ABSTRACT

Bifidobacteria were discovered and described by Henry Tissier during the period 1899-1900. Henry Tissier was a French pediatrician, studying infantile diarrhea. During his study, he observed that an irregular Y shaped bacterium was present in abundance in the feces of breast-fed infants, but was absent in the feces of infants suering

from diarrhea. He called these bid bacteria Bacillus bifidus (Leahy et al. 2005; Lee and O’Sullivan 2010). A historical overview of bi- dobacteria is presented in Table 10.2. From 1923 to 1934, in the 1st to 4th editions of Bergey’s Manual of Systematic Bacteriology, these bacteria were classied as Bacteroides bifidus. From 1939 to 1957, in the 5th to 7th editions of Bergey’s Manual, these were called as Lactobacillus bifidus, because of their rod-like shapes and obligate fermentative

characteristics similar to that of the genus Lactobacillus. In the 8th edition of Bergey’s Manual of Determinative Bacteriology (Rogosa 1974), bidobacteria were reclassied in the genus Bifidobacterium, initially adopted by Orla-Jensen. e genus Bifidobacterium belongs to phylum Actinobacteria, order Bidobacteriales, and family Bidobacteriaceae. Phylum Actinobacteria include Gram-positive microbes with a high G + C DNA content ranging between 51% and 70% (Turroni et al. 2011). Genus Bifidobacterium consisted of only 11 species. Later, this was updated to 24 species in 1986, and currently, there are 37 species divided into four taxa, namely, Bifidobacterium longum, B. pseudolongum, B. animalis, B. thermacidophilum, and further subdivided into subspecies, exhibiting >93% identity of their 16S rDNA sequences (Miyake et al. 1998) and comprising isolates from the intestines of humans, animals, and insects, and also from human dental caries and raw milk (Table  10.3). ree new  species, isolated from the bumblebee digestive tracts, that is, B. actinocoloniiforme, B. bohemicum, and B. bombi, have been added to the existing bidobacteria (Killer et al. 2009, 2011; Turroni et al. 2011).