Quantitative proteomic analysis of the influence of lignin on biofuel production by Clostridium acetobutylicum ATCC 824

• Published in: Biotechnology for biofuels 2016-05, Vol.9 (1), p.113-113, Article 113
• Main Authors: Raut, Mahendra P, Couto, Narciso, Pham, Trong K, Evans, Caroline, Noirel, Josselin, Wright, Phillip C
• Format: Article
• Language: English
• Subjects: Acids; Biodiesel fuels; Biosynthesis; Clostridium; Ethanol; Genetic aspects; Innovations; Lignin; Metabolites; Properties; Proteomics
• ISSN: 1754-6834; 1754-6834
• DOI: 10.1186/s13068-016-0523-0

Clostridium acetobutylicum has been a focus of research because of its ability to produce high-value compounds that can be used as biofuels. Lignocellulose is a promising feedstock, but the lignin-cellulose-hemicellulose biomass complex requires chemical pre-treatment to yield fermentable saccharides, including cellulose-derived cellobiose, prior to bioproduction of acetone-butanol-ethanol (ABE) and hydrogen. Fermentation capability is limited by lignin and thus process optimization requires knowledge of lignin inhibition. The effects of lignin on cellular metabolism were evaluated for C. acetobutylicum grown on medium containing either cellobiose only or cellobiose plus lignin. Microscopy, gas chromatography and 8-plex iTRAQ-based quantitative proteomic technologies were applied to interrogate the effect of lignin on cellular morphology, fermentation and the proteome. Our results demonstrate that C. acetobutylicum has reduced performance for solvent production when lignin is present in the medium. Medium supplemented with 1 g L(-1) of lignin led to delay and decreased solvents production (ethanol; 0.47 g L(-1) for cellobiose and 0.27 g L(-1) for cellobiose plus lignin and butanol; 0.13 g L(-1) for cellobiose and 0.04 g L(-1) for cellobiose plus lignin) at 20 and 48 h, respectively, resulting in the accumulation of acetic acid and butyric acid. Of 583 identified proteins (FDR