You might be a bit confused:
“Soil organisms show their greatest diversity of species and usually their largest populations in productive soils. The size of the microbial biomass usually shows direct correlation with the amount of plant growth…” - Soil Microbiology and Biochemistry by E.A. Paul and F.E. Clark, Academic Press, Inc.
The truth is that these spores that provide a Gardner with "living soil" are present in all forms of natural soil that has not been treated. Treated soil is treated for aesthetic purposes only and it is highly HIGHLY unlikely that this mold is doing anything but good things for you.
Mold on your surface dirt can actually be a sign of healthier dirt. Here is what I would do:
Rather than kill the fungus I would go to the garden center and pick up some Mycorrhizae powder. Pull up these guys and wash off their roots and before planting (in the same soil) spread some of this powder onto your roots and mix it into the soil.
This way we can be sure you are not going to loose all the great benefits of having a healthy "living soil" without having to worry weather or not the fungi in your soil is supposed to be there or not.