I haven't heard of any engineered yeasts or any patented yeasts. If you find a link to any information related to that, then please send it to me. I'd be very interested to see that. A quick search for 'yeast' on the USPTO site yields about 200 results. I glanced at a few and didn't see anything about DNA patents, but 200 is too many for me to weed through...
Yeah, I noticed this when brewing a Belgian Wit I read this from White Labs under their FAQ:
"I have a question about WLP400. Can you verify that it is not genetically modified?
None of our strains, including WLP400, are genetically modified."
This led me to believe that there must be enough genetically modified strains out there, for WL to make a statement like that. When reading this thread I noticed the unique name "Pacman Yeast" so I looked it up. From RebelBrewer's website, under the product description:
"Proprietary yeast strain from Rogue breweries in Oregon."
Then from the Wyeast release statement on their website:
"... And, we have also received permission from Brett Joyce, President of Rogue Brewing, to release the Pacman strain. This yeast is perfect for brewing big, rich stouts and porters. It is a clean aggressive strain that works well at lower temperatures. 1764-PC Rogue Pacman yeast is only available to home brewers! ..."
I was just curious about how all of this works in "big business" as far as yeasts are concerned. It got me wondering what would happen if a commercial brewery used the yeast, and how they (Rogue) could prove that the other brewery didn't cultivate it themselves. You know what I mean?