Science Forums 2

[Philip Small]

Fellow blogger, Back40, and I have been tossing out the potential glomalin link to TP function for awhile. I even emailed Dr. Lehman enthusiastically about glomalin a few weeks ago, thinking to pull my thoughts together on it for a blog post. He was not unaware of the rationale. His entirely neutral response reined me in a bit.

Since then my soil fungi:bacteria thinking has been highly stimulated by reading Jeff Lowenfels' "Teaming with Microbes" and it has hit me: it's got to be more complicated than just AMF kicking up their glomalin production. Maybe glomalin can account for the initial stages of transformation to TP, but there are pitfalls to fungi as an explanation for TP's self-replication once it has reached its full expression. By then the pH has come up, not so great for the fungi. By then the phosphorus levels have come up, not so great for mycorhhyzal mutualism.

The soils I see in the pictures of TP remind me of the types more conducive to high bacterial populations than fungal populations. If it is fungi, it would seem to be from a highly adapted fungal species. Perhaps, but could TP be an other-than-fungi/glomalin phenomenon? If so, we may be looking for a new recalcitrant organic carbon based substance in TP and an undiscovered pathway for its formation.

I think TP formation is driven by plant root exudates being delivered to grow microbial biomass, sequestering carbon pulled from the air. The fungi-like bacteria, actinomycetes, seems a candidate. Next I would consider the archeae. And because it is soil, the reality here has the potential to be deliciously nonlinear, multi-staged, complex and inter-connected.