POLYPHASIC CLASSIFICATION OF PROTEOBACTERIA ISOLATED FROM BIOFILTERS

70 Gram-negative, nonfermenting bacterial isolates from biofilters for off-gas treatment of animal-rendering plane emissions were analyzed f or respiratory quinones, polyamine patterns, fatty acid profiles, phys iological reaction profiles, and by reverse transcriptase partial sequ encing of 16S rRNA. Based on these data, the isolates were grouped int o six clusters, which were shown to belong to the alpha- and beta-subc lass of the Proteobacteria. Inclusion of fifteen reference strains all owed the assignment of one cluster to the species Brevundimonas diminu ta and the assignment of a second cluster to the species Alcaligenes f aecalis. The 49 strains of the Brevundimonas diminuta cluster and the clusters F, H, and I were shown to belong to the alpha-subclass of the Proteobacteria. Paracoccus denitrificans evolved as the next neighbou r of cluster F. The remaining 21 bacteria containing the beta-subclass specific polyamine 2-hydroxyputrescine grouped either into the Alcali genes faecalis cluster or formed a distinct group (cluster J) represen ting a new taxon within the Alcaligenaceae.