Algorithms|Conserved Sequence|DNA, Ribosomal Spacer|Databases, Genetic|Expressed Sequence Tags|Phylogeny|RNA, Bacterial|RNA, Ribosomal, 16S|RNA, Ribosomal, 23S|Sequence Alignment|Sequence Analysis, RNA|Sequence Homology, Nucleic Acid|Software|Species Specificity|Transcription, Genetic