Nick Maclaren wrote:
[...]
I have asked before in many forums, but never have had an answer
as to what breaks down keratin in the soil. One idiotic answer
was "nothing much", so I pointed out that much of the UK would be
knee deep in old wool if that were the case. The consensus is
"bacteria", which isn't exactly informative and may well be wrong.

Interesting. Fungi, it seems from several papers, such as:

http://72.14.203.104/search?q=cache:...&cd=6&ie=UTF-8

http://tinyurl.com/s4e8u

and

http://72.14.203.104/search?q=cache:...&cd=7&ie=UTF-8

http://tinyurl.com/gsdz9

Another reference, from Brazil, suggests that pathogenic keratophilic
fungi on the skin (presumably things like the athlete's foot family)
evolved from harmless soil-borne species. Presumably unsterilised
feathers and hair already carry populations of the necessary.

I didn't search further.

--
Mike.