2. Introduction
• Acetone is a colorless, volatile, flammable organic
solvent.
• IUPAC name______ Propan-2-one
• Molecular Formula____C3H6O or CH3-CO-CH3
• Boiling point________56°C
• Melting point_________94.8 °C
3. Uses
• Food additives -> Flavoring Agents
• Adhesives and sealant chemicals
• Derivatives (Isophorone )
• Ion exchange agents
• Laboratory chemicals
• Solvents (for cleaning or degreasing)
• Solvents (which become part of product formulation or
mixture)
• Viscosity adjustors
• Nail polish Remover
• Manufacture of artificial fibres
4. History
• The first to report about microbial butanol production
was Pasteur in 1862.
• At this time Chaim Weizmann isolated a
new bacterial culture, readily fermenting starchy
material into acetone and butanol.
• Clostridium acetobutylicum was the main
species in this culture.
5. Organisms, Substrates and Products
• C. acetobutylicum has high amylase activity, and thus
was once widely adopted in industrial ABE (acetone-
butanol-ethanol) fermentation using starchy materials,
such as corn and cassava.
• C. beijerinckii can also ferment like C. acetobutylicum
• C. ljungdahlii have the ability to use C1 gases (CO or
CO2) through the Wood-Ljungdahl pathway, yielding a
variety of 2- to 8-carbon chemicals
• P1 and P2 media is used
6. Synthetic P2 medium had the following
composition (in g/L)
yeast extract 1 K
KH2Po4 0.5
K2HPO4 0.5
para aminobenzoic acid 0.001
thiamin 0.001
biotin 1 × 10−5
MgSo47H2O 0.2
MnSo47H2O 0.0l
Fe2So47H2O, 0.01
NaCl 0.01
ammonium acetate 2.2
7.
8. Pathways
• The typical fermentation process of solventogenic
clostridia can be into two stages, i.e., acidogenesis and
solventogenesis
• In the acidogenic stage, a variety of organic acids are
produced, together with ATP formation which is
essential for cell growth as the energy supply; in the
solventogenic stage, acids are re-assimilated and
converted into other products, mainly alcohols
• All the three clostridia mentioned above exhibit a
biphasic behavior.
9.
10. Wood-Ljungdahl pathway
• In this pathway carbon dioxide is reduced to carbon
monoxide and formic acid or directly into a formyl
group, the formyl group is reduced to a methyl group
and then combined with the carbon monoxide
and Coenzyme A to produce acetyl-CoA.
