Brightwell Microbacter 7 also claims, iirc, to have denitrifiers. Though it does not sound to be as concentrated as FM Ultrabio.
Unfortunately for me, I’m not sure that the latter is distributed in the US.
Apologies if this breaks any rules, (so apologies and feel free to delete if so) but a quick google comes up with: http://cm-distributors.com/product-category/bacteria-based-products/
I've not used them, (having found FM UltraBio to be very effective) but there are a few broad range bacterial solutions that are used to seed the likes of Siporax. I'm sure a quick google would find you some recommendations I'm sure.