The purpose of this study was to compare the metabolic diversity of the whole microbial community in an oligotrophic saltern (Eilat, Israel) and in a saltern with a more enriched source water (Newark, California). Between 1993 and 1998 water samples were taken from selected locations within the solar salterns of the Cargill Solar Salt Plant, Newark, California, and the Israel Salt Co. in Eilat, Israel. To examine the whole community metabolic diversity, we used the 96-well BIOLOG GN™ plates which contain 95 different carbon sources and a control well. Plates from samples containing greater than 15% salt were excluded from the final analyses because of a lack of reproducibility when multiple plates were inoculated with the same sample. The data were analyzed by simple matching coefficient and principal component analysis. Both methods gave similar results. Two major clusters were formed. These could be subdivided into 10 sub-clusters with only three samples from the Newark saltern in December 1997 joining at the 95% similarity level. Most of the inlet and lower salinity samples from the Cargill samples comprised one large subcluster. Several carbon sources were used by 85% of the microbial community from the California samples, while 85% of the Eilat samples had no commonly used carbon sources. These results suggest that ponds in different geographic locations may have communities with different microbial populations despite the similarities in salt content and processing for salt production.
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The authors thank the personnel at the Cargill Solar Salt Plant in Newark, California, U.S.A. and the Israel Salt Company in Eilat, Israel, for their assistance in collecting samples, providing information on the salterns, and allowing access to the sites. We also appreciate the assistance of L. Nichols and G. P. Sto-jhovic, III for their work on the effects of high salt on BIOLOG plates. Portions of this study were supported by grant No. 95-00027 from the United States–Israel Binational Science Foundation (B.S.F., Jerusalem) and the Halophile Fund of the George Mason University Research Foundation. We also thank R. S. Oremland (U.S. Geological Survey, Menlo Park, California) for the use of his laboratory during the California field trips.