Adlercreutzia hattorii sp. nov., an equol non-producing bacterium isolated from human faeces
Mitsuo Sakamoto, Nao Ikeyama, Masahiro Yuki, Takumi Murakami, Hiroshi Mori, Takao Iino, Moriya Ohkuma
Abstract
Two obligately anaerobic, Gram-stain-positive, rod-shaped bacteria were isolated from faecal samples of healthy humans in Japan. 16S rRNA gene sequence analysis indicated that these two strains (8CFCBH1 T and 9CBH6) belonged to the genus Adlercreutzia , which is known as an equol-producing bacterium. The closest neighbours of strain 8CFCBH1 T were Adlercreutzia equolifaciens subsp. equolifaciens DSM 19450 T (98.6%), Adlercreutzia equolifaciens subsp. celatus do03 T (98.4%), Adlercreutzia muris WCA-131-CoC-2 T (96.6%), Parvibacter caecicola NR06 T (96.4%), Adlercreutzia caecimuris B7 T (95.3%) and Adlercreutzia mucosicola Mt1B8 T (95.3%). The closest relatives to strain 9CBH6 were A. equolifaciens subsp. equolifaciens DSM 19450 T (99.8%), A. equolifaciens subsp. celatus do03 T (99.6%) and A. muris WCA-131-CoC-2 T (96.8%). Strain 8CFCBH1 T showed 22.3–53.5% digital DNA–DNA hybridization (dDDH) values with its related species. In addition, the average nucleotide identity (ANI) values between strain 8CFCBH1 T and its related species ranged from 75.4 to 93.3%. On the other hand, strain 9CBH6 was considered as A. equolifaciens based on the dDDH and ANI values (>70% dDDH and >95–96% ANI). Strain 9CBH6 showed daidzein-converting activity, as expected from the result of genome analysis. The genome of strain 8CFCBH1 T lacked four genes involved in equol production. Growing cells of strain 8CFCBH1 T were not capable of converting daidzein. Based on the collected data, strain 8CFCBH1 T represents a novel species in the genus Adlercreutzia , for which the name Adlercreutzia hattorii sp. nov. is proposed. The type strain of A. hattorii is 8CFCBH1 T (=JCM 34083 T =DSM 112284 T ).