Abstract
Isobutanol is attracting attention as a biofuel because of its higher energy density and lower hygroscopicity compared with ethanol. The utilization of seawater in fermentation can potentially reduce the need for freshwater and trace minerals during isobutanol production. Here, we describe isobutanol production using seawater. When an isobutanol-producing Escherichia coli strain was cultured using 40 % seawater as the source of trace minerals, 4.93 g/L isobutanol was produced, with a theoretical yield of 66 %, consistent with the yield obtained using synthetic medium with trace minerals. This result suggests that seawater is a potentially useful medium component for isobutanol production.
