Phototrophic hydrogen production from glucose by pure and co-cultures of Clostridium butyricum and Rhodobacter sphaeroides

Fang, Hhp; Zhu, Huijie; Zhang, Tong

doi:10.1016/j.ijhydene.2006.03.005

Cited by 136 publications

(52 citation statements)

References 16 publications

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“…Cocultures pairing fermentative bacteria with purple photoheterotrophic bacteria have been of interest for over 30 years (Odom and Wall, 1983;Fang et al, 2006;Ding et al, 2009;Sun et al, 2010;Jiao et al, 2012), primarily as a consolidated bioprocess for converting plant-derived sugars into H 2 . However, this combination of bacteria also resembles a natural anaerobic food web; fermentative bacteria consume plant-derived sugars and excrete products that serve as a carbon source for photoheterotrophs ( Figure 1a).…”

Section: Introductionmentioning

confidence: 99%

Microbial mutualism dynamics governed by dose-dependent toxicity of cross-fed nutrients

et al. 2016

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Microbial interactions, including mutualistic nutrient exchange (cross-feeding), underpin the flow of energy and materials in all ecosystems. Metabolic exchanges are difficult to assess within natural systems. As such, the impact of exchange levels on ecosystem dynamics and function remains unclear. To assess how cross-feeding levels govern mutualism behavior, we developed a bacterial coculture amenable to both modeling and experimental manipulation. In this coculture, which resembles an anaerobic food web, fermentative Escherichia coli and photoheterotrophic Rhodopseudomonas palustris obligately cross-feed carbon (organic acids) and nitrogen (ammonium). This reciprocal exchange enforced immediate stable coexistence and coupled species growth. Genetic engineering of R. palustris to increase ammonium cross-feeding elicited increased reciprocal organic acid production from E. coli, resulting in culture acidification. Consequently, organic acid function shifted from that of a nutrient to an inhibitor, ultimately biasing species ratios and decreasing carbon transformation efficiency by the community; nonetheless, stable coexistence persisted at a new equilibrium. Thus, disrupting the symmetry of nutrient exchange can amplify alternative roles of an exchanged resource and thereby alter community function. These results have implications for our understanding of mutualistic interactions and the use of microbial consortia as biotechnology.

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Section: Introductionmentioning

confidence: 99%

Microbial mutualism dynamics governed by dose-dependent toxicity of cross-fed nutrients

et al. 2016

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“…Work with co-cultures of both C. butyricum and R. sphaeroides showed only a slight increase in the hydrogen yield when compared with production obtained from pure cultures separately [26]; even at high Rhodobacter ratios (~6:1) it appeared that R. sphaeroides was not able to compete with Clostridium for substrate (glucose). However, it is diffi cult to draw conclusions as to the effi cacy of having both types of organism present in the same reaction vessel since molar yields, either alone or in co-culture, were very low, < 1 mol H 2 /mole glucose, and large quantities of fermentation products, acetate and butyrate accumulated (i.e.…”

Section: Microbial Processes Producing Hydrogenmentioning

confidence: 83%

“…3, higher overall substrate conversion effi ciency is possible as the photosynthetic microbes can degrade the soluble metabolites from the fermentative step using sunlight to overcome the energy barrier. VFAs are the main soluble breakdown products from the fi rst step, and these are preferred substrates of photo-heterotrophic bacteria [26][27][28].…”

Section: Microbial Processes Producing Hydrogenmentioning

confidence: 99%

“…There have been a number of recent reports on two-stage systems as shown in Fig. 4 [26][27][28][29][30][31][32][33]. One study successfully produced hydrogen using olive mill wastewater for the production of biohydrogen in a two-stage process, with a three fold increase in hydrogen production when compared to photo-fermentation alone, and a COD conversion effi ciency of ~55% [29].…”

Section: Microbial Processes Producing Hydrogenmentioning

confidence: 99%

“…There have been several studies in which co-cultures of fermentative and photosynthetic organisms were examined [26,33]. Work with co-cultures of both C. butyricum and R. sphaeroides showed only a slight increase in the hydrogen yield when compared with production obtained from pure cultures separately [26]; even at high Rhodobacter ratios (~6:1) it appeared that R. sphaeroides was not able to compete with Clostridium for substrate (glucose).…”

Section: Microbial Processes Producing Hydrogenmentioning

confidence: 99%

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Microbiological and engineering aspects of biohydrogen production

et al. 2009

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Dramatically rising oil prices and increasing awareness of the dire environmental consequences of fossil fuel use, including startling effects of climate change, are refocusing attention worldwide on the search for alternative fuels. Hydrogen is poised to become an important future energy carrier. Renewable hydrogen production is pivotal in making it a truly sustainable replacement for fossil fuels, and for realizing its full potential in reducing greenhouse gas emissions. One attractive option is to produce hydrogen through microbial fermentation. This process would use readily available wastes as well as presently unutilized bioresources, including enormous supplies of agricultural and forestry wastes. These potential energy sources are currently not well exploited, and in addition, pose environmental problems. However, fuels are relatively low value products, placing severe constraints on any production process. Therefore, means must be sought to maximize yields and rates of hydrogen production while at the same time minimizing energy and capital inputs to the bioprocess. Here we review the various attributes of the characterized hydrogen producing bacteria as well as the preparation and properties of mixed microfl ora that have been shown to convert various substrates to hydrogen. Factors affecting yields and rates are highlighted and some avenues for increasing these parameters are explored. On the engineering side, we review the potential waste pre-treatment technologies and discuss the relevant bioprocess parameters, possible reactor confi gurations, including emerging technologies, and how engineering design-directed research might provide insight into the exploitation of the signifi cant energy potential of biomass resources.

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