Enhancement of biohydrogen production rate in Rhodospirillum rubrum by a dynamic CO-feeding strategy using dark fermentation

Biotechnology for Biofuels

José L. García¹  M. Auxiliadora Prieto²  Natalia Hernández-Herreros²  Alberto Rodríguez² 

[1] Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy‐of the Spanish National Research Council (SusPlast‐CSIC), Madrid, Spain;Environmental Biotechnology Group, Department of Plant and Microbial Biotechnology, Biological Research Center, Margarita Salas”-CSIC 28040, Madrid, Spain;Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy‐of the Spanish National Research Council (SusPlast‐CSIC), Madrid, Spain;Polymer Biotechnology Group, Department of Plant and Microbial Biotechnology, Biological Research Center, Margarita Salas”-CSIC, 28040, Madrid, Spain;

关键词: Hydrogen;    Rhodospirillum rubrum;    Syngas;    Dark fermentation;    Kinetic model;   

DOI  :  10.1186/s13068-021-02017-6

来源: Springer

【 摘 要 】

BackgroundRhodospirillum rubrum is a purple non-sulphur bacterium that produces H2 by photofermentation of several organic compounds or by water gas-shift reaction during CO fermentation. Successful strategies for both processes have been developed in light-dependent systems. This work explores a dark fermentation bioprocess for H2 production from water using CO as the electron donor.ResultsThe study of the influence of the stirring and the initial CO partial pressure (pCO) demonstrated that the process was inhibited at pCO of 1.00 atm. Optimal pCO value was established in 0.60 atm. CO dose adaptation to bacterial growth in fed-batch fermentations increased the global rate of H2 production, yielding 27.2 mmol H2 l−1 h−1 and reduced by 50% the operation time. A kinetic model was proposed to describe the evolution of the molecular species involved in gas and liquid phases in a wide range of pCO conditions from 0.10 to 1.00 atm.ConclusionsDark fermentation in R. rubrum expands the ways to produce biohydrogen from CO. This work optimizes this bioprocess at lab-bioreactor scale studying the influence of the stirring speed, the initial CO partial pressure and the operation in batch and fed-batch regimes. Dynamic CO supply adapted to the biomass growth enhances the productivity reached in darkness by other strategies described in the literature, being similar to that obtained under light continuous syngas fermentations. The kinetic model proposed describes all the conditions tested.

【 授权许可】

CC BY