Potential of biogenic hydrogen production for hydrogen driven remediation strategies in marine environments

Abstract

Fermentative production of bio-hydrogen (bio-H-2) from organic residues has emerged as a promising alternative for providing the required electron source for hydrogen driven remediation strategies. Unlike the widely used production of H-2 by bacteria in fresh water systems, few reports are available regarding the generation of biogenic H-2 and optimisation processes in marine systems. The present research aims to optimise the capability of an indigenous marine bacterium for the production of bio-H-2 in marine environments and subsequently develop this process for hydrogen driven remediation strategies. Fermentative conversion of organics in marine media to H-2 using a marine isolate, Pseudoalteromonas sp. BH11, was determined. A Taguchi design of experimental methodology was employed to evaluate the optimal nutritional composition in batch tests to improve bio-H-2 yields. Further optimisation experiments showed that alginate-immobilised bacterial cells were able to produce bio-H-2 at the same rate as suspended cells over a period of several weeks. Finally, bio-H-2 was used as electron donor to successfully dehalogenate trichloroethylene (TCE) using biogenic palladium nanoparticles as a catalyst. Fermentative production of bio-H-2 can be a promising technique for concomitant generation of an electron source for hydrogen driven remediation strategies and treatment of organic residue in marine ecosystems.