אסיף מאגר המחקר החקלאי

A salinity and sulfate manipulation of hypersaline microbial mats reveals stasis in the cyanobacterial community structure

Year:

2008

Source of publication :

Authors :

Volume :

2

Co-Authors:

Green, S.J., SETI Institute, Mountain View, CA, United States, Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
Blackford, C., Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States, Pioneer Hi-Bred International, El Cerrito, CA, United States
Bucki, P., Agricultural Research Organization of Israel, Volcani Center, Bet-Dagan, Israel
Jahnke, L.L., Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
Prufert-Bebout, L., Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States, Exobiology Branch, NASA Ames Research Center, MS 239-4, Moffett Field, CA 94035, United States

Facilitators :

Link :

Abstract:

The cyanobacterial community structure and composition of hypersaline mats were characterized in an experiment in which native salinity and sulfate levels were modified. Over the course of approximately 1 year, microbial mats collected from Guerrero Negro (Baja, California Sur, Mexico) were equilibrated to lowered salinity (to 35 p.p.t.) and lowered sulfate (below 1 mM) conditions. The structure and composition of the cyanobacterial community in the top 5 mm of these mats were examined using a multifaceted cultivation-independent molecular approach. Overall, the relative abundance of cyanobacteriaroughly 20% of the total bacterial community, as assayed with a PCR-based methodologywas not significantly affected by these manipulations. Furthermore, the mat cyanobacterial community was only modestly influenced by the dramatic changes in sulfate and salinity, and the dominant cyanobacteria were unaffected. Community composition analyses confirmed the dominant presence of the cosmopolitan cyanobacterium Microcoleus chthonoplastes, but also revealed the dominance of another Oscillatorian cyanobacterial group, also detected in other hypersaline microbial mats. Cyanobacterial populations increasing in relative abundance under the modified salinity and sulfate conditions were found to be most closely related to other hypersaline microbial mat organisms, suggesting that the development of these mats under native conditions precludes the development of organisms better suited to the less restrictive experimental conditions. These results also indicate that within a significant range of salinity and sulfate concentrations, the cyanobacterial community is remarkably stable. © 2008 International Society for Microbial Ecology All rights reserved.

Note:

Related Files :

Related Content

More details

You may also be interested in