Effects of Rhizobium Species Living with the Dark Septate Endophytic Fungus Veronaeopsis simplex on Organic Substrate Utilization by the Host.

Bacteria harbored in/on the hyphae of the dark septate endophyte, Veronaeopsis simplex Y34, were identified as a single Rhizobium species by molecular analyses of bacterial 16S rRNA genes, and were successfully isolated from the endophyte. The Rhizobium-cured fungus was prepared thoroughly by an antibiotic treatment, thereby allowing an examination of their effects on organic substrate utilization. Assays with Biolog® FF microplates revealed that the respiration potential for 52.6% of the tested compounds were significantly different between Rhizobium-harboring and -cured fungal hosts, indicating that organic substrate utilization by V. simplex Y34 was significantly influenced by the presence of the associated Rhizobium sp. VsBac-Y9.