Hi! Owner-operator at Hydrospace here. I assure you that these are very different products.
PNS ProBio is a high-density PNSB (purple nonsulfur bacteria) product containing three PNSB species, namely Rhodopseudomonas palustris, Rhodospirillum rubrum and Rhodobacter sphaeroides. It's formulated primarily as a food and probiotic. Microbacter Purple M contains a broad variety of species including one PNSB, Rhodopseudomonas palustris; I know because we produce the PNSB for them. That product is formulated primarily for bioremediation (especially nutrient control).
We're excited about this collaboration and are confident that Purple M is going to be wildly successful. I can say with certainty that we absolutely are not competitors. Indeed, these products are very different in composition, with theirs being a diverse consortium and ours being dominated by PNSB. And IMHO that's exactly what this industry needs right now--a greater range of more specialized, high-quality options, and fewer cheap copycats. :) Hope that helps!