NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Biogeochemistry of Microbial MatsThe hierarchical organization of microbial ecosystems determines the rates of processes that shape Earth's environment, define the stage upon which major evolutionary events occurred, and create biosignatures in sediments and atmospheres. In cyanobacterial mats, oxygenic photosynthesis provides energy, organic substrates and oxygen to the ecosystem. Incident light changes with depth in the mat, both in intensity and spectral composition, and counteracting gradients of oxygen and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Microliters produce hydrogen, small organic acids, nitrogen and sulfur species. Such compounds fuel a flow of energy and electrons in these ecosystems and thus shape interactions between groups of microorganisms. Coordinated observations of population distribution, abundance, and activity for an entire community are making fundamental questions in ecology accessible. These questions address those factors that sustain the remarkable diversity of microorganisms that are now being revealed by molecular techniques. These questions also target the processes that shape the various kinds of biosignatures that we will seek, both in ancient rocks from Earth and Mars, and in atmospheres of distant planets beyond our Solar System.
Document ID
20030001108
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
DesMarais, David J.
(NASA Ames Research Center Moffett Field, CA United States)
DeVincenizi, D.
Date Acquired
August 21, 2013
Publication Date
January 1, 2002
Subject Category
Geophysics
Meeting Information
Meeting: GeoBiology Summer 2002 Field Course
Location: Catalina Island, CA
Country: United States
Start Date: July 19, 2002
End Date: July 27, 2002
Funding Number(s)
PROJECT: RTOP 344-50-92-02
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available