Abstract
Four representative strains selected from algicidal filamentous bacteria isolated from shrimp aquacultural ponds and coastal seawater of Kagoshima Bay were tentatively identified as the genus Saprospira and divided into 4 taxonomic groups as described previously. The small subunit ribosomal DNA (SSU rDNA) sequences of the 4 representative strains were determined and applied to a phylogenetic analysis with the type species of the genus Saprospira (S. grandis ATCC23116 and ATCC23119). The results revealed a close relationship between the isolated strains and S. grandis which belongs to the Flexibacter-Bacteroides-Cytophaga (FBC) group. PCR products of intergenic spacer regions (IGS) between large and small subunit ribosomal RNA genes were shown to be composed of two or three fragments by agarose gel electrophoresis. Higher molecular weight fragments of PCR products for IGS included tRNAIle and tRNAAla genes but the similarity values of IGS sequences among test strains were less than 60%.
