TY - JOUR
T1 - Hydrogen-based syntrophy in an electrically conductive biofilm anode
AU - Dhar, Bipro Ranjan
AU - Park, Jeong Hoon
AU - Park, Hee Deung
AU - Lee, Hyung Sool
N1 - Funding Information:
This research was funded by Natural Sciences and Engineering Research Council of Canada Discovery Grant ( RGPIN-2016-04155 ). We appreciate Dr. Jangho Lee’s supports to calibration of the H 2 microsensor.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - We experimentally and theoretically investigated implications of H2 and a rate-limiting step in a mixed-culture biofilm anode fed with n-butyrate, one of the poorest substrates to exoelectrogens. Acetate and i-butyrate were formed as intermediates during anaerobic degradation of n-butyrate, which suggested oxidative acetogenesis of n-butyrate in syntrophy with H2 scavengers in the biofilm anode. Methane was not detected in an anode chamber, and no current was generated in the biofilm anode using H2 as the electron donor. These results indicated that acetogens would be a main H2 consumer in the biofilm. Pyrosequencing data showed dominance of Geobacter in the biofilm anode (83.6% of total sequences), along with Sphaerochaeta and Treponema, which supports the syntrophy between exoelectrogens and acetogens. Electrical conductivity of the butyrate-fed biofilm anode was as high as 0.67 mS/cm, demonstrating that EET does not limit current density in the biofilm. In-situ monitoring of dissolved H2 concentration proved H2 production (up to 12.4 µM) and consumption during current generation in the biofilm, which supports significance of H2–based syntrophy in the electrically conductive biofilm using n-butyrate as the primary electron donor.
AB - We experimentally and theoretically investigated implications of H2 and a rate-limiting step in a mixed-culture biofilm anode fed with n-butyrate, one of the poorest substrates to exoelectrogens. Acetate and i-butyrate were formed as intermediates during anaerobic degradation of n-butyrate, which suggested oxidative acetogenesis of n-butyrate in syntrophy with H2 scavengers in the biofilm anode. Methane was not detected in an anode chamber, and no current was generated in the biofilm anode using H2 as the electron donor. These results indicated that acetogens would be a main H2 consumer in the biofilm. Pyrosequencing data showed dominance of Geobacter in the biofilm anode (83.6% of total sequences), along with Sphaerochaeta and Treponema, which supports the syntrophy between exoelectrogens and acetogens. Electrical conductivity of the butyrate-fed biofilm anode was as high as 0.67 mS/cm, demonstrating that EET does not limit current density in the biofilm. In-situ monitoring of dissolved H2 concentration proved H2 production (up to 12.4 µM) and consumption during current generation in the biofilm, which supports significance of H2–based syntrophy in the electrically conductive biofilm using n-butyrate as the primary electron donor.
KW - Acetogenesis
KW - Biofilm conductivity
KW - Butyrate
KW - Direct interspecies electron transfer
KW - Geobacter
KW - Hydrogen
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U2 - 10.1016/j.cej.2018.11.138
DO - 10.1016/j.cej.2018.11.138
M3 - Article
AN - SCOPUS:85056860625
VL - 359
SP - 208
EP - 216
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
ER -