Flavonifractor porci sp. nov. and Flintibacter porci sp. nov., two novel butyrate-producing bacteria of the family Oscillospiraceae

Two Gram-stain-negative, strictly anaerobic, non-motile, non-­spore-forming and rod-shaped bacterial strains, namely, P01024Tand P01025T, were isolated from piglet manure. The strains P01024Tand P01025Tfermented glucose to acetate and butyrate. The major cellular fatty acids (>10.0%) of strain P01024Twere C14 : 0, C16 : 0and summed feature 9 (iso-C17:1ω9c and/or 10-Methyl-C16:0) and of strain P01025Twere C14 : 0, C16 : 0and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). Analysis of 16S rRNA gene sequences indicated that strains P01024Tand P01025Tbelonged to the familyOscillospiraceae. The strain P01024Tshowed high identities of 16S rRNA genes to type speciesFlavonifractor plautiiATCC 29863T(96.64%). The highest percentages of conserved protein (POCP) value between strain P01024TandFlavonifractor plautiiATCC 29863Twas 59.84%. The averagentidentity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain P01024TandFlavonifractor plautiiATCC 29863Twere 79.51% and 23.80%, respectively, supporting that strain P01024Trepresented a novel species of the genusFlavonifractor. Strain P01025Tshowed high identities of 16S rRNA genes to the type speciesFlintibacter butyricusBLS21T(95.87%). The highest POCP and AAI (averageaaidentity) values of strains P01025TtoFlintibacter hominisNew-19Twere 53.02% and 73.11%, respectively. The ANI and dDDH values between strains P01025TandFlintibacter hominisNew-19Twere 75.44% and 23.40%, respectively, supporting that strain P01025Trepresented a novel species in the genusFlintibacter. The calculated G+C molar contents for strains P01024Tand P01025Twere 58.43 and 56.44 mol%, respectively. Together with phenotypic features, we concluded that strains P01024Tand P01025Trepresented novel species in the generaFlavonifractorandFlintibacterof the familyOscillospiraceae, respectively, for which the namesFlavonifractor porcisp. nov. (type strain P01024T=CGMCC 1.18055T=KCTC 25793T) andFlintibacter porcisp. nov. (type strain P01025T=CGMCC 1.18060T=KCTC 25794T) are proposed.