Re: does the amount of O2, CO2, and N2 have any effect on mold growth?

If your goal is to grow mold, you will want a dark environment with a 
temperature between 70-80 degrees F and a relative humidity of 70% or 
higher. Room air (~20% oxygen, ~79% nitrogen, ~1% trace gases, including 
carbon dioxide) will serve perfectly as your atmosphere. For a reference 
try the current edition of Brock's Microbiology.