Shewanella oneidensis-based artificial conductive micro-niche for hydrogen augmentation

The synergetic integration of living microorganisms and nonliving matrices into a new artificial micro-ecological system is a crucial challenge in bio-manufacturing especially towards the development of sustainable energy technology. Here we develop a way of creating a Shewanella oneidensis based conductive micro-niche to boost hydrogen production by integrating graphene, polydopamine and alginate. We reveal that both the respiratory metabolism induces localized hypoxic conditions inside the micro-niche and the wired-up extracellular electron reverses transfer pathway from the outer environment to the periplasmic hydrogenases, contributing to the enhanced hydrogen production rate which is about 12.7 folds enhancement compared with that of the free Shewanella oneidensis in solution. Significantly, the whole assembly process shows good biocompatibility, ensuring that the Shewanella oneidensis inside the micro-niche could maintain hydrogen production for 30 days. Overall, it is anticipated the hybrid integration of microorganisms and abiotic material will provide an effective strategy to modulate green biomanufacturer as well as enhance biological hydrogen production.