Description of a new species, Bifidobacterium crudilactis sp. nov., isolated from raw milk and raw milk cheeses

A new Bifidobacterium species is described based on the study of ten Gram-positive strains with fructose-6-phosphate phosphoketolase activity. They are part of a phenotypic group comprising 141 strains isolated from raw milk and raw milk cheeses in French raw milk cheese factories. This group was separated by a numerical analysis based on API 50CH, API 32A tests and growth at 46 °C. A strong similarity of 16S rRNA sequences (99.8%) was shown between strain FR62/b/3T and Bifidobacterium psychraerophilum LMG 21775T. However, low DNA–DNA relatedness was observed between their DNAs (31%). The new isolates are able to grow at low temperatures (all ten strains up to 5 °C) and strain FR62/b/3T grows under aerobic conditions, as does B. psychraerophilum. However, contrary to B. psychraerophilum, they do not ferment l-arabinose, d-xylose, arbutin or melezitose, but they do acidify lactose. The DNA G+C content of FR62/b/3T is 56.4 mol%.Therefore, the name Bifidobacterium crudilactis sp. nov. is proposed, with its type strain being FR62/b/3T (=LMG 23609T=CNCM I-3342T).