DescriptionThe transportation sector contributes significantly to global carbon dioxide emissions and accounts for 65% of the world’s consumption of liquid fossil fuels (IEA, 2017), stressing the need for alternatives to energy sources like gasoline and diesel that allow for a more sustainable economy. Due to their similarities, butanol can already today be used as direct replacement for gasoline but its production still relies on expensive pure substrates (e.g. glucose), which carries some challenges such as competition with food production, and low adaptability to variations in substrate composition. Due to their microbial diversity, mixed microbial cultures (MMC) can overcome such limitations and potentially become the predominant bio-based production platform for butanol. Previous studies have shown that butanol formation by anaerobic mixed cultures was feasible using only butyrate and hydrogen (H2) (Steinbusch et al., 2008). Both substrates are common intermediates during the decomposition of organic residues, as is the case for industrial waste streams, offering a cheap feedstock alternative that avoids competition with food production.
In this work, we investigate the feasibility of butanol formation by anaerobic MMCs. In order to suppress competing side reactions such as anaerobic butyrate conversion and methanogenesis, elevated H2 partial pressures (2 bar) and acidic conditions (pH 5.5) were applied. Anaerobic butyrate conversion was selectively inhibited under these conditions and the butanol concentrations obtained were about three times larger than previously reported by Steinbusch et al. (2008), hinting at future applications of MMC for butanol production from waste streams.
1. International Energy Agency: Key world energy statistics, 2017.
2. Steinbusch et al.: Alcohol production through volatile fatty acids reduction with hydrogen as electron donor by mixed cultures. Water Research (2008), 42, 4059–4066.
|Period||30 Mar 2021|
|Event title||6th BioProScale Symposium: null|
|Degree of Recognition||International|