Isolation, cultivation and characterization of new bifidobacterial species

Bifidobacteria are important probiotic bacteria and the number of identified species of the genus Bifidobacterium is greatly increased in recent years mainly due to the study on poor investigated animal gastrointestinal niches. Thanks to the modern omics tools used for phylogenomic and genomic approaches, understanding host-bifidobacteria interactions (antibiotic resistance, adherence and biofilm formation as well as fitness, survival, and immunological functions) is becoming easier, allowing for more thorough molecular characterization. In this scenario on the other hand conventional microbial culture methods and identification processes for its accurate identification and characterization are not surpassed. Classical bacteriological studies targeted to one genus should be encouraged in order to accumulate isolates and their ecological, phenotypical and genotypical details: this is an important opportunity for useful, publishable, contributions to knowledge and to taxonomy and as support to molecular data and viceversa. For example, molecular data about the presence of bifidobacterial species in host microbiota where until now these species have not yet been isolated is a stimulus to unravel new findings. The addition of new species description should be considered not simply for academic validity, but also for their impact on applied microbiology especially for those species considered probiotics. The finding of recently new 23 bifidobacterial species in non-human primates, the most evolutionary closed species to humans, could be of great interest to obtain useful information also for human beings. Proposals for new species should include a suggested scheme for routine identification, and some reasonable basis for prediction of ecological, functional and technological properties as described in the Minimal Standards for new species description of Bifidobacterium, Lactobacillus and related genera. These requirements would provide a practical basis for the work in the routine laboratory. Academic taxonomists play an important role supplying expertise for probiotic applications because taxonomy should be the “working technical language of microbiology”.