Understanding the Temporal Dynamics of Biohydrogen-Producing Microbes from the Kongsfjordjen Sediments, Svalbard
The sediments in Arctic fjords contain diverse benthic microbial communities with hidden biotechnological applications. In this study, we assessed the bio-hydrogen production potential of native microbial consortia in the sediments of Kongsfjorden, Svalbard, under controlled temperature (4C vs. 20C) and 2-bromoethanosulfonate (BES) inhibition conditions over 60 days using the Biohydrogen Potential (BHP) assay. The combination of BES at 20C significantly decoupled indigenous methanogenic syntrophy and selected specific genera of Firmicutes, potentially capable of producing bio-hydrogen. This metabolic decoupling created a favorable pathway for optimal production of bio-hydrogen from the acetate and butyrate pathways. Functional classification of microbial genes revealed that hydrogen was produced as a primary byproduct of nitrogenase (nif) activity at 4C (cold-stressed); whereas at 20C with BES, operons associated with hydrogen production via hyper-efficient [FeFe]-hydrogenase (hyd, hyc) were activated. In addition, our kinetic models and Q10 values (Q10 > 4.0) indicated that the indigenous microbial communities in these sediments had the potential to generate bio-hydrogen through catalysis and responded exponentially to moderate increases in temperature. Ultimately, this research highlights Arctic benthic sediments as highly adaptable and manipulable biocatalysts for next-generation bio-hydrogen biofuel production, which utilizes low-energy inputs.