Fig. 3.

An overview of the composition of holdfast genes, hfaA and hfaB, encoded by Caulobacter in terrestrial, aquatic and plant-associated samples according to (a) the ranked relative abundance of gene copies in assembled shotgun metagenomes, and (b) taxonomic classifications. In (a), tables show the top five environmental sources where the greatest relative abundances occur. In (b), the taxonomic abbreviations stand for the following: Alpha (unclassified Alphaproteobacteria), Ast (Asticcacaulis), Brev (Brevundimonas), Cau (Caulobacter), Ellin (Ellin329), Mar (Maricaulis), Oce (Oceanicaulis), Par (Parvibaculum), and Phe (Phenylobacterium)