granulibacter granulibacter granulibacter is a gram-negative and non-motile bacterial genus from the family of acetobacteraceae. up to now there is only one species of this genus known (granulibacter bethesdensis). granulibacter scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: rhodospirillales family: acetobacteraceae genus: granulibactergreenberg et al. 2006 type species granulibacter bethesdensis species g. bethesdensis synonyms granulobacter