 ml:mg carbohydrates contained in the wastewater[ This yield corresponds to 42) or 54) of that from the glucose medium\ according to the di}erent expressions of the yield[ The TOC "total organic carbon# removal ratio in 74 h reached 30) which was comparable to that from the glucose medium[ The immobilization protected the bacterium from the inhibitory e}ect of ammonium ion[ Þ 0888 International Association for Hydrogen Energy[ Published by Elsevier Science Ltd[ All rights reserved[
Applied Energy, 2011
In this paper, Rhodobacter sphaeroides CIP 60.6 strain was newly used for the biohydrogen production in a perfectly shaken column photobioreactor, grown in batch culture under anaerobic and illumination conditions, to investigate the effects of some physico-chemical parameters in microbial hydrogen photofermentation. Luedeking-Piret model was considered for the data fitting to find out the mode of hydrogen generation and the relationship between the cell growth and hydrogen production. The results show that, both growth cells and resting cells can produce hydrogen at light intensities greater or equal to 2500 lux, however, at the weak intensities hydrogen is a metabolite associated to growth. Growth rate and hydrogen production rate increase with the increasing of light intensity. Moreover, hydrogen production rate become higher in stationary phase than that in logarithmic phase, with the enhancement of light intensity. Maximum hydrogen production rate obtained was 39.88 ± 0.14 ml/l/h, at the optimal conditions (4500-8500 lux). Modified Gompertz equation was applied for the data fitting to verify the accuracy and the agreement of the model with experimental results. It is revealed that, in the modified Gompertz equation, the lag time represents time for which hydrogen production becomes maximal, not the beginning time of hydrogen production. The stop of stirring reduced hydrogen production rate and created unstable hydrogen production in reactor. The pH ranges of 7.5 ± 0.1 were the favorable pH for hydrogen production.