Continuous lactose fermentation by Clostridium acetobutylicum--assessment of energetics and product yields of the acidogenesis.
An assessment of both the growth and the metabolism of acidogenic cells Clostridium acetobutylicum DSM 792 is reported in the paper. Tests were carried out in a CSTR under controlled pH conditions. Cultures were carried out using a semi-synthetic medium supplemented with lactose as carbon source. Acids and solvents, that represent products of the ABE process, have been purposely added in controlled amounts to the culture medium to investigate their effects on the product yields. The mass fractional yield of biomass and products were expressed as a function of the specific growth rate taking into account the Pirt model. The maximum ATP yield and the maintenance resulted 29.1 g(DM)/mol(ATP) and 0.012 mol(ATP)/g(DM)h, respectively. Quantitative features of the C. acetobutylicum growth model were in good agreement with experimental results. The model proposes as a tool to estimate the mass fractional yield even for fermentations carried out under conditions typical of the solventogenesis.
Chemical Engineering Department, Università degli Studi di Napoli Federico II, P.le V. Tecchio n. 80, 80125 Napoli, Italy.
Fabio
F
Napoli
Giuseppe
G
Olivieri
Maria Elena
ME
Russo
Antonio
A
Marzocchella
Piero
P
Salatino
D000085:Acetates / Q000378:metabolism* / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D002087:Butyrates / Q000378:metabolism* / Q000494:pharmacology; D046969:Clostridium acetobutylicum / Q000254:growth & development / Q000378:metabolism; D003470:Culture Media; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007785:Lactose / Q000378:metabolism*; D008954:Models, Biological; D012997:Solvents / Q000378:metabolism* / Q000494:pharmacology
D000085:Acetates; D002087:Butyrates; D003470:Culture Media; D012997:Solvents; D000255:Adenosine Triphosphate; D007785:Lactose