Production of Solvent (Acetone-Butanol-Ethanol)in Btach and Continuous Fermentation by Clostridium Saccharobutylicum Dsm 13864 Using Gelatinised Sago Starch as Substrate
Study on the feasibility of using improved computer-controlled HPLC and GC systems was carried out to simplify the analysis method used in solvent fermentation. The use of HPLC system with a single injection to analyse the composition of culture broth (substrates and products) during solvent ferm...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2005
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/6765/1/IB_2005_9.pdf |
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| Summary: | Study on the feasibility of using improved computer-controlled HPLC and GC
systems was carried out to simplify the analysis method used in solvent
fermentation. The use of HPLC system with a single injection to analyse the
composition of culture broth (substrates and products) during solvent fermentation
was achieved by raising the column temperature to 80°C. Although good separation
of the components in the mixture was achieved, a slight peak overlapped for butyric
acid and acetone was observed. However, improved GC system was developed and
capable to measure the products of solvent fermentation (acetone, butanol, ethanol,
acetic acid and butync acid) within 22 min of d y s i s time. In order to obtain
accurate quantification, GC was used to determine the products whereas HPLC was
used to detect the substrates.
The effect of different sago starch concentrations on solvent fermentation by
Clostridium saccharohutylicum DSM 13864 was studied in anaerobic condition using 250 rnL schott Duran bottle. The optimal sago starch concentration obtained
was 50 g/L where the total solvent concentration, total solvent yield and total solvent
productivity were 8.97 g/L, 0.20 g/g and 0.14 g/L.h, respectively. The performance
of solvent fermentation was greatly improved when 2 L stirred tank fermenter was
applied using 50 g L sago starch. The fermentation time to reach the maximum total
solvent concentration was shortened from 66 h to 28 k The total solvent
concentration, total solvent yleld and total solvent productivity obtained was 10.89
g/L,0 .24 g/g and 0.39 g/L.h, respectively.
The total solvent production in 2 L stirred tank fermenter was sigmficantly improved
when glycerol was added to the medium. With the addition of 2 to 10 g!L glycerol to
the medium, the production of total solvent was increased by about 3% to 50.4% as
compared to fermentation without the addition of glycerol (10.89 @), respectively.
Although there was a reduction in ethanol production, the production of acetone and
butanol was significantly increased. Glycerol with concentration of 6 @ was
optimal for improvement of the total solvent production (16.38 g/L), total solvent
yield (0.35 gig) and total solvent productivity (0.59 g1L.h).
From the study it was found that the condition could be adjusted to suit for acids
production (high dilution rate and high pH) or solvent production (low dilution rate
and low pH) by manipulating the dilution rate and culture pH of single stage
continuous fermentation. The highest solvent concentration in outflow (9.10 g/L)
was obtained at pH 4.5 and dilution rate of 0.05 h-*, whch gave the overall
productivity of 0.46 g1L.h. However, the highest total solvent productivity (0.85
gkh) was obtained at dilution rate of 0.11 h-I at pH 4.5. Although the total solvent productivity was greatly increased in continuous culture, the final solvent
concentration attained in outflow was decreased by about 53% as compared to batch
culture. |
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