There are a few cheeses now being made using sodium nitrate. Initially this was only used in a few Dutch cheeses like Herregaardsost but it's use has spread considerably in the past 10 to 15 years in Europe.
The article I found a few months back on Jarlsberg showed they found nitrates and the use of mixed cultures to be beneficial in some types of cheeses. The article reviewed several types of cheeses. I found it very enlightening.
Don't let the term nitates scare you - they are natually occuring in most root vegetables and the quantities are smaller than that which would be aboarbed from eatting a potatoe.