Document Detail

A model for diurnal patterns of carbon fixation in a Precambrian microbial mat based on a modern analog.
MedLine Citation:
PMID:  1854911     Owner:  NLM     Status:  MEDLINE    
Microbial mat communities are one of the first and most prevalent biological communities known from the Precambrian fossil record. These fossil mat communities are found as laminated sedimentary rock structures called stromatolites. Using a modern microbial mat as an analog for Precambrian stromatolites, a study of carbon fixation during a diurnal cycle under ambient conditions was undertaken. The rate of carbon fixation depends primarily on the availability of light (consistent with photosynthetic carbon fixation) and inorganic carbon, and not nitrogen or phosphorus. Atmospheric PCO2 is thought to have decreased from 10 bars at 4 Ga (10(9) years before present) to approximately 10(-4) bars today, implying a change in the availability of inorganic carbon for carbon fixation. Experimental manipulation of levels of inorganic carbon to levels that may have been available to Precambrian mat communities resulted in increased levels of carbon fixation during daylight hours. Combining these data with models of daylength during the Precambrian, models are derived for diurnal patterns of photosynthetic carbon fixation in a Precambrian microbial mat community. The models suggest that, even in the face of shorter daylengths during the Precambrian, total daily carbon fixation has been declining over geological time, with most of the decrease having occurred during the Precambrian.
L J Rothschild
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Review    
Journal Detail:
Title:  Bio Systems     Volume:  25     ISSN:  0303-2647     ISO Abbreviation:  BioSystems     Publication Date:  1991  
Date Detail:
Created Date:  1991-08-28     Completed Date:  1991-08-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0430773     Medline TA:  Biosystems     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  13-23     Citation Subset:  IM; S    
NASA-Ames Research Center, Moffett Field, CA 94035.
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MeSH Terms
Bacteria / metabolism*
Carbon / metabolism*
Circadian Rhythm
Models, Biological
Paleontology / methods*
Reg. No./Substance:
L J Rothschild / NASA ARC

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