(582au) Production of Bifunctional Molecules By Clostridium Sp. BOH3

Title

Production of bifunctional molecules by Clostridium sp. BOH3

Abstract

Clostridium
sp. BO3 produces high yield of butanol and volatile fatty acids (predominantly
acetic and butyric acids) from simple sugars and polysaccharides. When sp. BOH3
is cultured in reinforced clostridial medium with glycerol
and sugar alcohols including mannitol, galactitol, sorbitol and xylitol, it produces bifunctional
molecules including succinic acid and 1,3 propanediol (PDO). These bifunctional molecules are important feedstocks
for various applications. For instance, succinic acid
is as a precursor for the production adipic acid, 1,4 butanediol, terahydrofuran
and g-butyrolactone.
Similarly, PDO is used for the production of polymers, cosmetics and
lubricants. The strain BOH3 produces 6.8±0.2 g/l of PDO and 1.3 g/l of succinic acid as major fermentation products from 30 g/l of
glycerol. Meanwhile, it produces high level of succinic
acid (>5g/l) and low concentration of (< 2 g/l) of PDO from sugar
alcohols. Among the selected sugar alcohols, mannitol
(30 g/l) supports 7.2±0.2 g/l of succinic acid and 1.3±0.2 g/l of PDO after 5
days of fermentation. In batch fermentation, a higher initial concentration
(> 30 g/l) of glycerol and mannitol did not
inhibit the growth of sp. BOH3, and did not support the production of succinic
acid and PDO. While employing fed-batch process, addition of 30 g/l of glycerol
and mannitol after 3 days of fermentation is able to enhance
the production of PDO and succinic acid to 12.6±0.2 and 10.6±0.3 g/l
respectively. Furthermore, addition of Na₂S at lower concentration
(0.2 g/l) supports the PDO production (15.6±0.2 g/l) from glycerol. Meanwhile, CaCO₃,
and NaHCO₃ (2.5-5 g/l) enhance the production of succinic acid to 16.9±0.5
g/l from mannitol. Overall, the fed-batch production
process result the yield of PDO and succinic acid as 0.26±0.005 g /g of
glycerol and 0.28±0.008 g / g of mannitol,
respectively. To best of our knowledge, this is first report deals the
production of succinic acid by solventogenic
Clostridium strain.