枯草菌
"Bacillus subtilis" is a gram-positive rod-shaped bacteria. "Bacillus subtilis" offers many of the same advantages and disadvantages of "E. coli", but it is less prominently used and does not produce isobutanol in quantities as large as "E. coli". Similar to "E. coli", "Bacillus subtilis" is capable of producing isobutanol from lignocellulose, and is easily manipulated by common genetic techniques. Elementary mode analysis has also been used to improve the isobutanol-synthesis metabolic pathway used by "Bacillus subtilis", leading to higher yields of isobutanol being produced.