The cultures used are basically the same blend as is used for most of the Alpine type aoc cheeses.
The culture itself is passed on through the whey, and the starter powder is never added directly to the milk, but first incubated into a yogurt-like culture.
The proper procedure, as I learned it, is to make this yogurt culture and add it to the milk, holding over a portion of it. Then the whey from the first cheese is held over and reinforced with a little of the yogurt culture, this is repeated 2 or 3 times, and from that point on the culture can be maintained strictly from the whey. I like to take 2 whey cultures, and incubate them at different temperatures, then combining them together to inoculate the cheese.
To mimic the culture without the original Agroscope powder, you can use anything that contains Streptococcus Thermophilus and any variety of Lactobacillus