Photometabolic production of hydrogen from organic substrates by free and immobilized mixed cultures of Rhodospirillum rubrum and Klebsiella pneumoniae*

Abstract

SummaryA culture of R. rubrum cells apparently contaminated with K. pneumoniae were immobilized by entrapment in agar. This system was used as a model for hydrogen production by photometabolic means. Observed results indicated that the contaminant exerted a major influence on the observed results. This preparation, when immobilized and used in a specifically designed reactor with glucose substrate, showed operational half-lives of approximately lo00 hr. The feasibility of using this "mixed" culture for producing hydrogen from acid hydrolyzed cellulose and wood sawdust was also examined.

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

“…Sustained H 2 photoproduction is possible as the single photosystem (PSI) of these organisms does not generate O 2 (this is termed anoxygenic photosynthesis) and continuous H 2 -producing cultures have been operated for up to several months (Liessens & Verstraete 1986;Weetall et al 1989;Eroğlu et al 1997;Hassan et al 1997;Fascetti et al 1998;Tsygankov et al 1998;Yokoi et al 2001;Franchi et al 2004;Shi & Yu 2006). Rocha et al (2001) analysed a large number of reports, indicating that the efficiency of light conversion to H 2 is variable for PNS bacteria, the average value being ca.…”

“…While increasing the complexity and cost, sequential reactors permit the operator to maintain different conditions in separate parts of the dual system, allowing a combination of organisms, which may not be compatible in co-culture ( Figure 3B). For example, (wild-type) microalgae/cyanobacteria and PNS bacteria were not compatible in co-culture since the photosynthetic generation of oxygen inhibited nitrogenase-mediated H 2 production by the PNS bacteria (Miyamoto et al 1987;Weetall et al 1989). Further, sequential reactor systems can be potentially more effective as either component can be optimised without compromise to the other and may be preferred even for 'compatible' combinations of organisms.…”

“…However, this calculation was based on a H 2 yield of 1.3 mol H 2 /mol hexose from a single-stage bacterial fermentation. Several authors report multiorganism systems for H 2 production producing in excess of 7 mol H 2 /mol hexose (Weetall et al 1989;Miura et al 1992;Ike et al 2001;Kawaguchi et al 2001;Yokoi et al 2001;Asada et al 2006;Kim et al 2006c). Hence, a bio-H 2 process could be more energetically productive than a bio-methane process if dual H 2 -producing systems could be implemented.…”

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

“…Several pairs of co-culture have been studied for hydrogen production, including C. butyricum and R. sphaeroides for the conversion of glucose [7], Klebsiella pneumoniae and Rhodospirillum rubrum for glucose [8], Cellulomonas sp. and Rhodobacter capsulatus for cellulose [9,10], Vibrio fluvialis and Rhodobium marinum for starch [11], and C. butyricum and Rhodobacter for starch [12].…”

Relationship between the photoproduction of hydrogen and the accumulation of PHB in non-sulphur purple bacteria

“…Fatty acids are dominant products in mixed culture fermentation (Weetall et al 1981;Odom and Wall 1983;Miyake et al 1984). In Japan a biotechnological process has been developed for H2 production from waste-water (Kubota 1985).…”