Performance of mesophilic biohydrogen-producing cultures at thermophilic conditions

Medhavi Gupta; Maritza Gomez-Flores; Noha Nasr; Elsayed Elbeshbishy; Hisham Hafez; M Hesham El Naggar; George Nakhla

doi:10.1016/j.biortech.2015.06.047

Performance of mesophilic biohydrogen-producing cultures at thermophilic conditions

Bioresour Technol. 2015 Sep:192:741-7. doi: 10.1016/j.biortech.2015.06.047. Epub 2015 Jun 16.

Authors

Medhavi Gupta¹, Maritza Gomez-Flores¹, Noha Nasr², Elsayed Elbeshbishy², Hisham Hafez³, M Hesham El Naggar², George Nakhla⁴

Affiliations

¹ Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada.
² Department of Civil and Environmental Engineering, Western University, London, Ontario N6A 5B9, Canada.
³ Department of Civil and Environmental Engineering, Western University, London, Ontario N6A 5B9, Canada; GreenField Ethanol Inc., Chatham, Ontario N7M 5J4, Canada.
⁴ Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6A 5B9, Canada; Department of Civil and Environmental Engineering, Western University, London, Ontario N6A 5B9, Canada. Electronic address: gnakhla@eng.uwo.ca.

PMID: 26101964
DOI: 10.1016/j.biortech.2015.06.047

Abstract

In this study, batch tests were conducted to investigate the performance of mesophilic anaerobic digester sludge (ADS) at thermophilic conditions and estimate kinetic parameters for co-substrate fermentation. Starch and cellulose were used as mono-substrate and in combination as co-substrates (1:1 mass ratio) to conduct a comparative assessment between mesophilic (37 °C) and thermophilic (60 °C) biohydrogen production. Unacclimatized mesophilic ADS responded well to the temperature change. The highest hydrogen yield of 1.13 mol H2/mol hexose was observed in starch-only batches at thermophilic conditions. The thermophilic cellulose-only yield (0.42 mol H2/mol hexose) was three times the mesophilic yield (0.13 mol H2/mol hexose). Interestingly, co-fermentation of starch-cellulose at mesophilic conditions enhanced the hydrogen yield by 26% with respect to estimated mono-substrate yields, while under thermophilic conditions no enhancement in the overall yield was observed. Interestingly, the estimated overall Monod kinetic parameters showed higher rates at mesophilic than thermophilic conditions.

Keywords: Co-fermentation; Hydrogen; Mesophilic; Thermophilic; Unacclimatized.

MeSH terms

Biofuels / microbiology*
Bioreactors / microbiology*
Carbohydrate Metabolism / physiology*
Coculture Techniques / methods
Computer Simulation
Hydrogen / isolation & purification
Hydrogen / metabolism*
Models, Biological*
Starch / metabolism*
Temperature

Substances

Biofuels
Hydrogen
Starch