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Energetic analysis of the growth of Methanobrevibacter arboriphilus A2 in hydrogen‐limited continuous cultures
Author(s) -
Morii Hiroyuki,
Koga Yosuke,
Nagai Shiro
Publication year - 1987
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260290304
Subject(s) - chemostat , dilution , methane , methanogenesis , fermentation , chemistry , hydrogen , growth rate , biochemistry , food science , nuclear chemistry , biology , bacteria , organic chemistry , thermodynamics , physics , genetics , geometry , mathematics
Hydrogen‐limited chemostat cultures of Methanobrevibacter arboriphilus A2 were carried out. The available electron balance and carbon balance in M. arboriphilus A2 and other methanogenic strains grown on various substrates were well satisfied. This indicates that no extracellular organic products were formed during methanogenic growth. The molar growth yields for methane ( Y X /CH 4) were calculated as 1.06–1.42 g cell/mol CH 4 at dilution rate (0.21–0.43 day −1 ). The smaller Y X /CH 4of M. arboriphilus A2 compared with that of the other methanogenic strains was probably owing to the low growth rate of M. arboriphilus A2. The low value of Y X /CH 4may be favorable for methane fermentation because less sludge accumulation is expected. The efficiency of free energy transduction to ATP during methane formation from H 2 + CO 2 was 12–17% at the dilution rate (0.21–0.43 day −1 ) assuming that Y ATP was 6.5 g/mol and the free energy change of CO 2 reduction to methane with H 2 was −62.8 kJ/mol under physiological conditions.