Rahnella victoriana sp. nov., Rahnella bruchi sp. nov., Rahnella woolbedingensis sp. nov., classification of Rahnella genomospecies 2 and 3 as Rahnella variigena sp. nov. and Rahnella inusitata sp. nov., respectively and emended description of the genus Rahnella ☆

Abstract Isolations from oak symptomatic of Acute Oak Decline, alder and walnut log tissue, and buprestid beetles in 2009–2012 yielded 32 Gram-negative bacterial strains showing highest gyrB sequence similarity to Rahnella aquatilis and Ewingella americana . Multilocus sequence analysis (using partial gyrB , rpoB , infB and atpD gene sequences) delineated the strains into six MLSA groups. Two MLSA groups contained reference strains of Rahnella genomospecies 2 and 3, three groups clustered within the Rahnella clade with no known type or reference strains and the last group contained the type strain of E. americana . DNA–DNA relatedness assays using both the microplate and fluorometric methods, confirmed that each of the five Rahnella MLSA groups formed separate taxa. Rahnella genomospecies 2 and 3 were previously not formally described due to a lack of distinguishing phenotypic characteristics. In the present study, all five Rahnella MLSA groups were phenotypically differentiated from each other and from R. aquatilis . Therefore we propose to classify the strains from symptomatic oak, alder and walnut and buprestid beetles as: Rahnella victoriana sp. nov. (type strain FRB 225 T  = LMG 27717 T  = DSM 27397 T ), Rahnella variigena sp. nov. (previously Rahnella genomosp. 2, type strain CIP 105588 T  = LMG 27711 T ), Rahnella inusitata sp. nov. (previously Rahnella genomosp. 3, type strain DSM 30078 T  = LMG 2640 T ), Rahnella bruchi sp. nov. (type strain FRB 226 T  = LMG 27718 T  = DSM 27398 T ) and Rahnella woolbedingensis sp. nov. (type strain FRB 227 T  = LMG 27719 T  = DSM 27399 T ).