Composition of Fe(III)-reducing bacteria from marine sediments and characteristics of dissimilatory iron reduction coupled to hydrogen production

Abstract:

[Background] Some anaerobic bacteria with simultaneous dissimilatory iron reduction and hydrogen production, belonging to fermentative dissimilatory Fe(III)-reducing bacteria, have been paid more and more attention for dual characteristics of energy-saving and environment-friendliness. [Objective] The composition of dissimilatory Fe(III) reduction mixed bacteria in marine sediments was obtained, and the characteristics of dissimilatory Fe(III) reduction and hydrogen production were analyzed. [Methods] The dominant population of Fe(III)-reducing mixed culture was obtained using high-throughput sequencing data, and on this basis the characteristics of microbial Fe(III) reduction coupled to hydrogen production were analyzed under the condition with six different electron donors. [Results] The result of high-throughput sequencing data showed that the dominant population was Clostridium, which was attributed to fermentative-type dissimilatory Fe(III)-reducing bacteria. The mixed culture could reduce Fe(III) and produce hydrogen using sucrose, glucose and sodium pyruvate as electron donor and iron hydroxide as electron acceptor. Among the six electron donors, glucose was the most effective electron donor for double characteristics with high microbial Fe(III) reduction and hydrogen production, with Fe(II) concentration of 59.34±6.73 mg/L and hydrogen production of 629.70±11.42 mL/L. [Conclusion] The results provide evidence for the application of dissimilatory Fe(III)-reducing bacteria for biological hydrogen production, which will widen the germplasm resource of fermentative-type dissimilatory Fe(III)-reducing bacteria.