Enrichment of Marinobacter sp. and Halophilic Homoacetogens at the Biocathode of Microbial Electrosynthesis System Inoculated With Red Sea Brine Pool
Type
BioprojectDataset
Authors
AlQahtani, Manal Faisal
Bajracharya, Suman

Katuri, Krishna
Ali, Muhammad
Ragab, Alaa I.

Michoud, Gregoire

Daffonchio, Daniele

Saikaly, Pascal

KAUST Department
Environmental Science and Engineering ProgramBiological and Environmental Sciences and Engineering (BESE) Division
Water Desalination and Reuse Research Center (WDRC)
King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Biological and Environmental Science and Engineering Division, Thuwal, Saudi Arabia
Bioscience Program
Date
2019-11-27Permanent link to this record
http://hdl.handle.net/10754/666722
Metadata
Show full item recordAbstract
Homoacetogens are efficient CO2 fixing bacteria using H2 as electron donor to produce acetate. These organisms can be enriched at the biocathode of microbial electrosynthesis (MES) for electricity driven CO2 reduction to acetate. Studies exploring homoacetogens in MES are mainly conducted using pure or mix-culture anaerobic inocula from samples with standard environmental conditions. Extreme marine environments host unique microbial communities including homoacetogens that may have unique capabilities due to their adaptation to harsh environmental conditions. Anaerobic deep-sea brine pools are hypersaline and metalliferous environments and homoacetogens can be expected to live in these environments due to their remarkable metabolic flexibility and energy efficient biosynthesis. However, brine pools have never been explored as inocula for the enrichment of homacetogens in MES. Here we used the saline water from a Red Sea brine pool as inoculum for the enrichment of halophilic homoacetogens at the biocathode of MES. Volatile fatty acids, especially acetate, along with hydrogen gas were produced in MES systems operated at 25 and 10 percent salinity. Acetate concentration increased when MES was operated at a lower salinity 3.5 percent, representing typical seawater salinity. Amplicon sequencing and genome-centric metagenomics of matured cathodic biofilm showed the dominance of the genus Marinobacter and phylum Firmicutes at all tested salinities. Seventeen high quality draft metagenome assembled genomes (MAGs) were extracted from the biocathode samples. The recovered MAGs accounted for 87 percent of the quality filtered sequence reads. Genome analysis of the MAGs suggested CO2 fixation via Wood-Ljundahl pathway by members of the phylum Firmicutes and the fixed CO2 was possibly utilized by Marinobacter sp. for growth by consuming O2 escaping from the anode to the cathode for respiration. The enrichment of Marinobacter sp. with homoacetogens was only possible because of the specific cathodic environment in MES. These findings suggest that in organic carbon limited saline environments, Marinobacter spp. can live in consortia with CO2 fixing bacteria such as homoacetogens, which can provide them with fixed carbon as a source of carbon and energyPublisher
NCBIAdditional Links
https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA545216Relations
Is Supplement To:- [Article]
Alqahtani, M. F., Bajracharya, S., Katuri, K. P., Ali, M., Ragab, A., Michoud, G., … Saikaly, P. E. (2019). Enrichment of Marinobacter sp. and Halophilic Homoacetogens at the Biocathode of Microbial Electrosynthesis System Inoculated With Red Sea Brine Pool. Frontiers in Microbiology, 10. doi:10.3389/fmicb.2019.02563. DOI: 10.3389/fmicb.2019.02563 Handle: 10754/660090