Abstract

A survey of molecular signatures from microorganisms in an agricultural field in New York State revealed the presence of hundreds of novel organisms within a single Phylum of Bacteria and uncovered a group of deeply divergent microorganisms that have only been observed a handful of times anywhere in the world.

Issue

Although dominated by plants, terrestrial ecosystems are estimated to contain 26 by 1028 prokaryotic microorganisms that harbor 26 Pg of carbon, 6.2 Pg of nitrogen, and 0.65 Pg of phosphorus. Soils encompass an enormous fraction of the earth's biodiversity and soil microbes through their metabolic diversity. Their sheer numbers dominate the nutrient cycles that sustain agricultural productivity and underly ecosystem processes in terrestrial environments. Molecular and genomic techniques now make it possible to discover microorganisms that had previously gone undetected in soils. Through these techniques we are discovering forms of life previously unknown to science. The evolutionary history and ecological significance remain largely uncharacterized. As a result, we are now able to tap into the enormous reservoir of genomic and biochemical diversity present in our soil resources.

Response

Molecular techniques have only recently revealed that bacteria of the phylum Planctomycetes are present in soils, but now it is apparent that this group of the bacteria is a major contributor to soil biodiversity accounting for as much as 20 percent of the organisms in certain soils. Using molecular techniques, we have explored the microbial diversity of the phylum Planctomycetes in an agricultural soil from New York State.

Impact

More than 300 species of Planctomycetes were discovered in a simple survey of an agricultural field and 95 percent of these species were new to science. In addition, 66 percent of the taxa observed fall into novel groups at the genus level or higher. Evaluation of their community structure reveals that agricultural management practices affect the diversity of Planctomycetes, but the consequences of these shifts in diversity have not yet been determined. In addition, this survey resulted in the discovery of 13 taxa that belong to a newly identified phylum of bacteria. This deeply divergent Bacterial Phylum, tentatively named WS3, was first discovered in 2001 and currently only 50 taxa have been identified worldwide. In addition, only two taxa had previously been found in North American soils. Our discovery provides evidence that this novel group may be more widespread and diverse than previously anticipated serving an as yet unknown function in our soils.

Funding Sources

• Federal Formula Funds - Research (e.g., Hatch, McIntire-Stennis, Animal Health)
• Other Federal non-USDA (e.g., NSF, NIH, DOA, DOD)

Key Personnel

• Tyrrell Nelson, Cornell University