ok cool. Thank youI'm glad to see you are questioning this. I'm a firm believer that the more we question the more both parties learn. I've learned more when I was an instructor than I ever did as a student. And you shouldn't take my word for it if it doesn't make sense to you imo. Skeptical Reef Keeping is a wonderful thing.
If you would like to do your own research, it may help to do searches based on ammonia oxidizing bacteria(AOB's) instead of nitrifying bacteria. It is the more commonly used term in the scientific community.
Hope you don't mind, but I'm going to link a fairly fun article/advertisement on AOB's. They are the newest yet oldest trend in skin care!
Ammonia-oxidizing bacteria is about to seriously disrupt skin care
Probiotic science has piqued consumer interest, and one state-of-the-art company has been quietly selling personal care products that replenish and preserve skin’s natural microbiome with good bacteria.www.cosmeticsdesign.com