Handbook of Dough Fermentations
I picked up a copy of Handbook of Dough Fermentations by Karel Kulp and Klaus Lorenz. It is a detailed book on the biochemistry of various strains of lactobacilli and yeasts in sourdoughs. Much of it is summarized from lower level research articles which are cited in each chapter. It is definitely not 'light reading' but the authors do a great job of presenting the information in a way that if you can remember stuff from your high school biology class, you can keep up (though I have to refer to a dictionary myself, and I need to re-read certain passages a few times before it sinks in. I am not a scientist. :-)). I think it is a great book if one is interested in knowing more about 'the beasties' in our cultures.
One example (out of many), if you ever wanted to know what all of the flavor-producing compounds are that yeasts create as a result of fermentation, it lists them all out, and their flavors. :)
The authors cite research articles from many sources but there's one in particular, the Journal of Cereal Science, that I found online and thought I'd mention. The articles are not free, but I thought some of these were neat -- they have summaries that describe the overall points. For example:
Sourdough fermentation effects on buckwheat:
Durum bread fermentation timings:
Baguette crust aroma and fermentation time:
Searching the library for keywords such as yeast, fermentation, flavor, shows all sorts of interesting articles, I never knew people actually did formal research on these things. I thought I would mention it here. Might be useless, but anyway.