Mold growth in carpets is only possible in the presence of excess moisture and high humidity. This can lead to odor and staining caused by the mold. Sometimes, the mold can damage not only the carpet fibers, but the carpet backing as well.
Big Red can help restore such affected rugs, including a provision of an anti-microbial on the carpet to prevent a mold re-occurrence. However, you may want to consider doing an IAQ Testing of your working or living environment if there is mold. It is important to rectify the underlying root cause for the mold growth as well.