Journal: ISME Communications
Article Title: Bacterial synergies amplify nitrogenase activity in diverse systems
doi: 10.1093/ismeco/ycae158
Figure Lengend Snippet: Synergistic enhancement of nitrogenase activity by Sphingobium strains requires live cells. Nitrogenase activity was measured in cocultures of diazotrophs (A) Azorhizobium sp. HT1-9 or (B) Azospirillum sp. 11R-A with live or heat-killed Sphingobium strains HT1-2, WW5, or 11R-BB. For HT1-9, coculture with live HT1-2, WW5, and 11R-BB increased nitrogenase activity by 2.8-fold, 1.8-fold, and 1.7-fold, respectively, compared to HT1-9 alone (F6,28 = 186.505, p < < 0.001). For 11R-A, live HT1–2, WW5 and 11R-BB increased nitrogenase activity by 1.7-fold, 1.5-fold, and 1.5-fold, respectively ( F [6, 28] = 64.248, P < < 0.001). Heat-killed synergists had no effect on nitrogenase activity in either diazotroph (Bonferroni, P > .05). Data are mean ± SE ( n = 5), one-way ANOVA. Different letters indicate significant differences ( P < .05). Legend key: D, diazotroph; S, synergist, D + S, diazotroph and synergist; D + heat-killed S, diazotroph and heat-killed synergist.
Article Snippet: Four strains had very low genomic similarity to their closest type strains: Frondihabitans 4ASC-45 (21.4% with Frondihabitans australicus DSM 17894), Herbiconiux 11R-BC (24.5% with Herbiconiux ginsengi CGMCC 4.3491), Rhizobium HT1-10 (26.2% with Rh. tumorigenes 1078), Azorhizobium HT1-9 (37.4% with Azorhizobium oxalatiphilum CCM7897), while the remaining strains had moderate genomic similarity to the closest type strain: Brevundimonas HT1-5 (60.2% with Brevundimonas vesicularis NBRC 12165), Azospirillum 11R-A (65.2% with A. palustre B2), and the three Sphingobium strains, WW5 (66.3%), 11R-BB (66.2%), and HT1-2 (68.1%), with the type strain Sphingobium yanoikuyae ATCC 51230.
Techniques: Activity Assay