The Whole Earth Stromatolite Catalog: What Could It Tell Us?

Lithification

Yellowstone National Park

600 Million year old Stromatolite bedIn Morocco

Lithification

Precipitation by microbial processes and physiochemical characteristics is controlled by two factors:

Exopolymeric substances EPS

Saturation index (pH, {Ca2+} and {CO3

2-}

EPS matrix sequesters particulates which provides nutrients

Compounds aid in creating geochemical gradientsBinding and concentrating organic molecules and IonsClose to cells

EPS binds calcium carbonates.heterotrophic and sulfate reducers degrade the EPS

Favors the localized precipitation of calcium carbonate.

Whether or not a microbial mat becomes ‘lithified’, i.e. a stromatolite, depends upon the bacterial constituency and the environment.

3.4 billion year old stroms

Allwood 2006

Bahamas and Sharks Bay Australia Examples

As investigative targets, these biomes represent:

Long term, discreet microbial entities, tractable numbers.

Metabolic flux model targets, mesocosm experiment.

Confined to locations that do not allow natural predation to occur

Environmental dipsticks that span fresh and marine water systems.

Environmental harbingers (or canaries in the coal mine) of climactic, diversity tied to geography, and environmental change

Cuatro

Ciénegas

Case in point…

Proposed as remnant of an ancient ocean… Souza, et al PNAS 2006

Low in P - Total P ranges between 0.05 - .4 uM, with most of the poza's in the .1 - .3 uM range

Galápagan-like – >120 endemic species

Contain living microbialites

CCB is a living laboratory where we experiment and sequence.

Metagenomes of the Rios Mesquites and Poza Azules

Breitbart et al, 2009

16S sequence affiliation total and by valley

Total sample

Valleys samplesValle Ocampo Mina Reforma Cuatro Cienegas valle Hundido

Agricultural well subterranean superficial agricultural well

Souza et al., 2006

PNAS

50% of the clones

are affiliated with

marine microbes.

Desnues et al., 2008, Nature. Even the virus kept this ancient marine ancestry

Stoichiometry, Redfield ratios, and ecological stoichiometry… branch of chemistry that deals with

the relative quantities of reactants and products in chemical reactions

C:N:P = 106:16:1

Elser and team link the elemental physiology of organisms to the their food web interactions and ecosystem function.

EXPERIMENTAL TEST

Summer 2009:

Add +PO4 (high or low) and/or Organic Carbon to Río Mezquites water; water exchanged and re-spiked daily

Examine ecosystem responses and changes to microbial biomass N:P

Short experiment (16 days)

Stoichiometric knife edge

Elser et al “there are in situ stoichiometric constraints at CC, the balance between the microbial community and the eukaryotic community are delicately balanced around an ecological stoichiometry.”

The problem with Phosphorus

From Kansas to China's Sichuan province, farmers treat their fields with phosphorus-rich fertilizer to increase the yield of their crops. What happens next, however, receives relatively little attention. Large amounts of this resource are lost from farm fields, through soil erosion and runoff, and down swirling toilets, through our urine and feces.

The Catalog

150 targets in current working spread sheet,

Ripe for social networks

Stromatolites: Living

Laboratories Mya Breitbart (viral phylogeny,

metagenomics), David Hollander (Isotope geochemistry)

Valeria Souza (microbial population biology) Luis Eguiarte and the whole UNAM crew, CINVESTAV – Gabrielle Olmedo

Jim Elser (ASU) and all, freshwater limnology, stoichiometry

Abby Allwood (NASA), Shery Cady (Portland)

Brendan Burns (South Wales), Pam Reid (Miami)