DNA base composition of bacterial groups differentiated by a diagnostic scheme used for soil isolates

Abstract The first step in the systematic study of an unknown microorganism is to determine to which major groups of microorganisms it belongs. Over the past decades, bacterial taxonomy had traditionally relied on phenotypic analysis as the basis of classification although this approach was fraught with problems. Therefore, some simple diagnostic schemes based on phenotypic characters have been used to group the isolates roughly from natural habitats (Shewan et al. 1960; Ushikoshi 1974; Sato et al. 1987). These grouping schemes have provided valuable information about the natural distribution of bacteria.