I've had a little correspondence with Green Pastures today, and this is an edited example of my question and their answer-
Me: "Any information on the particular organisms, and how do you source them (or, if you are using a long running strain, how did you source them originally)?"
GP: "All you need to know is it is as it has been since biblical times. It is fermented fish livers. Similar to fermented fish. The product is the oil. The fermented part is not used. (snip) Maybe you can re-ask your question but hold back from wanting to know intimate details. Your initial question could not be answered the way it was asked"
Um. Intimate details??? I did explain that I'm not interested in proprietary information, and am just asking as an interested consumer. Answers I was expecting might have been "We started with a wild culture by exposing the product to the air for x number of days" or "Once a month we inoculate the livers with a sourdough starter that we've been using for 5 years" or "Our culture consists of bacterias x y and z and yeasts p q and r."
Soooooo. I'm turning to you all educated folks to help either answer my question or reformulate my question in a way that they can answer more specifically than just "biblical and that's all you need to know."