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Hydrogenogenic CO Conversion in a Moderately Thermophilic (55 °C) Sulfate‐Fed Gas Lift Reactor: Competition for CO‐Derived H 2
Author(s) -
Sipma Jan,
Lettinga Gatze,
Stams Alfons J. M.,
Lens Piet N. L.
Publication year - 2006
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp0601084
Subject(s) - thermophile , lift (data mining) , gas lift , competition (biology) , chemistry , environmental science , thermodynamics , biology , organic chemistry , physics , computer science , ecology , enzyme , data mining
Thermophilic (55 °C) sulfate reduction in a gas lift reactor fed with CO gas as the sole electron donor was investigated. The reactor was inoculated with mesophilic granular sludge with a high activity of CO conversion to hydrogen and carbon dioxide at 55 °C. Strong competition for H 2 was observed between methanogens and sulfate reducers, while the homoacetogens present consumed only small amounts of H 2 . The methanogens appeared to be more sensitive to pH and temperature shocks imposed to the reactor, but could not be completely eliminated. The fast growth rates of the methanogens (generation time of 4.5 h) enabled them to recover fast from shocks, and they rapidly consumed more than 90% of the CO‐derived H 2 . Nevertheless, steep increases in sulfide production in periods with low methane production suggests that once methanogenesis is eliminated, sulfate reduction with CO‐rich gas as electron donor has great potential for thermophilic biodesulfurization.