Thanks for your comment. To be honest, I was unaware of mushroom biobutanol. But it looks interesting. Overall, The Saners' movement doesn't really propose specific solutions to the climate crisis. The group is focused on authorizing and empowering qualified climate scientists to develop and head up a worldwide emergency program to address the crisis.
That said, I am curious! I may send an email to a reporter who covered this issue and ask him if he knows what the current state of research is.
Ok. I just wrote an email to the author of this article: https://www.siliconrepublic.com/author/colmgorey/
and asked if he knew the current state of research into mushroom biofuels.