I didn't save it. But it mentioned that the fermentation of corn was the source of methyl form, and that cyano came from animal waste.

This wiki article gives the names of the organisms that
make the cyano form...and I would assume they use animal
substrates to grow the bacteria.

http://en.wikipedia.org/wiki/Vitamin_B12

http://www.patentstorm.us/patents/59...scription.html

and if you search propionbacterium in Google you find that this species is used in waste treatment.

This discusses making methyl type from sugars (corn would be an example)
http://www.patentstorm.us/patents/55...scription.html

This last entry implies that all types of cobalamin may be made this way, with fractionating and removing the various types.

The process looks very complex. It is amazing that the end products are so inexpensive.

The methyl form is very important, because it is the only form the CNS uses. So irregardless of how it is made, it is superior.
Slowly it is replacing cyano.

Kind of creepy.... but many things are fermented..including penicillin. Human insulin comes from genetically altered E.coli.

So don't get tooooo grossed out!