Methods for Isolation and Recovery of Bifidobacteria

Abstract

Since their discovery, bifidobacteria have been considered to represent cornerstone commensal microorganisms in the host-microbiome interface at the intestinal level. Bifidobacteria have therefore enjoyed increasing scientific and commercial interest as a source of microorganisms with probiotic potential. However, since functional and probiotic traits are strictly strain-dependent, there is a constant need to isolate, cultivate, and characterize novel strains, activities that require the utilization of appropriate media, as well as robust isolation, cultivation, and preservation techniques. Besides, effective isolation of bifidobacteria from natural environments might require different manipulation and cultivation media and conditions depending on the specific characteristics of the sample material, the presence of competitive microbiota, the metabolic state in which bifidobacteria might be encountered within the sample and the particular metabolic traits of the bifidobacterial species adapted to such inhabitation. A wide array of culture media recipes have been described in the literature to routinely isolate and grow bifidobacteria under laboratory conditions. However, there is not a single and universally applicable medium for effective isolation, recovery, and cultivation of bifidobacteria, as each growth medium has its own particular advantages and limitations. Besides, the vast majority of these media formulations was not specifically formulated for these microorganisms, and thus information on bifidobacterial cultivation options is scarce while being scattered throughout literature. This chapter intends to serve as a resource summarizing the options to cultivate bifidobacteria that have been described to date, highlighting the main advantages and limitations of each of them.