日本海溝
During an exploration to the Japan Trench on January 1, 1999, a sample of deep-sea sediment was taken from a depth of from the use of a pressure-retaining sediment sampler. Samples from the expedition showed that the microbial diversity displayed a wide distribution of types in the Bacteria domain. 16S ribosomal RNA genes were amplified through the use of polymerase chain reaction (PCR) to determine the nucleotides and identify the bacteria phylogenetically. Further analysis of fatty acids extracted from the same cultures further supported the phylogenetic results observed. The discovery of different bacterial domains in these sediments can be used as indicators for microbial diversity found within the Japan Trench.