Taxonomy of the Genus Thiobacillus: the Outcome of Numerical Taxonomy Applied to the Group as a Whole

SUMMARY Data from previous numerical analyses have been combined to produce an over-all classification of the genus Thiobacillus; 93 strains were examined using 38 tests and 106 character states. The results indicated the possible existence of a new species and demonstrated an unexpectedly close similarity between T. neapolitanus and T. thio-oxidans. A number of diagnostic tests have been selected from those used for the numerical analysis. A brief description of the other important features of each species recognized is also given.