Liberibacter crescens gen. nov., sp. nov., the first cultured member of the genus Liberibacter

The Gram-stain-negative, rod-shaped bacterial isolate BT-1T is the closest relative to the genus ‘Candidatus Liberibacter ’ cultured to date. BT-1T was recovered from the phloem sap of a defoliating mountain papaya in Puerto Rico. The BT-1T 16S rRNA gene sequence showed that strain BT-1T is most closely related to members of the genus ‘Ca. Liberibacter ’ sharing 94.7 % 16S rRNA gene sequence similarity with ‘Ca. Liberibacter americanus ’ and ‘Ca. Liberibacter asiaticus ’. Additionally, average nucleotide identity, 16S rRNA gene sequences and conserved protein sequences supported inclusion of the previously described species of the genus ‘Ca. Liberibacter ’ in a genus with BT-1T. The prominent fatty acids of isolate BT-1T were C18 : 1ω7c (77.2 %), C16 : 0 OH (4.8 %), C18 : 0 (4.4 %) and C16 : 0 (3.5 %). Both physiological and genomic characteristics support the creation of the genus Liberibacter , as well as the novel species Liberibacter crescens gen. nov., sp. nov. with type strain BT-1T ( = ATCC BAA-2481T = DSM 26877T).