NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Ecophysiological Changes in Microbial Mats Incubated in a Greenhouse CollaboratoryMicrobial mats are modern examples of the earliest microbial communities known. Among the best studied are microbial mats growing in hypersaline ponds managed for the production of salt by Exportadora de Sal, S.A. de C.V., Guerrero Negro, Baja California Sur, Mexico. In May, 2001, we collected mats from Ponds 4 and 5 in this system and returned them to Ames Research Center, where they have been maintained for a period of over nine months. We report here on both the ecophysiological changes occurring in the mats over that period of time as well as the facility in which they were incubated. Mats (approximately 1 sq. meter total area) were incubated in a greenhouse facility modified to provide the mats with natural levels of visible and ultraviolet radiation as well as constantly flowing, temperature-controlled water. Two replicated treatments were maintained, a 'high salinity' treatment (about 120 ppt) and a 'low salinity' treatment (about 90 ppt). Rates of net biological activity (e.g., photosynthesis, respiration, trace gas production) in the mats were relatively constant over the several months, and were similar to rates of activity measured in the field. However, over the course of the incubation, mats in both treatments changed in physical appearance. The most obvious change was that mats in the higher salinity treatments developed a higher proportion of carotenoid pigments (relative to chlorophyll), resulting in a noticeably orange color in the high salinity mats. This trend is also seen in the natural salinity gradient present at the field site. Changes in the community composition of the mats, as assayed by denaturing gradient gel electrophoresis (DGGE), as well as biomarker compounds produced in the mats were also monitored. The degree to which the mats kept in the greenhouse changed from the originally collected mats, as well as differences between high and low salinity mats will be discussed. Additional information is contained in the original extended abstract.
Document ID
20020002148
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Bebout, Brad
(NASA Ames Research Center Moffett Field, CA United States)
DesMarais, David J.
(NASA Ames Research Center Moffett Field, CA United States)
GarciaPichel, Ferran
(Arizona State Univ. Tempe, AZ United States)
Hogan, Mary
(NASA Ames Research Center Moffett Field, CA United States)
Jahnke, Linda
(NASA Ames Research Center Moffett Field, CA United States)
Keller, Richard M.
(NASA Ames Research Center Moffett Field, CA United States)
Miller, Scott R.
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
August 20, 2013
Publication Date
April 1, 2001
Publication Information
Publication: General Meeting of the NASA Astrobiology Insititute
Subject Category
Exobiology
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Document Inquiry

Available Downloads

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