Pre-treatment and utilization of raw glycerol from sunflower oil biodiesel for growth and 1,3-propanediol production by Clostridium butyricum

✍ Scribed by Asad-ur-Rehman; Saman Wijesekara R.G; Nakao Nomura; Seigo Sato; Masatoshi Matsumura

• Publisher: Wiley (John Wiley & Sons)
• Year: 2008
• Tongue: English
• Weight: 1023 KB
• Volume: 83
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.1917

✦ Synopsis

Abstract

BACKGROUND: The objective of the present work is to report an efficient pre‐treatment process for sunflower oil biodiesel raw glycerol (SOB‐RG) and its fermentation to 1,3‐propanediol.

RESULTS: The growth inhibition percentages of Clostridium butyricum DSM 5431 on grade A (pH 4.0) and grade B (pH 5.0) phosphoric acid‐treated SOB‐RG were similar to those of pure glycerol at 20 g glycerol L^−1^; i.e., 18.5 ± 0.707% to 20.5 ± 0.7% inhibition. In grade A, growth inhibition was reduced from 85.25 ± 0.35% to 32 ± 1.4% (a 53.25% reduction) at 40 g glycerol L^−1^ by washing grade A raw glycerol twice with n‐hexanol (grade A‐2). The kinetic parameters for product formation and substrate consumption in anaerobic batch cultures gave almost similar values at 20 g glycerol L^−1^, while at 50 g glycerol L^−1^ volumetric productivity (Q~p~) and specific rate of 1,3‐propanediol formation (q~p~) were improved from 1.13 to 1.85 g L^−1^ h^−1^ and 1.60 to 2.65 g g^−1^ h^−1^, respectively, by employing grade A‐2 raw glycerol, while the yields were similar (0.5–0.52 g g^−1^).

CONCLUSION: The results are important as the pre‐treatment of SOB‐RG is necessary to develop bioprocess technologies for conversion of SOB‐RG to 1,3‐propanediol. Copyright © 2008 Society of Chemical Industry