Researchers at UCLA’s Henry Samueli School of Engineering and Applied Science have developed a way to produce butanol from bacteria at rates significantly higher than those achieved using current production methods.
The method produces n-butanol, a four-carbon chain alcohol that has been shown to work in vehicles designed for petrol without the modifications that would be required with other biofuels.
The UCLA team, led by James Liao, UCLA’s chancellor’s professor of chemical and biomolecular engineering, demonstrated success in producing 15–30g of n-butanol per litre of culture medium using genetically engineered Escherichia coli (E.coli) — an increase over the typical 1–4g produced per litre in the past.
For the study, Liao and his team initially constructed an n-butanol biochemical pathway in E.coli, a microbe that does not naturally produce n-butanol, but found that production levels were limited. However, after adding certain metabolic driving forces to the pathway, the researchers witnessed a tenfold increase in the production of n-butanol.
While certain microbes, including species of the bacteria Clostridium, naturally produce n-butanol, the team used E.coli because it is easier to manipulate and has been employed industrially in producing various chemicals.
’By using E.coli, we can make it produce only the compound with no other byproducts,’ Liao said. ’With native-producing organisms such as Clostridium, there are other byproducts that would add cost to the separation process.’
The next step in the research, according to the team, will be to develop a more robust industrial process.
The researchers’ work was funded by the KAITEKI Institute of Japan, a strategic arm of Mitsubishi Chemical Holdings, Japan’s largest chemical company.