| Abstract |
The effects of the nitrogen source and buffers used in butanol production with Clostridium
beijerinckii TISTR 1461 from sweet sorghum stem juice (SSJ) containing 60 g/L of total sugar were
first studied in this paper. Among the various nitrogen sources (dried spent yeast, urea, ammonium
acetate, ammonium sulfate), urea was found to be the most suitable for butanol production. SSJ
supplemented with urea (0.64 g/L) and cocktail buffers (KH2PO4, 0.5 g/L; K2HPO4, 0.5 g/L; ammonium
acetate, 2.2 g/L) gave the highest butanol concentration (PB, 10.13 g/L). Then, the capability of
immobilized C. beijerinckii TISTR 1461 cells for butanol fermentation was investigated. Two residual
waste materials were examined as immobilized cell carriers. Bamboo chopstick pieces were more appropriate
as carriers for cell immobilization than cigarette filter tips. The PB value of the immobilized
cells on the bamboo chopstick pieces was ~13% higher than that on the cigarette filter tips. Using
the response surface methodology (RSM), 1.9 cm bamboo chopstick pieces with a carrier loading
of 1:32 (w/v) were the optimum conditions for cell immobilization for butanol production. Under
these conditions, the PB value was 11.62 g/L. To improve the butanol production efficiency, a gas
stripping system (GS) was connected to the fermenter. It was found that the PB (14.02 g/L) and
butanol productivity (QB, 0.29 g/Lh) values improved by ~21% compared to butanol fermentation
using no gas stripping. |
Publication
Journal Publication
ไทย