Articles of Significant Interest Selected from This Issue by the Editors

摘要

Culture-independent molecular analyses have revealed the diversity of the human oral microbiome, but around one-third of oral bacterial taxa have yet to be cultivated. In vitro biofilms established by Thompson et al. (p. 83078314) from a dental plaque inoculum were found to harbor a complex bacterial community, including numerous previously uncultivated oral bacteria. A targeted approach led to the isolation of cultures of Lachnospiraceae HOT 500 from this source material. In vitro mixed-biofilm cultures can provide the first step in the isolation of novel bacteria, thereby enabling the study of their pathogenicity, antimicrobial resistance, and interactions with other bacteria and the human host.Bacterial microcompartments (BMCs) are proteinaceous, icosahedral organelles encapsulating sequential enzymatic reactions of metabolic pathways. Experimentally characterized examples of BMCs include carboxysomes, as well as the propanediol- and ethanolamine-utilizing metabolosomes. In-depth bioinformatic analyses by Zarzycki et al. (p. 83158329) provide insight into a widespread, recently discovered group of glycyl radical enzyme-associated microcompartments (GRMs). The study suggests that there are at least three functionally distinct types of GRMs, differing not only in their complements of encapsulated enzymes but also in the permeability of their shells and in the details of their assembly. The authors also discuss the evolution of GRMs and their roles in the environment and pathogenesis.