Isolation and characterization of halotolerant soil fungi from the Great Salt Plains of Oklahoma (USA)

Abstract

The Great Salt Plains (GSP) of Oklahoma is an inland terrestrial hypersaline environment where saturated brines leave evaporite crusts of NaCl. The current report examines the fungal community, complementing earlier reports on the bacterial and archaeal communities. Twenty-five fungal isolates from GSP soils were obtained on medium containing 10% NaCl and characterized. Based on 18S rRNA gene sequence analysis, all of the isolates fall within the ascomycetes, with a predominance of Trichocomaceae, represented by Aspergillus, Eurotium, and Penicillium species. Representatives of Anthrinium, Cladosporium, Debaryomyces, Fusarium, and Ulocladium also were isolated. Overall the isolates were widely halotolerant, with best growth observed at lower salinities and no halophilism. The fungal genera observed were all cosmopolitan, without strong specialization. Taken together, these results support the conclusion that hypersaline environments do not have a characteristic community, in contrast to what was observed at the GSP for bacteria and archaea.