The answer is b.Multiple processing steps can be avoided.
Traditionally, energy crops are used for ethanol production thanks to yeast cultures. But, cyanobacteria can naturally ferment alcohol, such as isobutanol, without the need of yeast cultures. This way some steps are avoided and the process is faster. Also, cyanobacteria have a fast life cycle, so it can be produced great amounts of isobutanol for a short period of time.
