Castellaniella gen. nov., to accommodate the phylogenetic lineage of Alcaligenes defragrans, and proposal of Castellaniella defragrans gen. nov., comb. nov and Castellaniella denitrificans sp nov.

Abstract

Comparative 16S rRNA gene sequence analysis indicates that two distinct sublineages exist within the genus Alcaligenes: the Alcaligenes faecalis lineage, comprising Alcaligenes aquatilis and A. faecalis (with the three subspecies A. faecalis subsp. faecalis, A. faecalis subsp. parafaecalis and A. faecalis subsp. phenolicus), and the Alcaligenes defragrans lineage, comprising A. defragrans. This phylogenetic discrimination is supported by phenotypic and chemotaxonomic differences. It is proposed that the A. defragrans lineage constitutes a distinct genus, for which the name Castellaniella gen. nov. is proposed. The type strain for Castellaniella defragrans gen. nov., comb. nov. is 54Pin(T) (= CCUG 39790(T) = CIP 105602(T) = DSM 12141(T)). Finally, on the basis of data from the literature and new DNA-DNA hybridization and phenotypic data, the novel species Castellaniella denitrificans sp. nov. (type strain NKNTAU(T) = DSM 11046(T) = CCUG 39541(T)) is proposed for two strains previously identified as strains of A. defragrans.