The invention relates to an isolated bacterium including a DNA sequence, referred to as 16S rDNA, coding for the 16S ribosomal RNA of said bacterium, said DNA sequence being 100 % homologous with the sequence of SEQ ID NO. 1, said isolated bacterium being selected from the group comprising: the bacterium filed and registered before the French National Collection of Microorganism Cultures (CNCM) with no. 1-4467; and mutants of said bacterium filed and registered before the CNCM with no. 1-4467.
