Pittman wrote: > > How can you determine if Saccharomyces cerevisiae, E. Coli k-12, or > Bacillus subtilis can utilize external starch? > > Thanks in advance! Grow the organisms on 10% starch agar for a week. Then flood the plate with an iodine solution. If you see a clear halo around the colonies, they can use the starch. Rick Bortnick Delaware Valley College