Microbial flora in the deepest sea mud of the Mariana Trench.

In an attempt to characterize the microbial flora on the deepest sea floor, we isolated thousands of microbes from a mud sample collected from the Mariana Trench. The microbial flora found at a depth of 10897 m was composed of actinomycetes, fungi, non-extremophilic bacteria, and various extremophilic bacteria such as alkaliphiles, thermophiles, and psychrophiles. Phylogenetic analysis of Mariana isolates based on 16S rDNA sequences revealed that a wide range of taxa were represented.