MM100 = (LL) Lactococcus lactis subsp. lactis + (LLC) Lactococcus lactis subsp. cremoris + (LLD) Lactococcus lactis subsp. lactis biovar diacetylactis
LM57 = (LMC) Leuconostoc mesenteroides subsp. cremoris.
MM100 + LM57 = Flora Danica or Creme Fraiche or Aromatic BThey all use the same 4 bacteria, but not necessarily in the same proportions. And there may be other things added like lactose, so read the label. The LM57 (LMC) is available separately so you can custom mix your starter.
So when Debi uses LM100
AND some Flora Danica, she is actually doubling up on the 3 bacteria in the LM100. Flora Danica (aka Creme Fraiche or Aromatic B) are stand alone cultures.
LMC does 3 significant things. It produces Diacetyl (buttery) flavor. It produces small quantities of CO2, and it has thickening properties. That's why you use Aromatic B or Creme Fraiche when making creme cheese, creme fraiche, or Mascarpone. It's unreal how thick creme cheese is when made with Aromatic B. The addition of LMC makes a huge difference. By comparison, yogurt is very runny. My next batch of yogurt, I am going to try adding a "little" LMC to see what happens. Should be interesting because the yogurt will have to be incubated below 100F because the LMC is a meso culture. Who will win the battle, the yeast or LMC? Can they work well together? Will it be thicker? Will it make a buttery tasting yogurt?
The LLD (Lactococcus lactis subsp. lactis biovar diacetylactis) in LM100 also produces a little buttery flavor and CO2, but not as much as the LMC.
So, I'm sure some producers are adding a little LMC to their Gouda, but I think it's overkill. The extra buttery flavor and thicker texture are not classic Gouda. Still a good cheese. Just a matter of preference.
Ironically, some beers, Ales for example, are supposed to have a Diacetyl (buttery) flavor from yeast and some brewmeisters struggle with keeping it out of their homebrew.
Here's a link -
Diacetyl Beer