Revisiting the Metabolic Capabilities of <i>Bifidobacterium longum</i> susbp. <i>longum</i> and <i>Bifidobacterium longum</i> subsp. <i>infantis</i> from a Glycoside Hydrolase Perspective

• Main Authors: Guillermo Blanco, Lorena Ruiz, Hector Tamés, Patricia Ruas-Madiedo, Florentino Fdez-Riverola, Borja Sánchez, Anália Lourenço, Abelardo Margolles
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Microorganisms
• Subjects: <i>Bifidobacterium</i>; <i>longum</i>; <i>infantis</i>; carbohydrates; glycoside hydrolases; computational screening
• Online Access: https://www.mdpi.com/2076-2607/8/5/723

Bifidobacteria are among the most abundant microorganisms inhabiting the intestine of humans and many animals. Within the genus <i>Bifidobacterium</i>, several beneficial effects have been attributed to strains belonging to the subspecies <i>Bifidobacterium longum</i> subsp. <i>longum</i> and <i>Bifidobacterium longum</i> subsp. <i>infantis</i>, which are often found in infants and adults. The increasing numbers of sequenced genomes belonging to these two subspecies, and the availability of novel computational tools focused on predicting glycolytic abilities, with the aim of understanding the capabilities of degrading specific carbohydrates, allowed us to depict the potential glycoside hydrolases (GH) of these bacteria, with a focus on those GH profiles that differ in the two subspecies. We performed an in silico examination of 188 sequenced <i>B. longum</i> genomes and depicted the commonly present and strain-specific GHs and GH families among representatives of this species. Additionally, GH profiling, genome-based and 16S rRNA-based clustering analyses showed that the subspecies assignment of some strains does not properly match with their genetic background. Furthermore, the analysis of the potential GH component allowed the distinction of clear GH patterns. Some of the GH activities, and their link with the two subspecies under study, are further discussed. Overall, our in silico analysis poses some questions about the suitability of considering the GH activities of <i>B. longum</i> subsp. <i>longum</i> and <i>B. longum</i> subsp. <i>infantis</i> to gain insight into the characterization and classification of these two subspecies with probiotic interest.