A two-stage, two-organism process for biohydrogen from glucose

Abstract

H2 can potentially be produced in a two-stage biological process: the fermentation of glucose by Escherichia coli HD701 and the photofermentation of the residual medium by Rhodobacter sphaeroides O.U. 001. In a typical batch fermentation, E. coli consumed glucose and produced H2, organic end-products and biomass. Organic end-products and residual glucose were removed during subsequent photofermentation by R. sphaeroides, with associated growth and neutralization of pH. However, photoproduction of H2 did not occur during photofermentation of the residual liquor per se due to the presence of fixed nitrogen compounds. Nevertheless, this two-stage approach could be applied to dispose of sugar-containing industrial wastes, H2 being used for on-site power generation.

Integrating dark and light bio-hydrogen production strategies: towards the hydrogen economy

“…25 % that of acetate (Ike et al 2001). Ethanol was rapidly removed from an Escherichia coli fermentation effluent by R. sphaeroides O.U.001 after a delay of 96 h, although the induction of ethanol-utilising enzymes was not monitored (Redwood & Macaskie 2006). Hence, it is plausible that other PNS bacteria would be capable of ethanol utilisation after an adaptation period.…”

“…Centrifugation followed by filtration or autoclaving is usually performed to generate a clear, sterile feed for the 2 nd stage (e.g. Yokoi et al 2002;Redwood & Macaskie 2006). For large-scale application, continuous processes are generally preferred over batch systems.…”

Towards an integrated system for bio-energy: hydrogen production by Escherichia coli and use of palladium-coated waste cells for electricity generation in a fuel cell

“…Hydrogen overproduction by E. coli strain HD701 (via derepression of the H 2 -producing formate hydrogen lyase complex (Penfold et al 2003)) and by strains deficient in uptake hydrogenases (Penfold et al 2006;Redwood et al 2008) were described previously and production of OA by the latter was also quantified (Redwood & Macaskie 2006). A combination of the hycA and tat mutations did not increase hydrogen production over that obtained with one mutation alone (Penfold et al 2006).…”

“…Glucose determination was by the colorimetric dinitrosalicylic acid assay (Chaplin 1986). Organic acids were measured by an anion HPLC (Dionex 600-series) as described previously (Redwood & Macaskie 2006). Ethanol was analysed using a Cecil Adept HPLC system equipped with Resex-RCM column (Phenomenex); RI detector; temperature 75 °C; eluate H 2 O; flow rate 0.5 ml/min; 30 min experiment time.…”

Biohydrogen Production from Wastewaters

“…Wang et al [21] mentioned that the hydrogen production eiciency of glucose (313.3 mL/g glucose) was improved with low supplementation of nitrate 0.1 g/L; however, increased concentration of nitrate over 0.1 g/L signiicantly afected the hydrogen yield and the substrate consumption rate. The drop in hydrogen production is atributed by the inhibition of nitrogenize activity by surplus ammonium ions [22,23]. The iron (Fe) is an important element essential for the hydrogenase activity, which directs the metabolic pathway by stimulating the active site for the ferredoxin (Fd).…”